Here’s an telegram from 1952 that might have been encrypted in a code. Can a reader find out which codebook has been used and decipher the message?

The cover of a well-known cryptography book shows a 16-letter cryptogram. Its solution is unknown.

An encrypted diary posted on Reddit last year is still unsolved.

About a century ago, a young man from Austria wrote an encrypted postcard with a sad motive to his lover. Can a reader decipher this cryptogram?

Gravestones bearing an encrypted or hidden message are rare, and they have a morbid charm. On Reddit, I have found one I hadn’t known before. I have no idea where it is located and what the inscription means.

In 1888, an encrypted advertisement was published in the “Daily Chronicle”. Can a reader decipher it?

Here’s another cryptogram that can be seen in a TV series. Can a reader break it?

David Oranchak, a leading expert on the cryptograms of the Zodiac Killer, has published a video. It’s a must-see for everybody interested in this case.

The Voynich Manuscript is the most famous unsolved crypto mystery in the world. For this reason, I put it at the first position of my top 50 list.

No footage taken at Bletchley Park during WW2 is known to exist. However, an eleven-minute silent film recorded at an outstation nearby has now been published.