Digital Fortress

Chapter 7-9
Chapter 7

Susan's mind was racing-Ensei Tankado wrote a program that creates unbreakable codes! She could barely grasp the thought.

"Digital Fortress," Strathmore said. "That's what he's calling it. It's the ultimate counterintelligence weapon. If this program hits the market, every third grader with a modem will be able to send codes the NSA can't break. Our intelligence will be shot."

But Susan's thoughts were far removed from the political implications of Digital Fortress. She was still struggling to comprehend its existence. She'd spent her life breaking codes, firmly denying the existence of the ultimate code. Every code is breakable-the Bergofsky Principle! She felt like an atheist coming face to face with God.

"If this code gets out," she whispered, "cryptography will become a dead science."

Strathmore nodded. "That's the least of our problems."

"Can we pay Tankado off? I know he hates us, but can't we offer him a few million dollars? Convince him not to distribute?"

Strathmore laughed. "A few million? Do you know what this thing is worth? Every government in the world will bid top dollar. Can you imagine telling the President that we're still cable-snooping the Iraqis but we can't read the intercepts anymore? This isn't just about the NSA, it's about the entire intelligence community. This facility provides support for everyone-the FBI, CIA, DEA; they'd all be flying blind. The drug cartels' shipments would become untraceable, major corporations could transfer money with no paper trail and leave the IRS out in the cold, terrorists could chat in total secrecy-it would be chaos."

"The EFF will have field day," Susan said, pale.

"The EFF doesn't have the first clue about what we do here," Strathmore railed in disgust. "If they knew how many terrorist attacks we've stopped because we can decrypt codes, they'd change their tune."

Susan agreed, but she also knew the realities; the EFF would never know how important TRANSLTR was. TRANSLTR had helped foil dozens of attacks, but the information was highly classified and would never be released. The rationale behind the secrecy was simple: The government could not afford the mass hysteria caused by revealing the truth; no one knew how the public would react to the news that there had been two nuclear close calls by fundamentalist groups on U.S. soil in the last year.

Nuclear attack, however, was not the only threat. Only last month TRANSLTR had thwarted one of the most ingeniously conceived terrorist attacks the NSA had ever witnessed. An anti-government organization had devised a plan, code-named Sherwood Forest. It targeted the New York Stock Exchange with the intention of "redistributing the wealth." Over the course of six days, members of the group placed twenty-seven nonexplosive flux pods in the buildings surrounding the Exchange. These devices, when detonated, create a powerful blast of magnetism. The simultaneous discharge of these carefully placed pods would create a magnetic field so powerful that all magnetic media in the Stock Exchange would be erased-computer hard drives, massive ROM storage banks, tape backups, and even floppy disks. All records of who owned what would disintegrate permanently.

Because pinpoint timing was necessary for simultaneous detonation of the devices, the flux pods were interconnected over Internet telephone lines. During the two-day countdown, the pods' internal clocks exchanged endless streams of encrypted synchronization data. The NSA intercepted the data-pulses as a network anomaly but ignored them as a seemingly harmless exchange of gibberish. But after TRANSLTR decrypted the data streams, analysts immediately recognized the sequence as a network-synchronized countdown. The pods were located and removed a full three hours before they were scheduled to go off.

Susan knew that without TRANSLTR the NSA was helpless against advanced electronic terrorism. She eyed the Run-Monitor. It still read over fifteen hours. Even if Tankado's file broke right now, the NSA was sunk. Crypto would be relegated to breaking less than two codes a day. Even at the present rate of 150 a day, there was still a backlog of files awaiting decryption.

"Tankado called me last month," Strathmore said, interrupting Susan's thoughts.

Susan looked up. "Tankado called you?"

He nodded. "To warn me."

"Warn you? He hates you."

"He called to tell me he was perfecting an algorithm that wrote unbreakable codes. I didn't believe him."

"But why would he tell you about it?" Susan demanded. "Did he want you to buy it?"

"No. It was blackmail."

Things suddenly began falling into place for Susan. "Of course," she said, amazed. "He wanted you to clear his name."

"No," Strathmore frowned. "Tankado wanted TRANSLTR."

"TRANSLTR?"

"Yes. He ordered me to go public and tell the world we have TRANSLTR. He said if we admitted we can read public E-mail, he would destroy Digital Fortress."

Susan looked doubtful.

Strathmore shrugged. "Either way, it's too late now. He's posted a complimentary copy of Digital Fortress at his Internet site. Everyone in the world can download it."

Susan went white. "He what!"

