Outsider artist James Hampton left behind an encrypted notebook and a sculpture bearing a few encrypted labels. When I was in Washington, D.C., recently, I took a video of both.

Blog reader Christof Rieber has sent me a potential solution of a major crypto mystery: the encrypted passages of Lady Gewndolen’s diary. Is Christof’s deciphering attempt correct?

In 1914, a man sent an encrypted postcard from Kiel to Hannoversch Münden. Contrary to all other encrypted postcards I know, this one was written with a typewriter.

Blog reader Norbert Biermann has recently solved a bigram substitution ciphertext consisting of 1346 letters – the shortest one ever broken. Here’s a 1000-letter ciphertext of the same kind.

In 1920, IRA member Patrick James McGuire received an encrypted Easter postcard. Does it contain a love message? Or is the content related to the Irish War of Independence?

In 1873, an unknown person published two encrypted advertisements in the Daily Telegraph. Can a reader break these cryptograms?

In 1916, a man living in Aschersleben, Germany, received an encrypted postcard. Can a reader decipher it?

In the end credits of the 2010 movie “Fair Game” some letters are marked. Do they spell out an encrypted message? Nine years after the release of the film, this question is still unanswered.

A picture of Arnold Schwarzenegger, taken at the set of “Conan the Barbarian”, shows an encrypted (?) text. Can a reader decipher it?

Today I’m going to present a 28 letter message that has been encrypted with a Playfair cipher. To my knowledge, such a short Playfair cryptogram has never been solved before.