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 four cryptograms contained in a book partially written by famous German author Arno Schmidt are among the most interesting I have seen recently. My readers have provided some additional information about them.

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.

Gestern ist in Rumänien die 59. Internationale Mathematikolympiade zu Ende gegangen. Es gab zwei Schüler mit voller Punktzahl, nämlich Agnijo Banerjee aus Großbritannien und James Lin aus den USA. (Bester Deutscher war Jonas Walter aus Rostock.) Agnijo Banerjee ist neben seinen Erfolgen bei Mathematikolympiaden auch bereits als Autor tätig. Mit dem Astronomen David Darling hat…

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

Hallo liebe Labernde ;), nach dem der letzte offene Laber-Thread (OLT 3) inzwischen über 1000 Kommentare angesammelt hat und langsam etwas schwerfällig lädt, gibt es heute und hier einen neuen OLT, auf dem Ihr sehr gerne und wie gewohnt Eure Gespräche fortsetzen könnt. Also, setzt Euch, nehmt Euch ‘nen Keks und laßt uns ‘ne Runde…

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.

The movie “Wanted” (starring Angelina Jolie and Morgan Freeman) contains a steganographic message. Can a reader decipher 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.