In January 2012 an anonymous post appeared on an online image board. It read, in plain white text on black: “Hello. We are looking for highly intelligent individuals. To find them, we have devised a test.” That was the start of Cicada 3301.
How the first puzzle worked
The first image hid a message using steganography, a technique for concealing data inside a picture. Decoding it led to a second clue, then to a cipher, a book code, a telephone number that played a recorded message, and posters with QR codes in cities including Seoul, Warsaw, Paris and Miami. Each step led to the next, and participants from around the world worked on it together.
Further rounds
Two more rounds followed in January 2013 and January 2014, and a further set of puzzles was posted in 2017. The puzzles drew on cryptography, number theory, literature, ancient alphabets and online privacy tools. Everything that was verifiably genuine was signed with the same cryptographic key, which is how followers tell real messages from imitations.
The Liber Primus
The 2014 round led solvers to a hidden website on the Tor network and a book called the Liber Primus (Latin for “first book”), written in an invented runic script. Participants decrypted some pages, which carry philosophical text about enlightenment and the self, but much of the book has resisted solving for years. Some pages remain unsolved.
Who was behind it?
Nobody has proven it. Theories have included an intelligence agency looking for recruits, a university research group, a cryptography company, a hacker collective and an elaborate game by artists. The creators have never explained their purpose beyond messages that spoke of enlightenment, privacy and self-reliance. Nobody who took part says they ever met them, and no group has claimed credit.
Why it still matters
Cicada 3301 showed how large numbers of strangers could work together on a hard problem, and it inspired many later puzzle hunts and online games. It remains one of the best examples of a mystery that was designed to be solved, but whose designers have never revealed themselves.
Frequently asked questions
What is Cicada 3301?
An anonymous series of internet puzzles that began in 2012 and appears to have been designed to find skilled codebreakers.
Has it been solved?
The first puzzle chain was solved by participants. The Liber Primus is only partly solved.
Who made it?
Unknown. Many theories exist and none has been proven.
Are new puzzles still appearing?
A round appeared in 2017. Since then, nothing has been verified as genuine.
How can you tell real messages from fakes?
Genuine messages were signed with the same PGP key.