Dive into the enigma of Kryptos, a CIA sculpture hiding an unsolved code, and meet Elonka Dunin, a dedicated cryptanalyst working to crack it.

BLOCK: Jim Sanborn is the artist who created the Kryptos sculpture at the CIA headquarters in Langley, Virginia. Elonka Dunin is a game developer and a co- moderator of a Yahoo group devoted to ...

Mr. SANBORN: Thank you for having me. KELLY: That's the sculptor Jim Sanborn, talking about his decision to drop a clue to the mystery of the Kryptos sculpture, at the CIA in Langley, Virginia.

It is perhaps one of the CIA s most mischievous secrets. Kryptos, the sculpture nestled in a courtyard of the agency s Virginia headquarters since 1990, is a work of art with a secret code embedded in ...

When NOVA first reported on Kryptos in a 2007 NOVA scienceNOW segment, three of the sculpture's four puzzles had been solved. But K4, a passage only 97 characters long, remained elusive.

For 15 years, a bronze sculpture in the CIA's courtyard has taunted amateur and professional code-breakers alike. Kryptos is a copper wall that features four long coded passages.