Bacon cipher

From Rosetta Code
Bacon cipher is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.

Bacon's cipher is a method of steganography created by Francis Bacon. This task is to implement a program for encryption and decryption of plaintext using the simple alphabet of the Baconian cipher or some other kind of representation of this alphabet (make anything signify anything).

The Baconian alphabet:

a   AAAAA   g     AABBA   n    ABBAA   t     BAABA
b   AAAAB   h     AABBB   o    ABBAB   u-v   BAABB
c   AAABA   i-j   ABAAA   p    ABBBA   w     BABAA
d   AAABB   k     ABAAB   q    ABBBB   x     BABAB
e   AABAA   l     ABABA   r    BAAAA   y     BABBA
f   AABAB   m     ABABB   s    BAAAB   z     BABBB
  1. The Baconian alphabet may optionally be extended to encode all lower case characters individually and/or adding a few punctuation characters such as the space.
  2. It is impractical to use the original change in font for the steganography. For this task you must provide an example that uses a change in the case of successive alphabetical characters instead. Other examples for the language are encouraged to explore alternative steganographic means.
  3. Show an example plaintext message encoded and then decoded here on this page.



11l

Translation of: Nim
V codes = [‘a’ = ‘AAAAA’, ‘b’ = ‘AAAAB’, ‘c’ = ‘AAABA’, ‘d’ = ‘AAABB’, ‘e’ = ‘AABAA’,
           ‘f’ = ‘AABAB’, ‘g’ = ‘AABBA’, ‘h’ = ‘AABBB’, ‘i’ = ‘ABAAA’, ‘j’ = ‘ABAAB’,
           ‘k’ = ‘ABABA’, ‘l’ = ‘ABABB’, ‘m’ = ‘ABBAA’, ‘n’ = ‘ABBAB’, ‘o’ = ‘ABBBA’,
           ‘p’ = ‘ABBBB’, ‘q’ = ‘BAAAA’, ‘r’ = ‘BAAAB’, ‘s’ = ‘BAABA’, ‘t’ = ‘BAABB’,
           ‘u’ = ‘BABAA’, ‘v’ = ‘BABAB’, ‘w’ = ‘BABBA’, ‘x’ = ‘BABBB’, ‘y’ = ‘BBAAA’,
           ‘z’ = ‘BBAAB’, ‘ ’ = ‘BBBAA’]

V rev_codes = Dict(codes.items(), (k, v) -> (v, k))

F encode(plaintext, message)
   V et = ‘’
   L(c) plaintext.lowercase()
      et ‘’= I c C ‘a’..‘z’ {:codes[c]} E :codes[Char(‘ ’)]

   V result = ‘’
   V count = 0
   L(c) message.lowercase()
      I c C ‘a’..‘z’
         result ‘’= I et[count] == ‘A’ {c} E c.uppercase()
         count++
         I count == et.len
            L.break
      E
         result ‘’= c
   R result

F decode(message)
   V result = ‘’
   V et = ‘’
   L(c) message
      I c C (‘A’..‘Z’, ‘a’..‘z’)
         et ‘’= I c.is_lowercase() {‘A’} E ‘B’
   L(i) (0 .< et.len - 4).step(5)
      result ‘’= :rev_codes[et[i .< i + 5]]
   R result

V plaintext = ‘the quick brown fox jumps over the lazy dog’
V message = ‘bacon's cipher is a method of steganography created by francis bacon.’""
            ‘this task is to implement a program for encryption and decryption of ’""
            ‘plaintext using the simple alphabet of the baconian cipher or some ’""
            ‘other kind of representation of this alphabet (make anything signify anything). ’""
            ‘the baconian alphabet may optionally be extended to encode all lower ’""
            ‘case characters individually and/or adding a few punctuation characters ’""
            ‘such as the space.’

V ciphertext = encode(plaintext, message)
print(‘Cipher text →’)
print(ciphertext)
V decodedtext = decode(ciphertext)
print("\nHidden text →")
print(decodedtext)
Output:
Cipher text →
BacON's cIPHer Is a METhoD of stEgAnogRaphy crEatEd By FRAncis baCOn.thIs TASk Is TO imPLeMENT a proGrAm FOR eNcRYPTIOn anD deCRyPtioN Of plAINTExt UsING the SIMpLe AlPhaBet Of thE BAConIan CIphER Or sOme OTHer kInD Of reprESenTATion OF This alPHaBET (makE An

Hidden text →
the quick brown fox jumps over the lazy dog

Ada

Translation of: Kotlin
-- Bacon cipher
with Ada.Text_IO;             use Ada.Text_IO;
with Ada.Strings.Unbounded;   use Ada.Strings.Unbounded;
with Ada.Characters.Handling; use Ada.Characters.Handling;
with Ada.Strings.Fixed;       use Ada.Strings.Fixed;
with Ada.Containers.Ordered_Maps;

procedure Main is
   subtype encode_str is String (1 .. 5);
   subtype lower_case is Character range 'a' .. 'z';
   subtype Upper_case is Character range 'A' .. 'Z';
   package Alphabet is new Ada.Containers.Ordered_Maps
     (Key_Type => Character, Element_Type => encode_str);
   use Alphabet;
   
   blank : constant Character := ' ';

   Bacon : Map;

   function encode (Plain_Text : String; Message : String) return String is
      plain_lower : String := To_Lower (Plain_Text);
      temp        : Unbounded_String;
      msg_lower   : String := To_Lower (Message);
      str         : encode_str;

   begin
      for c of plain_lower loop
         if c in lower_case then
            str := Bacon.Element (c);
         else
            str := Bacon.Element (blank);
         end if;
         Append (Source => temp, New_Item => str);
      end loop;

      declare
         encoded : String   := To_String (temp);
         Count   : Positive := encoded'First;
         result  : Unbounded_String;
      begin
         for c of msg_lower loop
            exit when Count > encoded'last;
            if c in lower_case then
               if encoded (Count) = 'A' then
                  Append (Source => result, New_Item => c);
               else
                  Append (Source => result, New_Item => To_Upper (c));
               end if;
               Count := Count + 1;
            else
               Append (Source => result, New_Item => c);
            end if;
         end loop;
         return To_String (result);
      end;
   end encode;

   function Index (Item : Map; Pattern : encode_str) return Character is
      result : Character := ' ';
      value  : encode_str;
   begin
      for key in lower_case loop
         value := Item.Element (key);
         if value = Pattern then
            result := key;
            exit;
         end if;
      end loop;
      return result;
   end Index;

   function decode (Message : String) return String is
      encoded : Unbounded_String;
   begin
      for c of Message loop
         if c in lower_case then
            Append (Source => encoded, New_Item => 'A');
         elsif c in Upper_case then
            Append (Source => encoded, New_Item => 'B');
         end if;
      end loop;

      declare
         encoded_string : String   := To_String (encoded);
         idx            : Positive := encoded_string'First;
         Result         : Unbounded_String;
         c              : Character;
         str            : encode_str;

      begin
         loop
            str := encoded_string (idx .. idx + 4);
            c   := Index (Item => Bacon, Pattern => str);
            Append (Source => Result, New_Item => c);
            idx := idx + 5;
            exit when idx + 4 > encoded_string'Last;
         end loop;
         return To_String (Result);
      end;
   end decode;

   P_Text : String := "the quick brown fox jumps over the lazy dog";
   P_Msg  : String :=
     "bacon's cipher is a method of steganography created by francis bacon. " &
     "this task is to implement a program for encryption and decryption of " &
     "plaintext using the simple alphabet of the baconian cipher or some " &
     "other kind of representation of this alphabet (make anything signify anything). " &
     "the baconian alphabet may optionally be extended to encode all lower " &
     "case characters individually and/or adding a few punctuation characters " &
     "such as the space.";

begin
   Bacon.Insert (Key => 'a', New_Item => "AAAAA");
   Bacon.Insert (Key => 'b', New_Item => "AAAAB");
   Bacon.Insert (Key => 'c', New_Item => "AAABA");
   Bacon.Insert (Key => 'd', New_Item => "AAABB");
   Bacon.Insert (Key => 'e', New_Item => "AABAA");
   Bacon.Insert (Key => 'f', New_Item => "AABAB");
   Bacon.Insert (Key => 'g', New_Item => "AABBA");
   Bacon.Insert (Key => 'h', New_Item => "AABBB");
   Bacon.Insert (Key => 'i', New_Item => "ABAAA");
   Bacon.Insert (Key => 'j', New_Item => "ABAAB");
   Bacon.Insert (Key => 'k', New_Item => "ABABA");
   Bacon.Insert (Key => 'l', New_Item => "ABABB");
   Bacon.Insert (Key => 'm', New_Item => "ABBAA");
   Bacon.Insert (Key => 'n', New_Item => "ABBAB");
   Bacon.Insert (Key => 'o', New_Item => "ABBBA");
   Bacon.Insert (Key => 'p', New_Item => "ABBBB");
   Bacon.Insert (Key => 'q', New_Item => "BAAAA");
   Bacon.Insert (Key => 'r', New_Item => "BAAAB");
   Bacon.Insert (Key => 's', New_Item => "BAABA");
   Bacon.Insert (Key => 't', New_Item => "BAABB");
   Bacon.Insert (Key => 'u', New_Item => "BABAA");
   Bacon.Insert (Key => 'v', New_Item => "BABAB");
   Bacon.Insert (Key => 'w', New_Item => "BABBA");
   Bacon.Insert (Key => 'x', New_Item => "BABBB");
   Bacon.Insert (Key => 'y', New_Item => "BBAAA");
   Bacon.Insert (Key => 'z', New_Item => "BBAAB");
   Bacon.Insert (Key => blank, New_Item => "BBBAA");

   declare
      ciphertext : String := encode (Plain_Text => P_Text, Message => P_Msg);
   begin
      Put_Line ("Cipher text:");
      Put_Line (ciphertext);
      New_Line;
      Put_Line ("Hidden text:");
      Put_Line (decode (ciphertext));
   end;
end Main;
Output:
Cipher text:
BacON's cIPHer Is a METhoD of stEgAnogRaphy crEatEd By FRAncis baCOn. thIs TASk Is TO imPLeMENT a proGrAm FOR eNcRYPTIOn anD deCRyPtioN Of plAINTExt UsING the SIMpLe AlPhaBet Of thE BAConIan CIphER Or sOme OTHer kInD Of reprESenTATion OF This alPHaBET (makE An

Hidden text:
the quick brown fox jumps over the lazy dog

Agena

Tested with Agena 2.9.5 Win32

Translation of: ALGOL 68
# Bacon cipher

# Bacon's letter codes but with distinct values for i & j and u & v and an extra for any non-letter
baconCodes := [ "A" ~ "AAAAA", "B" ~ "AAAAB", "C" ~ "AAABA", "D" ~ "AAABB", "E" ~ "AABAA"
              , "F" ~ "AABAB", "G" ~ "AABBA", "H" ~ "AABBB", "I" ~ "ABAAA", "J" ~ "ABAAB"
              , "K" ~ "ABABA", "L" ~ "ABABB", "M" ~ "ABBAA", "N" ~ "ABBAB", "O" ~ "ABBBA"
              , "P" ~ "ABBBB", "Q" ~ "BAAAA", "R" ~ "BAAAB", "S" ~ "BAABA", "T" ~ "BAABB"
              , "U" ~ "BABAA", "V" ~ "BABAB", "W" ~ "BABBA", "X" ~ "BABBB", "Y" ~ "BBAAA"
              , "Z" ~ "BBAAB", "*" ~ "BBBAA"
              ];
# yields plain text encoded via stego template
toBacon    :=
    proc( plainText :: string, stegoTemplate :: string ) :: string is
        local stegoPos   := 0;
        local stegoLen   := size stegoTemplate;
        # selects the next character from the stego template - wraps-around from the end to the beginning
        local nextStegoPos := proc() is inc stegoPos, 1; mod stegoPos, stegoLen end;
        # encode the plain text
        local encoded    := "";
        for pos to size plainText do
            # get the Bacon code of the next character #
            local plainChar := upper( plainText[ pos ] );
            local code := baconCodes[ if plainChar < "A" or plainChar > "Z" then "*" else plainChar fi ];
            for c to size code do
                # copy punctuation as is from the stego template to the result
                local s := upper( stegoTemplate[ stegoPos + 1 ] );
                while s < "A" or s > "Z" do
                    encoded := encoded & s;
                    nextStegoPos();
                    s       := if stegoPos < size stegoTemplate then upper( stegoTemplate[ stegoPos + 1 ] ) else "A" fi
                od;
                # encode the character by changing the case of the stego character as appropriate
                local templateChar := stegoTemplate[ stegoPos + 1 ];
                encoded := encoded & if code[ c ] = "A" then lower( templateChar ) else upper( templateChar ) fi;
                nextStegoPos()
            od
        od;
        return encoded
    end ; # toBacon
# yields bacon text decoded via stego template
toPlain := proc( baconText :: string, stegoTemplate :: string ) :: string is
    local decoded    := "";
    local codedChar  := 0;
    local letters    := 0;
    local codeLength := size baconCodes[ "A" ];
    for pos to size baconText do
        local c := baconText[ pos ];
        if c >= "a" and c <= "z"
        then
            # lower case letter
            mul codedChar, 2;
            inc letters,   1
        elif c >= "A" and c <= "Z"
        then
            # upper case letter
            mul codedChar, 2;
            inc codedChar, 1;
            inc letters,   1
        fi;
        if letters = codeLength
        then
            # have a full letter to decode
            decoded   := decoded & if codedChar > 25 then " " else char( abs( "a" ) + codedChar ) fi;
            letters   := 0;
            codedChar := 0
        fi
    od;
    return decoded
end ; # toPlain
# test encode and decode
scope
    local nl           := char( 10 );
    local testTemplate := "bacon's cipher is a method of steganography created by francis bacon."            & nl
                        & "this task is to implement a program for encryption and decryption of "            & nl
                        & "plaintext using the simple alphabet of the baconian cipher or some "              & nl
                        & "other kind of representation of this alphabet (make anything signify anything). " & nl
                        & "the baconian alphabet may optionally be extended to encode all lower "            & nl
                        & "case characters individually and/or adding a few punctuation characters "         & nl
                        & "such as the space."                                                               & nl
                        ;
    local plainText    := "the quick brown fox jumps over the lazy dog";
    local baconEncoded := toBacon( plainText,    testTemplate );
    local baconDecoded := toPlain( baconEncoded, testTemplate );
    print( "encoded..." );
    print( baconEncoded );
    print( "-----------------------------------------------------" );
    print( "decoded..." );
    print( baconDecoded );
    print( "-----------------------------------------------------" );
    print( if baconDecoded <> plainText then "UNSUCESSFUL" else "sucessful" fi, " decode" )
epocs
Output:
encoded...
BacON's cIPHer Is a METhoD of stEgAnogRaphy crEatEd By FRAncis baCOn.
thIs TASk Is TO imPLeMENT a proGrAm FOR eNcRYPTIOn anD deCRyPtioN Of 
plAINTExt UsING the SIMpLe AlPhaBet Of thE BAConIan CIphER Or sOme 
OTHer kInD Of reprESenTATion OF This alPHaBET (makE An
-----------------------------------------------------
decoded...
the quick brown fox jumps over the lazy dog
-----------------------------------------------------
sucessful	 decode

ALGOL 68

# Bacon's letter codes but with distinct values for i & j and u & v and an extra for any non-letter #
[]STRING bacon codes = ( #a# "AAAAA", "AAAAB", "AAABA", "AAABB", "AABAA", "AABAB", "AABBA", "AABBB", "ABAAA"
                       , #j# "ABAAB", "ABABA", "ABABB", "ABBAA", "ABBAB", "ABBBA", "ABBBB", "BAAAA", "BAAAB"
                       , #s# "BAABA", "BAABB", "BABAA", "BABAB", "BABBA", "BABBB", "BBAAA", "BBAAB", "BBBAA"
                       );
# operators to convert case #
OP LCASE = ( CHAR c )CHAR: IF c < "A" OR c > "Z" THEN c ELSE REPR ( ( ABS c - ABS "A" ) + ABS "a" ) FI;
OP UCASE = ( CHAR c )CHAR: IF c < "a" OR c > "z" THEN c ELSE REPR ( ( ABS c - ABS "a" ) + ABS "A" ) FI;
# yields plain text encoded via stego template #
PROC to bacon = ( STRING plain text, STRING stego template )STRING:
     BEGIN
         INT    stego pos   := 0;
         INT    stego len    = ( UPB stego template + 1 ) - LWB stego template;
         INT    stego start  = LWB stego template;
         # selects the next character from the stego template - wraps-around from the end to the beginning #
         PROC next stego pos = VOID: ( stego pos +:= 1; stego pos MODAB stego len);
         # encode the plain text #
         STRING encoded     := "";
         FOR pos FROM LWB plain text TO UPB plain text DO
             # get the Bacon code of the next character #
             CHAR   plain char = UCASE plain text[ pos ];
             STRING code =
                 bacon codes[ IF plain char < "A" OR plain char > "Z" THEN UPB bacon codes ELSE ( ABS plain char - ABS "A" ) + 1 FI ];
             FOR c FROM LWB code TO UPB code DO
                 # copy punctuation as is from the stego template to the result #
                 WHILE CHAR s := UCASE stego template[ stego pos + stego start ];
                       s < "A" OR s > "Z"
                 DO
                     encoded   +:= s;
                     next stego pos
                 OD;
                 # encode the character by changing the case of the stego character as appropriate #
                 CHAR template char = stego template[ stego pos + stego start ];
                 encoded +:= IF code[ c ] = "A" THEN LCASE template char ELSE UCASE template char FI;
                 next stego pos
             OD
         OD;
         encoded
     END ; # to bacon #
# yields bacon text decoded via stego template #
PROC to plain = ( STRING bacon text, stego template )STRING:
     BEGIN
         STRING decoded := "";
         INT coded char := 0;
         INT letters    := 0;
         INT code length = ( UPB bacon codes[ 1 ] - LWB bacon codes[ 1 ] ) + 1;
         FOR pos FROM LWB bacon text TO UPB bacon text DO
             CHAR c = bacon text[ pos ];
             IF c >= "a" AND c <= "z"
             THEN
                 # lower case letter #
                 coded char *:= 2;
                 letters    +:= 1
             ELIF c >= "A" AND c <= "Z"
             THEN
                 # upper case letter #
                 coded char *:= 2;
                 coded char +:= 1;
                 letters    +:= 1
             FI;
             IF letters = code length
             THEN
                 # have a full letter to decode #
                 decoded    +:= IF coded char > 25 THEN " " ELSE REPR ( ABS "a" + coded char ) FI;
                 letters     := 0;
                 coded char  := 0
             FI
         OD;
         decoded
     END ; # to plain #
# test encode and decode #
STRING test template = "bacon's cipher is a method of steganography created by francis bacon."            + REPR 10
                     + "this task is to implement a program for encryption and decryption of "            + REPR 10
                     + "plaintext using the simple alphabet of the baconian cipher or some "              + REPR 10
                     + "other kind of representation of this alphabet (make anything signify anything). " + REPR 10
                     + "the baconian alphabet may optionally be extended to encode all lower "            + REPR 10
                     + "case characters individually and/or adding a few punctuation characters "         + REPR 10
                     + "such as the space."                                                               + REPR 10
                     ;
STRING plain text    = "the quick brown fox jumps over the lazy dog";
STRING bacon encoded = to bacon( plain text,    test template );
STRING bacon decoded = to plain( bacon encoded, test template );
print( ( "encoded...", newline ) );
print( ( bacon encoded, newline ) );
print( ( "-----------------------------------------------------", newline, "decoded...", newline ) );
print( ( bacon decoded, newline ) );
print( ( "-----------------------------------------------------", newline ) );
print( ( IF bacon decoded /= plain text THEN "UNSUCESSFUL" ELSE "sucessful" FI, " decode", newline ) )
Output:
encoded...
BacON's cIPHer Is a METhoD of stEgAnogRaphy crEatEd By FRAncis baCOn.
thIs TASk Is TO imPLeMENT a proGrAm FOR eNcRYPTIOn anD deCRyPtioN Of
plAINTExt UsING the SIMpLe AlPhaBet Of thE BAConIan CIphER Or sOme
OTHer kInD Of reprESenTATion OF This alPHaBET (makE An
-----------------------------------------------------
decoded...
the quick brown fox jumps over the lazy dog
-----------------------------------------------------
sucessful decode

