Over 40 years ago, the infamous Zodiac Killer began a series of killings in Northern California that remain unsolved to this day. During his spree, he mailed letters to local media, boasting about his crimes and taunting the authorities. In several of these letters, he published mysterious cryptograms containing secret messages. The first cryptogram was solved very quickly by a high school teacher and his wife. But the remaining cryptograms (the 340-, 13-, and 32– symbol ciphers) are still unsolved, despite numerous attempts by many people to suggest possible solutions.
The mission of this site is to gather information about these ciphers, and to connect people to tools that might help solve them. This site is also an intersection of computer science, mathematics, classical cryptography, and skeptical thinking. We want to help separate fact from fiction. And there is plenty of fiction out there.