A postcard from 1906 is written in a combination of Morse code, numbers, and letters. Can a reader solve this unusal cryptogram?
Two years ago I blogged about an encrypted certificate, which was found in the wall of a house. Nobody could solve this cryptogram. So, it’s time to have a second look at it.
A blog reader has sent me pictures of a cigaret case from 1909, which bears an encrypted inscription. Can a reader decipher this cryptogram?
In a little known book I found a story about encrypted notes from 1905, including a diary. Can my readers support me with finding out more about these documents and decrypting two paragraphs?
The Polish city of Poznań offers a number of interesting Enigma sights. Now, a new one is planned: an Enigma information center. Suggestions from my readers on how this place might look like are highly welcome.
A Freemason ritual description from the 19th century is encrypted in two different ciphers. Can a reader find the solutions?
The first episode of the new HISTORY TV series about the Zodiac Killer has aired. It announced the biggest break-through in cryptology in the last 50 years.
Gary Klivans, a specialist in breaking gang encryptions, has been featured many times on this blog. Now, he has given an interesting interview to scientific magazine Nautilus.
The TV channel HISTORY is launching a series about the Zodiac Killer. Allegedly, a solution to one of the famous cryptograms created by this serial killer will be presented.
Codebreaker genius William Friedman needed 15 minutes to break this cryptogram. His wife Elizebeth, an outstanding cryptanalyst in her own right, needed 17 minutes. How fast can you solve it?