For 35 years, a mysterious sculpture outside the CIA headquarters in Langley, Virginia, has baffled the world's best codebreakers. Known as Kryptos, the copper plate carved with 1,735 letters contains four encrypted messages, three of which have been solved. The final section, K4, remains a secret known only to its creator, artist Jim Sanborn.
Now, Sanborn is auctioning off the solution to K4, along with the coding charts used to create it. Expected to fetch between $300,000 and $500,000 (£223,570–£372,600), the buyer will be free to reveal the secret or keep it hidden. Sanborn said: 'The burden of knowledge passes from artist to keeper.'
Kryptos was commissioned in 1990 for the CIA's new headquarters. Sanborn enlisted Edward Scheidt, the retiring chairman of the CIA's Cryptographic centre, to design four progressively difficult ciphers. The first three used a Vigenère tableaux, a common encryption method. The first passage reads: 'Between subtle shading and the absence of light lies the nuance of iqlusion.'
The third section took eight years to crack, but K4 remains unsolved despite three clues released by Sanborn. The encrypted text reads: OBKRUOXOGHULBSOLIFBBWFLRVQQPRNGKSSOTWTQSJQSSEKZZWATJKLUDIAWINFBNYPVTTMZFPKWGDKZXTJCDIGKUHUAUEKCAR. The auction offers a rare chance to unlock one of the world's most enduring mysteries.
