Cicada 3301 has been called "the most elaborate and mysterious puzzle of the internet age" and listed as one of the "top 5 eeriest, unsolved mysteries of the internet."
It started out when an anonymous 4chan user posted a black and white image seen below:
The post made people on the web started to search for the said hidden message. This was until Joel Eriksson, a computer analyst from Sweden, found the message. He knew it was an example of digital steganography, which is a way of hiding encoded messages within the pixels of an image.
Eriksson decoded the hidden message from the image above using steganography software with a shift cipher. He found a web address which contained another clue to proceed the puzzle trail. Each trail was becoming increasingly difficult to solve.
The next clue was an image of a wooden duck with another cryptic message. Again he used steganography to reveal a hidden book code with a list of two numbers separated by a colon. The book code led to a Reddit URL with Mayan numerals on the page.
Eriksson then noticed that several posts by a user using a pseudonym seemed to consist of encoded text. Analyzing the text, he saw that the book code could be used to decode, but the cypher was inside the key, which he then found by translating the Mayan numerals.
The decoded text revealed two images. After running steganography on them, he found strings of digits that was a phone number (214 – 390 – 9608). Calling the phone number led to a voicemail that read:
"Very good. You have done well. There are three prime numbers associated with the original final.jpg image. 3301 is one of them. You will have to find the other two. Multiply all three of these numbers together and add a .com to find the next step. Good luck. Goodbye."
Eriksson then analyzed the metadata of the first image, the image shown above. Using its height and width dimensions, he thought that those two can be the next two numbers. After doing the math, he found another URL, 845145127.com, with yet another image of Cicada with a countdown that told when when to return to the website.
When the countdown was over, the Cicada image was replaced with strings of digits that resembled GPS coordinates. The coordinates led to countries around the world, including Spain, Russia, America, France, Japan, and Poland.
Here, Eriksson had to rely on other people to seek those trails. What the locals found was that the coordinates were fixed to telephone poles that had posters with images sticking on them. The images had Cicada and a QR codes.
After scanning the QR codes, Eriksson was led to another two images, that again contained more hidden text. They were text from what Eriksson found on William Gibson poem Agrippa. Noting that the text referenced prime numbers, Eriksson used the book code to find what he should do with the Gibson poem. There he was directed to an address on the anonymous Tor network.
However, by the time he arrived, Cicada 3301 had put up a message stating that they were disappointed in the groups of people that had formed to share parts of the puzzles. They said that they discovered no one was able to complete all the steps along the way, as Eriksson had done.
"It was quite disappointing," said Eriksson.
The Unknown Puzzle
Cicada 3301 is a puzzle where participants were required to know a good deal of technical knowledge, an understanding of number theory, including: philosophy, knowledge of artistic references, classical music, cyberpunk literature, mathematics and technological references, Victorian poetry, Mayan numerology, Kabbalah, and the life cycles of cicadas.
After a month the puzzle was first posted, a new message was posted to the 4chan message board, saying that "We have now found the individuals we sought. Thus our month-long journey ends."
Nobody knows who was behind this, who is the winner and what happened to him/her. Theories said that Cicada 3301 was a recruitment method for a global spy organizations, while some others concluded that the group comprised of military and government officials, diplomats or other world class academics who were seeking out people with intelligent minds from across the globe. Some even concluded that it was the work of an underground cult or a network of anarchistic poet/hackers that were making an alternate reality game. Others have claimed it is run by a bank working on cryptocurrency and a Masonic conspiracy.
Speculation said that Cicada 3301 is large and well-funded, considering that it has the knowledge to create such complex puzzles and at the same time, capable of supporting the existence of clues in a large number of locations, all quite far from one another.
But since no company or individual has taken credit or tried to monetize it, the fact remains a mystery.
The puzzle continued the next year and the next. The new puzzles were posted on the 5th of January, starting a new game. The tests were also published on Twitter under the username @1231507051321.