Newspaper article collection

While Zamantha was digging up Thomas Dougherty’s letters at the San Francisco Public Library, she also made copies of their collection of newspaper article clippings. The collection contains an assortment of Zodiac-related articles from 1978 to 2009. Zamantha generously sent…

Thomas Dougherty’s “code theory”

Thirty-seven years ago, a man named Thomas Dougherty came up with a Zodiac “code theory”, and mailed dozens of bizarre letters from the Hotel Warfield in San Francisco to United States federal judge Oliver Carter. The letters were recently unearthed…

New FBI files

Updated Oct 17, 2014: Fixed the Google Drive link to the FBI files. Diligent researcher morf13‘s persistence recently paid off: He received over 800 pages of never before seen material from FBI files on the Zodiac case. Click here to…

In his own words

Forum user 4on4off had an interesting idea: Why not run the Gutenberg crib search program again, but against the Zodiac’s own writings instead of the massive collection of books in the Gutenberg collection? I ran the search, and it found…

Harold Kravcik’s 340 solution

Harold Kravcik created a stir a few years back when he produced a solution to the 340-character cipher. Some people believed it to be the correct solution, so it was submitted to the FBI, and Harold required others to sign…

Gutenberg addendum: Small ciphers

The program I wrote for the Project Gutenberg crib experiments also looked for pieces of text that fit into the entire 13-character cipher. This cipher has many repeated symbols: One symbol repeats three times, and three other symbols repeat twice….

Throw the book at him, Part 3

Back in Part 1 we talked about the idea of using a large collection of books as a source of cribs to plug into cipher texts. Can we use a large collection of books, such as Project Gutenberg, to find…

Cipher skin art

Have you ever wanted to do cryptanalysis on someone’s back?

This is the Zodiac eating

The latest tip jar doodle by a hot dog vendor in San Francisco shows a familiar figure with a brand new puzzle for you: Can you solve it before your frank gets cold? UPDATE: The tip jar doodle artist emerged,…

Zodiac Typewriter

In our many online discussions of the Zodiac’s ciphers, I’ve often needed to create pictures of symbols or pieces of the cipher text to illustrate a point. This became tedious after a while, so I created the “Zodiac Typewriter” to…