If you’ve ever picked up a war novel, you know they tend to deal with the exploits of soldiers and sailors, the dirt and danger of the front lines. Not Neal Stephenson’s “Cryptonomicon.” This best-selling, 918-page epic may contain its share of gripping battle scenes — not to mention Filipino treasure hunters, Cap’n Crunch-eating computer hackers, a young Ronald Reagan and a stash of Nazi war gold — but it looks at World War II and its aftermath primarily through the eyes of mathematicians.
But these are no ordinary mathematicians. They’re the Allied codebreakers, men and women who figured out how to decipher messages sent by the Nazis and the Japanese. These numbers-crunchers shortened the war by up to two years and helped make D-Day possible. Along the way, they also helped to kick off the computer revolution. “World War II gave the same sort of boost to computer technology as it gave to aerospace, microwaves, nuclear technology,” Stephenson says.
His book makes that connection clear. Mixing historical figures and fictional characters, it bounces between the early 1940s and the present day. The story alternates between the exploits of Allied codebreakers and those of modern-day computer hackers. The former work to decipher codes for the benefit of their governments, while the latter strive to create codes no government can break.
Stephenson, author of the sci-fi novels “Snow Crash” and “The Diamond Age,” has a long-standing interest in cryptography, the science of creating codes. The dust jacket of “Cryptonomicon” (Avon Books) features a photo of him, age 11 or so, buried in a book about the topic. But “The First Book of Codes and Ciphers” didn’t go far when it came to telling a story with the scope and complexity of “Cryptonomicon.” Stephenson needed a real cryptographer to make sure his ideas were valid.
“I had to become reasonably knowledgeable about crypto to write the book,” he says. “But at times it’s convenient, to put it mildly, to be able to talk or send e-mail to someone who really knows.”
That “someone” is Bruce Schneier. The author of “Applied Cryptography” (John Wiley & Sons), a classic in the field, and president of Minneapolis-based Counterpane Systems, Schneier has helped make it possible to buy things over the Internet, send private e-mail and even use cash cards. In fact, he says, because computers use elaborate codes to communicate, cryptography is intimately related to everything they do.
“Cryptography is a fundamental technology for taking business and social constructs that we use in the real world and putting them on computers,” Schneier says. “So when you write about the future of computers, especially when writing about human interactions on computers, you necessarily bump into cryptography because you can’t do it without cryptography.”
That may seem hard to believe when you consider how the World War II codebreakers worked. Relying on principles handed down from Roman times, they’d pore over pages of gibberish in search of patterns. But as methods to encrypt documents became more complex, it became virtually impossible to figure out their contents through human brain power. The notorious Enigma machine, a device found on every German U-boat, could encrypt messages without using the same letter twice to represent any given letter.
While the letter “e” might be replaced with an “x” the first time it was used in a message, the next time it would be replaced with, say, an “h.” The only way to learn what the message said was to feed it through another Enigma machine.
Eventually the Allies figured out how the Enigma machine worked, but it took an army of people to crack each message it generated. (Stephenson describes one such army in “Cryptonomicon.”) Top mathematicians and rapid-fingered typists poured into Britain’s Bletchley Park, a quiet agricultural area turned top-secret codebreaking headquarters. Those who knew Bletchley’s secret kept it until the early ’70s, when one official published his memoirs. Only then did the world learn that Bletchley was where one of the world’s first electronic computers was developed. It was called the Colossus.
This machine, Stephenson notes, was just one of many similar devices being developed about the same time in different parts of the world. In “Cryptonomicon,” one of Stephenson’s characters constructs a computer of his own inspired by the workings of his church’s organ. Such a cumbersome, unreliable contraption was never actually built, Stephenson says, but it might as well have been.
“All of the early computers had to solve certain technical problems over and over,” he says. “One of the thorniest problems was to have a way of storing memory and getting it back. There were all kinds of Rube Goldberg contraptions that were invented for that purpose. I just decided to make one up that was no crazier than any of the others but was consistent with this particular guy’s perspective. All these guys would take (devices) from their own experience that they knew about and turn it into a memory gizmo.”
