6.5 ANALYSIS OF A 1-ROTOR SYSTEM: CIPHERTEXT ONLY
Example 6.1
The ciphertext that follows contains eight rows, each containing 78 letters and a final ninth row of 26 letters. We begin the cryptanalysis by writing the ciphertext in Table 6.3 in columns of 26 letters. Denote by N(i) the length of the ith column and Nt(i) the number of times the letter t appears in the ith column.
______________________________________________________________________________ cipherEx6.1 ______________________________________________________________________________ rblfogzbkgcwuqfydkibkrfolsfjmyxvlhdwfeyuiwhguybqsrhhbolkagixxkritjwdhrqcwrkdae pcdyfrekdxwwuovrarqxihbrintjrrryhdfcwsmkicnnidgoxdhniwlbytelcqbmoxpwmsdszeglae ffqpyltbmkrwookdq jodlwbkuakoapeeobehtvoocnkrrpvllliqbgyijzyzqkrgsgmrsdcbielyvz agpetywbgpeijuicgvwczqtbchzfwvozhdibshmmnhtjdufabtsszflhhvjdrqembkphelvhfyjdkx rirmjmlcnvwgtsfvisgpfrgojrwistjzzxubpwlhwetjncbjwdlmpxlhtzjnmaxmmkeemxlegzldxw coslyehxjnchjscwquemqejlinzzcxzwojiqgvcnicdwrdrmibdoxyrvajhcixgwuzohtrwgqsaxqn ozsjzzrlnhunekpooaqxihlavycciphbobqhwbpdmcnkwcfyjrgekclyfvoljslxohfemkizfyjfvl xuiyfgrfiqiltkqqhkcpiklavcxpzaduwpisutlxpyuxusfrdmmabhxdzxxbujjgaqfydkoejuktgj ptfpzjybeotomkplyvrstrnbaq ______________________________________________________________________________
If t is the correct plaintext value for ciphertext s in the 0th column, then t – i will be the correct plaintext value for ciphertext s – i in the ith column for every i with 0 ≤ i < 26. It follows from the law ...
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