The Hidden History of Code Breaking: The Secret World of Cyphers, Uncrackable Codes, and Elusive Encryptions

Journalist, critic, and popular historian McKay (Secret Lives of Codebreakers) traces the increasingly sophisticated use and decryption of coded texts to wage and win wars, to woo lovers, and to conceal esoteric or scientific knowledge throughout the centuries. Each of the book’s 50 entries paints a picture of how a particular cypher was invented, used, or broken and the personalities behind these codes. McKay employs a broad definition of code to include translations of unknown languages or pictograms, artistic symbolism, alchemical conjecture, and scientific discoveries, in addition to the straightforward concept of a code as an intentionally obscured message. Nearly a third of the chapters are devoted to McKay’s particular expertise in the cryptography of the First and Second World Wars and of the 20th century in general, and these are the strongest sections. Each chapter concludes with a handful of word and number puzzles, which are only occasionally thematically connected to the specific codes discussed in the chapter. These pencil-and-paper games add an interesting element for readers but may pose problems for ebook users and shared library copies.