A reader from the Philippines has asked me for help. Can somebody solve the crypto puzzle he is currently working on?


An M4 Enigma from World War II has set a new world record price at a Christie’s auction in New York.


The Masked Man, a German serial killer, was arrested in 2011. Police couldn’t decipher his encrypted storage devices. Now he has revealed his encryption passwords.


Once again, the secret of the world’s most mysterious manuscript has been unlocked. This time the alleged solution comes from Russia. Does this one make more sense than the many others published before?


For centuries nomenclators were the most popular kind of encryption. Still today messages enciphered with a well-designed nomenclator are hard or even impossible to break.


An inscription found on the inside of an old fiddle has never been deciphered.


In one of his books British priest and novelist Sabine Baring-Gould (1834–1924) published a short cryptogram. Can a reader solve it?


In 1906 an unknown person sent an encrypted postcard from St. Petersburg, Russia, to Vaasa, Finland. Can a reader decrypt it?


Pietro Giannone (1791–1872), an Italian poet and patriot, left behind an encrypted poem filling a whole book. After nearly 150 years, mathematics teacher Paolo Bonavoglia broke the encryption.


In the 1950s the Germans used a unique crypto device named “Violine”. I have always wondered what it was used for. In a book about espionage I found the likely answer.