"It's a publicity stunt. Nothing to worry about. The copy he posted is encrypted. People can download it, but nobody can open it. It's ingenious, really. The source code for Digital Fortress has been encrypted, locked shut."

Susan looked amazed. "Of course! So everybody can have a copy, but nobody can open it."

"Exactly. Tankado's dangling a carrot."

"Have you seen the algorithm?"

The commander looked puzzled. "No, I told you it's encrypted."

Susan looked equally puzzled. "But we've got TRANSLTR; why not just decrypt it?" But when Susan saw Strathmore's face, she realized the rules had changed. "Oh my God." She gasped, suddenly understanding. "Digital Fortress is encrypted with itself?"

Strathmore nodded. "Bingo."

Susan was amazed. The formula for Digital Fortress had been encrypted using Digital Fortress. Tankado had posted a priceless mathematical recipe, but the text of the recipe had been scrambled. And it had used itself to do the scrambling.

"It's Biggleman's Safe," Susan stammered in awe.

Strathmore nodded. Biggleman's Safe was a hypothetical cryptography scenario in which a safe builder wrote blueprints for an unbreakable safe. He wanted to keep the blueprints a secret, so he built the safe and locked the blueprints inside. Tankado had done the same thing with Digital Fortress. He'd protected his blueprints by encrypting them with the formula outlined in his blueprints.

"And the file in TRANSLTR?" Susan asked.

"I downloaded it from Tankado's Internet site like everyone else. The NSA is now the proud owner of the Digital Fortress algorithm; we just can't open it."

Susan marveled at Ensei Tankado's ingenuity. Without revealing his algorithm, he had proven to the NSA that it was unbreakable.

Strathmore handed her a newspaper clipping. It was a translated blurb from the Nikkei Shimbun, the Japanese equivalent of the Wall Street Journal, stating that the Japanese programmer Ensei Tankado had completed a mathematical formula he claimed could write unbreakable codes. The formula was called Digital Fortress and was available for review on the Internet. The programmer would be auctioning it off to the highest bidder. The column went on to say that although there was enormous interest in Japan, the few U.S. software companies who had heard about Digital Fortress deemed the claim preposterous, akin to turning lead to gold. The formula, they said, was a hoax and not to be taken seriously.

Susan looked up. "An auction?"

Strathmore nodded. "Right now every software company in Japan has downloaded an encrypted copy of Digital Fortress and is trying to crack it open. Every second they can't, the bidding price climbs."

"That's absurd," Susan shot back. "All the new encrypted files are uncrackable unless you have TRANSLTR. Digital Fortress could be nothing more than a generic, public-domain algorithm, and none of these companies could break it."

"But it's a brilliant marketing ploy," Strathmore said. "Think about it-all brands of bulletproof glass stop bullets, but if a company dares you to put a bullet through theirs, suddenly everybody's trying."

"And the Japanese actually believe Digital Fortress is different? Better than everything else on the market?"

"Tankado may have been shunned, but everybody knows he's a genius. He's practically a cult icon among hackers. If Tankado says the algorithm's unbreakable, it's unbreakable."

But they're all unbreakable as far as the public knows!"

"Yes..." Strathmore mused. "For the moment."

"What's that supposed to mean?"

Strathmore sighed. "Twenty years ago no one imagined we'd be breaking twelve-bit stream ciphers. But technology progressed. It always does. Software manufacturers assume at some point computers like TRANSLTR will exist. Technology is progressing exponentially, and eventually current public-key algorithms will lose their security. Better algorithms will be needed to stay ahead of tomorrow's computers."

"And Digital Fortress is it?"

"Exactly. An algorithm that resists brute force will never become obsolete, no matter how powerful code-breaking computers get. It could become a world standard overnight."

Susan pulled in a long breath. "God help us," she whispered. "Can we make a bid?"

Strathmore shook his head. "Tankado gave us our chance. He made that clear. It's too risky anyway; if we get caught, we're basically admitting that we're afraid of his algorithm. We'd be making a public confession not only that we have TRANSLTR but that Digital Fortress is immune."

"What's the time frame?"

Strathmore frowned. "Tankado planned to announce the highest bidder tomorrow at noon."

Susan felt her stomach tighten. "Then what?"

"The arrangement was that he would give the winner the pass-key."

"The pass-key?"

"Part of the ploy. Everybody's already got the algorithm, so Tankado's auctioning off the pass-key that unlocks it."

