CHAPTER 4

The crypto door beeped once, waking Susan from her depressing reverie. The door had rotated past its fully open position and would be closed again in five seconds, having made a complete 360-degree rotation. Susan gathered her thoughts and stepped through the opening. A computer made note of her entry.

Although she had practically lived in Crypto since its completion three years ago, the sight of it still amazed her. The main room was an enormous circular chamber that rose five stories. Its transparent, domed ceiling towered 120 feet at its central peak. The Plexiglas cupola was embedded with a polycarbonate mesh—a protective web capable of withstanding a two-megaton blast. The screen filtered the sunlight into delicate lacework across the walls. Tiny particles of dust drifted upward in wide unsuspecting spirals—captives of the dome’s powerful deionizing system.

The room’s sloping sides arched broadly at the top and then became almost vertical as they approached eye level. Then they became subtly translucent and graduated to an opaque black as they reached the floor—a shimmering expanse of polished black tile that shone with an eerie luster, giving one the unsettling sensation that the floor was transparent. Black ice.

Pushing through the center of the floor like the tip of a colossal torpedo was the machine for which the dome had been built. Its sleek black contour arched twenty-three feet in the air before plunging back into the floor below. Curved and smooth, it was as if an enormous killer whale had been frozen mid-breach in a frigid sea.

This was TRANSLTR, the single most expensive piece of computing equipment in the world—a machine the NSA swore did not exist.

Like an iceberg, the machine hid 90 percent of its mass and power deep beneath the surface. Its secret was locked in a ceramic silo that went six stories straight down—a rocketlike hull surrounded by a winding maze of catwalks, cables, and hissing exhaust from the freon cooling system. The power generators at the bottom droned in a perpetual low-frequency hum that gave the acoustics in Crypto a dead, ghostlike quality.

TRANSLTR, like all great technological advancements, had been a child of necessity. During the 1980s, the NSA witnessed a revolution in telecommunications that would change the world of intelligence reconnaissance forever—public access to the Internet. More specifically, the arrival of E-mail.

Criminals, terrorists, and spies had grown tired of having their phones tapped and immediately embraced this new means of global communication. E-mail had the security of conventional mail and the speed of the telephone. Since the transfers traveled through underground fiber-optic lines and were never transmitted into the airwaves, they were entirely intercept-proof—at least that was the perception.

In reality, intercepting E-mail as it zipped across the Internet was child’s play for the NSA’s techno-gurus. The Internet was not the new home computer revelation that most believed. It had been created by the Department of Defense three decades earlier—an enormous network of computers designed to provide secure government communication in the event of nuclear war. The eyes and ears of the NSA were old Internet pros. People conducting illegal business via E-mail quickly learned their secrets were not as private as they’d thought. The FBI, DEA, IRS, and other U.S. law enforcement agencies—aided by the NSA’s staff of wily hackers—enjoyed a tidal wave of arrests and convictions.

Of course, when the computer users of the world found out the U.S. government had open access to their E-mail communications, a cry of outrage went up. Even pen pals, using E-mail for nothing more than recreational correspondence, found the lack of privacy unsettling. Across the globe, entrepreneurial programmers began working on a way to keep E-mail more secure. They quickly found one and public-key encryption was born.

Public-key encryption was a concept as simple as it was brilliant. It consisted of easy-to-use, home-computer software that scrambled personal E-mail messages in such a way that they were totally unreadable. A user could write a letter and run it through the encryption software, and the text would come out the other side looking like random nonsense—totally illegible—a code. Anyone intercepting the transmission found only an unreadable garble on the screen.

The only way to unscramble the message was to enter the sender’s “pass-key”—a secret series of characters that functioned much like a PIN number at an automatic teller. The pass-keys were generally quite long and complex; they carried all the information necessary to instruct the encryption algorithm exactly what mathematical operations to follow to re-create the original message.

A user could now send E-mail in confidence. Even if the transmission was intercepted, only those who were given the key could ever decipher it.

The NSA felt the crunch immediately. The codes they were facing were no longer simple substitution ciphers crackable with pencil and graph paper—they were computer-generated hash functions that employed chaos theory and multiple symbolic alphabets to scramble messages into seemingly hopeless randomness.

