Cryptonomicon.

Cryptonomicon, by Neal Stephenson, New York: Avon, 928 pages, $27.50

No aficionado of trendy, complex contemporary novels by writers such as Thomas Pynchon or David Foster Wallace will be terribly surprised to come across a work of fiction that traces a single thematic thread running through the lives of a mathematical genius in World War II, his slightly less gifted but equally nerdy grandson in 1999, a gung-ho Marine driven by love and morphine, and a Japanese soldier transmuted by the bestial horrors of war. What may be surprising to readers of Neal Stephenson's Cryptonomicon, however, is that the author makes that thread cryptology - the science (or, more accurately, dual sciences) of encoding messages to keep them secret and extracting secret messages from other people's communications.

In a wide range of linked scenarios that tie WWII code breaking to the modern "cypherpunk" effort to create a currency and an economic system beyond governmental control, Stephenson's novel continually demonstrates that there's something essentially human about the process of encoding and decoding messages. It's this thesis that makes Cryptonomicon far more than simply an enjoyable, exceedingly well-written, encyclopedic, and deeply comic novel. It is, in fact, an important book that illuminates a critical public issue of our era: whether the power of encryption tools for cryptography can be trusted to individuals - tools that have, for instance, the potential to make wiretaps a thing of the past.

Cryptonomicon presents the reader with several entwined narratives, switching among them on a chapter-by-chapter basis. Most of the sections are set in World War II and follow the adventures of two men: mathematical prodigy and Army officer Lawrence Waterhouse and his near-antithesis, man of action and Marine sergeant Bobby Shaftoe. Both of these characters manage to complete grand tours of the European and Pacific theaters, but, more important, both demonstrate in their respective ways the human capacity to extract meanings from the chaotic and mysterious situations generated by a world war.

For Waterhouse, whose life is dominated by his gift for mathematical reasoning, the primary challenge is to crack Axis codes (and, secondarily, to conceal from the enemy the fact that the codes have been cracked). For the less-cerebral Shaftoe, an occasional morphine addict, the goal is more basic. Though his official mission is to assist in concealing Allied code-breaking efforts, he labors to return to the Japanese-occupied Philippines to rescue his paramour and the child he may have fathered with her. Where Waterhouse reflexively resorts to mathematical models to characterize his experiences, Shaftoe turns to poetic ones - during his time in the Far East he's learned to compose haiku. Through Shaftoe - whose individual story begins and ends with haiku - Stephenson suggests the broad application of cryptography in human life. The haiku poet, after all, encodes a deep moment of experience into three short strings of words. Similarly, it takes an experienced reader of haiku to decode such a poem.

Along with the World War II narratives is a present-day story centered on Waterhouse's grandson, Randy, a computer nerd whose own genius remains unrealized until it is unlocked by a unique business opportunity. Randy is invited by a friend to take part in a cryptographically facilitated offshore "data haven" that will become the technological platform for a totally Internet-based economic system. Backing that digital monetary system will require real-world gold. Working with Shaftoe's son and granddaughter, Randy may have a source for that gold: the code-breaking efforts of his grandfather, who 50 years ago may have uncovered a Nazi plot to collect and horde German and Japanese gold bullion.

You'd think such a web of narratives would be hard to follow. Certainly, it's difficult to summarize. But Stephenson, whose science-fiction novels Snow Crash (1992) and The Diamond Age (1995) have been critical and commercial successes despite difficult plotting, has made a quantum jump here as a writer. In addition to his bravura style and interesting authorial choices (Stephenson tells each of his narratives in the present tense, regardless of when they occur chronologically), the book is so tightly plotted that you never lose the thread.

But Stephenson is not an author who's content just to tell good stories. Throughout the book, he takes on the task of explaining the relatively abstruse technical disciplines surrounding cryptology, almost always in ways that a reasonably intelligent educated adult can understand. As I read the book I marked in the margins where Stephenson found opportunities to explain the number theory that underlies modern cryptography; "traffic analysis" (deriving military intelligence from where and when messages are sent and received, without actually decoding them); steganography (hiding secret messages within other, non-secret communications); the electronics of computer monitors (and the security problems created by those monitors); the advantages to Unix-like operating systems compared to Windows or the Mac OS; the theory of monetary systems; and the strategies behind high-tech business litigation. Stephenson assumes that his readers are capable of learning the complex underpinnings of modern technological life. For the most part he's correct, although some otherwise intelligent readers may find a few of the mathematical discussions tough sledding.

Stephenson's technical virtuosity is supplemented by his extensive erudition - one finds allusions ranging from David Kahn's famous history of cryptology, The Codebreakers, to World War II narratives like The Man Who Never Was, Das Boot, and Guadalcanal Diary. And his scenes are populated with characters who could just as easily have stepped out of P.G. Wode-house as out of James Jones, with guest appearances by real-world figures such as Alan Turing, Ronald Reagan, and Douglas MacArthur. There's even a set piece about the death of Admiral Yamamoto that could stand alone as a short story.

