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?

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.

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?

Today I’m going to introduce two encrypted postcards I have recently found on a postcard blog. They are completely different from each other, but both still wait to be solved.

Russian teenager Vladimir Vinnichevsky (1923-1940) murdered several children and left behind an encrypted note. Can a reader make sense of it?

In 1904, a Bavarian theology student received a postcard written in a shorthand. Can a reader decrypt it?

Albrecht von Wallenstein is one of the most important military leaders in European history. A partially encrypted letter he wrote in 1616 is still unsolved.

In the early 20th century, an unknown person sent three encrypted postcards to a woman in Heidelberg, Germany. Can somebody break these cryptograms?

Henry Debosnys (1836-1883), a convicted murderer, left behind four cryptograms, which  are unsolved to date. Breaking them could shed light on the many mysteries that surround this case.

In one of his lectures, master codebreaker William Friedman once mentioned two encrypted telegrams. He knew the  solutions, but he didn’t reveal them. Can a reader break these encrypted messages?