Crypto
How the Code Rebels
Beat the Government —
Saving Privacy in the Digital Age
by Steven Levy
 

Viking, New York: 2001

Crypto: How the Code Rebels Beat the Government — Saving Privacy in the Digital Age was published early in 2001. After the terrorist attacks on 11 September 2001, many Americans discovered or revived an interest in the American government's secret agencies, and a closely related concern about risks and benefits of secret communications. Steven Levy's subtitle may sound a bit light-hearted after 9/11, but in fact he tries to be even-handed on the merits of cryptography for the masses, versus national security. In addition to the university and free-lance mathematicians, Levy tells us something of the National Security Agency (NSA).

The book is not for the casual reader. It helps if you are either a secret-codes buff or a computer programmer — or a mathematician with an interest in estoteric applications becoming mainstream. Nevertheless, even the mathematical ins and outs are presented clearly in conceptual terms, not equations. For background you should have read something about the history of cryptography before the computer age, perhaps ideally David Kahn's The Codebreakers: The Story of Secret Writing (1967). There are shorter introductions to cryptography; Kahn's is comprehensive at 1200 pages.

Levy follows concepts via the progress of some fringe thinkers and dedicated doers in Crypto, as in previous books: Hackers: Heroes of the Computer Revolution; and Insanely Great: The Life and Times of Macintosh, the Computer That Changed Everything. The book at hand is a similar story of a few people wrestling with breakthrough ideas, and then struggling to make them workable, perhaps even profitable. The inventors and defenders in Crypto mostly are at MIT or Stanford on the free-thinking side; on the government side, at the National Security Agency (NSA) at Fort Meade, Maryland, ultimately reporting to the elected officials in Washington, D.C.
  

Crypto is by no means a handbook to the crypto technology lately available on desktop computers; for that you want something like Simpson Garfinkel's PGP: Pretty Good Privacy. But where did this PGP come from? If you have wondered about the names, the real people behind the Diffie-Hellman algorithm (both mathematicians) or RSA Data Security (mathematicians Rivest, Shamir, and Adleman), this book sketches their stories, and their revolution in cryptography. The invention of public key cryptography turned inside-out the code-makers' assured wisdom of millennia.

While this revolution was still underway, home computers and the Internet hugely expanded the number of people who had access to computer technology and communications, and shortly were keen to preserve their privacy by encrypting their data. Of course, government agencies (particularly NSA), responsible for monitoring data and communications presumed to be either criminal or inimical to American security, see things from a different perspective. Key exchange, digital signatures, and the Clipper Chip are highly technical gambits on this board.

Levy does a good job of making these modern cryptographers' ideas and their personal and business trajectories understandable and interesting to the layman. The crypto experts have considerable affinity of knowledge, dedication, and sheer brilliance, even when at odds in policy. The garden of forking paths on the chessboard that the chess-player must analyze has its counterpart in the key space of cryptanalysis possibilities. Cryptographers, like chess masters, share a subtle realm that their audience only glimpses.
  

Both the technical and policy aspects of cryptography are ongoing; unlike some observers, I see no final breakthrough or stable policy at hand or even on the horizon. And which is more important, anyway, privacy or security? While some crypto rebels and libertarians want to secure privacy for all, valuing free or cheap cryptography as an important defense against Big Brother government, others of them believe just the opposite. For an analysis from an anti-privacy viewpoint, see our review of David Brin's The Transparent Society.

Steven Levy tells this computer-age cryptography story (so far) in terms of people and ideas, of start-up businesses versus government agencies. Winston S. Churchill called the scientists' and engineers' contribution to World War II, the wizard war. There is much more to come.

© 2004 Robert Wilfred Franson