Kryptos Kryptos is a sculpture by the American artist Jim Sanborn located on the grounds of the Central Intelligence Agency (CIA) in Langley, Virginia. Since its dedication on November 3, 1990, there has been much speculation about the meaning of the four encrypted messages it bears. Of these four messages, the first three have been solved, while the fourth message remains one of the most famous unsolved codes in the world. The sculpture continues to be of interest to cryptanalysts, both amateur and professional, who are attempting to decipher the fourth passage. The artist has so far given three clues to this passage. Description The main part of the sculpture is located in the northwest corner of the New Headquarters Building courtyard, outside of the Agency's cafeteria. The sculpture comprises four large copper plates with other elements consisting of water, wood, plants, red and green granite, white quartz, and petrified wood. The most prominent feature is a large vertical S-shaped copper screen resembling a scroll or a piece of paper emerging from a computer printer, half of which consists of encrypted text. The characters are all found within the 26 letters of the Latin alphabet, along with question marks, and are cut out of the copper plates. The main sculpture contains four separate enigmatic messages, three of which have been deciphered. In addition to the main part of the sculpture, Jim Sanborn also placed other pieces of art at the CIA grounds, such as several large granite slabs with sandwiched copper sheets outside the entrance to the New Headquarters Building. Several morse code messages are found on these copper sheets, and one of the stone slabs has an engraving of a compass rose pointing to a lodestone. Other elements of Sanborn's installation include a landscaped garden area, a fish pond with opposing wooden benches, a reflecting pool, and other pieces of stone including a triangle shaped black stone slab. The name Kryptos comes from the ancient Greek word for "hidden", and the theme of the sculpture is "Intelligence Gathering". The cost of the sculpture in 1988 was US $250,000 (worth US $501,000 in 2016). Encrypted messages The ciphertext on the left-hand side of the sculpture (as seen from the courtyard) of the main sculpture contains 869 characters in total: 865 letters and 4 question marks. In April 2006, however, Sanborn released information stating that a letter was omitted from this side of Kryptos "for aesthetic reasons, to keep the sculpture visually balanced". There are also three misspelled words in the plaintext of the deciphered first three passages, which Sanborn has said was intentional, and three letters (YAR) near the beginning of the bottom half of the left side are the only characters on the sculpture in superscript. The right-hand side of the sculpture comprises a keyed Vigenère encryption tableau, consisting of 867 letters. One of the lines of the Vigenère tableau has an extra character (L). Bauer, Link and Molle suggest that this may be a reference to the Hill cipher as an encryption method for the fourth passage of the sculpture. Sanborn worked with a retiring CIA employee named Ed Scheidt, Chairman of the CIA Office of Communications, to come up with the cryptographic systems used on the sculpture. Sanborn has revealed that the sculpture contains a riddle within a riddle, which will be solvable only after the four encrypted passages have been deciphered. He has given conflicting information about the sculpture's answer, saying at one time that he gave the complete solution to the then-CIA director William Webster during the dedication ceremony; but later, he also said that