Susan groaned. "Of course." It was perfect. Clean and simple. Tankado had encrypted Digital Fortress, and he alone held the pass-key that unlocked it. She found it hard to fathom that somewhere out there-probably scrawled on a piece of paper in Tankado's pocket-there was a sixty-four-character pass-key that could end U.S. intelligence gathering forever.

Susan suddenly felt ill as she imagined the scenario. Tankado would give his pass-key to the highest bidder, and that company would unlock the Digital Fortress file. Then it probably would embed the algorithm in a tamper-proof chip, and within five years every computer would come preloaded with a Digital Fortress chip. No commercial manufacturer had ever dreamed of creating an encryption chip because normal encryption algorithms eventually become obsolete. But Digital Fortress would never become obsolete; with a rotating cleartext function, no brute-force attack would ever find the right key. A new digital encryption standard. From now until forever. Every code unbreakable. Bankers, brokers, terrorists, spies. One world-one algorithm.

Anarchy.

"What are the options?" Susan probed. She was well aware that desperate times called for desperate measures, even at the NSA.

"We can't remove him, if that's what you're asking."

It was exactly what Susan was asking. In her years with the NSA, Susan had heard rumors of its loose affiliations with the most skilled assassins in the world-hired hands brought in to do the intelligence community's dirty work.

Strathmore shook his head. "Tankado's too smart to leave us an option like that."

Susan felt oddly relieved. "He's protected?"

"Not exactly."

"In hiding?"

Strathmore shrugged. "Tankado left Japan. He planned to check his bids by phone. But we know where he is."

"And you don't plan to make a move?"

"No. He's got insurance. Tankado gave a copy of his pass-key to an anonymous third party... in case anything happened."

Of course, Susan marveled. A guardian angel. "And I suppose if anything happens to Tankado, the mystery man sells the key?"

"Worse. Anyone hits Tankado, and his partner publishes."

Susan looked confused. "His partner publishes the key?"

Strathmore nodded. "Posts it on the Internet, puts it in newspapers, on billboards. In effect, he gives it away."

Susan's eyes widened. "Free downloads?"

"Exactly. Tankado figured if he was dead, he wouldn't need the money-why not give the world a little farewell gift?"

There was a long silence. Susan breathed deeply as if to absorb the terrifying truth. Ensei Tankado has created an unbreakable algorithm. He's holding us hostage.

She suddenly stood. Her voice was determined. "We must contact Tankado! There must be a way to convince him not to release! We can offer him triple the highest bid! We can clear his name! Anything!"

"Too late," Strathmore said. He took a deep breath. "Ensei Tankado was found dead this morning in Seville, Spain."

Chapter 8

The twin-engine Learjet 60 touched down on the scorching runway. Outside the window, the barren landscape of Spain's lower extremadura blurred and then slowed to a crawl.

"Mr. Becker?" a voice crackled. "We're here."

Becker stood and stretched. After unlatching the overhead compartment, he remembered he had no luggage. There had been no time to pack. It didn't matter-he'd been promised the trip would be brief, in and out.

As the engines wound down, the plane eased out of the sun and into a deserted hangar opposite the main terminal. A moment later the pilot appeared and popped the hatch. Becker tossed back the last of his cranberry juice, put the glass on the wet bar, and scooped up his suit coat.

The pilot pulled a thick manila envelope from his flight suit. "I was instructed to give you this." He handed it to Becker. On the front, scrawled in blue pen, were the words:

KEEP THE CHANGE.

Becker thumbed through the thick stack of reddish bills. "What the...?"

"Local currency," the pilot offered flatly.

"I know what it is," Becker stammered. "But it's... it's too much. All I need is taxi fare." Becker did the conversion in his head. "What's in here is worth thousands of dollars!"

"I have my orders, sir." The pilot turned and hoisted himself back into the cabin. The door slid shut behind him.

Becker stared up at the plane and then down at the money in his hand. After standing a moment in the empty hangar, he put the envelope in his breast pocket, shouldered his suit coat, and headed out across the runway. It was a strange beginning. Becker pushed it from his mind. With a little luck he'd be back in time to salvage some of his Stone Manor trip with Susan.

In and out, he told himself. In and out.

There was no way he could have known.

Chapter 9

Systems security technician Phil Chartrukian had only intended to be inside Crypto a minute-just long enough to grab some paperwork he'd forgotten the day before. But it was not to be.

After making his way across the Crypto floor and stepping into the Sys-Sec lab, he immediately knew something was not right. The computer terminal that perpetually monitored TRANSLTR's internal workings was unmanned and the monitor was switched off.

Chartrukian called out, "Hello?"

