In a scene of the TV series Twin Peaks a flickering air plane window seems to hide some code. Can a reader solve it?


In the end credits of the movie Fair Game (2010) some letters are marked. Blog reader Rossignol has now provided me screenshots that are very helpful for studying this code.


The Peralta Stones are a set of engraved stones. Some people believe they indicate the location of a lost gold mine.


A crypto book published in 1939 contains an excercise cryptogram. Many have tried to solve it, but the solution is still unknown.


British private detective Ignatius Pollaky (1828-1918) published a number of encrypted newspaper ads. Some of them have never been solved.


Bruno Borges, a Brazilian student who has mysteriously vanished from his home, left behind numerous encrypted notes. Now a Brazilian newspaper reports on new activities in this case.


Crypto history expert Prof. Gerhard Strasser once wanted to test if a musical cryptogram from the 17th century really sounded like music. Here’s the result.


Participants of the International Students’ Olympiad in Cryptography have to solve a number of tough crypto challenges. Here are a few of the nicest ones. Can you solve them?


A German memorial coin minted in 2011 bears a hidden code. Maybe my readers can help me to find out more about it.


Earlier this year I blogged about Printer Identification Codes, which are one of the IT world’s best-kept secrets. As it seems, a US secret service has now used this technology to track down a whistleblower.