In 1991, an unknown person sent a number of letters to the presenter of the TV show “America’s Most Wanted”. The anonymous writer claimed to have committed 23 crimes. Some of the letters were encrypted in a similar style as the Zodiac Killer messages.

The year 2018 has its first alleged Voynich Manuscript solution. This time, two researchers say that Hebrew is the language the enigmatic book was written in. What’s behind this new hypothesis?

If you understand German you should listen to this radio broadcast about the Voynich Manuscript – including an interview with me. And then, there are two articles I have published recently.

Two encrypted newspaper advertisements from 1875 puzzle cryptologists. Is the first ad the key to the second?

In 2013 George Lasry broke a ciphertext many had considered unbreakable. In the wake of this success, a few crypto experts created a similar challenge with an even higher level of difficulty. Is this one unbreakable? So far, nobody has solved it.

Israeli codebreaker and reader of this blog, George Lasry, has solved cryptogram #42 from my top 50 list.

The Codex Seraphinianus is an unusual book, a beautiful artwork, and an unsolved crypto mystery. It’s the Voynich Manuscript of the 20th century.

US military technician Brian Regan was sentenced to life in prison, after he had tried to sell secret information to foreign governments. He used a few interesting ciphers.

This is the shortest cryptogram I have ever introduced on this blog: 46, 9, 4-57, 3, 5. Can a reader decipher it?

A new internet mystery game, named “Red Triangle”, has surfaced. Meanwhile, six chapters with crypto puzzles and other challenges are known to exist. Is the Red Triangle the new Cicada 3301?