Christie-Stamps-bar

The British mail authority has issued a set of six stamps devoted to crime writer Agatha Christie. The stamps are packed with steganographic messages. Can you find them?

World-War

A British censorship manual from WW2 gives an overview on message hiding techniques. Some of the examples given are messages hidden in letters from prisoners of war.

LeRay-bar

A researcher from Liechtenstein has asked me for help. She has encountered three partially encrypted letters from the early 19th century. Can a reader decrypt them?

Monoco-bar

Today’s post is about a book with strange illustrations written in an unknown script. This book still waits to be deciphered. And no, I’m not talking about the Voynich manuscript.

Janes-Tenzer-bar

130 years ago, Briton Alfred Janes published a self-invented encryption method along with a challenge cryptogram. My blog readers could solve this tricky mystery.

Kortum-Cryptogram-bar

A crypto book published in 1808 contains an exercise cryptogram. The solution is not given. Can you find it?

Postcard-San-Francisco-bar

Three encrypted postcards from San Francisco are discussed in an internet forum. The solutions still seem to be unknown. Can a reader of this blog help?

Sauniere-Cryptogram-bar

Bérenger Saunière (1852-1917) was a French preacher, who has become famous among conspiration theorists and Dan Brown readers. A cryptogram he allegedly left behind is said to have led to a treasure.

Kaliningrad-Cryptogram-bar

An encrypted bottle post was found in Kaliningrad, Russia, in 2015. As it seems, the cleartext is still unknown. Can a reader break this unusual cryptogram?