Arturo

Codes: #[
    a: "AAAAA" b: "AAAAB" c: "AAABA" d: "AAABB" e: "AABAA"
    f: "AABAB" g: "AABBA" h: "AABBB" i: "ABAAA" j: "ABAAB"
    k: "ABABA" l: "ABABB" m: "ABBAA" n: "ABBAB" o: "ABBBA"
    p: "ABBBB" q: "BAAAA" r: "BAAAB" s: "BAABA" t: "BAABB"
    u: "BABAA" v: "BABAB" w: "BABBA" x: "BABBB" y: "BBAAA"
    z: "BBAAB"
]
space: "BBBAA"

RevCodes: #[]
loop Codes [k,v]-> RevCodes\[v]: k

encodeBacon: function [plaintext,message][
    et: new ""
    result: new ""
    loop lower plaintext 'c [
        'et ++ (lower? c)? -> Codes\[c] -> space
    ]
    cnt: 0
    loop lower message 'c [
        if? lower? c [
            'result ++ (et\[cnt] = `A`)? -> c -> upper c
            cnt: cnt + 1
            if cnt = size et -> break
        ]
        else -> 'result ++ c
    ]
    return result
]

decodeBacon: function [message][
    et: new ""
    result: new ""
    loop message 'c [
        if or? lower? c upper? c [
            if? lower? c -> 'et ++ `A`
            else -> 'et ++ `B`

            if 5 = size et [
                if? key? RevCodes et -> 'result ++ RevCodes\[et]
                else -> 'result ++ " "
                et: new ""
            ]
        ]
    ]
    return result
]

PlainText: "the quick brown fox jumps over the lazy dog"
Message: join [
    "bacon's cipher is a method of steganography created by francis bacon. "
    "this task is to implement a program for encryption and decryption of "
    "plaintext using the simple alphabet of the baconian cipher or some "
    "other kind of representation of this alphabet (make anything signify anything). "
    "the baconian alphabet may optionally be extended to encode all lower "
    "case characters individually and/or adding a few punctuation characters "
    "such as the space."
]

cipherText: encodeBacon PlainText Message
print "Cipher text:"
print cipherText
print ""
print "Message:"
print decodeBacon cipherText
Output:
Cipher text:
BacON's cIPHer Is a METhoD of stEgAnogRaphy crEatEd By FRAncis baCOn. thIs TASk Is TO imPLeMENT a proGrAm FOR eNcRYPTIOn anD deCRyPtioN Of plAINTExt UsING the SIMpLe AlPhaBet Of thE BAConIan CIphER Or sOme OTHer kInD Of reprESenTATion OF This alPHaBET (makE An

Message:
the quick brown fox jumps over the lazy dog

AutoHotkey

Bacon_Cipher(message, plaintext:=""){
    codes := {"a":"AAAAA", "b":"AAAAB", "c":"AAABA", "d":"AAABB", "e":"AABAA"
            , "f":"AABAB", "g":"AABBA", "h":"AABBB", "i":"ABAAA", "j":"ABAAB"
            , "k":"ABABA", "l":"ABABB", "m":"ABBAA", "n":"ABBAB", "o":"ABBBA"
            , "p":"ABBBB", "q":"BAAAA", "r":"BAAAB", "s":"BAABA", "t":"BAABB"
            , "u":"BABAA", "v":"BABAB", "w":"BABBA", "x":"BABBB", "y":"BBAAA"
            , "z":"BBAAB", " ":"BBBAA"}
        
    if (plaintext<>"") {
        for i, letter in StrSplit(plaintext)
            code .= codes[letter]
        
        x := StrSplit(code)
        for i, letter in StrSplit(message)
            if (Asc(letter) >= 97 and Asc(letter) <= 122)
                if !(l := x.RemoveAt(1))
                    break
                else if (l = "A")
                    cipher .= letter
                else
                    cipher .= Chr(Asc(letter) - 32)
            else
                cipher .= letter            
        return cipher
    } else {
        Keys := []
        for l, c in codes
            Keys[c] := l
        
        for i, letter in StrSplit(message)
            if (Asc(letter) >= 97 and Asc(letter) <= 122)
                pattern .= "A"
            else if (Asc(letter) >= 65 and Asc(letter) <= 90)
                pattern .= "B"
            
        while StrLen(pattern)
            str .= Keys[SubStr(pattern, 1, 5)]
            , pattern := SubStr(pattern, 6)            
        return str
    }
}
Examples:
Message:= "
(join
bacon's cipher is a method of steganography created by francis bacon. 
this task is to implement a program for encryption and decryption of 
plaintext using the simple alphabet of the baconian cipher or some 
other kind of representation of this alphabet (make anything signify anything). 
the baconian alphabet may optionally be extended to encode all lower 
case characters individually and/or adding a few punctuation characters 
such as the space.
)"

plaintext := "the quick brown fox jumps over the lazy dog"

MsgBox, 262144, ,% "plain text = " plaintext
                . "`n`nencoded = `n" (cipher := Bacon_Cipher(message, plaintext))
                . "`n`ndecoded = " recoveredText := Bacon_Cipher(cipher)
Output:
plain text = the quick brown fox jumps over the lazy dog

encoded = 
BacON's cIPHer Is a METhoD of stEgAnogRaphy crEatEd By FRAncis baCOn.thIs TASk Is TO imPLeMENT a proGrAm FOR eNcRYPTIOn anD deCRyPtioN OfplAINTExt UsING the SIMpLe AlPhaBet Of thE BAConIan CIphER Or sOmeOTHer kInD Of reprESenTATion OF This alPHaBET (makE An

decoded = the quick brown fox jumps over the lazy dog

BASIC

BaCon

A Bacon cipher in BaCon. Using unique identifiers 'aaaaa'-'bbaab' for a-z and, as other examples on this page, using 'bbbaa' (28) for the space character.

msg$ = "the quick brown fox jumps over the lazy dog"

txt$ = "Bacon's cipher is a method of steganography created by Francis Bacon." \
"This task is to implement a program for encryption and decryption of plaintext " \
"using the simple alphabet of the Baconian cipher or some other kind of representation " \
"of this alphabet (make anything signify anything)."

position = 1

FOR x = 1 TO LEN(msg$)
    value = ASC(MID$(msg$, x, 1))-97

    IF value < 0 OR value > 25 THEN value = 28

    FOR b = 4 DOWNTO 0
        WHILE NOT(REGEX(MID$(txt$, position, 1), "[[:alpha:]]"))
            steg$ = steg$ & MID$(txt$, position, 1)
            INCR position
        WEND

        IF value & BIT(b) THEN
            steg$ = steg$ & UCASE$(MID$(txt$, position, 1))
        ELSE
            steg$ = steg$ & LCASE$(MID$(txt$, position, 1))
        END IF

        INCR position
    NEXT
NEXT

PRINT "Encoded:", NL$, steg$

position = 0

FOR x = 1 TO LEN(steg$)
    IF NOT(REGEX(MID$(steg$, x, 1), "[[:alpha:]]")) THEN CONTINUE

    letter = letter << 1

    IF ASC(MID$(steg$, x, 1))-97 < 0 THEN letter = letter | 1

    INCR position

    IF MOD(position, 5) = 0 THEN
        result$ = result$ & CHR$(IIF(letter=28, 32, letter+97))
        letter = 0
    END IF
NEXT

PRINT "Decoded:", NL$, result$
Output:
Encoded:
BacON's cIPHer Is a METhoD of stEgAnogRaphy crEatEd By FRAncis baCOn.thIs TASk Is TO imPLeMENT a proGrAm FOR eNcRYPTIOn anD deCRyPtioN Of plAINTExt UsING the SIMpLe AlPhaBet Of thE BAConIan CIphER Or sOme OTHer kInD Of reprESenTATion OF This alPHaBET (makE An
Decoded:
the quick brown fox jumps over the lazy dog

Visual Basic .NET

Translation of: C#
Imports System.Text

Module Module1

    ReadOnly CODES As New Dictionary(Of Char, String) From {
        {"a", "AAAAA"}, {"b", "AAAAB"}, {"c", "AAABA"}, {"d", "AAABB"}, {"e", "AABAA"},
        {"f", "AABAB"}, {"g", "AABBA"}, {"h", "AABBB"}, {"i", "ABAAA"}, {"j", "ABAAB"},
        {"k", "ABABA"}, {"l", "ABABB"}, {"m", "ABBAA"}, {"n", "ABBAB"}, {"o", "ABBBA"},
        {"p", "ABBBB"}, {"q", "BAAAA"}, {"r", "BAAAB"}, {"s", "BAABA"}, {"t", "BAABB"},
        {"u", "BABAA"}, {"v", "BABAB"}, {"w", "BABBA"}, {"x", "BABBB"}, {"y", "BBAAA"},
        {"z", "BBAAB"}, {" ", "BBBAA"} ' use " " To denote any non-letter
    }

    Function Encode(plainText As String, message As String) As String
        Dim pt = plainText.ToLower()
        Dim sb As New StringBuilder()
        For Each c In pt
            If "a" <= c AndAlso c <= "z" Then
                sb.Append(CODES(c))
            Else
                sb.Append(CODES(" "))
            End If
        Next

        Dim et = sb.ToString()
        Dim mg = message.ToLower() '"A"s to be in lower case, "B"s in upper case

        sb.Length = 0
        Dim count = 0
        For Each c In mg
            If "a" <= c AndAlso c <= "z" Then
                If et(count) = "A" Then
                    sb.Append(c)
                Else
                    sb.Append(Chr(Asc(c) - 32)) ' upper case equivalent
                End If
                count += 1
                If count = et.Length Then
                    Exit For
                End If
            Else
                sb.Append(c)
            End If
        Next

        Return sb.ToString()
    End Function

    Function Decode(message As String) As String
        Dim sb As New StringBuilder

        For Each c In message
            If "a" <= c AndAlso c <= "z" Then
                sb.Append("A")
            ElseIf "A" <= c AndAlso c <= "Z" Then
                sb.Append("B")
            End If
        Next

        Dim et = sb.ToString()
        sb.Length = 0
        For index = 0 To et.Length - 1 Step 5
            Dim quintet = et.Substring(index, 5)
            Dim key = CODES.Where(Function(a) a.Value = quintet).First().Key
            sb.Append(key)
        Next

        Return sb.ToString()
    End Function

    Sub Main()
        Dim plainText = "the quick brown fox jumps over the lazy dog"
        Dim message =
            "bacon's cipher is a method of steganography created by francis bacon. " +
            "this task is to implement a program for encryption and decryption of " +
            "plaintext using the simple alphabet of the baconian cipher or some " +
            "other kind of representation of this alphabet (make anything signify anything). " +
            "the baconian alphabet may optionally be extended to encode all lower " +
            "case characters individually and/or adding a few punctuation characters " +
            "such as the space."

        Dim cipherText = Encode(plainText, message)
        Console.WriteLine("Cipher text ->" & Environment.NewLine & "{0}", cipherText)

        Dim decodedText = Decode(cipherText)
        Console.WriteLine(Environment.NewLine & "Hidden text ->" & Environment.NewLine & "{0}", decodedText)
    End Sub

End Module
Output:
Cipher text ->
BacON's cIPHer Is a METhoD of stEgAnogRaphy crEatEd By FRAncis baCOn. thIs TASk Is TO imPLeMENT a proGrAm FOR eNcRYPTIOn anD deCRyPtioN Of plAINTExt UsING the SIMpLe AlPhaBet Of thE BAConIan CIphER Or sOme OTHer kInD Of reprESenTATion OF This alPHaBET (makE An

Hidden text ->
the quick brown fox jumps over the lazy dog

C

Translation of: Kotlin
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

/* maps successively from 'a' to 'z' plus ' ' to denote any non-letter */
char *codes[] = {
    "AAAAA", "AAAAB", "AAABA", "AAABB", "AABAA",
    "AABAB", "AABBA", "AABBB", "ABAAA", "ABAAB",
    "ABABA", "ABABB", "ABBAA", "ABBAB", "ABBBA",
    "ABBBB", "BAAAA", "BAAAB", "BAABA", "BAABB",
    "BABAA", "BABAB", "BABBA", "BABBB", "BBAAA",
    "BBAAB", "BBBAA"
};

char *get_code(const char c) {
    if (c >= 97 && c <= 122) return codes[c - 97];
    return codes[26];
}

char get_char(const char *code) {
    int i;
    if (!strcmp(codes[26], code)) return ' ';
    for (i = 0; i < 26; ++i) {
        if (strcmp(codes[i], code) == 0) return 97 + i;
    }
    printf("\nCode \"%s\" is invalid\n", code);
    exit(1);
}

void str_tolower(char s[]) {
    int i;
    for (i = 0; i < strlen(s); ++i) s[i] = tolower(s[i]);
}

char *bacon_encode(char plain_text[], char message[]) {
    int i, count;
    int plen = strlen(plain_text), mlen = strlen(message);
    int elen = 5 * plen;
    char c;
    char *p, *et, *mt;
    et = malloc(elen + 1);  
    str_tolower(plain_text);
    for (i = 0, p = et; i < plen; ++i, p += 5) {
        c = plain_text[i];
        strncpy(p, get_code(c), 5);
    }
    *++p = '\0';

    /* 'A's to be in lower case, 'B's in upper case */
    str_tolower(message);
    mt = calloc(mlen + 1, 1);
    for (i = 0, count = 0; i < mlen; ++i) {
        c = message[i];
        if (c >= 'a' && c <= 'z') {
            if (et[count] == 'A')
                mt[i] = c;
            else
                mt[i] = c - 32;  /* upper case equivalent */
            if (++count == elen) break;
        }
        else mt[i] = c;
    }
    free(et);     
    return mt;
}

char *bacon_decode(char cipher_text[]) {
    int i, count, clen = strlen(cipher_text);
    int plen;
    char *p, *ct, *pt;
    char c, quintet[6];
    ct = calloc(clen + 1, 1);
    for (i = 0, count = 0; i < clen; ++i) {
        c = cipher_text[i];
        if (c >= 'a' && c <= 'z')
            ct[count++] = 'A';
        else if (c >= 'A' && c <= 'Z')
            ct[count++] = 'B';
    }

    plen = strlen(ct) / 5; 
    pt = malloc(plen + 1);
    for (i = 0, p = ct; i < plen; ++i, p += 5) {
        strncpy(quintet, p, 5);
        quintet[5] = '\0';
        pt[i] = get_char(quintet);
    }
    pt[plen] = '\0';
    free(ct);
    return pt;
} 

int main() {
    char plain_text[] = "the quick brown fox jumps over the lazy dog";
    char message[] = "bacon's cipher is a method of steganography created by francis bacon."
        "this task is to implement a program for encryption and decryption of "
        "plaintext using the simple alphabet of the baconian cipher or some "
        "other kind of representation of this alphabet (make anything signify anything). "
        "the baconian alphabet may optionally be extended to encode all lower "
        "case characters individually and/or adding a few punctuation characters "
        "such as the space.";
    char *cipher_text, *hidden_text;
    cipher_text = bacon_encode(plain_text, message);
    printf("Cipher text ->\n\n%s\n", cipher_text);
    hidden_text = bacon_decode(cipher_text);
    printf("\nHidden text ->\n\n%s\n", hidden_text);
    free(cipher_text);
    free(hidden_text);
    return 0;
}
Output:
Cipher text ->

BacON's cIPHer Is a METhoD of stEgAnogRaphy crEatEd By FRAncis baCOn.thIs TASk Is TO imPLeMENT a proGrAm FOR eNcRYPTIOn anD deCRyPtioN Of plAINTExt UsING the SIMpLe AlPhaBet Of thE BAConIan CIphER Or sOme OTHer kInD Of reprESenTATion OF This alPHaBET (makE An

