Articles and details about the 340

• Encyclopedia of observations - A collection of observations about the cipher text
• Comparison of cipher alphabets
• Comparison of character repetition rates
• Comparison of sequence repetition rates
• Levenshtein distance analysis - A look at the occurrences of repeated sequences that are not exact matches.
• Quadrant analysis - Do the n-gram counts improve If we split the cipher text into four quadrants?
• Quadrant analysis Part 2 - An expansion of the previous quadrant analysis experiment. Is it possible to produce quadrant arrangements that increase the number and quality of homophones detected algorithmically?
• Information theory (entropy, randomness, etc)
• FBI analysis from Dan Olson
• Cipher-related excerpts from case documents
• Word frequency analysis (word frequencies derived from a corpus of Zodiac correspondences)
• Omnidirectional repetitions - An investigation into patterns that repeat in arbitrary directions by following "snake-like" paths.
  • (Above link is broken. Click here for an archived copy.)
• "Complexification" - Did the cipher author begin with a simpler set of cipher symbols, then "complexify" certain symbols to further flatten the symbol distributions?
• Substring ranking - Can we apply measurements that give us a way to find interesting sections of cipher text for focused attacks?
• Catalog of repeating fragments - A comprehensive list of portions of cipher text that occur more than once in the cipher text.
• Cipher Legitimacy - Are the Zodiac ciphers real, or are they hoaxes?
• Corpus Experiments - A collection of corpus-based experiments performed on the Zodiac ciphers
• Outline of ongoing work on Z340
• Another outline of ongoing work on Z340