These gizmos used a whole junk shop’s worth of parts: Rubber bands, meat skewers, jars of liquid mercury, wooden rods, catgut strings, cathode-ray tubes, even an old macaroni box turned up in early calculating machines. Bletchley Park’s Colossus used 2,400 vacuum tubes to parse German messages at the then-unheard-of rate of thousands of characters a second.
The Colossus was the brainchild of Alan Turing, who turns up several times in “Cryptonomicon.” A brilliant and eccentric mathematician, he’s considered by many today to be the father of modern computer technology. Amazingly, though, his importance wasn’t widely known until the 1970s, when the Bletchley secret was revealed. In fact, neither he, nor the Colossus, nor Bletchley Park itself is mentioned in “The Codebreakers,” David Kahn’s monumental 1967 work on the history of cryptography. It wasn’t until the 1990s, when he issued a revised edition of “The Codebreakers” and wrote another book, “Seizing the Enigma,” that Kahn delved into the mysteries of Bletchley.
Today Turing is remembered both for his scientific achievements and for his idiosyncratic personal life. An avid cyclist, he sometimes rode around Bletchley wearing a gas mask to combat his hay fever. At one point, in an anecdote Stephenson recounts in “Cryptonomicon,” he began having trouble with his bike chain. He developed a mathematical formula to predict when it would fall off and rode along, counting the chain’s revolutions, until the moment before it did. Then he’d get off and adjust it. It never occurred to him to have the chain repaired.
Turing would be well at home in the chaotic world of modern cryptography. Today’s methods of making and breaking codes may be infinitely more complex than those of the ’40s, but they’re just as bizarre to the outsider’s eye. In his work Schneier encounters everything from “smart cards” like those you use at the automatic teller machine to devices that determine a person’s identity by scanning his eyeball.
“I would like very much when I walk up to my front door not to fiddle with the key,” he says. “Wouldn’t it be neat if it could recognize who I am and let me in? That kind of product is likely to exist. But you can imagine environments where it makes no sense to have (this kind of device). Are you going to have your eyeball scanned every time you ride the `L’? That’s unlikely.”
Still weirder is a device Stephenson describes in “Cryptonomicon” that allows eavesdroppers to monitor words scrolling across a computer screen by tracing the electrical impulses the screen emits.
“All electronic equipment radiates data,” he says. “You can put an eavesdropping device on the power distribution point outside someone’s house and pull data off their computer. You can sit outside a building with 100 computers and separate out each one.”
In a world full of such high-tech snooping devices, it seems impossible for an individual to rely on his privacy without access to powerful computers. Schneier’s done a lot of thinking about that problem.
“Before computers there were a lot of ciphers that were created using pencil and paper,” he says. “With the invention of computers that whole class of ciphers effectively was broken. We don’t have a cipher you can implement using a piece of paper that is secure against computers.”
Thinking about this, Schneier decided to try and create a low-tech cipher that even the fastest computer couldn’t break. He came up with Solitaire, a cipher generated using a simple deck of cards. Stephenson was intrigued, and decided to use Solitaire in “Cryptonomicon.”
In the book, a hacker named Randy uses Solitaire to communicate with a fellow prisoner when he finds himself in a Philippine jail — illustrating, Schneier says, the power cryptography gives individuals. “Twenty years ago Howard Hughes could get anonymity because he could afford it,” he says. “Cryptography will allow anyone to get that kind of anonymity in the computer environment.”
On the other hand, Stephenson is quick to point out, cryptography is as important to a government’s security as an individual’s, and he deliberately structured his book to illustrate this double-bladed quality. Throughout “Cryptonomicon,” parallel storylines follow modern-day hackers seeking to subvert their governments and patriotic codebreakers laboring to protect them.
“Cryptography is technologically neutral,” Schneier says. “You can do a good thing with it or a bad thing with it, but it’s still just a tool.”
