Two manually encrypted notes found in a murder victim's pocket are causing the FBI sleepless nights. The authorities believe the notes could indicate who the murderer is. The murder was committed 12 years ago, but the FBI still has not been able to decrypt the notes – not even with help from the American Cryptogram Association, a group of hobby cryptologists.

No one even knows how the cryptology found on the victim works. The FBI has therefore published the notes on its web site. At first glance, it seems that encryption is based on transposition and substitution, but the matter cannot be that simple, for the FBI's Cryptanalysis and Racketeering Records Unit (CRRU) has also failed to crack the code.

Letters, numbers, and punctuation: the FBI has failed to decrypt these notes by conventional means. Modern cryptography procedures require tools that 41-year-old murder victim Ricky McCormick did not yet have. McCormick's family says he made encrypted notes even as a youth.

Now, the FBI wants to see those notes because it is not making any progress with the known methods of crypto-analysis. But the FBI says that even if the notes do not reveal anything once they are encrypted, we will have at least learned something new about encryption.