4.5 FINDING THE KEY OF VERNAM–VIGENÈRE CIPHERTEXT WITH KNOWN PERIOD BY CORRELATION
____________________________________________________________ cipherEx4.1 ___________________________________________________________ xeedt nerye rthti lpxtl xpbae itrxe eucoy wqrup wmdbd odfrx oiqhz jxeei dcpht hawlz ikeht cleaa znnsr qaoih mxeca bayxb rerzq trtqg devbn alcsy qiztw cypep uzvqr nppyi xxswh dygea eecsh rcucr fekke ilxij ezidj mkazr tepoe bdcxw blqre vmzif nmmpi smcot evsxx awllt qalrh xidat rioee tczeq iacdc wqeyh sezbb qtyqe aebdd wmylq qjgsj pgipv wfnuc oywqr krzqt rtqgd gsktd dwqez hucpx sllep yhgee yxnep mlmce wgfez itwxp uetns qmuft cwxla zpwcw bejep vmjez ilphx tmszg xlrev prioa ftnvs psetn xmlnj glcwm ioifv ippen nlsio sxdxw piyjw exbmq ceepm rarpw wbsyp yriaa zsfrq xnzto wtxcq titpl rmits rtoga oleod xnmit lsexm pitif wzyxq hqpdw mptmc niscc abayx bredy xlbfd xgspl uehth izoye fxios tpgif bezec skoay bphxl pxpjk ejeeh fglxs npnok xmydy eract tdw ____________________________________________________________
Example 4.1
cipherEx4.1 of length 623 letters is the encipherment of ASCII plaintext by a Vigenère substitution with period 7. The plaintext x and ciphertext y are each divided into 7 plain- and ciphertext files consisting of the letters separated by 7 places:
The ith subfiles xi and yi are each of length ni; each letter ...
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