Hidden text ->

the quick brown fox jumps over the lazy dog

C#

Translation of: Java
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace BaconCipher {
    class Program {
        private static Dictionary<char, string> codes = new Dictionary<char, string> {
            {'a', "AAAAA" }, {'b', "AAAAB" }, {'c', "AAABA" }, {'d', "AAABB" }, {'e', "AABAA" },
            {'f', "AABAB" }, {'g', "AABBA" }, {'h', "AABBB" }, {'i', "ABAAA" }, {'j', "ABAAB" },
            {'k', "ABABA" }, {'l', "ABABB" }, {'m', "ABBAA" }, {'n', "ABBAB" }, {'o', "ABBBA" },
            {'p', "ABBBB" }, {'q', "BAAAA" }, {'r', "BAAAB" }, {'s', "BAABA" }, {'t', "BAABB" },
            {'u', "BABAA" }, {'v', "BABAB" }, {'w', "BABBA" }, {'x', "BABBB" }, {'y', "BBAAA" },
            {'z', "BBAAB" }, {' ', "BBBAA" }, // use ' ' to denote any non-letter
        };

        private static string Encode(string plainText, string message) {
            string pt = plainText.ToLower();
            StringBuilder sb = new StringBuilder();
            foreach (char c in pt) {
                if ('a' <= c && c <= 'z') sb.Append(codes[c]);
                else sb.Append(codes[' ']);
            }
            string et = sb.ToString();
            string mg = message.ToLower();  // 'A's to be in lower case, 'B's in upper case
            sb.Length = 0;
            int count = 0;
            foreach (char c in mg) {
                if ('a' <= c && c <= 'z') {
                    if (et[count] == 'A') sb.Append(c);
                    else sb.Append((char)(c - 32)); // upper case equivalent
                    count++;
                    if (count == et.Length) break;
                }
                else sb.Append(c);
            }

            return sb.ToString();
        }

        private static string Decode(string message) {
            StringBuilder sb = new StringBuilder();
            foreach (char c in message) {
                if ('a' <= c && c <= 'z') sb.Append('A');
                else if ('A' <= c && c <= 'Z') sb.Append('B');
            }
            string et = sb.ToString();
            sb.Length = 0;
            for (int i = 0; i < et.Length; i += 5) {
                string quintet = et.Substring(i, 5);
                char key = codes.Where(a => a.Value == quintet).First().Key;
                sb.Append(key);
            }
            return sb.ToString();
        }

        static void Main(string[] args) {
            string plainText = "the quick brown fox jumps over the lazy dog";
            string message = "bacon's cipher is a method of steganography created by francis bacon. " +
                "this task is to implement a program for encryption and decryption of " +
                "plaintext using the simple alphabet of the baconian cipher or some " +
                "other kind of representation of this alphabet (make anything signify anything). " +
                "the baconian alphabet may optionally be extended to encode all lower " +
                "case characters individually and/or adding a few punctuation characters " +
                "such as the space.";
            string cipherText = Encode(plainText, message);
            Console.WriteLine("Cipher text ->\n{0}", cipherText);
            string decodedText = Decode(cipherText);
            Console.WriteLine("\nHidden text ->\n{0}", decodedText);
        }
    }
}
Output:
Cipher text ->
BacON's cIPHer Is a METhoD of stEgAnogRaphy crEatEd By FRAncis baCOn. thIs TASk Is TO imPLeMENT a proGrAm FOR eNcRYPTIOn anD deCRyPtioN Of plAINTExt UsING the SIMpLe AlPhaBet Of thE BAConIan CIphER Or sOme OTHer kInD Of reprESenTATion OF This alPHaBET (makE An

Hidden text ->
the quick brown fox jumps over the lazy dog

C++

Bacon cipher implementation

#include <iostream>
#include <algorithm>
#include <vector>
#include <bitset>
#include <string>

class bacon {
public:
    bacon() {
        int x = 0;
        for( ; x < 9; x++ )
            bAlphabet.push_back( std::bitset<5>( x ).to_string() );
        bAlphabet.push_back( bAlphabet.back() );
        
        for( ; x < 20; x++ )
            bAlphabet.push_back( std::bitset<5>( x ).to_string() );
        bAlphabet.push_back( bAlphabet.back() );
        
        for( ; x < 24; x++ )
            bAlphabet.push_back( std::bitset<5>( x ).to_string() );
    }

    std::string encode( std::string txt ) {
        std::string r;
        size_t z;
        for( std::string::iterator i = txt.begin(); i != txt.end(); i++ ) {
            z = toupper( *i );
            if( z < 'A' || z > 'Z' ) continue;
            r.append( bAlphabet.at( ( *i & 31 ) - 1 ) );
        }
        return r;
    }

    std::string decode( std::string txt ) {
        size_t len = txt.length();
        while( len % 5 != 0 ) len--;
        if( len != txt.length() ) txt = txt.substr( 0, len );
        std::string r;
        for( size_t i = 0; i < len; i += 5 ) {
            r.append( 1, 'A' + std::distance( bAlphabet.begin(), std::find( bAlphabet.begin(), bAlphabet.end(), txt.substr( i, 5 ) ) ) );
        }
        return r;
    }

private:
    std::vector<std::string> bAlphabet;
};

These next 2 classes use the 0's & 1's generated by the 'Bacon encryption' to create different the outputs. One could go wild here...

class cipherI {
public:
    std::string encode( std::string txt ) {
        txt = b.encode( txt );
        std::string e, d = "one morning, when gregor samsa woke from troubled dreams, he found himself transformed "
        "in his bed into a horrible vermin. he lay on his armour-like back, and if he lifted his head a little he "
        "could see his brown belly, slightly domed and divided by arches into stiff sections.";
        size_t r = 0; 
        char t;
        for( std::string::iterator i = txt.begin(); i != txt.end(); i++ ) {
            t = d.at( r );
            while( t < 'a' || t > 'z' ) {
                e.append( 1, t );
                r++;
                t = d.at( r );
            }
            r++;
            e.append( 1, *i == '1' ? t - 32 : t );
        }

        return e;
    }

    std::string decode( std::string txt ) {
        std::string h;
        for( std::string::iterator i = txt.begin(); i != txt.end(); i++ ) {
            if( *i < 'a' && ( *i < 'A' || *i > 'Z' ) || *i > 'z' ) continue;
            h.append( 1, *i & 32 ? '0' : '1' );
        }
        return b.decode( h );
    }

private:
    bacon b;
};

class cipherII {
public:
    std::string encode( std::string txt ) {
        txt = b.encode( txt );
        std::string e;
        for( std::string::iterator i = txt.begin(); i != txt.end(); i++ )
            e.append( 1, *i == '0' ? 0xf9 : 0xfa );
        return e;
    }

    std::string decode( std::string txt ) {
        std::string h;
        for( std::string::iterator i = txt.begin(); i != txt.end(); i++ ) {
            h.append( 1, *i == ( char )0xf9 ? '0' : '1' );
        }
        return b.decode( h );
    }

private:
    bacon b;
};

int main( int argc, char* argv[] ) {
    cipherI c1;
    cipherII c2;
    std::string s = "lets have some fun with bacon cipher";

    std::string h1 = c1.encode( s ),
                h2 = c2.encode( s );

    std::cout << h1 << std::endl << std::endl << c1.decode( h1 ) << std::endl << std::endl;
    std::cout << h2 << std::endl << std::endl << c2.decode( h2 ) << std::endl << std::endl;

    return 0;
}
Output:
oNe MornIng, WheN gRegoR saMSA woke fRom TRouBleD dreAmS, He FoUnD HimSelf tRaNS
foRMeD In hIs Bed iNto a HorRiblE VErmin. He lay on hiS arMOuR-lIKe back, And If
 he lIFTed hIS HeaD a lIttle

LETSHAUESOMEFUNWITHBACONCIPHER

¨·¨·¨¨¨·¨¨·¨¨·¨·¨¨¨·¨¨···¨¨¨¨¨·¨¨··¨¨·¨¨·¨¨¨·¨··¨·¨·¨··¨¨·¨¨¨¨·¨··¨¨··¨··¨¨·¨·¨¨
¨·¨¨¨·¨¨·¨¨¨···¨¨¨¨·¨¨¨¨¨¨¨¨·¨¨··¨·¨··¨¨¨¨¨·¨¨·¨¨¨¨···¨¨¨···¨¨·¨¨·¨¨¨¨

LETSHAUESOMEFUNWITHBACONCIPHER

Common Lisp

Association lists

1. Note

Codes are stored in association lists.

#\x -> assoc -> code -> rassoc -> #\x

For instance.

(cdr (assoc #\a +codes+)) = (a a a a a)  (car (rassoc '(a a a a a) +codes+) = #\a 

2. Program

;; 22.06.16

(defconstant +codes+
  '((#\a . (a a a a a)) (#\b . (a a a a b)) (#\c . (a a a b a))
    (#\d . (a a a b b)) (#\e . (a a b a a)) (#\f . (a a b a b))
    (#\g . (a a b b a)) (#\h . (a a b b b)) (#\i . (a b a a a))
    (#\j . (a b a a b)) (#\k . (a b a b a)) (#\l . (a b a b b))
    (#\m . (a b b a a)) (#\n . (a b b a b)) (#\o . (a b b b a))
    (#\p . (a b b b b)) (#\q . (b a a a a)) (#\r . (b a a a b))
    (#\s . (b a a b a)) (#\t . (b a a b b)) (#\u . (b a b a a))
    (#\v . (b a b a b)) (#\w . (b a b b a)) (#\x . (b a b b b))
    (#\y . (b b a a a)) (#\z . (b b a a b)) (#\space . (b b b a a))))

(defun encode (text message) 
  (let (cipher key code)
    (loop for c across message do
      (setf code (cdr (assoc (char-downcase c) +codes+)))
      (setf key (append key code)))
    (loop for c across text always key do
      (when (alpha-char-p c)
        (if (eq (car key) 'B)
          (setf c (char-upcase c))
          (setf c (char-downcase c)))
        (setf key (cdr key)))
      (setf cipher (append cipher (list c))))
    (coerce cipher 'string)))

(defun decode (message)
  (let (key code letter)
    (loop for c across message when (alpha-char-p c) do
      (if (lower-case-p c)
        (setf code (append code '(A)))
        (setf code (append code '(B))))
      (when (= (length code) 5)
        (setf letter (car (rassoc code +codes+ :test #'equal)))
        (setf key (append key (list letter)))
        (setf code nil)))
      (coerce key 'string)))

3. Example

(defconstant +monologue+ (concatenate 'string
  "I've known adventures, seen places you people will never see, I've been Offw"
  "orld and back... frontiers ! I've stood on the back deck of a blinker bound "
  "for the Plutition Camps with sweat in my eyes watching stars fight on the sh"
  "oulder of Orion... I’ve felt wind in my hair, riding test boats off the blac"
  "k galaxies and seen an attack fleet burn like a match and disappear. I've se"
  "en it, felt it..."))

(defconstant +key+ "« tears in rain »")

4. Execution

Output:
(encode +monologue+ +key+)
"I'VE knOwn ADveNtures, seEn plACes YoU PEoplE will NEvER SEe, i'Ve beEn offwoRl
d anD BaCK... FRon"
(decode (encode +monologue+ +key+))
" tears in rain "

That's All Folks !

cyril nocton (cyril.nocton@gmail.com)

D

import std.array;
import std.stdio;
import std.uni;

immutable string[char] codes;
shared static this() {
    codes = [
        'a': "AAAAA", 'b': "AAAAB", 'c': "AAABA", 'd': "AAABB", 'e': "AABAA",
        'f': "AABAB", 'g': "AABBA", 'h': "AABBB", 'i': "ABAAA", 'j': "ABAAB",
        'k': "ABABA", 'l': "ABABB", 'm': "ABBAA", 'n': "ABBAB", 'o': "ABBBA",
        'p': "ABBBB", 'q': "BAAAA", 'r': "BAAAB", 's': "BAABA", 't': "BAABB",
        'u': "BABAA", 'v': "BABAB", 'w': "BABBA", 'x': "BABBB", 'y': "BBAAA",
        'z': "BBAAB", ' ': "BBBAA", // use ' ' to denote any non-letter
    ];
}

string encode(string plainText, string message) {
    string pt = plainText.toLower;
    auto sb = appender!string;
    foreach (c; pt) {
        if ('a' <= c && c <= 'z') {
            sb ~= codes[c];
        } else {
            sb ~= codes[' '];
        }
    }
    string et = sb.data;
    string mg = message.toLower;
    sb = appender!string;
    int count = 0;
    foreach (c; mg) {
        if ('a' <= c && c <= 'z') {
            if (et[count] == 'A') {
                sb ~= c;
            } else {
                sb ~= cast(char)(c - 32);
            }
            count++;
            if (count == et.length) {
                break;
            }
        } else {
            sb ~= c;
        }
    }

    return sb.data;
}

string decode(string message) {
    auto sb = appender!string;
    foreach (c; message) {
        if ('a' <= c && c <= 'z') {
            sb ~= 'A';
        } else if ('A' <= c && c <= 'Z') {
            sb ~= 'B';
        }
    }
    string et = sb.data;
    sb = appender!string;
    for (int i=0; i<et.length; i+=5) {
        string quintet = et[i .. i+5];
        foreach (k,v; codes) {
            if (v == quintet) {
                sb ~= k;
                break;
            }
        }
    }
    return sb.data;
}

void main() {
    string plainText = "the quick brown fox jumps over the lazy dog";
    string message = "bacon's cipher is a method of steganography created by francis bacon. " ~
                    "this task is to implement a program for encryption and decryption of " ~
                    "plaintext using the simple alphabet of the baconian cipher or some " ~
                    "other kind of representation of this alphabet (make anything signify anything). " ~
                    "the baconian alphabet may optionally be extended to encode all lower " ~
                    "case characters individually and/or adding a few punctuation characters " ~
                    "such as the space.";
    string cipherText = encode(plainText, message);
    writeln("Cipher text ->");
    writeln(cipherText);
    writeln;

    string decodedText = decode(cipherText);
    writeln("Hidden text ->");
    writeln(decodedText);
}
Output:
Cipher text ->
BacON's cIPHer Is a METhoD of stEgAnogRaphy crEatEd By FRAncis baCOn. thIs TASk Is TO imPLeMENT a proGrAm FOR eNcRYPTIOn anD deCRyPtioN Of plAINTExt UsING the SIMpLe AlPhaBet Of thE BAConIan CIphER Or sOme OTHer kInD Of reprESenTATion OF This alPHaBET (makE An

Hidden text ->
the quick brown fox jumps over the lazy dog

Fōrmulæ

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Solution

Program for encoding. It uses the extended version of the alphabeth, which can be calculated programatically, with no table.

Test case for encoding

Program for decoding

Test case for decoding

Go

Translation of: Kotlin
package main

import(
    "fmt"
    "strings"
)

var codes = map[rune]string {
    'a' : "AAAAA", 'b' : "AAAAB", 'c' : "AAABA", 'd' : "AAABB", 'e' : "AABAA",
    'f' : "AABAB", 'g' : "AABBA", 'h' : "AABBB", 'i' : "ABAAA", 'j' : "ABAAB",
    'k' : "ABABA", 'l' : "ABABB", 'm' : "ABBAA", 'n' : "ABBAB", 'o' : "ABBBA",
    'p' : "ABBBB", 'q' : "BAAAA", 'r' : "BAAAB", 's' : "BAABA", 't' : "BAABB",
    'u' : "BABAA", 'v' : "BABAB", 'w' : "BABBA", 'x' : "BABBB", 'y' : "BBAAA",
    'z' : "BBAAB", ' ' : "BBBAA",  // use ' ' to denote any non-letter
}

func baconEncode(plainText string, message string) string {
    pt := strings.ToLower(plainText)
    var sb []byte
    for _, c := range pt {
        if c >= 'a' && c <= 'z' {
            sb = append(sb, codes[c]...)
        } else {
            sb = append(sb, codes[' ']...)
        }
    }
    et := string(sb)
    mg := strings.ToLower(message)  // 'A's to be in lower case, 'B's in upper case
    sb = nil  // clear the byte slice
    var count = 0
    for _, c := range mg {
        if c >= 'a' && c <= 'z' {
            if et[count] == 'A' {
                sb = append(sb, byte(c))
            } else {
                sb = append(sb, byte(c - 32))  // upper case equivalent
            }
            count++
            if count == len(et) { break }
        } else {
            sb = append(sb, byte(c))
        }
    }
    return string(sb)
}

func baconDecode(message string) string {
    var sb []byte
    for _, c := range message {
        if c >= 'a' && c <= 'z' {
            sb = append(sb, 'A')
        } else if c >= 'A' && c <= 'Z' {
            sb = append(sb, 'B')
        }
    }
    et := string(sb)
    sb = nil  // clear the byte slice
    for i := 0; i < len(et); i += 5 {
        quintet := et[i : i + 5]
        for k, v := range codes {
            if v == quintet {
                sb = append(sb, byte(k))
                break
            }
        }
    }
    return string(sb)
} 

func main() {
    plainText := "the quick brown fox jumps over the lazy dog"
    message := "bacon's cipher is a method of steganography created by francis bacon." +
        "this task is to implement a program for encryption and decryption of " +
        "plaintext using the simple alphabet of the baconian cipher or some " +
        "other kind of representation of this alphabet (make anything signify anything). " +
        "the baconian alphabet may optionally be extended to encode all lower " +
        "case characters individually and/or adding a few punctuation characters " +
        "such as the space."
    cipherText := baconEncode(plainText, message)
    fmt.Printf("Cipher text ->\n\n%s\n", cipherText)
    decodedText := baconDecode(cipherText)
    fmt.Printf("\nHidden text ->\n\n%s\n", decodedText)
}
Output:
Cipher text ->

BacON's cIPHer Is a METhoD of stEgAnogRaphy crEatEd By FRAncis baCOn.thIs TASk Is TO imPLeMENT a proGrAm FOR eNcRYPTIOn anD deCRyPtioN Of plAINTExt UsING the SIMpLe AlPhaBet Of thE BAConIan CIphER Or sOme OTHer kInD Of reprESenTATion OF This alPHaBET (makE An

