Three weeks ago I introduced Ernest Rinzi’s encrypted journal – one of the most spectacular cryptograms I have ever seen. London-based codebreaker Tony Gaffney has now broken a large part of the cipher. Maybe a reader fluent in Italian can fill in the gaps and supply a translation.

The greatest European crypto history event ever will take place in June 2018. The Call for Papers has now been published.

A few weeks ago I introduced two unsolved encrypted letters from the Thirty Years’ War. Scientist and blog reader Thomas Ernst has deciphered them now.

Encryption technology of the Cold War is a very interesting, yet also difficult topic. Much of the relevant information is still classified. This is also the case for a simple German encryption device named ACP 212. Does a reader know anything about it?

In July 1918 a British officer, who was imprisoned in Turkey, sent a letter to a girl in London. This letter contains a hidden message. Can somebody help me to find out what kind of code was used?

Blog reader Martin Lohner has created a piece of music that hides a message. Can you find it?

A PhD student has come across an encrypted message written by a 19th century anarchist. Can a reader break this encryption?

A fourth encrypted bottle post has been found in the river Alster in Hamburg. Still nobody seems to have a clue what these strange messages mean.

Here are ten criminals who used encryption – including the notorious Unabomber.

Here are episodes 21 to 25 of my comic strip “Chief Security Officer”.