Kome > INLS 187 > Book Review

The Code Book, by Simon Singh, presents a substantial history of cryptography and of code breaking. He presents stories of cryptographers and cryptanalysts from ancient history (Caesar) up to present day. The constant tension between the two groups is a theme of the book; Singh implies that cryptography progresses precisely because of the constant pressure applied by code breakers. He uses the context of historical figures and events to explore essential aspects of cryptography and presents fairly technical information in a conversational tone that is neither trite nor too dry. Although algorithms are given where relevant, this is not Applied Cryptography. Readers from computer science backgrounds will get background and context from The Code Book, but not C++ code or anything like it.

What Do You Get?

The Code Book progresses linearly through the long history of cryptography and cryptanalysis one anecdote at a time; Singh chooses historical events and/or personalities which represent pivotal moments in the state of the art. While there may be moments not covered by this book, at least the major advances are covered, and used to explain the methodological progression from simple codes to the Caesar cipher, to public key, to quantum cryptography (which has yet to be developed). Each step along the way, Singh gives a brief biography or two, and ties the new to the old. In essence, this book explains the environment in which cryptographic science (and art) has evolved.

Singh also delves a bit into the tensions between government and citizen efforts to find better en/decryption methods. He makes the point that the US government's efforts to suppress progress (by the general public)in encryption techniques has failed, only resulting in the perception that the government wants to keep privacy tools out of the hands of its citizens. The best example of this is the battle over key length which has been ceded by the government. Where the government has probably maintained an advantage is in the realm of cryptanalysis, which can be attacked as a "big simple" problem; i.e.; something at which to throw vast resources.

Another important point raised by Singh is the classification of knowledge by the government agencies as impedance to progress. Singh gives the examples of Jame Ellis and Clifford Cocks, who made significant contributions to the concept and implementation of the public key concept years earlier than the team at MIT (Rivest, Shamir, Adlemen). Because their work was considered Top Secret by the British government, it didn't see the light of today until...actually some of it is still held in the dark.

The Code book edition I have shows its age in various places, like, "a 100MHz Intel Pentium computer with 8MB of RAM would take roughly 50 years..." I know that there are newer revisions, but the issues raised bear mentioning: in the discussion of public key strength estimates are given for time to solve mathematical problems. The times are given for systems that today are sufficiently out of date as to cast doubt on the premise; that the key strength represents an adequate barrier. This issue addresses the 800 pound gorilla in the room (NSA), which at any time likely has hardware far more advanced than the typical use of cryptography envisions.

Bonus

Following the discussion of quantum computing comes a contest which offers to pay real money for decrypting a cipher, ten appendices, a glossary and a bibliography. The Cipher Challenge offers to pay $15,000 that I believe is yet to be claimed. The appendices offer demonstrations of various odd cipher systems, the math behind RSA, exercises, etc. The bibliography, organized by chapter, offers additional reading on specific cryptographic events, people, and topics. It includes internet sites of interest.

The Code Book presents cryptography through a story-telling mode that is infinitely more approachable than Schneier's Applied Cryptography, and may in fact provide a gateway to such tomes, or may be enough to satisfy a casual interest in the subject.