TheCodeBreakers
one. Suppose that the cryptanalyst deciphers a four-letter military
message with every key, beginning with AAAA. He strikes plaintext at key
AABI: kiss. Unlikely in this context. He presses on. Key AAEL yields
plaintext kill. Better—but he wants to make sure. He continues through
key AAEM, giving kilt, which might be an oblique reference to a Scottish
maneuver, and AAER, kiln. Further down the line he reaches fast at
GZBM and slow at KHIA, stop at HRIW and gogo at XSTT, hard at PZVQ
and easy at RZBU. He finds when he ends at ZZZZ that he has merely
compiled a list of every possible four-letter word—the hard way. He can
no more pick the right solution from this list than he can from a
dictionary of military terms. The key does not help in limiting the
selection because, since it is random, any group of four letters is as
acceptable a keytext as
any other. The worst of it is that the possible solutions increase as the
message lengthens
annaabi.ee 
