Bifid cipher: Difference between revisions

Bifid cipher (view source)

Revision as of 11:14, 17 July 2022

101 bytes added , 1 year ago

J: move normalization out of the encrypt/decrypt routines and show an example with a 9x9 reference "square"

Rdm

6,951

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Revision as of 16:58, 16 July 2022 (view source) Petelomax (talk \| contribs) (→‎{{header\|Phix}}) ← Older edit		Revision as of 11:14, 17 July 2022 (view source) Rdm (talk \| contribs) (J: move normalization out of the encrypt/decrypt routines and show an example with a 9x9 reference "square") Newer edit →
Line 64: Implementation:<lang J>alpha=: a.{~65+i.26 normalize=: {{ rplc&'JI'(toupper y)([-.-.)alpha }} bifid=: {{ m{~_2 (5t&#.)\,\|:~~5 5~~(t,t=.%:#m)#:m i.~~normalize~~ y([-.-.)m }} difib=: {{ m{~5t#.\|:(\|.@$$,)~~5 5~~(t,t=.%:#m)#:m i.~~normalize~~ y([-.-.)m }}</lang> This is pretty much a literal implementation of the algorithm, except that our indices range from 0..4 instead of 1..5 (or, for letter indices, they range from 0..24 instead of 1..25). Line 75: ref3=: 'PLAYFIREXMBCDGHKNOQSTUVWZ' ref1 bifid normalize 'attack at dawn' DQBDAXDQPDQH ref1 difib ref1 bifid normalize 'attack at dawn' ATTACKATDAWN ref2 bifid normalize 'flee at once' UAEOLWRINS ref2 difib ref2 bifid normalize 'flee at once' FLEEATONCE ref2 bifid normalize 'attack at dawn' EYFENGIWDILA ref2 difib ref2 bifid normalize 'attack at dawn' ATTACKATDAWN ref3 bifid normalize 'The invasion will start on the first of January' VRSYXSIYTMQVIRSKISLPVLDTCKRTCAIVTMATCEX ref3 difib ref3 bifid normalize 'The invasion will start on the first of January' THEINVASIONWILLSTARTONTHEFIRSTOFIANUARY~~</lang>~~ (_81{.123{.a.)bifid 'The invasion will start on the first of January' TgqhpqpqxzpxfqzoKqhxw/O3eWH53BYw`+Be8F1 We could include both I and J by increasing the square size to 64: take all ascii characters in the range from 32 (space) to 126 (tilde). Discard the lower case letters. Discard four other characters. Use the remainder for the square. (_81{.123{.a.)difib(_81{.123{.a.)bifid 'The invasion will start on the first of January' TheinvasionwillstartonthefirstofJanuary</lang> =={{header\|Julia}}==