My readers have shown that a Playfair cryptogram consisting of only 50 letters can be broken. Here’s a Playfair challenge with only 40 letters. Can you break it, too?

The four cryptograms contained in a book partially written by famous German author Arno Schmidt are among the most interesting I have seen recently. My readers have provided some additional information about them.

The hijacking of a Boeing 727 aircraft in 1971 is considered one of the most spectacular crimes in the history of the USA. After the hijacker had left the plane with a parachute, he was never seen again. According to a recent newspaper article, a deciphered cryptogram might now solve this mysterious case.

18-year-old chemistry student Paul Rubin was found dead with a cyanide poisoning in 1953. In his possession police found an encrypted message. This cryptogram has never been deciphered.

English actress Diana Dors left behind an encrypted message. This cryptogram allegedly leads to two million pounds.

Today’s crypto mystery is about a postcard written to a noblewoman in 1914. Can a reader solve it?

Last year, press reports said that the Devil’s Letter, a notable Italian cryptogram, was solved. It was a good example of how fake news are born.

Two encrypted letters written by Spanish king Ferdinand II of Aragon baffled historians. Thanks to secret service codebreakers, the mystery is now solved.

Just like every end of year, I am awarding the Golden Alice for outstanding achievements in the field of crypto history and codebreaking.

Four episodes of the Zodiac Killer documentary on HISTORY have aired now. The fourth one ended with Craig Bauer saying that he has broken Z340. Will episode 5 tell us the solution?