The book goes into excruciating details at explaining the details of various cryptographic systems; from the Vigenere ciper to Quantum cryptography, without being prosaic. The story of the German Enigma and the cracking of the same by the ‘Ultras’ at Bletchley Park has been wonderfully described. What sets this book apart from many other popular books on cryptography is the intermingling of stories and technical details in a harmonious proportion.
The book begins from the decipherment of the ciper of Mary, the queen of Scots and concludes with a fine discussion of PGP and quantum cryptography; on the way covering such important and interesting topics including the Enigma Machine, Linear B and other ancient writings, public key cryptography and much more. What I found particularly interesting and new was the use of the Navajo people as code-talkers during World War II.