Kryptos: The Cipher the CIA Can't Crack in Its Own Courtyard

2026-07-10 · Unsolved Ciphers · 8 min read

In a small courtyard outside the cafeteria at CIA headquarters in Langley, Virginia, stands a wave of copper rising out of a petrified tree. It is curled like a scroll caught mid-unfurling, pierced with roughly 1,800 letters. It is called Kryptos. It was dedicated in November 1990, and it carries four separate encrypted messages. Thirty-five years later, one of them has still never been read by anyone doing the work of decryption.

The artist was Jim Sanborn, a sculptor from Washington who was not a cryptographer. To learn the craft he worked with Ed Scheidt, a recently retired chairman of the Agency's own Cryptographic Center. Together they designed four ciphers and set them into the metal, in four sections that solvers came to label K1, K2, K3 and K4. Three of them were meant to be hard. The fourth was meant to be, for a while, impossible.

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