In 1858, an unknown sender sent an encrypted letter from Salt Lake City to an unknown recipient. Can a reader break this cipher?

German painter Göbel left behind a notebook with about ten ciphertext passages and something that looks like a key. Can a reader solve this crypto mystery?

English actress Diana Dors left behind an encrypted message, which was deciphered years ago. Here’s another one, the solution of which is unknown.

Blog reader Gerry Haynaly has found five encrypted postcards that were mailed between two lovers in 1911. Here are all these cards, including the plaintexts and some interesting background information.

Edwin Emmanuel Bradford was an English poet known for his homoerotic verse. He left behind an encrypted message that is still unsolved.

My friend George Keller has provided me pictures of a coin that bears an encrypted inscription. Can a reader decipher it?

In 1877, US engineer Frank S. Baldwin received a patent for a cipher disk. Blog reader Matthias Brüstle has encrypted two plaintexts with this method. Can a reader break these?

In an online forum, two encrypted postcards from 1911 have been posted. Can a reader solve them?

For years, my readers and I have been wondering what’s behind the Cylob cryptogram, a printed booklet that contains strange symbols. Now I have learned about a similar work. The author of it is known.

An imprisoned murder suspect has tried to send an encrypted message to a friend. Can my readers help to break this ciphertext?