In 1906 an unknown person sent an encrypted postcard from St. Petersburg, Russia, to Vaasa, Finland. Can a reader decrypt it?
“Who can solve this encrypted book?”, I asked five weeks ago. Blog reader Klaus Tappeiner from South Tyrol, Italy, could. His solution of the Tengri 137 cryptogram is absolutely ingenious.
US citizen David Rayburn killed his wife, his step-son, and himself. Years later, an encrypted text allegedly written by him emerged. This cryptogram is unsolved to this day.
Two years ago a detectorist found an encrypted note hidden in a WW2 bullet in central Italy. Despite many tries this cryptogram is still unsolved.
Here’s my latest publication: a free brochure about cryptography and codebreaking especially for school children. Thanks to a great graphic artist it looks very professional.