At first, the pass-keys being used were short enough for the NSA’s computers to “guess.” If a desired pass-key had ten digits, a computer was programmed to try every possibility between 0000000000 and 9999999999. Sooner or later the computer hit the correct sequence. This method of trial-and-error guessing was known as “brute force attack.” It was time-consuming but mathematically guaranteed to work.

As the world got wise to the power of brute-force code-breaking, the pass-keys started getting longer and longer. The computer time needed to “guess” the correct key grew from weeks to months and finally to years.

By the 1990s, pass-keys were over fifty characters long and employed the full 256-character ASCII alphabet of letters, numbers, and symbols. The number of different possibilities was in the neighborhood of 10¹²⁰—one with 120 zeros after it. Correctly guessing a pass-key was as mathematically unlikely as choosing the correct grain of sand from a three-mile beach. It was estimated that a successful brute-force attack on a standard sixty-four-bit key would take the NSA’s fastest computer—the top-secret Cray/Josephson II—over nineteen years to break. By the time the computer guessed the key and broke the code, the contents of the message would be irrelevant.

Caught in a virtual intelligence blackout, the NSA passed a top-secret directive that was endorsed by the President of the United States. Buoyed by federal funds and a carte blanche to do whatever was necessary to solve the problem, the NSA set out to build the impossible: the world’s first universal code-breaking machine.

Despite the opinion of many engineers that the newly proposed code-breaking computer was impossible to build, the NSA lived by its motto: Everything is possible. The impossible just takes longer.

Five years, half a million man-hours, and $1.9 billion later, the NSA proved it once again. The last of the three million stamp-size processors was hand-soldered in place, the final internal programming was finished, and the ceramic shell was welded shut. TRANSLTR had been born.

Although the secret internal workings of TRANSLTR were the product of many minds and were not fully understood by any one individual, its basic principle was simple: Many hands make light work.

Its three million processors would all work in parallel—counting upward at blinding speed, trying every new permutation as they went. The hope was that even codes with unthinkably colossal passkeys would not be safe from TRANSLTR’s tenacity. This multibillion-dollar masterpiece would use the power of parallel processing as well as some highly classified advances in cleartext assessment to guess pass-keys and break codes. It would derive its power not only from its staggering number of processors but also from new advances in quantum computing—an emerging technology that allowed information to be stored as quantum-mechanical states rather than solely as binary data.

The moment of truth came on a blustery Thursday morning in October. The first live test. Despite uncertainty about how fast the machine would be, there was one thing on which the engineers agreed—if the processors all functioned in parallel, TRANSLTR would be powerful. The question was how powerful.

The answer came twelve minutes later. There was a stunned silence from the handful in attendance when the printout sprang to life and delivered the cleartext—the broken code. TRANSLTR had just located a sixty-four-character key in a little over ten minutes, almost a million times faster than the two decades it would have taken the NSA’s second-fastest computer.

Led by the deputy director of operations, Commander Trevor J. Strathmore, the NSA’s Office of Production had triumphed. TRANSLTR was a success. In the interest of keeping their success a secret, Commander Strathmore immediately leaked information that the project had been a complete failure. All the activity in the Crypto wing was supposedly an attempt to salvage their $2 billion fiasco. Only the NSA elite knew the truth—TRANSLTR was cracking hundreds of codes every day.

With word on the street that computer-encrypted codes were entirely unbreakable—even by the all-powerful NSA—the secrets poured in. Drug lords, terrorists, and embezzlers alike—weary of having their cellular phone transmissions intercepted—were turning to the exciting new medium of encrypted E-mail for instantaneous global communications. Never again would they have to face a grand jury and hear their own voice rolling off tape, proof of some long-forgotten cellular phone conversation plucked from the air by an NSA satellite.

Intelligence gathering had never been easier. Codes intercepted by the NSA entered TRANSLTR as totally illegible ciphers and were spit out minutes later as perfectly readable cleartext. No more secrets.

To make their charade of incompetence complete, the NSA lobbied fiercely against all new computer encryption software, insisting it crippled them and made it impossible for lawmakers to catch and prosecute the criminals. Civil rights groups rejoiced, insisting the NSA shouldn’t be reading their mail anyway. Encryption software kept rolling off the presses. The NSA had lost the battle—exactly as it had planned. The entire electronic global community had been fooled … or so it seemed.

CHAPTER 5

“Where is everyone?” Susan wondered as she crossed the deserted Crypto floor. Some emergency.

