October 16, 2025
3 minute read
Solution to CIA Kryptos code found after 35 years
After decades of speculation, two writers have found the answer to the final cipher of the Kryptos code.
Kryptos, a piece of art created from encrypted code, is located on the grounds of the CIA headquarters in Virginia.
Buyenlarge/Author/Getty Images
After 35 years of searching, the final solution to the famous puzzle called Kryptos has been found. Two writers have discovered a fourth answer to the code hidden in the archives of the Smithsonian Institution.
Puzzle, a copper sculpture engraved with four coded messages, has fascinated professional and amateur cryptographers since 1990, when artist Jim Sanborn installed it at CIA headquarters in Virginia. The four encrypted messages consist of 869 characters. The last section, K4, begins with “OBKR” and contains 97 letters. To get the solution, they need to show how they decrypted it from this ciphertext.
The first three passages were revealed in the 1990s, but the solution to the fourth, known as K4, remained a secret until now.
About supporting science journalism
If you enjoyed this article, please consider supporting our award-winning journalism. subscription. By purchasing a subscription, you help ensure a future of influential stories about the discoveries and ideas shaping our world today.
After years of failed attempts by enthusiasts to decode the K4, Sanborn was preparing to put the solution up for auction, expected to fetch between $300,000 and $500,000. However, on September 3, he received an email from journalists Jaret Kobeck and Richard Byrne containing the full transcript.
Kobeck and Byrne found a solution when they noticed at an auction that Sanborn's “coding tables” were in the collection of the Smithsonian Institution. Byrne photographed the papers, and Kobeck later realized that they included scraps taped together revealing the original plaintext of K4. The notes contained the previously published clues “BERLIN WATCH” and “EAST-NORTHEAST”, part of a fully decrypted message.
Sanborn confirmed the authenticity of the decision, explaining that he had mistakenly included the notes in the records while compiling documents during cancer treatment years earlier. After the discovery, he asked the Smithsonian to seal the files for the next 50 years, and it complied.
In response to this news, RR Auction, the company handling the sale, warned Kobeck and Byrne against publishing the text, threatening legal action for interference and copyright infringement. Both men said New York Times they're not going to release it.
A statement of RR Auction said the materials offered at the planned sale provide the only official insight into how the K4 functions as part of Sanborn's artistic vision. He emphasized that while Kobeck and Byrne may now know the plaintext, they do not have the method by which K4 was encoded, nor the full creative context of the work. “It's one thing to have words. It's another to have a method,” says Ilonka Dunin, a retired game developer who co-moderates one of the world's largest fan groups, Kryptos. “Over the years, many people have come to us and said they have solved the problem, but if they can’t show the method, they are simply kicked out of the room.”
RR Auction's statement noted that even if the K4 text eventually becomes public, only the winning bidder will have access to Sanborn's full explanation of the connection between K4 and the previously rumored fifth passage, as well as the purported meaning of Kryptos' full message.
The crypto community's reaction to the news was divided. Some, including Dunin, are relieved that someone has finally solved the long-standing mystery of Kryptos. Others have described the way Kobeck and Byrne found the answer as “ugly ending“
No matter how the saga ends, the craze for Kryptos will likely continue. “For a piece of art, if you can grab someone's attention for 10 minutes, that's very good,” Dunin says. “Sanborn now has a piece of art that has held people's attention for 35 years.”
It's time to stand up for science
If you liked this article, I would like to ask for your support. Scientific American has been a champion of science and industry for 180 years, and now may be the most critical moment in that two-century history.
I was Scientific American I have been a subscriber since I was 12, and it has helped shape my view of the world. science always educates and delights me, instills a sense of awe in front of our vast and beautiful universe. I hope it does the same for you.
If you subscribe to Scientific Americanyou help ensure our coverage focuses on meaningful research and discovery; that we have the resources to report on decisions that threaten laboratories across the US; and that we support both aspiring and working scientists at a time when the value of science itself too often goes unrecognized.
In return you receive important news, fascinating podcastsbrilliant infographics, newsletters you can't missvideos worth watching challenging gamesand the world's best scientific articles and reporting. You can even give someone a subscription.
There has never been a more important time for us to stand up and show why science matters. I hope you will support us in this mission.
