In 1854, Sir Charles Wheatstone invented the cipher known as "Playfair," named for his friend Lyon Playfair, first Baron Playfair of St. Andrews, who popularized and promoted the cipher.

A block cipher is a symmetric-key cipher that breaks a plaintext message into segments of ... Any method of key distribution, including public-key cryptography, can be used. To save this book to your ...

Inside, you’ll find a cipher machine sided by a set of lettered code reels and a locked door that requires a code. Your task is to use the documents and the code wheels in the room to decipher ...