It is one of the world's most famous unsolved codes whose answer could sell for a fortune—but two US friends say they have already found the secret hidden by Kryptos. The S-shaped copper sculpture has baffled cryptography enthusiasts since its 1990 installation on the grounds of the CIA headquarters in Virginia, with three of its four messages deciphered so far. Yet K4, the final passage, has kept codebreakers scratching their heads. The sculptor Jim Sanborn, 80, has been so overwhelmed by guesses that he started charging $50 for each response. In August, Sanborn announced he would auction the 97-character solution to K4 as he no longer had the "physical, mental or financial resources" to maintain the code. In a sign of wide interest in Kryptos, which has inspired cultural figures including The Da Vinci Code author Dan Brown, the code's solution is on course to fetch more than $240,000 in a sale due to end this Thursday. So when two friends announced in October they had uncovered the last message held by Kryptos ("hidden" in ancient Greek), it invoked fury and concern from the auction house and Sanborn.
It is one of the world's most famous unsolved codes whose answer could sell for a fortune—but two US friends say they have already found the secret hidden by Kryptos.
The Kryptos sculpture, created by Jim Sanborn and installed at the CIA grounds in Langley, Virginia, has three of its four inscriptions deciphered, leaving K4 as the elusive final passage. Sanborn’s decision to auction the 97-character final solution underscored both the mystery’s allure and the controversy around ownership and disclosure. The auction is expected to attract considerable interest given Kryptos’s cultural footprint and its influence on cryptography conversations worldwide.
The S-shaped copper sculpture has baffled cryptography enthusiasts since its 1990 installation on the grounds of the CIA headquarters in Virginia, with three of its four messages deciphered so far. Yet K4, the final passage, has kept codebreakers scratching their heads.
Sanborn, who has publicly discussed the pressures of solving or revealing the puzzle, announced the plan to auction the K4 solution because he felt unable to sustain the project any longer. The auction’s outcome could set a precedent for discussions about authorship, ownership, and the monetization of puzzle solutions embedded in art. Kryptos has long captivated readers and investigators, including figures in popular culture who have cited its enduring mystique as a source of inspiration and debate.
In August, Sanborn announced he would auction the 97-character solution to K4 as he no longer had the "physical, mental or financial resources" to maintain the code.
Two late-breaking developments added another layer of urgency: the publicized claim by two friends that they had deciphered the final message, and the resulting scrutiny from the auction house and Sanborn himself. The dynamic surrounding Kryptos—between artistic creation, cryptographic challenge, and market interest—continues to fuel discussion about whether a solved artifact should remain public knowledge or be privatized through sale.
So when two friends announced in October they had uncovered the last message held by Kryptos ("hidden" in ancient Greek), it invoked fury and concern from the auction house and Sanborn.
Author’s note: The story sits at the intersection of art, cryptography, and market dynamics, illustrating how a long-standing puzzle can evolve into a contested asset that tests ideas about public legacy versus private ownership.
Author’s résumé: The Kryptos saga blends cryptographic mystery with art-world dynamics, highlighting how unresolved puzzles can become valuable cultural artifacts and spark debates about access, ownership, and the potential ethics of monetizing hidden knowledge.