Hidden text ->

the quick brown fox jumps over the lazy dog

Groovy

Translation of: Java
class BaconCipher {
    private static final Map<Character, String> codes

    static {
        codes = new HashMap<>()
        codes['a' as Character] = "AAAAA"
        codes['b' as Character] = "AAAAB"
        codes['c' as Character] = "AAABA"
        codes['d' as Character] = "AAABB"
        codes['e' as Character] = "AABAA"
        codes['f' as Character] = "AABAB"
        codes['g' as Character] = "AABBA"
        codes['h' as Character] = "AABBB"
        codes['i' as Character] = "ABAAA"
        codes['j' as Character] = "ABAAB"
        codes['k' as Character] = "ABABA"
        codes['l' as Character] = "ABABB"
        codes['m' as Character] = "ABBAA"
        codes['n' as Character] = "ABBAB"
        codes['o' as Character] = "ABBBA"
        codes['p' as Character] = "ABBBB"
        codes['q' as Character] = "BAAAA"
        codes['r' as Character] = "BAAAB"
        codes['s' as Character] = "BAABA"
        codes['t' as Character] = "BAABB"
        codes['u' as Character] = "BABAA"
        codes['v' as Character] = "BABAB"
        codes['w' as Character] = "BABBA"
        codes['x' as Character] = "BABBB"
        codes['y' as Character] = "BBAAA"
        codes['z' as Character] = "BBAAB"
        codes[' ' as Character] = "BBBAA"
    }

    private static String encode(String plainText, String message) {
        String pt = plainText.toLowerCase()
        StringBuilder sb = new StringBuilder()
        for (char c : pt.toCharArray()) {
            if (('a' as char) <= c && c <= ('z' as char)) sb.append(codes.get(c))
            else sb.append(codes.get(' ' as char))
        }
        String et = sb.toString()
        String mg = message.toLowerCase()  // 'A's to be in lower case, 'B's in upper case
        sb.setLength(0)
        int count = 0
        for (char c : mg.toCharArray()) {
            if (('a' as char) <= c && c <= ('z' as char)) {
                if (et.charAt(count) == ('A' as char)) sb.append(c)
                else sb.append((c - 32) as char) // upper case equivalent
                count++
                if (count == et.length()) break
            } else sb.append(c)
        }
        return sb.toString()
    }

    private static String decode(String message) {
        StringBuilder sb = new StringBuilder()
        for (char c : message.toCharArray()) {
            if (('a' as char) <= c && c <= ('z' as char)) sb.append('A')
            if (('A' as char) <= c && c <= ('Z' as char)) sb.append('B')
        }
        String et = sb.toString()
        sb.setLength(0)
        for (int i = 0; i < et.length(); i += 5) {
            def maxIdx = Math.min(i + 5, et.length())
            String quintet = et.substring(i, maxIdx)
            Character key = codes.entrySet().stream().filter({ a -> Objects.equals(a.getValue(), quintet) }).findFirst().map({ e -> e.getKey() }).orElse(null) as Character
            sb.append(key)
        }
        return sb.toString()
    }

    static void main(String[] args) {
        String plainText = "the quick brown fox jumps over the lazy dog"
        String message = "bacon's cipher is a method of steganography created by francis bacon. " +
                "this task is to implement a program for encryption and decryption of " +
                "plaintext using the simple alphabet of the baconian cipher or some " +
                "other kind of representation of this alphabet (make anything signify anything). " +
                "the baconian alphabet may optionally be extended to encode all lower " +
                "case characters individually and/or adding a few punctuation characters " +
                "such as the space."
        String cipherText = encode(plainText, message)
        System.out.printf("Cipher text ->\n\n%s\n", cipherText)
        String decodedText = decode(cipherText)
        System.out.printf("\nHidden text ->\n\n%s\n", decodedText)
    }
}
Output:
Cipher text ->

BacON's cIPHer Is a METhoD of stEgAnogRaphy crEatEd By FRAncis baCOn. thIs TASk Is TO imPLeMENT a proGrAm FOR eNcRYPTIOn anD deCRyPtioN Of plAINTExt UsING the SIMpLe AlPhaBet Of thE BAConIan CIphER Or sOme OTHer kInD Of reprESenTATion OF This alPHaBET (makE An

Hidden text ->

the quick brown fox jumps over the lazy dog

Haskell

-- Necessary imports
import Data.List (elemIndex, unfoldr)
import Data.Bool (bool)
import Data.Char (isAlpha, isUpper, toLower, toUpper)
import Data.List.Split (chunksOf)

-- The list of characters to be encoded:
chars :: String
chars = ['a' .. 'z'] ++ ['0' .. '9'] ++ ",.;?! "

bitsPerChar :: Int
bitsPerChar = 6

-- Some simple helper functions:
toBinary :: Int -> [Bool]
toBinary = unfoldr (pure . (\(a, b) -> (odd b, a)) . (`divMod` 2))

fromBinary :: [Bool] -> Int
fromBinary = foldr (\x n -> (2 * n) + bool 0 1 x) 0

-- And finally, main functions -- encoding:
encode :: String -> String -> Either String String
encode txt message = do
  mask <- traverse coding message
  zipAlphas (bool toLower toUpper) (concat mask) txt
  where
    coding ch =
      case elemIndex ch chars of
        Nothing -> Left $ "Unknown symbol " ++ show ch
        Just i -> Right $ take bitsPerChar (toBinary i)
    zipAlphas f = go
      where
        go _ [] = Left "Text is not long enough!"
        go [] _ = Right []
        go (x:xs) (y:ys)
          | isAlpha y = (f x y :) <$> go xs ys
          | otherwise = (y :) <$> go (x : xs) ys

-- And decoding:
decode :: String -> String
decode = map decipher . chunksOf bitsPerChar . filter isAlpha
  where
    decipher = (chars !!) . min (length chars - 1) . fromBinary . map isUpper
    chunksOf n = takeWhile (not . null) . unfoldr (pure . splitAt n)

-- Examples
text :: String
text =
  unwords
    [ "Bacon's cipher is a method of steganography created by Francis Bacon."
    , "This task is to implement a program for encryption and decryption of"
    , "plaintext using the simple alphabet of the Baconian cipher or some"
    , "other kind of representation of this alphabet (make anything signify"
    , "anything). The Baconian alphabet may optionally be extended to encode"
    , "all lower case characters individually and/or adding a few punctuation"
    , "characters such as the space."
    ]

message :: String
message = "the quick brown fox jumps over the lazy dog"

main :: IO ()
main = do
  let m = encode text message
  mapM_
    (either
       (putStrLn . ("-> " ++))
       (putStrLn . (++ "\n") . unlines . fmap unwords . chunksOf 10 . words))
    [ m
    , decode <$> m
    , encode text "something wrong @  in the message"
    , encode "abc" message
    ]
Output:
BAcoN's CIPher is A metHod Of StegaNogrApHy creAted By franCiS
baCon. ThIS task iS to iMplEMEnt a PRoGrAm FOr eNcrYpTIoN
and dECRypTIOn Of PlaInTExt Using ThE simPLe aLPHAbet Of tHe
BacOnIaN CIphEr Or Some OtheR kinD oF rePrESEntAtION of thiS
alpHabEt (MAKe Anything sIgnIFy anyTHiNg). tHe BAConian ALPhabET may


the quick brown fox jumps over the lazy dog


-> Unknown symbol '@'
-> Text is not long enough!

J

Implementation:

alfa=: 'ABCDEFGHIKLMNOPQRSTUWXYZ'
beta=: 26{.(}.~i.&'A')a.
norm=: ([ -. -.)&alfa@(rplc&('JIVU'))@toupper
enca=:(5#2),@:#:alfa i. norm
gena=: ]`((,:tolower)@(beta {~ 26 ?@#~ #))}

encrypt=: gena@enca@norm
decrypt=: alfa {~ _5 #.\ 90 < a.&i.

We use random letters as the basis for our steganography and we use case to represent "font".

Example use:

   encrypt 'this is a test'
nWVkJAPkamEuUJIeTGKnUsTVRfAWWuNBIIHdEIcOAPuTBeXKQduQAdU
   encrypt 'this is a test'
sFLkBQKqqaQsGGXzAXQsKlZFBcILRlUIRAQaEQoNUBcHIhFTWbeRAlM
   decrypt encrypt 'this is a test'
THISISATEST

Java

Translation of: Kotlin
Works with: Java version 9
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;

public class BaconCipher {
    private static final Map<Character, String> codes;

    static {
        codes = new HashMap<>();
        codes.putAll(Map.of(
            'a', "AAAAA", 'b', "AAAAB", 'c', "AAABA", 'd', "AAABB", 'e', "AABAA",
            'f', "AABAB", 'g', "AABBA", 'h', "AABBB", 'i', "ABAAA", 'j', "ABAAB"
        ));
        codes.putAll(Map.of(
            'k', "ABABA", 'l', "ABABB", 'm', "ABBAA", 'n', "ABBAB", 'o', "ABBBA",
            'p', "ABBBB", 'q', "BAAAA", 'r', "BAAAB", 's', "BAABA", 't', "BAABB"
        ));
        codes.putAll(Map.of(
            'u', "BABAA", 'v', "BABAB", 'w', "BABBA", 'x', "BABBB", 'y', "BBAAA",
            'z', "BBAAB", ' ', "BBBAA" // use ' ' to denote any non-letter
        ));
    }

    private static String encode(String plainText, String message) {
        String pt = plainText.toLowerCase();
        StringBuilder sb = new StringBuilder();
        for (char c : pt.toCharArray()) {
            if ('a' <= c && c <= 'z') sb.append(codes.get(c));
            else sb.append(codes.get(' '));
        }
        String et = sb.toString();
        String mg = message.toLowerCase();  // 'A's to be in lower case, 'B's in upper case
        sb.setLength(0);
        int count = 0;
        for (char c : mg.toCharArray()) {
            if ('a' <= c && c <= 'z') {
                if (et.charAt(count) == 'A') sb.append(c);
                else sb.append(((char) (c - 32))); // upper case equivalent
                count++;
                if (count == et.length()) break;
            } else sb.append(c);
        }
        return sb.toString();
    }

    private static String decode(String message) {
        StringBuilder sb = new StringBuilder();
        for (char c : message.toCharArray()) {
            if ('a' <= c && c <= 'z') sb.append('A');
            if ('A' <= c && c <= 'Z') sb.append('B');
        }
        String et = sb.toString();
        sb.setLength(0);
        for (int i = 0; i < et.length(); i += 5) {
            String quintet = et.substring(i, i + 5);
            Character key = codes.entrySet().stream().filter(a -> Objects.equals(a.getValue(), quintet)).findFirst().map(Map.Entry::getKey).orElse(null);
            sb.append(key);
        }
        return sb.toString();
    }

    public static void main(String[] args) {
        String plainText = "the quick brown fox jumps over the lazy dog";
        String message = "bacon's cipher is a method of steganography created by francis bacon. " +
            "this task is to implement a program for encryption and decryption of " +
            "plaintext using the simple alphabet of the baconian cipher or some " +
            "other kind of representation of this alphabet (make anything signify anything). " +
            "the baconian alphabet may optionally be extended to encode all lower " +
            "case characters individually and/or adding a few punctuation characters " +
            "such as the space.";
        String cipherText = encode(plainText, message);
        System.out.printf("Cipher text ->\n\n%s\n", cipherText);
        String decodedText = decode(cipherText);
        System.out.printf("\nHidden text ->\n\n%s\n", decodedText);
    }
}
Output:
Cipher text ->

BacON's cIPHer Is a METhoD of stEgAnogRaphy crEatEd By FRAncis baCOn. thIs TASk Is TO imPLeMENT a proGrAm FOR eNcRYPTIOn anD deCRyPtioN Of plAINTExt UsING the SIMpLe AlPhaBet Of thE BAConIan CIphER Or sOme OTHer kInD Of reprESenTATion OF This alPHaBET (makE An

Hidden text ->

the quick brown fox jumps over the lazy dog

jq

Translation of: Wren
Works with: jq

Works with gojq, the Go implementation of jq (*)

Preliminaries

def is_upper: . >= "A" and . <= "Z";

def is_lower: . >= "a" and . <= "z";

# Output: a stream
def chars: explode[] | [.] | implode;

# (*) Change to `keys` for gojq
def key($s): first( keys_unsorted[] as $k | if .[$k] == $s then $k else empty end) // "?";

Bacon Cipher

def Bacon:
    {
            "a" : "AAAAA", "b" : "AAAAB", "c" : "AAABA", "d" : "AAABB", "e" : "AABAA",
            "f" : "AABAB", "g" : "AABBA", "h" : "AABBB", "i" : "ABAAA", "j" : "ABAAB",
            "k" : "ABABA", "l" : "ABABB", "m" : "ABBAA", "n" : "ABBAB", "o" : "ABBBA",
            "p" : "ABBBB", "q" : "BAAAA", "r" : "BAAAB", "s" : "BAABA", "t" : "BAABB",
            "u" : "BABAA", "v" : "BABAB", "w" : "BABBA", "x" : "BABBB", "y" : "BBAAA",
            "z" : "BBAAB", " " : "BBBAA"  # use " " to denote any non-letter
     };

def encode($plaintext; $message):
  (reduce ($plaintext|ascii_downcase|chars) as $c ("";
     if $c|ascii_downcase == . then . + Bacon[$c] else . + Bacon[" "] end)) as $et
  # "A"s to be in lower case, "B"s in upper case
  | label $out
  | foreach ($message|ascii_downcase|chars) as $c ( {sb: "", count: 0};
      if ($c | is_lower)
      then .sb = if $et[.count: .count+1] == "A" then .sb + $c else .sb + ($c|ascii_upcase) end
      | .count += 1
      | if .count == ($et|length) then .emit = .sb, break $out else . end
      else .sb += $c
      end;
      select(.emit).emit ) ;

def decode($message):
  Bacon as $Bacon
  | (reduce ($message|chars) as $c ("";
       if   ($c|is_lower) then . + "A"
       elif ($c|is_upper)   then . + "B"
       else .
       end)) as $et
  | reduce range(0; $et|length; 5) as $i ("";
       $et[$i : $i+5] as $quintet
       | . + ($Bacon | key($quintet)) ) ;


{ plainText: "the quick brown fox jumps over the lazy dog",
  message: (
    "bacon's cipher is a method of steganography created by francis bacon." +
    "this task is to implement a program for encryption and decryption of " +
    "plaintext using the simple alphabet of the baconian cipher or some " +
    "other kind of representation of this alphabet (make anything signify anything). " +
    "the baconian alphabet may optionally be extended to encode all lower " +
    "case characters individually and/or adding a few punctuation characters " +
    "such as the space.") }
| .cipherText = encode(.plainText; .message)
| .decodedText = decode(.cipherText)
|  "Cipher text ->\n\n\(.cipherText)",
   "\nHidden text ->\n\n\(.decodedText)"
Output:
Cipher text ->

BacON's cIPHer Is a METhoD of stEgAnogRaphy crEatEd By FRAncis baCOn.thIs TASk Is TO imPLeMENT a proGrAm FOR eNcRYPTIOn anD deCRyPtioN Of plAINTExt UsING the SIMpLe AlPhaBet Of thE BAConIan CIphER Or sOme OTHer kInD Of reprESenTATion OF This alPHaBET (makE An

Hidden text ->

the quick brown fox jumps over the lazy dog


Julia

Works with: Julia version 0.6
Translation of: Python

Module:

module BaconCipher

using Formatting, IterTools.chain

const text = """All children, except one, grow up. They soon know that they will grow
    up, and the way Wendy knew was this. One day when she was two years old
    she was playing in a garden, and she plucked another flower and ran with
    it to her mother. I suppose she must have looked rather delightful, for
    Mrs. Darling put her hand to her heart and cried, "Oh, why can't you
    remain like this for ever!" This was all that passed between them on
    the subject, but henceforth Wendy knew that she must grow up. You always
    know after you are two. Two is the beginning of the end.

    Of course they lived at 14 [their house number on their street], and
    until Wendy came her mother was the chief one. She was a lovely lady,
    with a romantic mind and such a sweet mocking mouth. Her romantic
    mind was like the tiny boxes, one within the other, that come from the
    puzzling East, however many you discover there is always one more; and
    her sweet mocking mouth had one kiss on it that Wendy could never get,
    though there it was, perfectly conspicuous in the right-hand corner.""" |> lowercase

const byte = FormatSpec("05b")
const lc2bin = Dict{Char,String}(ch => fmt(byte, i) for (i, ch) in
    enumerate(chain('a':'z', '.', ' ')))
const bin2lc = Dict{String,Char}(v => k for (k, v) in lc2bin)

to5binary(msg::AbstractString) = collect(ch == '1' for lt in lowercase(msg) for ch in get(lc2bin, lt, ""))

function encrypt(msg::AbstractString, text::AbstractString=text)::String
    bin5 = to5binary(msg)
    tlist = collect(Char, lowercase(text))
    out = IOBuffer()
    for capitalise in bin5
        while !isempty(tlist)
            ch = shift!(tlist)
            if isalpha(ch)
                if capitalise
                    ch = uppercase(ch)
                end
                print(out, ch)
                break
            else
                print(out, ch)
            end
        end
    end
    println(out, "...")
    return take!(out)
end

function decrypt(text::AbstractString)::String
    binary = Char[]
    out    = IOBuffer()
    for ch in text
        if isalpha(ch)
            push!(binary, ifelse(isupper(ch), '1', '0'))
            if length(binary) == 5
                print(out, bin2lc[join(binary)])
                empty!(binary)
            end
        end
    end
    return take!(out)
end

end  # module BaconCipher

Main:

let msg = "Rosetta code Bacon cipher example secret phrase to encode in the capitalisation of peter pan"
    enc = BaconCipher.encrypt(msg)
    dec = BaconCipher.decrypt(enc)
    println("\nOriginal:\n", msg)
    println(" -> Encrypted:\n", enc)
    println(" -> Decrypted:\n", dec)
end
Output:
Original:
Rosetta code Bacon cipher example secret phrase to encode in the capitalisation of peter pan
 -> Encrypted:
All ChiLDREN, exCEpt OnE, GrOw uP. tHey soon KNOW that tHEy WILL grOw
up, aNd THE Way wenDy knew Was tHIs. ONE DaY WHeN SHe was tWO yEarS Old
she Was plaYiNG in A gARDen, anD sHE Plucked aNoTHeR Flower ANd ran WiTH
IT to Her MOthEr. I supPOSe sHe muSt HAvE loOKEd rAther dEligHtfUl, for
mRS. daRLinG pUT HEr hAnD to hER HEART and cRiEd, "OH, Why caN'T yOU
REmaIn likE tHIS For eVer!" ThIS WaS ALl tHaT pasSed betWeEN THem on
tHE subjECt, but hEncEFoRth wendY kNEw thAt sHE muST grow UP. yOu alWayS
kNOW AfTER yOU Are tWO. TWo iS ThE BEgiNning of ThE EnD.

of coUrSE thEy LIVed At 14 [their hoUsE NUm...