Although most NSA departments were fully staffed seven days a week, Crypto was generally quiet on Saturdays. Cryptographic mathematicians were by nature high-strung workaholics, and there existed an unwritten rule that they take Saturdays off except in emergencies. Code-breakers were too valuable a commodity at the NSA to risk losing them to burnout.

As Susan traversed the floor, TRANSLTR loomed to her right. The sound of the generators eight stories below sounded oddly ominous today. Susan never liked being in Crypto during off hours. It was like being trapped alone in a cage with some grand, futuristic beast. She quickly made her way toward the commander’s office.

Strathmore’s glass-walled workstation, nicknamed “the fishbowl” for its appearance when the drapes were open, stood high atop a set of catwalk stairs on the back wall of Crypto. As Susan climbed the grated steps, she gazed upward at Strathmore’s thick, oak door. It bore the NSA seal—a bald eagle fiercely clutching an ancient skeleton key. Behind that door sat one of the greatest men she’d ever met.

Commander Strathmore, the fifty-six-year-old deputy director of operations, was like a father to Susan. He was the one who’d hired her, and he was the one who’d made the NSA her home. When Susan joined the NSA over a decade ago, Strathmore was heading the Crypto Development Division—a training ground for new cryptographers—new male cryptographers. Although Strathmore never tolerated the hazing of anyone, he was especially protective of his sole female staff member. When accused of favoritism, he simply replied with the truth: Susan Fletcher was one of the brightest young recruits he’d ever seen, and he had no intention of losing her to sexual harassment. One of the senior cryptographers foolishly decided to test Strathmore’s resolve.

One morning during her first year, Susan dropped by the new cryptographers’ lounge to get some paperwork. As she left, she noticed a picture of herself on the bulletin board. She almost fainted in embarrassment. There she was, reclining on a bed and wearing only panties.

As it turned out, one of the cryptographers had digitally scanned a photo from a pornographic magazine and edited Susan’s head onto someone else’s body. The effect had been quite convincing.

Unfortunately for the cryptographer responsible, Commander Strathmore did not find the stunt even remotely amusing. Two hours later, a landmark memo went out:

From that day on, nobody messed with her; Susan Fletcher was Commander Strathmore’s golden girl.

But Strathmore’s young cryptographers were not the only ones who learned to respect him; early in his career Strathmore made his presence known to his superiors by proposing a number of unorthodox and highly successful intelligence operations. As he moved up the ranks, Trevor Strathmore became known for his cogent, reductive analyses of highly complex situations. He seemed to have an uncanny ability to see past the moral perplexities surrounding the NSA’s difficult decisions and to act without remorse in the interest of the common good.

There was no doubt in anyone’s mind that Strathmore loved his country. He was known to his colleagues as a patriot and a visionary … a decent man in a world of lies.

In the years since Susan’s arrival at the NSA, Strathmore had skyrocketed from head of Crypto Development to second-in-command of the entire NSA. Now only one man outranked Commander Strathmore there—Director Leland Fontaine, the mythical overlord of the Puzzle Palace—never seen, occasionally heard, and eternally feared. He and Strathmore seldom saw eye to eye, and when they met, it was like the clash of the titans. Fontaine was a giant among giants, but Strathmore didn’t seem to care. He argued his ideas to the director with all the restraint of an impassioned boxer. Not even the President of the United States dared challenge Fontaine the way Strathmore did. One needed political immunity to do that—or, in Strathmore’s case, political indifference.

Susan arrived at the top of the stairs. Before she could knock, Strathmore’s electronic door lock buzzed. The door swung open, and the commander waved her in.

“Thanks for coming, Susan. I owe you one.”

“Not at all.” She smiled as she sat opposite his desk.

Strathmore was a rangy, thick-fleshed man whose muted features somehow disguised his hard-nosed efficiency and demand for perfection. His gray eyes usually suggested a confidence and discretion born from experience, but today they looked wild and unsettled.

“You look beat,” Susan said.

“I’ve been better.” Strathmore sighed.

I’ll say, she thought.

Strathmore looked as bad as Susan had ever seen him. His thinning gray hair was disheveled, and even in the room’s crisp air-conditioning, his forehead was beaded with sweat. He looked like he’d slept in his suit. He was sitting behind a modern desk with two recessed keypads and a computer monitor at one end. It was strewn with computer printouts and looked like some sort of alien cockpit propped there in the center of his curtained chamber.

