Three encrypted newspaper advertisements from 1879 are still unsolved. Can you decipher them?

An evelope found in a stamp album contains two encrypted messages. Can a reader solve them?

The Rohonc Codex is one of the most famous cryptograms in the world. But is it still an unsolved one? That’s difficult to say.

A sixth encrypted bottle post has been found in the river Alster in Hamburg. Still, nobody seems to have a clue what these strange messages mean.

The Dorabella cryptogram, an encrypted message left behind by British composer Edward Elgar, is one of the most famous crypto mysteries in the world. Here are two more crypto mysteries Elgar created. They have not received much attention so far.

Here’s a postcard that was sent from the Isle of Wight to London in 1905. Can a reader decipher it?

A workshop at HistoCrypt was dedicated to codes and nomenclators – for centuries the most popular kind of encryption. One of the topics discussed was a consistent terminology. Here is my suggestion. Perhaps, my readers can help to improve it.

Last year I reported on an encrypted inscription on a cigaret case from 1909. Though it looks like a simple substitution cryptogram that can be broken without much effort, it is still unsolved.

At the HistoCrypt 2018 I presented a poster about an analysis of the Dorabella Cryptogram. Here are the details of this work.

A text written by the legendary German author Arno Schmidt contains a series of numbers that might represent encrypted texts. So far, nobody has found the solution of these cryptograms.