 -> Decrypted:
rosetta code bacon cipher example secret phrase to encode in the capitalisation of peter pan

Kotlin

The 'full' Bacon alphabet, which has separate letters for i, j, u and v, has been used in the following:

object Bacon {
    private val codes = mapOf(
        'a' to "AAAAA", 'b' to "AAAAB", 'c' to "AAABA", 'd' to "AAABB", 'e' to "AABAA",
        'f' to "AABAB", 'g' to "AABBA", 'h' to "AABBB", 'i' to "ABAAA", 'j' to "ABAAB",
        'k' to "ABABA", 'l' to "ABABB", 'm' to "ABBAA", 'n' to "ABBAB", 'o' to "ABBBA",
        'p' to "ABBBB", 'q' to "BAAAA", 'r' to "BAAAB", 's' to "BAABA", 't' to "BAABB",
        'u' to "BABAA", 'v' to "BABAB", 'w' to "BABBA", 'x' to "BABBB", 'y' to "BBAAA",
        'z' to "BBAAB", ' ' to "BBBAA" // use ' ' to denote any non-letter
    )

    fun encode(plainText: String, message: String): String {
        val pt = plainText.toLowerCase()
        val sb = StringBuilder()
        for (c in pt)
            if (c in 'a'..'z') sb.append(codes[c])
            else sb.append(codes[' '])
        val et = sb.toString()
        val mg = message.toLowerCase()  // 'A's to be in lower case, 'B's in upper case
        sb.setLength(0)
        var count = 0
        for (c in mg)
            if (c in 'a'..'z') {
                if (et[count] == 'A') sb.append(c)
                else sb.append(c - 32) // upper case equivalent
                count++
                if (count == et.length) break
            } else sb.append(c)
        return sb.toString()
    }

    fun decode(message: String): String {
        val sb = StringBuilder()
        for (c in message)
            when (c) {
                in 'a'..'z' -> sb.append('A')
                in 'A'..'Z' -> sb.append('B')
            }
        val et = sb.toString()
        sb.setLength(0)
        for (i in 0 until et.length step 5) {
            val quintet = et.substring(i, i + 5)
            val key = codes.entries.find { it.value == quintet }!!.key
            sb.append(key)
        }
        return sb.toString()
    }
}

fun main(args: Array<String>) {
    val plainText = "the quick brown fox jumps over the lazy dog"
    val message = "bacon's cipher is a method of steganography created by francis bacon." +
        "this task is to implement a program for encryption and decryption of " +
        "plaintext using the simple alphabet of the baconian cipher or some " +
        "other kind of representation of this alphabet (make anything signify anything). " +
        "the baconian alphabet may optionally be extended to encode all lower " +
        "case characters individually and/or adding a few punctuation characters " +
        "such as the space."
    val cipherText = Bacon.encode(plainText, message)
    println("Cipher text ->\n\n$cipherText")
    val decodedText = Bacon.decode(cipherText)
    println("\nHidden text ->\n\n$decodedText")
}
Output:
Cipher text ->

BacON's cIPHer Is a METhoD of stEgAnogRaphy crEatEd By FRAncis baCOn.thIs TASk Is TO imPLeMENT a proGrAm FOR eNcRYPTIOn anD deCRyPtioN Of plAINTExt UsING the SIMpLe AlPhaBet Of thE BAConIan CIphER Or sOme OTHer kInD Of reprESenTATion OF This alPHaBET (makE An

Hidden text ->

the quick brown fox jumps over the lazy dog

Lua

Based on C++ version

function Bacon( txt, secret, e )
    local alpha = {}
    function encode( txt, secret )
        function toAlpha( secret )
            local str, z = "", 0
            secret = secret:upper()
            for i = 1, string.len( secret ) do
                z = secret:sub( i, i )
                if z < 'A' or z > 'Z'  then
                    str = str .. alpha[27]
                else
                    k = z:byte( 1 ) - 65 + 1
                    str = str .. alpha[k]
                end
            end
            return str
        end

        local sec, encoded, idx = toAlpha( secret ), "", 0
        if sec:len() > txt:len() then
            print( "Text is too short!" )
           return
        end

        txt = txt:lower()
        for i = 1, string.len( sec ) do
            t = txt:sub( idx, idx )
            while( t < 'a' or t > 'z' ) do
                encoded = encoded .. t
                idx = idx + 1
                t = txt:sub( idx, idx )
            end

            idx = idx + 1
            if sec:sub( i, i ) == '1' then
                encoded = encoded .. string.char( t:byte(1) - 32 )
            else
                encoded = encoded .. t
            end
        end
        return encoded
    end

    function decode( txt )
        local secret, c = "", 0
        for i = 1, string.len( txt ) do
            c = txt:sub( i, i )
            if not( c < 'a' and ( c < 'A' or c > 'Z' ) or c > 'z' ) then
                local s = 0
                if c == c:upper() then s = 1 end
                secret = secret .. s
            end
        end

        function fromAlpha( secret )
            function find( a, arr )
                for i = 1, #arr do
                    if arr[i] == a then return i end
                end
                return -1
            end

            local l, msg, c, idx = secret:len(), "", 0, 0
            if math.fmod( l, 5 ) ~= 0 then
                print( "Message length does not match!" )
                return
            end
            for i = 1, l, 5 do
                c = secret:sub( i, i + 4 )
                idx = find( c, alpha )
                if idx > 0 then
                    if idx == 27 then
                        msg = msg .. " "  -- unknown char - add space
                    else
                        msg = msg .. string.char( 64 + idx )
                    end
                end
            end
            return msg
        end
        return fromAlpha( secret )
    end

    -- create alphabet
    for i = 0, 26 do
        local t, num = "", i
        for b = 5, 1, -1 do
            t =  math.fmod( num, 2 ) .. t
            num = math.floor( num / 2 )
        end
        alpha[#alpha + 1] = t
    end

    -- encode or decode
    if e == 1 then
        return encode( txt, secret )
    elseif e == 0 then
        return decode( secret )
    end
end

local a = Bacon( "Chase the pig around the house present belly, scratch hand when stroked. "..
                 "When in doubt, wash jump around on couch, meow constantly until given food, "..
                 "favor packaging over toy. And sometimes switches in french and say 'miaou' "..
                 "just because well why not has closed eyes but still sees you lick yarn hanging "..
                 "out of own butt so pelt around the house and up and down stairs chasing phantoms.",
                 "Fall over dead, not really but gets sypathy", 1 )
print( a )
print( Bacon( "", a, 0 ) )
Output:
>lua -e "io.stdout:setvbuf 'no'" "bacon.lua" 
chAsE the pig ArOUnD tHE HOuSe pRESeNt BeLly, ScrAtch HANd When sTRokEd. when in douBT, WAsH jUMp AroUNd On COUcH, meOW COnStAntlY unTil given fOoD, FaVoR PACkagINg Over toY. AnD soMetIMES sWitcHEs in FreNch AND saY 'mIAoU' jUst BeCAuse wELL Why not Has CLosED EYEs bu
FALL OVER DEAD  NOT REALLY BUT GETS SYPATHY

MiniScript

c = {}
c["a"] = "AAAAA"; c["b"] = "AAAAB"; c["c"] = "AAABA"; c["d"] = "AAABB"; c["e"] = "AABAA"; c["f"] = "AABAB"; 
c["g"] = "AABBA"; c["h"] = "AABBB"; c["i"] = "ABAAA"; c["j"] = "ABAAB"; c["k"] = "ABABA"; c["l"] = "ABABB"; 
c["m"] = "ABBAA"; c["n"] = "ABBAB"; c["o"] = "ABBBA"; c["p"] = "ABBBB"; c["q"] = "BAAAA"; c["r"] = "BAAAB"; 
c["s"] = "BAABA"; c["t"] = "BAABB"; c["u"] = "BABAA"; c["v"] = "BABAB"; c["w"] = "BABBA"; c["x"] = "BABBB"; 
c["y"] = "BBAAA"; c["z"] = "BBAAB"; c[" "] = "BBBAA";
codeMap = c  // (used "c" above just to make the lines shorter)
decodeMap = {}
for kv in codeMap
	decodeMap[kv.value] = kv.key
end for

message = "Computers are everywhere.  There are the obvious ones, like your smart phone or game system. "
message = message + "There are less obvious ones, like in your microwave or your bedside clock.  And then "
message = message + "there are the really invisible ones, like the 50 or so small computers in your car."
message = message + "All these computers work in pretty much the same way."
message = message.values  // (convert to list)

encodeChar = function(ch)
	out = []
	for bit in codeMap[ch]
		while message[0].upper == message[0].lower
			out.push message.pull   // (not a letter we can use; pass through as-is)
		end while
		if bit == "A" then out.push message.pull.upper else out.push message.pull.lower
	end for
	return out
end function
	
encode = function(s)
	out = []
	for ch in s
		out = out + encodeChar(ch)
	end for
	return out.join("")
end function

decodeChar = function(encodedChar)
	code = ""
	for ch in encodedChar
		if ch == ch.upper then code = code + "A" else code = code + "B"
	end for
	if decodeMap.hasIndex(code) then return decodeMap[code]
	return "?"
end function

decode = function(s)
	// strip out all non-letters
	schars = s.values
	for i in range(schars.len-1, 0)
		if schars[i].lower == schars[i].upper then schars.remove i
	end for
	s = schars.join("")
	// now, decode using groups of 5 characters
	out = []
	for i in range(0, s.len-1, 5)
		out.push decodeChar(s[i:i+5])
	end for
	return out.join("")
end function

codedMsg = encode("the quick brown fox jumps over the lazy dog")
print codedMsg
print decode(codedMsg)
Output:
cOMpuTErs aRE eVErywHErE.  THErE aRE ThE OBVIOuS OnEs, Like YOUR SMarT PHoNe or GaMe sYSteM. therE ARE lEsS obvIoUs ones, lIKE iN YouR mICRowAVE or youR BeDsidE CLock.  AnD tHeN ThERe ARE the rEAlLY inVIsibLE oNEs, liKE ThE 50 or SO SMAll COmpuTERs in YOUR Car.All tHESe cO
the quick brown fox jumps over the lazy dog

Nim

Translation of: Kotlin
import strutils, sugar, tables

const Codes = {'a': "AAAAA", 'b': "AAAAB", 'c': "AAABA", 'd': "AAABB", 'e': "AABAA",
               'f': "AABAB", 'g': "AABBA", 'h': "AABBB", 'i': "ABAAA", 'j': "ABAAB",
               'k': "ABABA", 'l': "ABABB", 'm': "ABBAA", 'n': "ABBAB", 'o': "ABBBA",
               'p': "ABBBB", 'q': "BAAAA", 'r': "BAAAB", 's': "BAABA", 't': "BAABB",
               'u': "BABAA", 'v': "BABAB", 'w': "BABBA", 'x': "BABBB", 'y': "BBAAA",
               'z': "BBAAB", ' ': "BBBAA"}.toTable

let RevCodes = collect(newTable, for k, v in Codes.pairs: {v: k})

proc encode(plaintext, message: string): string =
  var et: string
  for c in plaintext.toLowerAscii:
    et.add if c in 'a'..'z': Codes[c] else: Codes[' ']
  var count = 0
  for c in message.toLowerAscii:
    if c in 'a'..'z':
      result.add if et[count] == 'A': c else: c.toUpperAscii
      inc count
      if count == et.len: break
    else:
      result.add c


proc decode(message: string): string =
  var et: string
  for c in message:
    if c.isAlphaAscii:
      et.add if c.isLowerAscii: 'A' else: 'B'
  for i in countup(0, et.high - 4, 5):
    result.add RevCodes[et[i..(i+4)]]


when isMainModule:
  const
    PlainText = "the quick brown fox jumps over the lazy dog"
    Message = "bacon's cipher is a method of steganography created by francis bacon." &
              "this task is to implement a program for encryption and decryption of " &
              "plaintext using the simple alphabet of the baconian cipher or some " &
              "other kind of representation of this alphabet (make anything signify anything). " &
              "the baconian alphabet may optionally be extended to encode all lower " &
              "case characters individually and/or adding a few punctuation characters " &
              "such as the space."
  let cipherText = PlainText.encode(Message)
  echo "Cipher text →\n", cipherText
  let decodedText = cipherText.decode()
  echo "\nHidden text →\n", decodedText
Output:
Cipher text →
BacON's cIPHer Is a METhoD of stEgAnogRaphy crEatEd By FRAncis baCOn.thIs TASk Is TO imPLeMENT a proGrAm FOR eNcRYPTIOn anD deCRyPtioN Of plAINTExt UsING the SIMpLe AlPhaBet Of thE BAConIan CIphER Or sOme OTHer kInD Of reprESenTATion OF This alPHaBET (makE An

Hidden text →
the quick brown fox jumps over the lazy dog

Perl

Translation of: Raku
use strict;
use warnings;
use utf8;
binmode(STDOUT, ':utf8');

my $secret = <<'END';
This task is to implement a program for encryption and decryption
of plaintext using the simple alphabet of the Baconian cipher or
some other kind of representation of this alphabet (make anything
signify anything). This example will work with anything in the
ASCII range... even code! $r%_-^&*(){}+~ #=`/\';*1234567890"'
END

my $text = <<'END';
Bah. It isn't really practical to use typeface changes to encode
information, it is too easy to tell that there is something going
on and will attract attention. Font changes with enough regularity
to encode mesages relatively efficiently would need to happen so
often it would be obvious that there was some kind of manipulation
going on. Steganographic encryption where it is obvious that there
has been some tampering with the carrier is not going to be very
effective. Not that any of these implementations would hold up to
serious scrutiny anyway. Anyway, here's a semi-bogus implementation
that hides information in white space. The message is hidden in this
paragraph of text. Yes, really. It requires a fairly modern file
viewer to display (not display?) the hidden message, but that isn't
too unlikely any more. It may be stretching things to call this a
Bacon cipher, but I think it falls within the spirit of the task,
if not the exact definition.
END

my @enc = ("\N{U+FEFF}", "\N{U+200B}"); # zero-width spaces
my %dec;
$dec{$enc[0]} = 0;
$dec{$enc[1]} = 1;

sub encode { my($c) = @_; join '', @enc[split '', sprintf "%07b", ord($c)] }
sub hide {
    my($text, @msg) = @_;
    my $head = substr($text, 0, @msg);
    my $tail = substr($text, @msg);
    my @head = split '', $head;
    my $merge;
    while (@msg) { $merge .= shift(@head) . shift(@msg) }
    $merge . $tail;
}

sub reveal {
    my($steganography) = @_;
    my $message;
    (my $cleaned = $steganography) =~ s/\w|[,?:.!\-&*()*"']| |\n//g;
    for my $coded_char (split /(.{7})/, $cleaned) {
        next if length $coded_char == 0;
        my $bits = '';
        $bits .= $dec{$_} for split //, $coded_char;
        $message .= chr eval('0b'.$bits);
    }
    $message;
}
my @hidden = map  { encode($_) } split '', $secret;
my $steganography = hide($text, @hidden);
my $decoded       = reveal $steganography;

print "$steganography\n"
print "$decoded\n"
Output:
Steganograpic message hidden in text:
B​​​​a​​​​h​​​​​.​​​ ​​​​I​​t​​​​​​ ​​​​​i​​​s​​​​​n​​​'​​​​t​​​​​ ​​r​​​​​e​​​​​​a​​​l​​​​l​​​​​​y​​​​ ​​​​​​p​​​​r​​​a​​c​​​t​​​i​​​​​​c​​​​​​a​​​​​l​​​​ ​​​​t​​o​​​​​​ ​​​​​​u​s​​​​​e​​​​​​ ​​​​​t​​​​​y​​​​p​​​​e​​​​f​​​​​​​a​​​​​c​​e​​​​ ​​​​​c​h​​​a​​​​​n​​​​​g​​​​​e​​​​​s​​​​ ​​​t​​​​​​​o​​​​​ ​​​​e​​​​​​n​​​c​​​o​​​​d​​​e​​​​​
i​​​​n​​​​​​f​​​​o​r​​​​​m​​​​​​a​​​​​t​​​​​i​​​​o​​​​n​​​,​​​​ ​​i​​​​​​t​​​​ ​​​​​​i​​​​s​​​ ​​t​​​​o​​​​​o​​​ ​​​e​​​a​​​​s​​​​​y​​ ​​​​​​​t​​​o​​​ ​​​​t​​​e​​l​​​l​​​​ ​​​​t​​​​​​​h​​​​​a​​​t​​​​​​ ​​t​​​​​h​​​​​e​​​r​​​e​​​​​ ​i​​​​​​​s​​​ ​​​​​s​​​​​o​​​​​​​m​​​​e​​t​​​​​​​h​​​​​i​​​n​​​​​g​​ ​​​​g​​​​​o​​​​​​i​​​n​​g​​​​​​
o​​​​n​​​​ ​​​​a​​​​​n​​​​​d​​​​ ​​​​​​w​​​​​i​​​l​​​​​l​​​​​ ​​​​​​a​​​​t​​​​t​​​​​​r​a​​​​​c​​​​t​​​​​ ​​​a​​t​​​​​t​​​e​​​​n​​​​t​​​i​​​​​o​​n​​.​​​​​ ​​​​F​​​​​​o​​​n​​t​​​​​ ​​​​​c​​​​​h​​​​a​​​​​n​​​​​g​​​​e​​​​s​​​​​ ​​​​​​w​​​​​​i​​​​​t​​​​​h​​​ ​​e​​​​​​n​​​​​o​​​​​u​​​​g​​​​h​​​​​ ​​​​​r​​​​​e​g​​​​u​​​​l​​​​​a​​​r​​​i​​​​​t​​​y​​​​​​
t​​​​o​​​ ​​​​e​​​​​n​​​​​c​​​​o​​​d​​​​​​e​​​​​​​ ​​​​m​​​e​​​​​​s​​​​​a​​​​​g​​e​​s​​​​​ ​​​​​r​​​​​e​​​​l​​​​​a​​​​​t​​​​i​​​v​​​​​​e​l​​​​​y​​​​ ​​e​​​f​​​f​​​​i​​​​c​​​i​​​e​​​​n​​​​t​​​​​l​​​​​y​​​​​ ​​​​w​​​​​o​​u​​​​​l​​​​​d​​​​​​ ​n​​​​​e​​​​​​​e​​​d​​​ ​​t​​o​​​​ ​​​​h​​​​​​a​​​​​p​​​​p​​​​e​​​n​​​ ​​​​​​​s​​​​​​o​​​​​​
o​f​​​​​​t​​​e​​​​​​n​​​​ ​​​​​i​​​​​t​​​ ​​​​w​​​​o​​​u​​​​​l​​​​​d​​​​​​ ​​​b​​​e​​ ​​​​o​​bvious that there was some kind of manipulation
going on. Steganographic encryption where it is obvious that there
has been some tampering with the carrier is not going to be very
effective. Not that any of these implementations would hold up to
serious scrutiny anyway. Anyway, here's a semi-bogus implementation
that hides information in white space. The message is hidden in this
paragraph of text. Yes, really. It requires a fairly modern file
viewer to display (not display?) the hidden message, but that isn't
too unlikely any more. It may be stretching things to call this a
Bacon cipher, but I think it falls within the spirit of the task,
if not the exact definition.

