A blog reader has told me about strange email messages he receives occasionally. Does a reader know what they mean?
A blog reader has sent me a picture of a medal that bears unusual inscriptions on both sides. Can a reader make sense of these?
Crypto collector Glen Miranker has come across an interesting strip cipher device. He can’t find any information about it. Can a reader help?
A Reddit user recently purchased a cryptologic document from the Second World War. Can a reader make sense of it?
“The Professional”, a French movie with Jean-Paul Belmondo, involves an encrypted telegram. The plaintext and the ciphertext are known. Is the encryption real?
A telegram sent by a British colonel in 1916 still waits to be solved. The encryption method used might be a letter-pair substitution.
Blog reader Christoph Tenzer has solved the Rubik’s Cube challenge I introduced last October. His work is an amazing act of cryptanalysis.
The encrypted inscription on the Kryptos sculpture is one of the most famous crypto mysteries in the world. Recently, a TV documentary about Kryptos was made. Here’s my making-of report.
In 1910, a man living in Bedford, Ohio, received an encrypted postcard. Can a reader decipher it?
In 1909, a woman living in Toledo, Ohio, received an encrypted postcard. Can a reader decipher it?