On May 23, 6:49 am, David Bernier <david...@videotron.ca> wrote: > David Bernier wrote: > > David Bernier wrote: > >> timro21 wrote: > >>> TheUnsolvedProblems web site at > >>>http://unsolvedproblems.org/ > >>> has been updated. > > >>> Thanks to those who pointed out expired links. > > >>> If you think you have a solution to any of the problems, please read > >>> the FAQ. > > >> I had a look at the Zodiac 340 Cipher. There are 340 characters: > >> 17 per line and 20 lines. There close to 63 different symbols. In the > >> first cipher (cracked), a letter could be represented by more than one > >> symbol: for example E could be symbol_1, symbol_2 , ... > >> [ the solution is "well-known"]. > > >> There's a substitution applet (or webtoy) on-line here: > > >> <http://oranchak.com/zodiac/webtoy/> . > > >> I digitized the 340-cipher from here: > >> <http://www.zodiackiller.com/340Cipher.html> > > [...] > > > Thang Dao wrote a Master's degree thesis on computer methods to solve > > homophonic substitution ciphers with about 300 or more characters. > > > The 340-cipher has about 63 symbols. He mentions using cribs, > > and frequencies of monographs, digraphs and trigrams ; > > also 4-grams and higher (trigrams: the, ing, ion, nce, ...). > > > The thesis was submitted in 2008: > > > < > >http://scholarworks.sjsu.edu/cgi/viewcontent.cgi?article=4566&context..."Zodiac+340+Cipher" > > > (at San Jose State University) . > > By the way, I downloaded and installed ZKDecrypto for Windows: > <http://code.google.com/p/zkdecrypto/> . > > It looks for words, and has many parameters and options. It gives > a score to every substitution. But it doesn't know the context. > Still, it might be useful, as one can supplement the score by > "points" for probable words ...- Hide quoted text - > > - Show quoted text
I think two potential clues to any decryption are the use of the Zodiac's own chosen symbol within the code in several places, and the fact that he would very likely sign off with "Zodiac" - all the letters of which are amongst the final two lines of characters.