Hidden message revealed:
This task is to implement a program for encryption and decryption
of plaintext using the simple alphabet of the Baconian cipher or
some other kind of representation of this alphabet (make anything
signify anything). This example will work with anything in the
ASCII range... even code! $r%_-^&*(){}+~ #=`/\';*1234567890"'

Phix

Rather than explictly using 'a'="AAAAA", 'b'='AAAAB', c='AAABA", etc, this notes that "AAAAA".."BBBAA" are just another form of binary, and therefore handles them as 0..26, ie a-z plus space for any non-letters.

You could of course extend this to encode full binary, by changing the bits to 8, and accepting every input byte as-is, or use an image file instead of plaintext simply by reading it using get_text() and (from some appropriate offset) setting the pixel colours to odd/even instead of upper/lower, and start by encoding the message length in bytes, that is rather than sending half of/an obviously corrupt image file.

constant bits = 5,
         mask = power(2,bits-1)
 
function bacon(string msg, plaintext)
    plaintext = lower(plaintext)
    integer ptdx = 0
    for i=1 to length(msg) do
        integer inch = lower(msg[i])-'a'
        if inch<0 or inch>25 then inch = 26 end if
        integer m = mask
        while true do       -- encode one character
            while true do       -- find an a-z for this bit
                ptdx += 1
                if ptdx>length(plaintext) then
                    crash("plaintext too short")
                end if
                integer ch = plaintext[ptdx]
                if ch>='a' and ch<='z' then
                    if and_bits(inch,m) then
                        plaintext[ptdx] = upper(ch)
                    end if
                    exit
                end if
            end while
            if m=1 then exit end if
            m /= 2
        end while
    end for
    return plaintext[1..ptdx]
--  return plaintext -- note: yields ...dogaaaaaaaaaa.....
end function         --       [or the "oops?" in nocab()]
 
function nocab(string plaintext)
    string res = ""
    integer m = mask, ch = 'a'
    for i=1 to length(plaintext) do
        integer inch = lower(plaintext[i])
        if inch>='a' and inch<='z' then
            if inch!=plaintext[i] then
                ch += m
            end if
            if m=1 then
                res &= iff(ch>'z'?' ':ch)
                m = mask
                ch = 'a'
            else
                m /= 2
            end if
        end if
    end for
    if m!=mask or ch!='a' then crash("oops?") end if
    return res
end function
 
constant plaintext = """
Bacon's cipher is a method of steganography created by Francis Bacon.
This task is to implement a program for encryption and decryption of 
plaintext using the simple alphabet of the baconian cipher or other
representation of this alphabet. The baconian alphabet may optionally 
be extended to encode all lower case characters individually and/or 
add a few punctuation characters such as the space."""
 
constant msg = "The quick brown fox jumps over the lazy dog"
 
string ant = bacon(msg,plaintext),
       dec = nocab(ant)
puts(1,"Encrypted:\n"&ant&"\n")
puts(1,"Decrypted:\n"&dec&"\n")
Output:
Encrypted:
BacON's cIPHer Is a MEtHoD of stEgAnogRaphy crEatEd By FRaNcis baCOn.
thIs TASk Is TO imPLeMENt A proGrAm FOR eNcRYPTIoN anD deCRyPtioN Of
plAINTExt UsINg The SIMpLe AlPhaBet Of thE BAcOnIan CIphER Or oTheR
RePreSeNTation OF thIS AlphABeT. the bACoNIAn alPHa
Decrypted:
the quick brown fox jumps over the lazy dog

Python

This deviates from the Bacon method as it encodes to different capitalisation of text rather than differences in font.

import string

sometext = """All children, except one, grow up. They soon know that they will grow
up, and the way Wendy knew was this. One day when she was two years old
she was playing in a garden, and she plucked another flower and ran with
it to her mother. I suppose she must have looked rather delightful, for
Mrs. Darling put her hand to her heart and cried, "Oh, why can't you
remain like this for ever!" This was all that passed between them on
the subject, but henceforth Wendy knew that she must grow up. You always
know after you are two. Two is the beginning of the end.

Of course they lived at 14 [their house number on their street], and
until Wendy came her mother was the chief one. She was a lovely lady,
with a romantic mind and such a sweet mocking mouth. Her romantic
mind was like the tiny boxes, one within the other, that come from the
puzzling East, however many you discover there is always one more; and
her sweet mocking mouth had one kiss on it that Wendy could never get,
though there it was, perfectly conspicuous in the right-hand corner.""".lower()

lc2bin = {ch: '{:05b}'.format(i) 
          for i, ch in enumerate(string.ascii_lowercase + ' .')}
bin2lc = {val: key for key, val in lc2bin.items()}

phrase = 'Rosetta code Bacon cipher example secret phrase to encode in the capitalisation of peter pan'.lower()

def to_5binary(msg):
    return ( ch == '1' for ch in ''.join(lc2bin.get(ch, '') for ch in msg.lower()))

def encrypt(message, text):
    bin5 = to_5binary(message)
    textlist = list(text.lower())
    out = []
    for capitalise in bin5:
        while textlist:
            ch = textlist.pop(0)
            if ch.isalpha():
                if capitalise:
                    ch = ch.upper()
                out.append(ch)
                break
            else:
                out.append(ch)
        else:
            raise Exception('ERROR: Ran out of characters in sometext')
    return ''.join(out) + '...'


def  decrypt(bacontext):
    binary = []
    bin5 = []
    out = []
    for ch in bacontext:
        if ch.isalpha():
            binary.append('1' if ch.isupper() else '0')
            if len(binary) == 5:
                bin5 = ''.join(binary)
                out.append(bin2lc[bin5])
                binary = []
    return ''.join(out)
                

print('PLAINTEXT = \n%s\n' % phrase)
encrypted = encrypt(phrase, sometext)
print('ENCRYPTED = \n%s\n' % encrypted)
decrypted = decrypt(encrypted)
print('DECRYPTED = \n%s\n' % decrypted)
assert phrase == decrypted, 'Round-tripping error'
Output:
PLAINTEXT = 
rosetta code bacon cipher example secret phrase to encode in the capitalisation of peter pan

ENCRYPTED = 
All cHiLDReN, exCept One, GroW UP. thEY soon kNOw That tHey WILl groW
Up, aNd tHE wAy wendY knew was tHis. ONE daY WhEN ShE was tWo yEars oLD
SHe wAS PlaYinG in a GARdEn, anD shE pLUCked anoTHer fLOWEr AnD Ran WitH
It To Her MothEr. i supPoSe shE muSt hAve LOOKeD raTHER deLIGHtfuL, for
mrS. daRlinG puT HeR hAnd TO hER HeARt And cRied, "OH, wHy caN't yOU
RemaiN LikE thIS fOr eVer!" thIS wAS AlL tHat PAssED BetWeeN ThEm on
tHe subjecT, BUT hEnceForTH wendy kNeW ThAt shE muSt grow uP. yoU AlWays
kNOW afTEr YOU aRe tWO. Two iS tHE BeGinNING of The End.

OF coUrsE theY LIvEd aT 14 [THEir housE NuM...

DECRYPTED = 
rosetta code bacon cipher example secret phrase to encode in the capitalisation of peter pan

Quackery

  [ dup upper swap lower != ]               is ischar     (   c --> b )

  [ char a char z 1+ clamp
    char a -  
    [ table
      $ "AAAAA" $ "AAAAB" $ "AAABA" ( abc )
      $ "AAABB" $ "AABAA" $ "AABAB" ( def )
      $ "AABBA" $ "AABBB" $ "ABAAA" ( ghi )
      $ "ABAAB" $ "ABABA" $ "ABABB" ( jkl )
      $ "ABBAA" $ "ABBAB" $ "ABBBA" ( mno )
      $ "ABBBB" $ "BAAAA" $ "BAAAB" ( pqr )
      $ "BAABA" $ "BAABB" $ "BABAA" ( stu )
      $ "BABAB" $ "BABBA" $ "BABBB" ( vwx )
      $ "BBAAA" $ "BBAAB" ( y z ) ] do ]    is baconian   (   c --> $ )
      
  [ $ "abcdefghijklmnopqrstuvwxyz" 
    0 rot witheach 
      [ char A = swap 1 << + ] 
    0 25 clamp peek ]                       is debacon    (   $ --> c )

  [ [] swap
    witheach
      [ dup ischar iff
          [ lower baconian join ]
        else drop ] ]                       is ->bacon$   (   $ --> $ )

  [ [] [] rot
    dup size 5 / times
      [ 5 split 
        dip [ nested join ] ]
    drop
    witheach [ debacon join ] ]             is debacon$   (   $ --> $ )

  [ [] unrot ->bacon$ swap
    witheach 
      [ over size if
        [ dup ischar if
          [ swap behead
            dip swap
            char A = iff
              lower else upper ] ]
        swap dip join ] drop ]              is baconise   ( $ $ --> $ )

  [ [] swap
    witheach
      [ dup ischar iff
          [ char A char Z 1+ within iff
            [ char A ] else [ char B ]
            join ]
        else drop ] 
    debacon$ ]                              is debaconise (   $ --> $ )

  $ "If it looks like a duck, and quacks like a duck, "
  $ "we have at least to consider the possibility that "
  $ "we have a small aquatic bird of the family anatidae "
  $ " on our hands. "
  $ "(This is a quote from the noted author Douglas Adams)"
  4 times join
  $ "Dirk Gently's Holistic Detective Agency"
  baconise
  dup nest$ 60 wrap$ cr cr 
  debaconise echo$
Output:
if iT LoOks lIke a DuCk, And qUAcks Like A DuCK, we HAvE aT
LEAst tO coNsidER ThE POssIbILiTy thAt wE hAve A SmAll
aquaTic biRD of The FamILy aNatidaE oN ouR HaNds. (tHiS iS a
qUote from thE NoteD autHOr DougLaS Adams)

dirkgentlysholisticdetectiveagency

Racket

#lang racket
(require xml)

(define (char->bacon-number C)
  (define c (char-downcase C))
  (define c-code (- (char->integer c) (char->integer #\a)))
  (and (<= 0 c-code 26) (- c-code (if (> c-code  8) 1 0) (if (> c-code 20) 1 0))))

(define (inr-encode bacons f-cs seg/r rv/r last-bacon-bit fce)  
  (cond
    [(null? bacons) (append (reverse (if (null? seg/r) rv/r (cons seg/r rv/r))) (list f-cs))]    
    [(null? f-cs) (error 'bacon-encode->list "not enough false message to hide the text")]    
    [(zero? last-bacon-bit) (inr-encode (cdr bacons) f-cs seg/r rv/r 5 fce)]    
    [(not (char-alphabetic? (car f-cs)))
     (inr-encode bacons (cdr f-cs) (cons (car f-cs) seg/r) rv/r last-bacon-bit fce)]    
    [else
     (define bit (sub1 last-bacon-bit))
     (define bs? (bitwise-bit-set? (car bacons) bit))
     (match-define (cons f-a f-d) f-cs)
     (match (cons bs? fce)
       [(or '(#f . 1) '(#t . 2)) (inr-encode bacons f-d (cons f-a seg/r) rv/r bit fce)]
       [_ (inr-encode bacons f-d (list f-a) (cons (reverse seg/r) rv/r) bit (if bs? 2 1))])]))

(define (bacon-encode->segments-list plain-text false-message)
  (define bacon-numbers (filter-map char->bacon-number (string->list plain-text)))
  (map list->string (inr-encode bacon-numbers (string->list false-message) null null 5 1)))

(define (bacon-encode->html plain-text false-message
                            (->face1 (λ (s) `(span ((face "1")) ,s)))
                            (->face2 (λ (s) `(span ((face "2")) ,s))))
  (define segments (bacon-encode->segments-list plain-text false-message))
  (xexpr->string
   (list* 'div '((style "white-space: pre"))
          (for/list ((seg (in-list segments)) (face (in-cycle (in-list (list ->face1 ->face2)))))
            (face seg)))))

(module+ main
  (define plain-text "i wrote this F.B.")
  (define false-text #<<EOS
To be, or not to be, that is the question:
Whether 'tis Nobler in the mind to suffer
The Slings and Arrows of outrageous Fortune,
[...]
EOS
    )
  
  (displayln (bacon-encode->html plain-text false-text values (λ (s) `(i ,s)))))
Output:
  • Literal
<div style="white-space: pre">T<i>o </i>be, o<i>r </i>n<i>o</i>t t<i>o </i>be, tha<i>t i</i>s <i>th</i>e q<i>u</i>est<i>i</i>on:
<i>W</i>he<i>t</i>her '<i>tis </i>N<i>o</i>ble<i>r </i>in t<i>h</i>e m<i>i</i>n<i>d </i>to su<i>f</i>fer
The Slings and Arrows of outrageous Fortune,
[...]</div>
  • HTML
To be, or not to be, that is the question:

Whether 'tis Nobler in the mind to suffer The Slings and Arrows of outrageous Fortune,

[...]

Raku

(formerly Perl 6)

alternative steganography algorithm

Not truly a Bacon Cipher as it doesn't encode using font variations. But fits with the spirit if not the exact definition.

Works with: Rakudo version 2015-11-20
my $secret = q:to/END/;
    This task is to implement a program for encryption and decryption
    of plaintext using the simple alphabet of the Baconian cipher or
    some other kind of representation of this alphabet (make anything
    signify anything). This example will work with anything in the
    ASCII range... even code! $r%_-^&*(){}+~ #=`/\';*1234567890"'
    END

my $text = q:to/END/;
    Bah. It isn't really practical to use typeface changes to encode
    information, it is too easy to tell that there is something going
    on and will attract attention. Font changes with enough regularity
    to encode mesages relatively efficiently would need to happen so
    often it would be obvious that there was some kind of manipulation
    going on. Steganographic encryption where it is obvious that there
    has been some tampering with the carrier is not going to be very
    effective. Not that any of these implementations would hold up to
    serious scrutiny anyway. Anyway, here's a semi-bogus implementation
    that hides information in white space. The message is hidden in this
    paragraph of text. Yes, really. It requires a fairly modern file
    viewer to display (not display?) the hidden message, but that isn't
    too unlikely any more. It may be stretching things to call this a
    Bacon cipher, but I think it falls within the spirit of the task,
    if not the exact definition.
    END
#'
my @enc = "", "​";
my %dec = @enc.pairs.invert;

sub encode ($c) { @enc[($c.ord).fmt("%07b").comb].join('') }

sub hide ($msg is copy, $text) { 
    $msg ~= @enc[0] x (0 - ($msg.chars % 8)).abs;
    my $head = $text.substr(0,$msg.chars div 8);
    my $tail = $text.substr($msg.chars div 8, *-1);
    ($head.comb «~» $msg.comb(/. ** 8/)).join('') ~ $tail;
}

sub reveal ($steg) {
    join '', map { :2(%dec{$_.comb}.join('')).chr }, 
    $steg.subst( /\w | <punct> | " " | "\n" /, '', :g).comb(/. ** 7/);
}

my $hidden = join '', map  { .&encode }, $secret.comb;

my $steganography = hide $hidden, $text;

say "Steganograpic message hidden in text:";
say $steganography;

say '*' x 70;

