WATAE TXLAL PDIBI MGTBU YBTMM FJBJW KBEIZ SGLZQ CCOCT XMQHM QSLFS
AOBFX QQRCK CJSME XFHLT GYSJN QEQUM FNPIZ ZMCWE PXQOD UIDLO SXLCV
CGIWI UIVYC HLYAE TKYKY RVOVZ FJWAR RCYCN SSJNN ADVZB BMQJQ UVGKC
UCPVN BGRZA EVOMF THBSK OZUYQ QDGUO FUIAT XOWPN QESJM MUHHU XBTMM
NYGYF YFNFH VIATB UOHPD QVJAT AEYLT MQTLE EXBTH MMYCT BDDAX

Determine what this cipher says, and the method of encryption, using the following hints:

• It is not a simple substitution cipher.
• Both the original plain text message and the encrypted message contain 270 characters (maybe with meaningless filler characters at the end).
• Only one rather simple method of encryption has been used.
• The encryption method is fairly robust. In other words, an error (while encrypting or decrypting) does not scramble the entire remaining message. Some very complicated ciphers have this problem.
• In the encrypted text, M and T appear most often, and R appears least often (I do not think these facts help at all).
• Both the original plain text and the encrypted message read from left to right.
• You might be able to guess the full text after determining only the first three words.

(In reply to re: Solution? by fwaff)

In any case, I did not miscount; since the letters are arranged in groups of 5, it's fairly easy to confirm that there are indeed 270 letters. The original message also contains 270 letters, "with meaningless filler characters at the end" just to make the letter blocks come out even. The point is that the method of encryption demands that there are the same number of letters in the encrypted message as in the original.

I will confirm that the passage in question is the Preamble to the Constitution, and the first three words are indeed "We the people." The fact that the first three blocks of letters in the encrypted message have W, T, and P as their initial letters is a mild coincidence.

Actually, the very first letter will always be the same as that of the original message, but every letter after that could turn out to be any. That may be enough of a hint to point someone in the right direction.

If not, try converting each letter to its alphanumeric value. Since you now know the encrypted message as well as the original one, the pattern may be easier to find...

Posted by DJ on 2003-12-08 12:12:50