The Code Book – Simon Singh

Simon Singh makes geek as delightful as watching a gripping television series- one can binge read through entire chapters one after the other. The topics of his books are fascinating, and they are explained with such lucidity that when you are done reading you might feel like a quasi-expert on a subject that you knew little about prior to the reading. In Fermat’s Enigma (1997) he leads you on a quest to solve a 350+ year old conjecture by the mathematician Pierre de Fermat that was proved by Andrew Wiles in 1995. In Big Bang (2004), he tracks the evolution of the Big Bang Theory and how it became the dominant theory of the origin of the universe, and the numerous discoveries along the way. In The Code Book (1999), he deciphers the fascinating world of cryptography and cryptanalysis.

The Code Book begins with the trial of Mary, Queen of Scots, in 1586 where she is accused of conspiring in a plot to kill Queen Elizabeth. The case rests on the ability to decipher encrypted letter exchanges between Mary and the plotters. Subsequent chapters cover the Vigenère cipher, the Enigma machine used in WWII by the Germans, and how these were cracked. The last three chapters cover RSA, PGP, and quantum cryptography. One of my favorite chapters was the deciphering of ancient scripts such as the Egyptian hieroglyphics by Jean-François Champollion in 1824, and the Cretan script known as Linear B by Michael Ventris – an architect, and John Chadwick.

Simon Singh touches on the debate on whether good encryption tools should be available for everyone to use, or whether government should limit their usage lest it falls in the wrong hands and gives them a means to communicate their nefarious plans. The book highlights well the passion of the people involved, their struggle with finding a solution, often within short timelines as in the case of the Enigma, and often their unheralded success. Each of these successes in cryptography (safe encryption) and cryptanalysis (deciphering encrypted messages) is built on the partial successes of those that have attempted the solution before. Simon Singh explains each of the methods going from the monoalphabetic ciphers, to quantum cryptography in a simple style that is easy to understand, and engaging to read to the very end.