say "Hidden message revealed:";
say reveal $steganography;
Output:
Steganograpic message hidden in text:
B​​​​a​​​​h​​​​​.​​​ ​​​​I​​t​​​​​​ ​​​​​i​​​s​​​​​n​​​'​​​​t​​​​​ ​​r​​​​​e​​​​​​a​​​l​​​​l​​​​​​y​​​​ ​​​​​​p​​​​r​​​a​​c​​​t​​​i​​​​​​c​​​​​​a​​​​​l​​​​ ​​​​t​​o​​​​​​ ​​​​​​u​s​​​​​e​​​​​​ ​​​​​t​​​​​y​​​​p​​​​e​​​​f​​​​​​​a​​​​​c​​e​​​​ ​​​​​c​h​​​a​​​​​n​​​​​g​​​​​e​​​​​s​​​​ ​​​t​​​​​​​o​​​​​ ​​​​e​​​​​​n​​​c​​​o​​​​d​​​e​​​​​
i​​​​n​​​​​​f​​​​o​r​​​​​m​​​​​​a​​​​​t​​​​​i​​​​o​​​​n​​​,​​​​ ​​i​​​​​​t​​​​ ​​​​​​i​​​​s​​​ ​​t​​​​o​​​​​o​​​ ​​​e​​​a​​​​s​​​​​y​​ ​​​​​​​t​​​o​​​ ​​​​t​​​e​​l​​​l​​​​ ​​​​t​​​​​​​h​​​​​a​​​t​​​​​​ ​​t​​​​​h​​​​​e​​​r​​​e​​​​​ ​i​​​​​​​s​​​ ​​​​​s​​​​​o​​​​​​​m​​​​e​​t​​​​​​​h​​​​​i​​​n​​​​​g​​ ​​​​g​​​​​o​​​​​​i​​​n​​g​​​​​​
o​​​​n​​​​ ​​​​a​​​​​n​​​​​d​​​​ ​​​​​​w​​​​​i​​​l​​​​​l​​​​​ ​​​​​​a​​​​t​​​​t​​​​​​r​a​​​​​c​​​​t​​​​​ ​​​a​​t​​​​​t​​​e​​​​n​​​​t​​​i​​​​​o​​n​​.​​​​​ ​​​​F​​​​​​o​​​n​​t​​​​​ ​​​​​c​​​​​h​​​​a​​​​​n​​​​​g​​​​e​​​​s​​​​​ ​​​​​​w​​​​​​i​​​​​t​​​​​h​​​ ​​e​​​​​​n​​​​​o​​​​​u​​​​g​​​​h​​​​​ ​​​​​r​​​​​e​g​​​​u​​​​l​​​​​a​​​r​​​i​​​​​t​​​y​​​​​​
t​​​​o​​​ ​​​​e​​​​​n​​​​​c​​​​o​​​d​​​​​​e​​​​​​​ ​​​​m​​​e​​​​​​s​​​​​a​​​​​g​​e​​s​​​​​ ​​​​​r​​​​​e​​​​l​​​​​a​​​​​t​​​​i​​​v​​​​​​e​l​​​​​y​​​​ ​​e​​​f​​​f​​​​i​​​​c​​​i​​​e​​​​n​​​​t​​​​​l​​​​​y​​​​​ ​​​​w​​​​​o​​u​​​​​l​​​​​d​​​​​​ ​n​​​​​e​​​​​​​e​​​d​​​ ​​t​​o​​​​ ​​​​h​​​​​​a​​​​​p​​​​p​​​​e​​​n​​​ ​​​​​​​s​​​​​​o​​​​​​
o​f​​​​​​t​​​e​​​​​​n​​​​ ​​​​​i​​​​​t​​​ ​​​​w​​​​o​​​u​​​​​l​​​​​d​​​​​​ ​​​b​​​e​​ ​​​​o​​bvious that there was some kind of manipulation
going on. Steganographic encryption where it is obvious that there
has been some tampering with the carrier is not going to be very
effective. Not that any of these implementations would hold up to
serious scrutiny anyway. Anyway, here's a semi-bogus implementation
that hides information in white space. The message is hidden in this
paragraph of text. Yes, really. It requires a fairly modern file
viewer to display (not display?) the hidden message, but that isn't
too unlikely any more. It may be stretching things to call this a
Bacon cipher, but I think it falls within the spirit of the task,
if not the exact definition.
**********************************************************************
Hidden message revealed:
This task is to implement a program for encryption and decryption
of plaintext using the simple alphabet of the Baconian cipher or
some other kind of representation of this alphabet (make anything
signify anything). This example will work with anything in the
ASCII range... even code! $r%_-^&*(){}+~ #=`/\';*1234567890"'

Bacon cipher solution

my @abc = 'a' .. 'z';
my @symb = ' ', |@abc;  # modified Baconian charset - space and full alphabet
# TODO original one with I=J U=V, nice for Latin

my %bacon = @symb Z=> (^@symb).map(*.base(2).fmt("%05s"));
my %nocab = %bacon.antipairs;

sub bacon ($s, $msg) {
  my @raw = $s.lc.comb;
  my @txt := @raw[ (^@raw).grep({@raw[$_] (elem) @abc}) ];
  for $msg.lc.comb Z @txt.batch(5) -> ($c-msg, @a) {
    for @a.kv -> $i, $c-str {
      (my $x := @a[$i]) = $x.uc if %bacon{$c-msg}.comb[$i].Int.Bool;
  } }
  @raw.join;
}

sub unbacon ($s) {
  my $chunks = ($s ~~ m:g/\w+/)>>.Str.join.comb(/.**5/);
  $chunks.map(*.comb.map({.uc eq $_})».Int».Str.join).map({%nocab{$_}}).join;
}

my $msg = "Omnes homines dignitate et iure liberi et pares nascuntur";

my $str = <Lorem ipsum dolor sit amet, consectetur adipiscing elit,
sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi
ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit
in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
Excepteur sint occaecat cupidatat non proident, sunt in culpa
qui officia deserunt mollit anim id est laborum.>;

my $baconed = bacon $str, $msg;
$baconed = $baconed.?naive-word-wrapper || $baconed;
# FIXME ^^^ makes dbl space after .
say "text:\n$baconed\n";
my $unbaconed = unbacon($baconed).trim.uc;
say "hidden message:\n$unbaconed";
Output:
text:
lOREM iPSuM dOLOr siT aMEt, cONsectetUr adiPISCiNG eLiT, seD dO EIusmOd
TEmpOR incididUnt uT laBorE ET dOLOre MagNA aLiqua.  ut ENiM ad miNiM
veniam, qUiS NoStrud exerCitATiOn ULlaMco lAbOris nisI Ut alIquIp ex Ea
coMmODo cOnsEquAt.  duis auTe IRuRe dolor iN reprehenDEriT in vOlUPtaTE
velit eSSE cilluM DolORe eu FUGiAt NuLLA pArIatUr.  ExCEptEur sint
occaecat cupidatat non proident, sunt in culpa qui officia deserunt
mollit anim id est laborum.

hidden message:
OMNES HOMINES DIGNITATE ET IURE LIBERI ET PARES NASCUNTUR

REXX

assigned cipher codes

This REXX version supports a full (26-letter) Roman (Latin) alphabet, plus a few punctuation symbols:
      .   (period),     ,   (comma),     ?   (question mark),     :   (colon),     !   (exclamation mark),   and blanks.

All alphabetic letters are handled as if they were in uppercase   (i.e., lowercase letters are uppercased).

/*REXX program implements and demonstrates a (full)  "Bacon"  cipher (cypher).*/
parse arg plain                        /*obtain optional arguments from the CL*/
if plain=''  then plain =  "The quick brown fox jumped over the lazy dog."
                                       /* [↓]  code supports complete alphabet*/
@.=; @.a=11111; @.b=11110; @.c=11101; @.d=11100; @.e=11011; @.f=11010; @.g=11001
     @.h=11000; @.i=10111; @.j=00111; @.k=10110; @.l=10101; @.m=10100; @.n=10011
     @.o=10010; @.p=10001; @.q=10000; @.r=01111; @.s=01110; @.t=01101; @.u=01100
     @.v=00100; @.w=01011; @.x=01010; @.y=01001; @.z=01000; @.?=00000; @.!=00101
     @..=00110;   _=','  ; @._=00001;   _=' '  ; @._=00011;   _=':'  ; @._=00010
                                       /* [↑]  code supports some punctuation.*/
say ' plain text: '    plain           /*display the original  (plain)  text. */
      encoded=BaconEnc(plain)          /*encode using a (full)  Bacon  cipher.*/
say 'cipher text: '    encoded         /*display the ciphered  (coded)  text. */
      decoded=BaconDec(encoded)        /*decode ciphered text──►plain (almost)*/
say 'cycled text: '    decoded         /*display the recycled text  (~ plain),*/
exit                                   /*stick a fork in it,  we're all done. */
/*────────────────────────────────────────────────────────────────────────────*/
BaconEnc: procedure expose @.;        arg x;                $=;     Lx=length(x)
            do j=1  for Lx;           _=substr(x,j,1);      $=$ || @._;      end
          return $
/*────────────────────────────────────────────────────────────────────────────*/
BaconDec: procedure expose @.;        parse arg x;          $=;     Lx=length(x)
            do k=0 for 256; _=d2c(k); if @._=='' then iterate; q=@._; !.q=_; end
            do j=1  to Lx  by 5;      y=substr(x,j,5);      $=$ || !.y;      end
          return $

output   when using the default input:

 plain text:  The quick brown fox jumped over the lazy dog.
cipher text:  011011100011011000111000001100101111110110110000111111001111100100101110011000111101010010010100001100111011001010010001110111110000011100100010011011011110001101101110001101100011101011111101000010010001111100100101100100110
cycled text:  THE QUICK BROWN FOX JUMPED OVER THE LAZY DOG.

generated cipher codes

The twp glyphs (characters) chosen for this REXX program are:

  •   the   bottom tee       (sometimes known as the   bottom junction)
  •   the     top tee           (sometimes known as the   top junction)
/*REXX program implements and demonstrates a (full)  "Bacon"  cipher (cypher).*/
parse arg plain                        /*obtain optional arguments from the CL*/
if plain=''  then plain =  "The quick brown fox jumped over the lazy dog."
                                       /*alphabet must be in uppercase letters*/
alphabet= 'ABCDEFGHIJKLMNOPQRSTUVWXYZ .,?!:'  /*list of letters & punctuation.*/
@.=                                           /*assign a default for all chars*/
     do j=0  for min(32,length(alphabet));              _=substr(alphabet,j+1,1)
     @._=translate(right(x2b(d2x(j)), 5, 0),  '┴┬', 01)
     end   /*j*/                       /* [↑]  build the symbol table (max=32)*/
                                       /* [↑]  code supports some punctuation.*/
say ' plain text: '    plain           /*display the original  (plain)  text. */
      encoded=BaconEnc(plain)          /*encode using a (full)  Bacon  cipher.*/
say 'cipher text: '    encoded         /*display the ciphered  (coded)  text. */
      decoded=BaconDec(encoded)        /*decode ciphered text──►plain (almost)*/
say 'cycled text: '    decoded         /*display the recycled text  (~ plain),*/
exit                                   /*stick a fork in it,  we're all done. */
/*────────────────────────────────────────────────────────────────────────────*/
BaconEnc: procedure expose @.;        arg x;                $=;     Lx=length(x)
            do j=1  for Lx;           _=substr(x,j,1);      $=$ || @._;      end
          return $
/*────────────────────────────────────────────────────────────────────────────*/
BaconDec: procedure expose @.;        parse arg x;          $=;     Lx=length(x)
            do k=0 for 256; _=d2c(k); if @._=='' then iterate; q=@._; !.q=_; end
            do j=1  to Lx  by 5;      y=substr(x,j,5);      $=$ || !.y;      end
          return $

output   when using the default input:

 plain text:  The quick brown fox jumped over the lazy dog.
cipher text:  ┬┴┴┬┬┴┴┬┬┬┴┴┬┴┴┬┬┴┬┴┬┴┴┴┴┬┴┬┴┴┴┬┴┴┴┴┴┴┬┴┴┬┴┬┴┬┬┴┬┴┴┴┴┴┬┬┴┴┴┬┴┬┬┬┴┬┴┬┬┴┴┬┬┴┬┬┬┴┬┴┴┴┬┴┬┴┬┬┬┴┬┴┬┬┬┬┬┴┬┴┴┬┴┴┬┬┴┬┴┴┴┬┬┴┴┴┬┬┬┬┴┴┬┴┴┴┴┴┬┬┬┬┴┬┴┴┬┬┬┴┬┴┬┴┬┴┴┬┴┴┬┴┴┴┬┬┬┴┬┴┬┴┴┬┬┴┴┬┬┬┴┴┬┴┴┬┬┴┬┴┴┬┴┬┬┴┴┴┴┴┬┬┴┴┬┬┬┴┴┴┬┬┴┬┴┴┴┴┬┬┴┬┬┬┴┴┴┬┬┴┬┬┴┬┬
cycled text:  THE QUICK BROWN FOX JUMPED OVER THE LAZY DOG.

uses upper/lower case

/*REXX program implements and demonstrates a (full)  "Bacon"  cipher (cypher).*/
parse arg plain                        /*obtain optional arguments from the CL*/
if plain=''  then plain =  "The quick brown fox jumped over the lazy dog."
                                       /*alphabet must be in uppercase letters*/
alphabet= 'ABCDEFGHIJKLMNOPQRSTUVWXYZ .,?!:'  /*list of letters & punctuation.*/
@.=                                           /*assign a default for all chars*/
     do j=0  for min(32,length(alphabet));              _=substr(alphabet,j+1,1)
     @._=translate(right(x2b(d2x(j)), 5, 0),  'sS', 01)
     end   /*j*/                       /* [↑]  build the symbol table (max=32)*/
                                       /* [↑]  code supports some punctuation.*/
say ' plain text: '    plain           /*display the original  (plain)  text. */
      encoded=BaconEnc(plain)          /*encode using a (full)  Bacon  cipher.*/
say 'cipher text: '    encoded         /*display the ciphered  (coded)  text. */
      decoded=BaconDec(encoded)        /*decode ciphered text──►plain (almost)*/
say 'cycled text: '    decoded         /*display the recycled text  (~ plain),*/
exit                                   /*stick a fork in it,  we're all done. */
/*────────────────────────────────────────────────────────────────────────────*/
BaconEnc: procedure expose @.;        arg x;                $=;     Lx=length(x)
            do j=1  for Lx;           _=substr(x,j,1);      $=$ || @._;      end
          return $
/*────────────────────────────────────────────────────────────────────────────*/
BaconDec: procedure expose @.;        parse arg x;          $=;     Lx=length(x)
            do k=0 for 256; _=d2c(k); if @._=='' then iterate; q=@._; !.q=_; end
            do j=1  to Lx  by 5;      y=substr(x,j,5);      $=$ || !.y;      end
          return $

output   when using the default input:

 plain text:  The quick brown fox jumped over the lazy dog.
cipher text:  SssSSssSSSssSssSSsSsSssssSsSsssSssssssSssSsSsSSsSsssssSSsssSsSSSsSsSSssSSsSSSsSsssSsSsSSSsSsSSSSSsSssSssSSsSsssSSsssSSSSssSsssssSSSSsSssSSSsSsSsSssSssSsssSSSsSsSssSSssSSSssSssSSsSssSsSSsssssSSssSSSsssSSsSssssSSsSSSsssSSsSSsSS
cycled text:  THE QUICK BROWN FOX JUMPED OVER THE LAZY DOG.

Ruby

Translation of: C#
CODES = {
    'a' => "AAAAA", 'b' => "AAAAB", 'c' => "AAABA", 'd' => "AAABB", 'e' => "AABAA",
    'f' => "AABAB", 'g' => "AABBA", 'h' => "AABBB", 'i' => "ABAAA", 'j' => "ABAAB",
    'k' => "ABABA", 'l' => "ABABB", 'm' => "ABBAA", 'n' => "ABBAB", 'o' => "ABBBA",
    'p' => "ABBBB", 'q' => "BAAAA", 'r' => "BAAAB", 's' => "BAABA", 't' => "BAABB",
    'u' => "BABAA", 'v' => "BABAB", 'w' => "BABBA", 'x' => "BABBB", 'y' => "BBAAA",
    'z' => "BBAAB", ' ' => "BBBAA", # use ' ' to denote any non-letter
}

def encode(plainText, message)
    pt = plainText.downcase
    et = ""
    pt.each_char { |c|
        if 'a' <= c and c <= 'z' then
            et.concat(CODES[c])
        else
            et.concat(CODES[' '])
        end
    }

    mg = message.downcase
    result = ""
    count = 0
    mg.each_char { |c|
        if 'a' <= c and c <= 'z' then
            if et[count] == 'A' then
                result.concat(c)
            else
                result.concat(c.upcase)
            end

            count = count + 1
            if count == et.length then
                break
            end
        else
            result.concat(c)
        end
    }

    return result
end

def decode(message)
    et = ""
    message.each_char { |c|
        if 'a' <= c and c <= 'z' then
            et.concat('A')
        elsif 'A' <= c and c <= 'Z' then
            et.concat('B')
        end
    }

    result = ""
    i = 0
    while i < et.length do
        quintet = et[i,5]
        for k,v in CODES do
            if v == quintet then
                result.concat(k)
                break
            end
        end

        i = i + 5
    end

    return result
end

def main
    plainText = "the quick brown fox jumps over the lazy dog"
    message = "bacon's cipher is a method of steganography created by francis bacon. " \
            + "this task is to implement a program for encryption and decryption of " \
            + "plaintext using the simple alphabet of the baconian cipher or some " \
            + "other kind of representation of this alphabet (make anything signify anything). " \
            + "the baconian alphabet may optionally be extended to encode all lower " \
            + "case characters individually and/or adding a few punctuation characters " \
            + "such as the space."

    cipherText = encode(plainText, message)
    puts "Cipher text -> ", cipherText

    decodedText = decode(cipherText)
    puts "\nHidden text ->", decodedText
end

main()
Output:
Cipher text ->
BacON's cIPHer Is a METhoD of stEgAnogRaphy crEatEd By FRAncis baCOn. thIs TASk Is TO imPLeMENT a proGrAm FOR eNcRYPTIOn anD deCRyPtioN Of plAINTExt UsING the SIMpLe AlPhaBet Of thE BAConIan CIphER Or sOme OTHer kInD Of reprESenTATion OF This alPHaBET (makE An

