Kryptos is a sculpture that artist Jim Sanborn created in 1990 for the CIA headquarters in Langley Virginia. The artwork contains four cryptographic puzzles and only three have been solved so far. The dustjacket to The Da Vinci Code contains subtle references to the puzzle and it apparently will play a role Dan Brown's next book, the Solomon Key. From a Wired News report:
The CIA required Sanborn to write the solution down and present it to (former CIA director William) Webster so the agency wouldn't be embarrassed if the sculpture turned out to contain a message that was pornographic or critical of the agency. Sanborn gave officials an envelope with a wax seal. But Sanborn said he didn't give Webster the whole story.
"Well, you know, I wasn't completely truthful with the man," Sanborn said, laughing. "And I'm sure he realizes that. I mean that's part of trade craft, isn't it? Deception is everywhere….
