For over three decades, the copper S-curve sculpture known as Kryptos has stood outside CIA headquarters in Langley, Virginia, holding four panels of encrypted text. Three panels have been solved, but the 97-character fourth panel (K4) has resisted all attempts by professional and amateur cryptanalysts. Now the mystery has a new owner—and a new process for would-be codebreakers.
The Auction and the Buyer
Artist Jim Sanborn, now 80, had grown tired of fielding incorrect guesses—many generated by AI—and sought to boost his retirement fund. In 2025 he auctioned the solution to K4 and K5 (an additional, unrevealed panel). The winning bid came from Paradigm, a crypto-focused venture capital firm led by a cofounder of Coinbase. The bid was nearly $1 million; Sanborn received $770,000. Paradigm’s Dan Robinson, who joined the firm in 2019, said the puzzle “fit a lot of our philosophy” and that owning Kryptos could help attract top talent.
How the Verification Works
Under Paradigm’s stewardship, the submission process has changed:
- Submission fee: $1 per guess (down from Sanborn’s $50).
- Hash verification: Submissions are run through the same hash function used to compress Sanborn’s secret message. If the resulting hash matches the stored hash, the guess is correct.
- Contests: Paradigm will hold increasingly difficult decoding challenges. The first to crack each will win $1,000.
- Prize for solving K4: Not cash, but “glory” and exclusive access to a video Sanborn pretaped for the successful codebreaker.
| Feature | Sanborn’s approach | Paradigm’s approach |
|---|---|---|
| Submission fee | $50 | $1 |
| Vetting | Sanborn alone | Paradigm, plus contests |
| Prize for solving K4 | None | Glory + video |
The Smithsonian Discovery
Just before the auction, researchers Jarett Kobek and Richard Byrne discovered that Sanborn had unintentionally included K4 plaintext in papers held at the Smithsonian Institution. Byrne photographed the holdings; Kobek spotted the plaintext. The pair agreed not to release it, and the Smithsonian locked down the archives. Kobek reiterated this week: “There will never be a moment in which the plaintext is published by me.”
Even Paradigm’s own team does not know the answer. Robinson told Steven Levy of WIRED that they have not looked at the sealed envelopes containing the solutions to K4 and K5.
What’s Next: K5 and Beyond
Sanborn has said that once K4 is solved, K5 will become solvable. Paradigm plans to publish the encrypted K5 and invite the public to crack it. Meanwhile, Sanborn has not fully let go. He may embed K5 in one of his “projection cylinders”—artworks that beam long text onto surfaces. He says, “I could embed K5 in that. It would be in there, waiting.” So the puzzle endures, with Paradigm as the official keeper and Sanborn still fielding the occasional email—not quite ready to shut down that channel.
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