Now that the LCS35 time-lock puzzle has been solved, cryptographer Ron Rivest has published a new challenge of the same kind. This time, he estimates that it’s going to take 15 years to find the solution.

The Czech Pirate Party has hidden a short message, a so-called acrostic, in the Czech EU election ballots. Pranks like these have a long tradition.

Blog reader Christof Rieber has solved the Ghostemane cryptogram, a crypto challenge published by a US music magazine. Here’s how he found the solution.

I’m looking forward to HistoCrypt 2019 (June 23-26 in Mons, Belgium). Among the speakers are many readers of this blog.

German comedian Jan Böhmermann announced that he would present something “special” in his TV show. A steganographic message indicated that there was a relationship to the Ibiza affair. The truth proved much less spectacular.

A Munich auction house is going to sell an SG-41 (Hitler mill) at auction. Blog reader Markus Sperl has been on site and has provided me a few pictures of the machine.

A recently published paper introducing an alleged solution of the Voynich manuscript has received many critical comments. The negative feedback has caused the university the paper author works for to retract a press release .

Singer and rapper Ghostemane has published a crypto challenge in a US music magazine. Can a reader solve it?

Here’s an encrypted postcard from the early 20th century, which was sent to a young woman in Landreville, France. Can a reader decipher it?

In a well-known codebreaking book from the 1930s, a Playfair-encrypted message with a (probably fictive) background story is provided. Can a reader break this cipher?