Last week I presented the mystery of an encrypted note found in an antique silk dress. Has the codebook used now been found?


A young man, who had disappeared from his home in California, sent an encrypted message from Israel to his parents. This cryptogram has been unsolved for over four decades. Can a reader decipher it?


A letter sent by some Oscar P. Schaub in the 1920s looks like it has been written in Hebrew or a similar script. However, even Hebrew experts can’t read it. Is it encrypted in a clever cipher?


Yesterday and today about 25 European cipher history experts have met at Smolenice Castle in Slovakia. It was a great event.


There are hundreds of places in the world that are worth seeing for people interested in cryptology. This is why I have created a list of cryptographic sights. I hope, my readers can help me to extend it.


A postcard from 1910 is encrypted in three different ciphers. Can a reader solve this unusual cryptogram?


In 2014 Maryland-based costume collector Sara Rivers-Cofield discovered an encrypted note in an antique silk dress. This cryptogram is unsolved to date.


Italian cryptologist Luigi Sacco left behind a text encrypted with a Fleissner grille. Paolo Bonavoglia and Bart Wenmeckers, both readers of this blog, solved it.


The Masked Man, a German serial killer, was arrested in 2011. Police couldn’t decipher his encrypted storage devices. Now he has revealed his encryption passwords.


In a British censorship manual from WW2 two pictures containing hidden messages are displayed. My readers have now found at least a part of the solutions.