The “Playfair for Three” is a manual cipher that works similar as the Playfair, but is based on trigraphs instead of digraphs. Can you solve a challenge cryptogram that has been made with this method?
Ignaz Meyer, a Bavarian teacher and town writer, wrote an encrypted diary. The content of this joural gives interesting insights into the life of a 19th century individual who had a drinking problem and was not very successful in his job.
An anamorphic is a puzzle based on a special kind of secret writing. Here are two postcards with anamorphic motives. Can you decrypt them?
The Bank of England has announced that Enigma cryptanalyst Alan Turing will appear on the new £50 banknote.
Substituting letter pairs (also known as bigrams or digraphs) is an encryption method invented in the 16th century. Can you break a new challenge I have made?
In March, I blogged about a TV documentary about the Kryptos sculture produced by CNN. It has now aired and is available on Youtube.
Blog reader Eugen Antal has found a beautiful chronogram in a Slovak archive. Can a reader decode it?
In the 19th century, a series of over 40 encrypted ads was published in a British newspaper. Can a reader decipher them?
Fort Meade, a United States Army installation known as the home of the NSA, has launched a new logo, which bears an encrypted message. Can a reader decipher it?
At the HistoCrypt in Mons I took a ten minutes video. Here it is.