There was no reply. The lab was spotless-as if no one had been there for hours.

Although Chartrukian was only twenty-three and relatively new to the Sys-Sec squad, he'd been trained well, and he knew the drill: There was always a Sys-Sec on duty in Crypto... especially on Saturdays when no cryptographers were around.

He immediately powered up the monitor and turned to the duty board on the wall. "Who's on watch?" he demanded aloud, scanning the list of names. According to the schedule, a young rookie named Seidenberg was supposed to have started a double shift at midnight the night before. Chartrukian glanced around the empty lab and frowned. "So where the hell is he?"

As he watched the monitor power up, Chartrukian wondered if Strathmore knew the Sys-Sec lab was unmanned. He had noticed on his way in that the curtains of Strathmore's workstation were closed, which meant the boss was in-not at all uncommon for a Saturday; Strathmore, despite requesting his cryptographers take Saturdays off, seemed to work 365 days a year.

There was one thing Chartrukian knew for certain-if Strathmore found out the Sys-Sec lab was unmanned, it would cost the absent rookie his job. Chartrukian eyed the phone, wondering if he should call the young techie and bail him out; there was an unspoken rule among Sys-Sec that they would watch each other's backs. In Crypto, Sys-Secs were second-class citizens, constantly at odds with the lords of the manor. It was no secret that the cryptographers ruled this multibillion-dollar roost; Sys-Secs were tolerated only because they kept the toys running smoothly.

Chartrukian made his decision. He grabbed the phone. But the receiver never reached his ear. He stopped short, his eyes transfixed on the monitor now coming into focus before him. As if in slow motion, he set down the phone and stared in open-mouthed wonder.

In eight months as a Sys-Sec, Phil Chartrukian had never seen TRANSLTR's Run-Monitor post anything other than a double zero in the hours field. Today was a first.

TIME ELAPSED: 15:17:21

"Fifteen hours and seventeen minutes?" he choked. "Impossible!"

He rebooted the screen, praying it hadn't refreshed properly. But when the monitor came back to life, it looked the same.

Chartrukian felt a chill. Crypto's Sys-Secs had only one responsibility: Keep TRANSLTR "clean"-virus free.

Chartrukian knew that a fifteen-hour run could only mean one thing-infection. An impure file had gotten inside TRANSLTR and was corrupting the programming. Instantly his training kicked in; it no longer mattered that the Sys-Sec lab had been unmanned or the monitors switched off. He focused on the matter at hand-TRANSLTR. He immediately called up a log of all the files that had entered TRANSLTR in the last forty-eight hours. He began scanning the list.

Did an infected file get through? he wondered. Could the security filters have missed something?

As a precaution, every file entering TRANSLTR had to pass through what was known as Gauntlet-a series of powerful circuit-level gateways, packet filters, and disinfectant programs that scanned inbound files for computer viruses and potentially dangerous subroutines. Files containing programming "unknown" to Gauntlet were immediately rejected. They had to be checked by hand. Occasionally Gauntlet rejected entirely harmless files on the basis that they contained programming the filters had never seen before. In that case, the Sys-Secs did a scrupulous manual inspection, and only then, on confirmation that the file was clean, did they bypass Gauntlet's filters and send the file into TRANSLTR.

Computer viruses were as varied as bacterial viruses. Like their physiological counterparts, computer viruses had one goal-to attach themselves to a host system and replicate. In this case, the host was TRANSLTR.

Chartrukian was amazed the NSA hadn't had problems with viruses before. Gauntlet was a potent sentry, but still, the NSA was a bottom feeder, sucking in massive amounts of digital information from systems all over the world. Snooping data was a lot like having indiscriminate sex-protection or no protection, sooner or later you caught something.

Chartrukian finished examining the file list before him. He was now more puzzled than before. Every file checked out. Gauntlet had seen nothing out of the ordinary, which meant the file in TRANSLTR was totally clean.

"So what the hell's taking so long?" he demanded of the empty room. Chartrukian felt himself break a sweat. He wondered if he should go disturb Strathmore with the news.

"A virus probe," Chartrukian said firmly, trying to calm himself down. "I should run a virus probe."

Chartrukian knew that a virus probe would be the first thing Strathmore would request anyway. Glancing out at the deserted Crypto floor, Chartrukian made his decision. He loaded the viral probe software and launched it. The run would take about fifteen minutes.

"Come back clean," he whispered. "Squeaky clean. Tell Daddy it's nothing."

But Chartrukian sensed it was not "nothing." Instinct told him something very unusual was going on inside the great decoding beast.