“Tough week?” she inquired.

Strathmore shrugged. “The usual. The EFF’s all over me about civilian privacy rights again.”

Susan chuckled. The EFF, or Electronics Frontier Foundation, was a worldwide coalition of computer users who had founded a powerful civil liberties coalition aimed at supporting free speech on-line and educating others to the realities and dangers of living in an electronic world. They were constantly lobbying against what they called “the Orwellian eavesdropping capabilities of government agencies”—particularly the NSA. The EFF was a perpetual thorn in Strathmore’s side.

“Sounds like business as usual,” she said. “So what’s this big emergency you got me out of the tub for?”

Strathmore sat a moment, absently fingering the computer trackball embedded in his desktop. After a long silence, he caught Susan’s gaze and held it. “What’s the longest you’ve ever seen TRANSLTR take to break a code?”

The question caught Susan entirely off guard. It seemed meaningless. This is what he called me in for?

“Well…” She hesitated. “We hit a COMINT intercept a few months ago that took about an hour, but it had a ridiculously long key—ten thousand bits or something like that.”

Strathmore grunted. “An hour, huh? What about some of the boundary probes we’ve run?”

Susan shrugged. “Well, if you include diagnostics, it’s obviously longer.”

“How much longer?”

Susan couldn’t imagine what Strathmore was getting at. “Well, sir, I tried an algorithm last March with a segmented million-bit key. Illegal looping functions, cellular automata, the works. TRANSLTR still broke it.”

“How long?”

“Three hours.”

Strathmore arched his eyebrows. “Three hours? That long?”

Susan frowned, mildly offended. Her job for the last three years had been to fine-tune the most secret computer in the world; most of the programming that made TRANSLTR so fast was hers. A million-bit key was hardly a realistic scenario.

“Okay,” Strathmore said. “So even in extreme conditions, the longest a code has ever survived inside TRANSLTR is about three hours?”

Susan nodded. “Yeah. More or less.”

Strathmore paused as if afraid to say something he might regret. Finally he looked up. “TRANSLTR’s hit something …” He stopped.

Susan waited. “More than three hours?”

Strathmore nodded.

She looked unconcerned. “A new diagnostic? Something from the Sys-Sec Department?”

Strathmore shook his head. “It’s an outside file.”

Susan waited for the punch line, but it never came. “An outside file? You’re joking, right?”

“I wish. I queued it last night around eleven thirty. It hasn’t broken yet.”

Susan’s jaw dropped. She looked at her watch and then back at Strathmore. “It’s still going? Over fifteen hours?”

Strathmore leaned forward and rotated his monitor toward Susan. The screen was black except for a small, yellow text box blinking in the middle.

Susan stared in amazement. It appeared TRANSLTR had been working on one code for over fifteen hours. She knew the computer’s processors auditioned thirty million keys per second—one hundred billion per hour. If TRANSLTR was still counting, that meant the key had to be enormous—over ten billion digits long. It was absolute insanity.

“It’s impossible!” she declared. “Have you checked for error flags? Maybe TRANSLTR hit a glitch and—”

“The run’s clean.”

“But the pass-key must be huge!”

Strathmore shook his head. “Standard commercial algorithm. I’m guessing a sixty-four-bit key.”

Mystified, Susan looked out the window at TRANSLTR below. She knew from experience that it could locate a sixty-four-bit key in under ten minutes. “There’s got to be some explanation.”

Strathmore nodded. “There is. You’re not going to like it.”

Susan looked uneasy. “Is TRANSLTR malfunctioning?”

“TRANSLTR’s fine.”

“Have we got a virus?”

Strathmore shook his head. “No virus. Just hear me out.”

Susan was flabbergasted. TRANSLTR had never hit a code it couldn’t break in under an hour. Usually the cleartext was delivered to Strathmore’s printout module within minutes. She glanced at the high-speed printer behind his desk. It was empty.

“Susan,” Strathmore said quietly. “This is going to be hard to accept at first, but just listen a minute.” He chewed his lip. “This code that TRANSLTR’s working on—it’s unique. It’s like nothing we’ve ever seen before.” Strathmore paused, as if the words were hard for him to say. “This code is unbreakable.”

