Viewing Single Post From: A New Challenge

Viewing Single Post From: A New Challenge
jdege	Jun 24 2007, 01:51 AM
Elite member Posts: 263 Group: Admin Member #246 Joined: December 7, 2006	tidmiste Jun 23 2007, 05:49 PM I'm kind of new to this particular forum, but not to cryptography. And I believe this is the best forum for cryptography, so I'm glad I found it. About this code: It was made by myself, so there's nothing bad about it. Also, it's a passage from a book, but no hint toward which book. Others have attempted to solve it on different forums, email accounts, and even my teachers... So I hope someone here can... Other hints will be put at the end as spoilers. 10748 24478 12412 63110 92980 25125 27425 24319 10225 21441 06111 05262 24710 34522 42295 96045 41341 06424 36740 56873 72242 85262 63612 15610 85449 36823 78525 48118 94914 05847 34842 31071 68218 14146 12252 49262 05610 76662 34692 76675 85451 26318 52810 42685 55426 24357 60468 32412 42110 54740 66415 56811 85190 SPOILER 1: (Not very helpful) It's substitution, but not direct simple substitution. SPOILER 2: (Sort of helpful) It is paper-and-pencil encrypted. (Well, not really paper and pencil... but in the head.) SPOILER 3: (Helpful) It uses basic algebra or pre-algebra. Those are the only ones I could think of as being good hints without giving it away. Ok. Good luck on this! 265 characters factors to 5*53. Which means that either characters don't encrypt to a constant number of digits, or each character or group of characters encrypts to five digits. But there are zero repetitions of the five-digit groups. Which would unlikely if each five-dgit group represented either a single character or a bigram. (And a five-digit group can't represent more than a bigram.) Which sends us back to characters not encrypting to constant numbers of digits. Which raises the question, how does the decipherer know how many digits make up a character? And which ends my patience for exploring this. Describe the cipher, provide plaintext/ciphertext pairs, so I can test to ensure that I understand how it works. And then encrypt ten plain text messages, each of >200 characters, with the same key, and I'll see if I can break it.
	When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl.

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