J K Rowling’s The Hallmarked Man features the Pigpen Cipher, a centuries-old code once used by Freemasons and revolutionaries ...

Some ciphers have simple keys, others, complex ones. The key for a cipher used by Augustus Caesar, some 2,000 years ago, was simple enough: The receiver just had to shift the alphabet one position.

Object Details Author Churchhouse, R. F Contents 1. Introduction -- 2. From Julius Caesar to simple substitution -- 3. Polyalphabetic systems -- 4. Jigsaw ciphers -- 5. Two-letter ciphers -- 6. Codes ...

The value is the cipher key. For example, the code IBDLBEBZ is encrypted with a Caesar Cipher. It doesn’t take very much to see that a shift of “1” would reveal HACKADAY.

Joshua Holden shows how mathematical principles underpin the ways that different codes and ciphers operate, as he focuses on both code making and code breaking. He discusses the majority of ancient ...