The result is a book that is readable, funny, humane, literary, and technically sophisticated (in every sense). But as I suggested at the outset, it is far more than a good read. It is vitally engaged with debates central to a world in which access to and control of information, data, and messaging is increasingly important. Stephenson forces readers to see cryptography (the creation of ciphertexts) and cryptanalysis (the decoding of such texts) - as something that's not only comprehensible by ordinary people but also something that each of us is, in some sense, born to do. To that end, he quotes Alan Turing, England's master codebreaker and the father of modern computing, at the very beginning of the book: "There is a remarkably close parallel between the problems of the physicist and those of the cryptographer. The system on which a message is enciphered corresponds to the laws of the universe, the intercepted messages to the evidence available, the keys for a day or a message to important constants which have yet to be determined. The correspondence is very close, but the subject matter of cryptography is very easily dealt with by discrete machinery, physics not so easily."

In short, the task of making sense of the universe - a task that, on some level or other, is one that each of us must face - is very much like a decoding problem. We have to figure out what is meaningful or true based on the inherently limited and untrustworthy evidence that the real world provides. And one finds this theme sounded again and again - especially when one of the Waterhouse males has to deal with the opposite sex (which turns out to be a very special kind of cryptanalytic problem for each of them). This idea applies even to the novel's title: In the book's fictive world, Cryptonomicon is the name given to a collection of scholarly works, compiled over centuries, that focus on the problems of cryptanalysis. In an analogous way, Stephenson's novel is itself a collection of individual stories that each provide a way into understanding the larger story of the crucial role that cryptology has played in shaping the culture we live in now.

That role is underscored early in the novel when Lawrence Waterhouse first joins the cryptanalytic team at England's Bletchley Park: "Some information comes into Waterhouse's eyes at least: on the other side of that window, men are gathered around a machine. Most of them are wearing civilian clothes, and they have been too busy, for too long, to trifle much with combs and razors and shoe polish. The men are intensely focused upon their work, which all has to do with this large machine. The machine consists of a large framework of square steel tubing, like a bedstead set up on one end. Metal drums with the diameter of dinner plates, an inch or so thick, are mounted at several locations on this framework. Paper tape has been threaded into a bewilderingly loopy trajectory from drum to drum. It looks as if a dozen yards of tape are required to thread the machine."

This is it in a nutshell: The confluence of the beginnings of modern decoding, computing, and disheveled hacker culture - it's a short step from Bletchley Park to the personal computer, now a fixture of everyday life in the industrialized world. And from PCs it's a short step back to cryptology, since cheap computing makes it possible for everyone to do cryptography more crack-proof than the most powerful encryption that governments could do half a century ago. This is, of course, a development that has troubled governments everywhere, and the United States government in particular. Thanks to some pioneering work done by American cryptographers only a couple of decades ago, the knowledge and techniques necessary for encoding or scrambling the things you write or say are no longer the sole preserve of government intelligence agencies; in fact, they are easily reproduced and implemented and available at low prices to most Americans today.

In a world full of governments that have grown accustomed - even comfortable - in their ability to keep track of their citizens, and to gather evidence about them when necessary, these developments are disorienting. What happens in a world where one cannot guarantee that a working wiretap will recover anything useful because the message traffic on the phone in question is encrypted? What happens when the perpetrator of a criminal threat can easily disappear from an online environment because no one has the information necessary to track or identify him? The question raised by the subplot of Cryptonomicon set in 1999 is even more troubling: What happens when you establish a monetary system that does not depend on government and that does not lend itself easily to government tracking and supervision? (The novel's short answer is large-scale money laundering, among other things - no wonder the international criminal underworld evinces a deep interest in Randy Waterhouse's "data haven" project.)

For these reasons, our real-world government has been fighting a war against the spread of cryptographic tools. That war has been largely unpublicized, in part because the general public has yet to deem cryptography policy a matter of central concern. There is no groundswell of public support for keeping encryption technologies available to everybody, nor any anti-encryption-control group the equivalent of the National Rifle Association. Civil-liberties groups like the Electronic Privacy Information Center and the ACLU are fighting the Department of Justice and the National Security Agency over this issue, but it's a pretty lonely fight. The U.S. government has been sufficiently successful in suppressing the spread of encryption technologies both at home and abroad that the kinds of protections we should have - such as transparent encoding and decoding of e-mail in transmission or truly secure cell phones - are still in the future for most of us.

Why have civil libertarians so often found cryptography issues a tough sell? The problem is that for most people the subject seems awfully esoteric - codes and ciphers are what spies do, and are out of the range of concerns for ordinary people. Cryptonomicon challenges that notion by demonstrating in countless contexts not only how good human beings are at decoding and encoding their environments but also how instinctive that process is. We can't help functioning as cryptographers and cryptoanalysts because, at bottom, that is what we as human beings do. Which means that our government's current obsession with suppressing the spread of cryptographic information and tools is really a kind of suppression of human nature - and history tells us that any such effort at suppressing something that everybody does is invariably futile over the long run.

Will Cryptonomicon turn the tide of public opinion about cryptography or inform the political will to challenge the government's anti-cryptography policies? On the one hand, it's hard to believe that a 900-page novel of any sort could change the political landscape in an era in which the novel is an increasingly marginal mass-media form. Still, this book is compulsively readable, and word of how good it is has flooded throughout the Internet and into our literary culture. Cryptonomicon has already found its way onto The New York Times bestseller list (it made it to Amazon's top 100 even before publication). Whether the book will help trigger a sea change in the cultural dialogue about cryptological issues remains to be seen, but I for one am pretty hopeful about the prospect.

Mike Godwin ([e-mail]) is a lawyer and the author of Cyber Rights: Defending Free Speech in the Digital Age (Times Books).