A newspaper article published earlier this year covers an encrypted message written by a supermax-prison inmate. The content of this note is about steganography.

A German news magazine has published an encrypted message from a German 1970s terrorist. The solution is known, but some of the details remain unclear.

Five years ago I asked my readers for information about seven little-known cryptograms created by criminals. Meanwhile, I’m a little wiser, but I still would like to know more about some of these encrypted messages.

In 2016 several Brazilian newspapers reported on two encrypted letters sent by imprisoned members of the criminal organization PCC. Can my readers help to decipher the letter excerpts that are publicly available?

Nathan Allen from Maryland died from a bomb that exploded in his car. The murderer was found with the help of a steganographic technique.

Victor Lustig (1890-1947), “the man who sold the Eiffel tower”, was a successful con artist. In 1935, master codebreaker William Friedman was asked to break an encrypted message Lustig had in his possession.