Hidden text ->
the quick brown fox jumps over the lazy dog

Scala

Translation of: Java
import scala.util.control.Breaks._

object BaconCipher {
  private val CODES = Map(
    'a' -> "AAAAA", 'b' -> "AAAAB", 'c' -> "AAABA", 'd' -> "AAABB", 'e' -> "AABAA",
    'f' -> "AABAB", 'g' -> "AABBA", 'h' -> "AABBB", 'i' -> "ABAAA", 'j' -> "ABAAB",
    'k' -> "ABABA", 'l' -> "ABABB", 'm' -> "ABBAA", 'n' -> "ABBAB", 'o' -> "ABBBA",
    'p' -> "ABBBB", 'q' -> "BAAAA", 'r' -> "BAAAB", 's' -> "BAABA", 't' -> "BAABB",
    'u' -> "BABAA", 'v' -> "BABAB", 'w' -> "BABBA", 'x' -> "BABBB", 'y' -> "BBAAA",
    'z' -> "BBAAB", ' ' -> "BBBAA" // use ' ' to denote any non-letter
  )

  def encode(plainText: String, message: String): String = {
    val sb = new StringBuilder

    val pt = plainText.toLowerCase()
    for (c <- pt.toCharArray) {
      if ('a' <= c && c <= 'z') {
        sb.append(CODES(c))
      } else {
        sb.append(CODES(' '))
      }
    }
    val et = sb.toString()

    var count = 0

    val mg = message.toLowerCase()
    sb.setLength(0)

    breakable {
      for (c <- mg.toArray) {
        if ('a' <= c && c <= 'z') {
          if ('A' == et(count)) {
            sb.append(c)
          } else {
            sb.append(c.toUpper)
          }
          count = count + 1
          if (count == et.length) {
            break()
          }
        } else {
          sb.append(c)
        }
      }
    }

    sb.toString
  }

  def decode(message: String): String = {
    val sb = new StringBuilder
    for (c <- message.toCharArray) {
      if ('a' <= c && c <= 'z') {
        sb.append('A')
      }
      if ('A' <= c && c <= 'Z') {
        sb.append('B')
      }
    }
    val et = sb.toString()
    sb.setLength(0)

    val default = ('@', "")
    for (g <- et.toCharArray.grouped(5)) {
      val q = new String(g)
      val key = CODES.find(_._2 == q).getOrElse(default)._1
      sb.append(key)
    }

    sb.toString()
  }

  def main(args: Array[String]): Unit = {
    val plainText = "the quick brown fox jumps over the lazy dog"
    val message = "bacon's cipher is a method of steganography created by francis bacon. " +
      "this task is to implement a program for encryption and decryption of " +
      "plaintext using the simple alphabet of the baconian cipher or some " +
      "other kind of representation of this alphabet (make anything signify anything). " +
      "the baconian alphabet may optionally be extended to encode all lower " +
      "case characters individually and/or adding a few punctuation characters " +
      "such as the space."
    val cipherText = encode(plainText, message)
    println(s"Cipher text ->\n\n$cipherText")
    val decodedText = decode(cipherText)
    println(s"Hidden text ->\n\n$decodedText")
  }
}
Output:
Cipher text ->

BacON's cIPHer Is a METhoD of stEgAnogRaphy crEatEd By FRAncis baCOn. thIs TASk Is TO imPLeMENT a proGrAm FOR eNcRYPTIOn anD deCRyPtioN Of plAINTExt UsING the SIMpLe AlPhaBet Of thE BAConIan CIphER Or sOme OTHer kInD Of reprESenTATion OF This alPHaBET (makE An
Hidden text ->

the quick brown fox jumps over the lazy dog

V (Vlang)

Translation of: go
const codes = {
    `a` : "AAAAA", `b` : "AAAAB", `c` : "AAABA", `d` : "AAABB", `e` : "AABAA",
    `f` : "AABAB", `g` : "AABBA", `h` : "AABBB", `i` : "ABAAA", `j` : "ABAAB",
    `k` : "ABABA", `l` : "ABABB", `m` : "ABBAA", `n` : "ABBAB", `o` : "ABBBA",
    `p` : "ABBBB", `q` : "BAAAA", `r` : "BAAAB", `s` : "BAABA", `t` : "BAABB",
    `u` : "BABAA", `v` : "BABAB", `w` : "BABBA", `x` : "BABBB", `y` : "BBAAA",
    `z` : "BBAAB", ` ` : "BBBAA"
}

fn bacon_encode(plain_text string, message string) string {
    pt := plain_text.to_lower()
    mut sb := []u8{}
    for c in pt.runes() {
        if c >= `a` && c <= `z` {
            sb << codes[c].bytes()
        } else {
            sb << codes[` `].bytes()
        }
    }
    et := sb.bytestr()
    mg := message.to_lower()  // 'A's to be in lower case, 'B's in upper case
    sb = []  // clear the byte slice
    mut count := 0
    for c in mg {
        if c >= u8(`a`) && c <= u8(`z`) {
            if et[count] == `A` {
                sb << c
            } else {
                sb << c - 32  // upper case equivalent
            }
            count++
            if count == et.len { break }
        } else {
            sb << c
        }
    }
    return sb.bytestr()
}
 
fn bacon_decode(message string) string {
    mut sb := []u8{}
    for c in message {
        if c >= u8(`a`) && c <= u8(`z`) {
            sb << `A`
        } else if c >= u8(`A`) && c <= u8(`Z`) {
            sb << `B`
        }
    }
    et := sb.bytestr()
    sb = []  // clear the byte slice
    for i := 0; i < et.len; i += 5 {
        quintet := et[i .. i + 5]
        for k, v in codes {
            if v == quintet {
                sb << u8(k)
                break
            }
        }
    }
    return sb.bytestr()
} 
 
fn main() {
    plain_text := "the quick brown fox jumps over the lazy dog"
    message := "bacon's cipher is a method of steganography created by francis bacon." +
        "this task is to implement a program for encryption and decryption of " +
        "plaintext using the simple alphabet of the baconian cipher or some " +
        "other kind of representation of this alphabet (make anything signify anything). " +
        "the baconian alphabet may optionally be extended to encode all lower " +
        "case characters individually and/or adding a few punctuation characters " +
        "such as the space."
    cipher_text := bacon_encode(plain_text, message)
    println("Cipher text ->\n\n$cipher_text")
    decoded_text := bacon_decode(cipher_text)
    println("\nHidden text ->\n\n$decoded_text")
}
Output:
Cipher text ->

BacON's cIPHer Is a METhoD of stEgAnogRaphy crEatEd By FRAncis baCOn.thIs TASk Is TO imPLeMENT a proGrAm FOR eNcRYPTIOn anD deCRyPtioN Of plAINTExt UsING the SIMpLe AlPhaBet Of thE BAConIan CIphER Or sOme OTHer kInD Of reprESenTATion OF This alPHaBET (makE An

Hidden text ->

the quick brown fox jumps over the lazy dog

Wren

Translation of: Kotlin
Library: Wren-str
Library: Wren-iterate
import "./str" for Str, Char
import "./iterate" for Stepped

class Bacon {
    static init() {
        __codes = {
            "a" : "AAAAA", "b" : "AAAAB", "c" : "AAABA", "d" : "AAABB", "e" : "AABAA",
            "f" : "AABAB", "g" : "AABBA", "h" : "AABBB", "i" : "ABAAA", "j" : "ABAAB",
            "k" : "ABABA", "l" : "ABABB", "m" : "ABBAA", "n" : "ABBAB", "o" : "ABBBA",
            "p" : "ABBBB", "q" : "BAAAA", "r" : "BAAAB", "s" : "BAABA", "t" : "BAABB",
            "u" : "BABAA", "v" : "BABAB", "w" : "BABBA", "x" : "BABBB", "y" : "BBAAA",
            "z" : "BBAAB", " " : "BBBAA"  // use " " to denote any non-letter
        }
    }

    static encode(plainText, message) {
        var pt = Str.lower(plainText)
        var sb = ""
        for (c in pt) sb = Char.isLower(c) ? sb + __codes[c] : sb + __codes[" "]
        var et = sb
        sb = ""
        var mg = Str.lower(message) // 'A's to be in lower case, 'B's in upper case
        var count = 0
        for (c in mg) {
            if (Char.isLower(c)) {
                sb = (et[count] == "A") ? sb + c : sb + Char.upper(c)
                count = count + 1
                if (count == et.count) break
            } else {
                sb = sb + c
            }
        }
        return sb
    }

    static decode(message) {
        var sb = ""
        for (c in message) {
            if (Char.isLower(c)) {
                sb = sb + "A"
            } else if (Char.isUpper(c)) {
                sb = sb + "B"
            }
        }
        var et = sb
        sb = ""
        for (i in Stepped.new(0...et.count, 5)) {
            var quintet = Str.sub(et, i...i+5)
            var key = __codes.keys.where { |k| __codes[k] == quintet }.toList[0]
            sb = sb + key
        }
        return sb
    }
}

Bacon.init()
var plainText = "the quick brown fox jumps over the lazy dog"
var message =
    "bacon's cipher is a method of steganography created by francis bacon." +
    "this task is to implement a program for encryption and decryption of " +
    "plaintext using the simple alphabet of the baconian cipher or some " +
    "other kind of representation of this alphabet (make anything signify anything). " +
    "the baconian alphabet may optionally be extended to encode all lower " +
    "case characters individually and/or adding a few punctuation characters " +
    "such as the space."
var cipherText = Bacon.encode(plainText, message)
System.print("Cipher text ->\n\n%(cipherText)")
var decodedText = Bacon.decode(cipherText)
System.print("\nHidden text ->\n\n%(decodedText)")
Output:
Cipher text ->

BacON's cIPHer Is a METhoD of stEgAnogRaphy crEatEd By FRAncis baCOn.thIs TASk Is TO imPLeMENT a proGrAm FOR eNcRYPTIOn anD deCRyPtioN Of plAINTExt UsING the SIMpLe AlPhaBet Of thE BAConIan CIphER Or sOme OTHer kInD Of reprESenTATion OF This alPHaBET (makE An

Hidden text ->

the quick brown fox jumps over the lazy dog

XPL0

Translation of: C

Works on Raspberry Pi. (MAlloc works differently in other versions.)

include xpllib; \for StrCmp, StrLen, Print, ToLower, StrNCopy

int Codes;

func GetCode(C);
char C;
[if C >= 97 and C <= 122 then return Codes(C-97);
return Codes(26);
];

func GetChar(Code);
char Code;
int  I;
[if StrCmp(Codes(26), Code) = 0 then return ^ ;
for I:= 0 to 26-1 do
    if StrCmp(Codes(I), Code) = 0 then return 97+I;
Print("\nCode ^"%s^" is invalid\n", Code);
exit(1);
];

proc StrToLower(S);
char S;
int  I;
for I:= 0 to StrLen(S)-1 do S(I):= ToLower(S(I));

func BaconEncode(PlainText, Message);
char PlainText, Message;
int  I, Count;
int  PLen, MLen, ELen;
char C, P, Et, Mt;
[PLen:= StrLen(PlainText);
 MLen:= StrLen(Message);
 ELen:= 5 * PLen;
Et:= MAlloc(ELen+1);
StrToLower(PlainText);
P:= Et;
for I:= 0 to PLen-1 do
    [C:= PlainText(I);
    StrNCopy(P, GetCode(C), 5);
    P:= P+5;
    ];
P:= P+1;  P(0):= 0;

\'A's to be in lowercase, 'B's in uppercase
StrToLower(Message);
Mt:= MAlloc(MLen+1);
Count:= 0;
for I:= 0 to MLen-1 do
    [C:= Message(I);
    if C >= ^a and C <= ^z then
        [if Et(Count) = ^A then Mt(I):= C
        else Mt(I):= C-32;      \uppercase equivalent
        Count:= Count+1;
        if Count = ELen then I:= MLen;
        ]
    else Mt(I):= C;
    ];
Release(Et);
return Mt;
];

func BaconDecode(CipherText);
char CipherText;
int  I, Count, CLen, PLen;
char P, Ct, Pt, C, Quintet(6);
[CLen:= StrLen(CipherText);
Ct:= MAlloc(CLen+1);
Count:= 0;
for I:= 0 to CLen-1 do
    [C:= CipherText(I);
    if C >= ^a and C <= ^z then
        [Ct(Count):= ^A;  Count:= Count+1]
    else if C >= ^A and C <= ^Z then
        [Ct(Count):= ^B;  Count:= Count+1];
    ];
PLen:= StrLen(Ct) / 5;
Pt:= MAlloc(PLen+1);
P:= Ct;
for I:= 0 to PLen-1 do
    [StrNCopy(Quintet, P, 5);
    Quintet(5):= 0;
    Pt(I):= GetChar(Quintet);
    P:= P+5;
    ];
Pt(PLen):= 0;
Release(Ct);
return Pt;
];

char PlainText, Message, CipherText, HiddenText;
[\Maps successively from 'a' to 'z' plus ' ' to denote any non-letter
Codes:= ["AAAAA", "AAAAB", "AAABA", "AAABB", "AABAA",
         "AABAB", "AABBA", "AABBB", "ABAAA", "ABAAB",
         "ABABA", "ABABB", "ABBAA", "ABBAB", "ABBBA",
         "ABBBB", "BAAAA", "BAAAB", "BAABA", "BAABB",
         "BABAA", "BABAB", "BABBA", "BABBB", "BBAAA",
         "BBAAB", "BBBAA"];
PlainText:= "the quick brown fox jumps over the lazy dog";

Message:= "bacon's cipher is a method of steganography created by francis bacon.
this task is to implement a program for encryption and decryption of 
plaintext using the simple alphabet of the baconian cipher or some 
other kind of representation of this alphabet (make anything signify anything). 
the baconian alphabet may optionally be extended to encode all lower 
case characters individually and/or adding a few punctuation characters 
such as the space.";

CipherText:= BaconEncode(PlainText, Message);
Print("Cipher text ->\n\n%s\n", CipherText);
HiddenText:= BaconDecode(CipherText);
Print("\nHidden text ->\n\n%s\n", HiddenText);
Release(CipherText);
Release(HiddenText);
]
Output:
Cipher text ->

BacON's cIPHer Is a METhoD of stEgAnogRaphy crEatEd By FRAncis baCOn.thIs TASk Is TO imPLeMENT a proGrAm FOR eNcRYPTIOn anD deCRyPtioN Of plAINTExt UsING the SIMpLe AlPhaBet Of thE BAConIan CIphER Or sOme OTHer kInD Of reprESenTATion OF This alPHaBET (makE An

Hidden text ->

the quick brown fox jumps over the lazy dog

zkl

Translation of: Python
class Bacon{
   fcn init(_keyText){
      var [const] keyText=_keyText.toLower(),
        lowerLetters=["a".."z"].pump(String), 
	upperLetters=["A".."Z"].pump(String),
	letters=String(lowerLetters,upperLetters),
	lc2bin=[0..].zip(lowerLetters + " .") //-->("a":"00000", ...)
	   .pump(Dictionary(),fcn([(n,ch)]){ T(ch,"%05.2B".fmt(n)) }),
	bin2lc=lc2bin.pump(Dictionary(),"reverse");  //-->("00000":"a", ...),
      ;
   }
   fcn to5binary(msg){ //-->stream of 1s and 0s (1 means capitalize)
      msg.toLower().pump(String,lc2bin.get.fp1(""))  //-->("abcde"|"") * length
      .pump(Data,"toAsc",'-(0x30)).howza(0)  // "1"-->1, treat result as bytes
   }
   fcn encrypt(msg){
      bin5:=to5binary(msg).walker();  // capitalization overlay of keyText
      e:=keyText.pump(String, 'wrap(ch){
	 if(not lowerLetters.holds(ch)) return(Void.Write); // encrypt only ASCII
	 if(not bin5._next())           return(Void.Stop);  // end of msg
	 (bin5.value and ch.toUpper() or ch);
      });
      if(not bin5.atEnd) throw(Exception.ValueError("Ran out of characters in key text"));
      e + "...."  // pad
   }
   fcn decrypt(bacontext){
      bacontext.filter(letters.holds).pump(String,T(Void.Read,4),
        fcn{ vm.arglist.pump(String,upperLetters.holds,"toInt") : bin2lc[_] });
   } 
}
bacon:=Bacon(
#<<<
0'|All children, except one, grow up. They soon know that they will grow
up, and the way Wendy knew was this. One day when she was two years old
she was playing in a garden, and she plucked another flower and ran with
it to her mother. I suppose she must have looked rather delightful, for
Mrs. Darling put her hand to her heart and cried, "Oh, why can't you
remain like this for ever!" This was all that passed between them on
the subject, but henceforth Wendy knew that she must grow up. You always
know after you are two. Two is the beginning of the end.
 
Of course they lived at 14 [their house number on their street], and
until Wendy came her mother was the chief one. She was a lovely lady,
with a romantic mind and such a sweet mocking mouth. Her romantic
mind was like the tiny boxes, one within the other, that come from the
puzzling East, however many you discover there is always one more; and
her sweet mocking mouth had one kiss on it that Wendy could never get,
though there it was, perfectly conspicuous in the right-hand corner.|
);
#<<<

phrase:="Rosetta code Bacon cipher example secret phrase to encode in the capitalization of peter pan";

println("PLAINTEXT = \n%s".fmt(phrase));
encrypted,decrypted:=bacon.encrypt(phrase), bacon.decrypt(encrypted); 
println("ENCRYPTED = \n%s".fmt(encrypted));
println("DECRYPTED = \n%s".fmt(decrypted));
if(phrase.toLower()!=decrypted) throw(Exception.AssertionError("Round-tripping error"));
Output:
PLAINTEXT = 
Rosetta code Bacon cipher example secret phrase to encode in the capitalization of peter pan
ENCRYPTED = 
All cHiLDReN, exCept One, GroW UP. thEY soon kNOw That tHey WILl groW
Up, aNd tHE wAy wendY knew was tHis. ONE daY WhEN ShE was tWo yEars oLD
SHe wAS PlaYinG in a GARdEn, anD shE pLUCked anoTHer fLOWEr AnD Ran WitH
It To Her MothEr. i supPoSe shE muSt hAve LOOKeD raTHER deLIGHtfuL, for
mrS. daRlinG puT HeR hAnd TO hER HeARt And cRied, "OH, wHy caN't yOU
RemaiN LikE thIS fOr eVer!" thIS wAS AlL tHat PAssED BetWeeN ThEm on
tHe subjecT, BUT hEnceForTH wendy kNeW ThAt shE MusT grow uP. yoU AlWays
kNOW afTEr YOU aRe tWO. Two iS tHE BeGinNING of The End.
 
OF coUrsE theY LIvEd aT 14 [THEir housE NuM....
DECRYPTED = 
rosetta code bacon cipher example secret phrase to encode in the capitalization of peter pan