“Maybe you’re mistaken–maybe this first part of the Kryptos code is really not a polyalphabetic Vigenere Tableau after all — maybe it’s a different type of code entirely. Or maybe it is a Vigenere code, but it’s been double or triple encoded — or maybe it was encoded backwards.”
David Stein
CIA analyst
Directorate of Intelligence
November 3 2025 — Kryptos, the sculpture by American artist Jim Sanborn on the grounds of the CIA in Langley, Virginia, has revealed a major surprise. Of its four encrypted sections, the first three had long been solved. The final section, one of the world’s most famous unsolved codes, has now been uncovered — thanks to an unexpected “gigantic mistake.” Always expect the unexpected! Follow us on Twitter: @INTEL_TODAY
RELATED POST: KRYPTOS 30-Year Anniversary — Introduction : Sculpture Dedication Ceremony at the CIA (November 3 1990)
RELATED POST: KRYPTOS 30 Years Anniversary — How to Break a Vigenère Code
RELATED POST: KRYPTOS 30 Years Anniversary — The Solution of Section II
RELATED POST: KRYPTOS 30 Years Anniversary — History of the NSA Involvement
RELATED POST: KRYPTOS 30 Years Anniversary — SECTION I : A KEYED Vigenère Cipher [And why does the CIA lie so much about it?]
RELATED POST : KRYPTOS 30 Years Anniversary — SECTION III : A Transposition Cipher
RELATED POST : KRYPTOS Sculpture — Jim Sanborn : “This is the third and to be sure final clue.” [UPDATE : And then came a 4th clue!]
“The greatest secrets are always hidden in the most unlikely places.”
Roald Dahl (*)
The Minpins (1991)
UPDATE (November 3, 2025) — On the 35th anniversary of the Kryptos dedication at CIA Headquarters, Jim Sanborn’s biggest blunder yet finally revealed the sculpture’s last great secret.
Kryptos, Section 1, begins with the line: “It was totally invisible. How’s that possible?”
But this time, it wasn’t invisible at all. Sanborn’s most recent (and perhaps most ironic) mistake has exposed what he spent decades keeping hidden.
This is not without irony. Cryptography — no matter how secure from a mathematical standpoint — always breaks down because of human error. The legendary German Enigma code is testimony to that.
It all began, fittingly, in the archives. Two journalists — Jarett Kobek and Richard Byrne — discovered that Sanborn had quietly donated a trove of personal materials to the Smithsonian Institution’s Archives of American Art.
Among the notes, sketches, and cipher charts, they found something extraordinary: documents that effectively revealed the plaintext of Kryptos’s final section, K4. In other words, the answer to a 35-year mystery had been sitting in a public collection, waiting for someone to notice.
Sanborn, upon realizing the discovery, admitted he had made a “gigantic mistake.” The irony was brutal. For decades, cryptanalysts, codebreakers, and enthusiasts around the world had pored over every letter of Kryptos, chasing mathematical perfection.
And in the end, it wasn’t the cipher that cracked. It was the artist himself. A simple archival oversight, not a computational breakthrough, had undone one of the most famous unsolved codes in modern history.
As the dust settles, the lesson is as old as intelligence itself: no system is stronger than its weakest human link.
Whether it’s the operators of Enigma or an artist guarding his masterpiece, secrecy always falters not through machines, but through men.
RELATED POST : Crypto AG : Was Boris Hagelin Jr. Murdered by the CIA? [UPDATE : The Scandalous History of the Last Rotor Cipher Machine]
On this anniversary, Kryptos once again reminds us that the boundary between mystery and mistake is perilously thin — and endlessly fascinating.
P.S. — For the cryptographic purists: yes, the plaintext may now be known, but the encryption method used for K4 remains a mystery. The puzzle, as ever, isn’t entirely solved — just transformed, even if much of its enigmatic charm has faded.
End of UPDATE
UPDATE (November 3, 2024) — It has been 34 years, and, as the CIA reminds us, the fourth section (now referred to as K4) has not been broken.
According to the agency website, the code for the remaining 97-character message utilizes a more difficult cryptographic code.
End of UPDATE
“They will be able to read what I wrote, but what I wrote is a mystery itself.”
James Sanborn
Since its dedication on November 3 1990, there has been much speculation about the meaning of the four encrypted messages it bears.
The sculpture continues to be of interest to crypto-analysts, both amateur and professional, who are attempting to decipher the fourth passage.
The artist has so far given four clues to this passage.
RELATED POST: The KRYPTOS Sculpture — Jim Sanborn : “This is the third and to be sure final clue.” [UPDATE : And now, a 4th clue!?!]
In a piece published in CIA Studies in Intelligence, David Stein concluded:
“I hope I have inspired some people to study the Kryptos puzzle and to give it a try.
Even the parts of the code that already have been decrypted still have to be interpreted for their deeper meaning.
There are many pieces to be put together and many layers to be peeled away.”
In this series, I explain how various parts of this code were encrypted, who decoded them and how.
I will also keep you informed on the progress made in decoding the last part of this enigma.
Stay tuned!
Kryptos: The Unsolved Cipher of the CIA
REFERENCES
Kryptos — Wikipedia
Stein, David D. (1999). “The Puzzle at CIA Headquarters: Cracking the Courtyard Crypto” — Studies in Intelligence. 43 (1).
—
Roald Dahl (1916 – 1990) was a British author best known for his darkly imaginative children’s books — like Charlie and the Chocolate Factory, Matilda, The BFG, and James and the Giant Peach — as well as several macabre short stories for adults (Tales of the Unexpected).
Before becoming a writer, Dahl was a Royal Air Force pilot during World War II and later worked with British intelligence in Washington, D.C. — which adds a delightful twist of irony to the quote.
His quote — “The greatest secrets are always hidden in the most unlikely places.” — comes from The Minpins (1991), the last children’s book he wrote, published shortly after his death. It fits Kryptos perfectly: a secret hidden in plain sight.
=
KRYPTOS Week — Introduction : Sculpture Dedication Ceremony at the CIA (November 3 1990)
Intel Today 