Despite its brevity, this 96-page book provides a detailed survey of cryptology from Julius Caesar’s time to 2001. Most readers will find the cryptographic algorithms included at specific points to be of greatest interest. In short, the work has restricted but specific appeal to cryptographers.
In nine chapters, there is a parallel rise from the real beginning of codes and ciphers generated by the need for secrecy and diplomacy during the creation of modern nations and city-states. Dooley discusses “black chambers,” described as “those organizations created by the newly formed nations to break the codes and ciphers of their neighbors.” The 19th century ushered in the era of the telegraph, and the “breaking of the unbreakable cipher, the Vignere,” despite a dearth of traditional cryptography. Radio “marked the advent of modern cryptology” during World War I. In the interwar period, cryptology became a permanent fixture of the American military, and during World War II, radio necessitated “vastly increased security, speed, and accuracy,” resulting in the development of the Enigma and M-134C/SIGABA encryption devices. Modern cryptology was standardized with the introduction of the US Federal Data Encryption Standard (DES), which was then superseded by the Advanced Encryption Standard (AES). The summary of the history of the field culminates with a discussion of the key exchange problem involving the transmission of a public key and private key, in which the same key is used for both enciphering and deciphering.
The primary value of the work is for those interested in the development of DES and AES, or for those working on the key exchange issue, which lies at the heart of the RSA algorithm. It will also be useful for readers who might want to use it as a text in computer security courses, especially since that is how the author intended it in the first place. Readers who require more comprehensive references about cryptology might consider David Kahn’s book  or, for a more mathematical approach, Craig Bauer’s .