When Ricky McCormick's body was discovered in a Missouri cornfield in 1999, police officers discovered something unusual in his pockets: Two curious notes that appeared to be written in code. If McCormick had been murdered, as investigators suspected, they figured these cryptic clues might lead them to the culprit. Soon the FBI was involved.
It may seem strange that McCormick, a high-school dropout who spent most of his time on the street, could baffle the FBI's top cryptologists. But according to Jonathan Katz, an associate computer-science professor at the University of Maryland who teaches cryptography, amateur ciphers can be the most difficult to unlock.
When experts attempt to break a wartime code, they know the general context of the message. They know who's communicating with whom and what they're communicating about. But when it comes to rogue codes, cryptologists don't even know what language the cipher was written in.
If, that is, they have any meaning at all. "For a lot of these [ciphers], it's not clear whether they're even solvable," Katz explains. "They could be a hoax. You aren't guaranteed that there is even a solution at all."
Even so, the FBI has been flooded with calls in response to its posting. Special Agent Ann Todd says they've received more than 1,600 tips through the link on the FBI's website and about 325 letters via snail mail. "We're already following up on leads and coordinating with other agencies," Todd wrote in an email. But if no one manages to crack the messages, Ricky McCormick's notes may join an elite group of the world's most mystifying ciphers and codes.
Click here for a slide-show essay about some of the most enigmatic cryptographs that still elude the code breakers.
Editor's note: The headline on this article, "Cxjlrp Zfmebop," is a simple Caesar cipher in which every letter of the original headline is shifted three letters back in the alphabet. To decode it, you just go in reverse: C+3 is F, X+3 is A, and so forth.