Between 1945 and 1954, the staff of Spanish prisons used an encryption method based on a cipher slide and a table. Can my readers help to understand how this system worked?

In 1905, a woman in Dorchester, UK received an encrypted postcard. Can a reader decipher it?

It took over three months and 55 comments on my blog. Now, Magnus Ekhall and Patrik Almqvist have solved the Ivory Coast cryptogram. Their work is based on a discovery by Christoph Tenzer.

The solution of an anamorphic I reently found online might be considered obscene. I’m going to cover it in this article anyway.

An encrypted message, created probably in 1932, has been found on the back of a photograph. Can a reader decipher it?

Ross Ulbricht was condemned to two life sentences plus 40 years for operating the darknet market website Silk Road. Here’s an interview his mother gave me.

In 1902, a female aristocrat living near Bayreuth, Germany, received an encrypted postcard. Can a reader decipher it?

Can a reader decipher an encrypted message from Thuringia, Germany?

Here’s a selection of news related to cryptology and its history.

NKRYPT, located in Canberra Australia, is a set of eight sculptures that bear encrypted inscriptions. Today, I’m going to introduce one of these: the PVL cryptogram.