CRAQUEREZ, SAUKNOTEN, INCLEMENTE – these are three words from an encrypted message sent from Manila to Washington in 1898. Can a reader break this cryptogram?


The biannual Symposium on Cryptologic History organized by the NSA is the most important crypto history event in the world. Here’s my report on the 2017 edition.


Two years ago an encrypted bottle post was found in Kaliningrad, Russia. Can a reader break this cryptogram?


William and Elizebeth Friedman, two of history’s greatest codebreakers, published a book dubunking the idea of hidden codes in the works of Shakespeare. However, the book itself contains a code. Can you find it?


Cardsharping with steganography is a popular motive on classical paintings. Here are five examples.


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?