Introduction to ciphers and substitution. Alice and Bob and Carl and Julius: terminology and Caesar Cipher ; The key to the matter: generalizing the Caesar Cipher ; Multiplicative ciphers ; Affine ...

Introduction: A revolutionary cipher -- Cryptology before 1500: a bit of magic -- The black chambers: 1500-1776 -- Crypto goes to war: the American Revolution -- Crypto goes to war: the American Civil ...

Since ancient times, people have relied on cryptography, the art of writing and solving coded messages, to keep their secrets secure. In the fifth century, enciphered messages were inscribed on ...

The 35-year-old saga of Kryptos, an enigmatic sculpture containing four encrypted messages outside the CIA headquarters, just ...