A few years after the Zodiac murders, an unknown person sent a letter to an address in Albany, NY, claiming that he was the Zodiac Killer and that he intended to start killing again. A few lines of this letter are encrypted. The cleartext is unknown.

During the Second World War, an unknown person stuck sheets with seemingly random letter sequences into a book. The meaning of these letters is unknown.

In the 2006 British-American mystery thriller “The Prestige” a stage magician keeps an encrypted  journal. Some passages of it can be seen in the movie. Is it possible to decipher them?

Edgar Allan Poe once asked the readers of a magazine to send him encrypted messages. He could break all of them, except two.

US standardization authority NIST has published the algorithms that participate in the Post-Quantum Crypto Competition. No fewer than 69 crypto systems enter the race.

A Reddit user has found an encrypted message written in a dictionary. Can a reader break this cryptogram?