Image courtesy of the Central Intelligence Agency.
Situated in a closed off courtyard of the CIA headquarters in Lanley, Virginia, a very unique sculpture exists. Named "Kryptos," and created by sculptor James Sanborn, it contains a hidden message 865 characters in length, encrypted using classical means. However, that's not to say it isn't extremely hard to decode.
The idea for creating "Kryptos" came in the late 80s, out of a General Services Administration initiative to improve the appearance of government buildings, such as the CIA headquarters.
Ed Scheidt, a CIA master of encryption, created the coding system used in the sculpture. According to one of the people trying to break it, there are multiple layers. The solution to some of it is another puzzle. (This is referred to as superencipherment.) In fact, the encryption system had stumped everyone who tried to decrypt it for years. However, now several people have come close to breaking the code.
One man, David Stein, 38, has spent over 400 hours trying to crack the code of Kryptos. He has succeeded, for the most part; all but the last 97 characters have succumbed to him. The creator used a much stronger method of encryption for those 97 characters than for the ones before it.
Specifically, the end of the message uses a transposition cipher, which is where the letters themselves aren't changed; just their relative positions. The message already cracked uses a less sophisticated form of the substitution cipher, where letters are substituted for other letters.
Several other people have also come close to solving the encryption. One man, working on the Internet, as well as three employees of the NSA have solved the encryption to the same point.
Other than a piece of paper locked in a safe in the office of the CIA director, and the head of the artist, the rest of the message remains hidden. The artist has consistently refused anybody's request for advice on how to solve it. However, Scheidt has confirmed that the analysts are on the right track.
If you want to try breaking the code yourself, you are welcome to examine, analyze, and crack. Here is the encoded text.If you're feeling especially greedy, you can instead look at the part of the message already deciphered. The message is quite cryptic (no pun intended).