Susan stared at him and almost laughed. Unbreakable? What was THAT supposed to mean? There was no such thing as an unbreakable code—some took longer than others, but every code was breakable. It was mathematically guaranteed that sooner or later TRANSLTR would guess the right key. “I beg your pardon?”

“The code’s unbreakable,” he repeated flatly.

Unbreakable? Susan couldn’t believe the word had been uttered by a man with twenty-seven years of code analysis experience.

“Unbreakable, sir?” she said uneasily. “What about the Bergofsky Principle?”

Susan had learned about the Bergofsky Principle early in her career. It was a cornerstone of brute-force technology. It was also Strathmore’s inspiration for building TRANSLTR. The principle clearly stated that if a computer tried enough keys, it was mathematically guaranteed to find the right one. A code’s security was not that its pass-key was unfindable but rather that most people didn’t have the time or equipment to try.

Strathmore shook his head. “This code’s different.”

“Different?” Susan eyed him askance. An unbreakable code is a mathematical impossibility! He knows that!

Strathmore ran a hand across his sweaty scalp. “This code is the product of a brand-new encryption algorithm—one we’ve never seen before.”

Now Susan was even more doubtful. Encryption algorithms were just mathematical formulas, recipes for scrambling text into code. Mathematicians and programmers created new algorithms every day. There were hundreds of them on the market—PGP, Diffie-Hellman, ZIP, IDEA, El Gamal. TRANSLTR broke all of their codes every day, no problem. To TRANSLTR all codes looked identical, regardless of which algorithm wrote them.

“I don’t understand,” she argued. “We’re not talking about reverse-engineering some complex function, we’re talking brute force. PGP, Lucifer, DSA—it doesn’t matter. The algorithm generates a key it thinks is secure, and TRANSLTR keeps guessing until it finds it.”

Strathmore’s reply had the controlled patience of a good teacher. “Yes, Susan, TRANSLTR will always find the key—even if it’s huge.” He paused a long moment. “Unless…”

Susan wanted to speak, but it was clear Strathmore was about to drop his bomb. Unless what?

“Unless the computer doesn’t know when it’s broken the code.”

Susan almost fell out of her chair. “What!”

“Unless the computer guesses the correct key but just keeps guessing because it doesn’t realize it found the right key.” Strathmore looked bleak. “I think this algorithm has got a rotating cleartext.”

Susan gaped.

The notion of a rotating cleartext function was first put forth in an obscure, 1987 paper by a Hungarian mathematician, Josef Harne. Because brute-force computers broke codes by examining cleartext for identifiable word patterns, Harne proposed an encryption algorithm that, in addition to encrypting, shifted decrypted cleartext over a time variant. In theory, the perpetual mutation would ensure that the attacking computer would never locate recognizable word patterns and thus never know when it had found the proper key. The concept was somewhat like the idea of colonizing Mars—fathomable on an intellectual level, but, at present, well beyond human ability.

“Where did you get this thing?” she demanded.

The commander’s response was slow. “A public sector programmer wrote it.”

“What?” Susan collapsed back in her chair. “We’ve got the best programmers in the world downstairs! All of us working together have never even come close to writing a rotating cleartext function. Are you trying to tell me some punk with a PC figured out how to do it?”

Strathmore lowered his voice in an apparent effort to calm her. “I wouldn’t call this guy a punk.”

Susan wasn’t listening. She was convinced there had to be some other explanation: A glitch. A virus. Anything was more likely than an unbreakable code.

Strathmore eyed her sternly. “One of the most brilliant cryptographic minds of all time wrote this algorithm.”

Susan was more doubtful than ever; the most brilliant cryptographic minds of all time were in her department, and she certainly would have heard about an algorithm like this.

“Who?” she demanded.

“I’m sure you can guess,” Strathmore said. “He’s not too fond of the NSA.”

“Well, that narrows it down!” she snapped sarcastically.

“He worked on the TRANSLTR project. He broke the rules. Almost caused an intelligence nightmare. I deported him.”

Susan’s face was blank only an instant before going white. “Oh my God …”

Strathmore nodded. “He’s been bragging all year about his work on a brute-force-resistant algorithm.”

“B-but…” Susan stammered. “I thought he was bluffing. He actually did it?”

“He did. The ultimate unbreakable code-writer.”

Susan was silent a long moment. “But… that means…”

Strathmore looked her dead in the eye. “Yes. Ensei Tankado just made TRANSLTR obsolete.”