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.
Chapter 10
"Ensei Tankado is dead?" Susan felt a wave of nausea. "You killed him? I thought you said-"
"We didn't touch him," Strathmore assured her. "He died of a heart attack. COMINT phoned early this morning. Their computer flagged Tankado's name in a Seville police log through Interpol."
"Heart attack?" Susan looked doubtful. "He was thirty years old."
"Thirty-two," Strathmore corrected. "He had a congenital heart defect."
"I'd never heard that."
"Turned up in his NSA physical. Not something he bragged about."
Susan was having trouble accepting the serendipity of the timing. "A defective heart could kill him-just like that?" It seemed too convenient.
Strathmore shrugged. "Weak heart… combine it with the heat of Spain. Throw in the stress of blackmailing the NSA…."
Susan was silent a moment. Even considering the conditions, she felt a pang of loss at the passing of such a brilliant fellow cryptographer. Strathmore's gravelly voice interrupted her thoughts.
"The only silver lining on this whole fiasco is that Tankado was traveling alone. Chances are good his partner doesn't know yet he's dead. The Spanish authorities said they'd contain the information for as long as possible. We only got the call because COMINT was on the ball." Strathmore eyed Susan closely. "I've got to find the partner before he finds out Tankado's dead. That's why I called you in. I need your help."
Susan was confused. It seemed to her that Ensei Tankado's timely demise had solved their entire problem. "Commander," she argued, "if the authorities are saying he died of a heart attack, we're off the hook; his partner will know the NSA is not responsible."
"Not responsible?" Strathmore's eyes widened in disbelief. "Somebody blackmails the NSA and turns up dead a few days later-and we're not responsible? I'd bet big money Tankado's mystery friend won't see it that way. Whatever happened, we look guilty as hell. It could easily have been poison, a rigged autopsy, any number of things." Strathmore paused. "What was your first reaction when I told you Tankado was dead?"
She frowned. "I thought the NSA had killed him."
"Exactly. If the NSA can put five Rhyolite satellites in geosynchronous orbit over the Mideast, I think it's safe to assume we have the resources to pay off a few Spanish policemen." The commander had made his point.
Susan exhaled. Ensei Tankado is dead. The NSA will be blamed. "Can we find his partner in time?"
"I think so. We've got a good lead. Tankado made numerous public announcements that he was working with a partner. I think he hoped it would discourage software firms from doing him any harm or trying to steal his key. He threatened that if there was any foul play, his partner would publish the key, and all firms would suddenly find themselves in competition with free software."
"Clever." Susan nodded.
Strathmore went on. "A few times, in public, Tankado referred to his partner by name. He called him North Dakota."
"North Dakota? Obviously an alias of some sort."
"Yes, but as a precaution I ran an Internet inquiry using North Dakota as a search string. I didn't think I'd find anything, but I turned up an E-mail account." Strathmore paused. "Of course I assumed it wasn't the North Dakota we were looking for, but I searched the account just to be sure. Imagine my shock when I found the account was full of E-mail from Ensei Tankado." Strathmore raised his eyebrows. "And the messages were full of references to Digital Fortress and Tankado's plans to blackmail the NSA."
Susan gave Strathmore a skeptical look. She was amazed the commander was letting himself be played with so easily. "Commander," she argued, "Tankado knows full well the NSA can snoop E-mail from the Internet; he would never use E-mail to send secret information. It's a trap. Ensei Tankado gave you North Dakota. He knew you'd run a search. Whatever information he's sending, he wanted you to find-it's a false trail."
"Good instinct," Strathmore fired back, "except for a couple of things. I couldn't find anything under North Dakota, so I tweaked the search string. The account I found was under a variation-NDAKOTA."
Susan shook her head. "Running permutations is standard procedure. Tankado knew you'd try variations until you hit something. NDAKOTA's far too easy an alteration."
"Perhaps," Strathmore said, scribbling words on apiece of paper and handing it to Susan. "But look at this."
Susan read the paper. She suddenly understood the Commander's thinking. On the paper was North Dakota's E-mail address.
[email protected] It was the letters ARA in the address that had caught Susan's eye. ARA stood for American Remailers Anonymous, a well-known anonymous server.
Anonymous servers were popular among Internet users who wanted to keep their identities secret. For a fee, these companies protected an E-mailer's privacy by acting as a middleman for electronic mail. It was like having a numbered post office box-a user could send and receive mail without ever revealing his true address or name. The company received E-mail addressed to aliases and then forwarded it to the client's real account. The remailing company was bound by contract never to reveal the identity or location of its real users.
"It's not proof," Strathmore said. "But it's pretty suspicious."
Susan nodded, suddenly more convinced. "So you're saying Tankado didn't care if anybody searched for North Dakota because his identity and location are protected by ARA."
"Exactly."
Susan schemed for a moment. "ARA services mainly U.S. accounts. You think North Dakota might be over here somewhere?"
Strathmore shrugged. "Could be. With an American partner, Tankado could keep the two pass-keys separated geographically. Might be a smart move."
Susan considered it. She doubted Tankado would have shared his pass-key with anyone except a very close friend, and as she recalled, Ensei Tankado didn't have many friends in the States.
"North Dakota,"
she mused, her cryptological mind mulling over the possible meanings of the alias. "What does his E-mail to Tankado sound like?"
"No idea. COMINT only caught Tankado's outbound. At this point all we have on North Dakota is an anonymous address."
Susan thought a minute. "Any chance it's a decoy?"
Strathmore raised an eyebrow. "How so?"
"Tankado could be sending bogus E-mail to a dead account in hopes we'd snoop it. We'd think he's protected, and he'd never have to risk sharing his pass-key. He could be working alone."
Strathmore chuckled, impressed. "Tricky idea, except for one thing. He's not using any of his usual home or business Internet accounts. He's been dropping by Doshisha University and logging on to their mainframe. Apparently he's got an account there that he's managed to keep secret. It's a very well-hidden account, and I found it only by chance." Strathmore paused. "So… if Tankado wanted us to snoop his mail, why would he use a secret account?"
Susan contemplated the question. "Maybe he used a secret account so you wouldn't suspect a ploy? Maybe Tankado hid the account just deep enough that you'd stumble on to it and think you got lucky. It gives his E-mail credibility."
Strathmore chuckled. "You should have been a field agent. The idea's a good one. Unfortunately, every letter Tankado sends gets a response. Tankado writes, his partner responds."
Susan frowned. "Fair enough. So, you're saying North Dakota's for real."
"Afraid so. And we've got to find him. And quietly. If he catches wind that we're onto him, it's all over."
Susan now knew exactly why Strathmore had called her in. "Let me guess," she said. "You want me to snoop ARA's secure database and find North Dakota's real identity?"
Strathmore gave her a tight smile. "Ms. Fletcher, you read my mind."
When it came to discreet Internet searches, Susan Fletcher was the woman for the job. A year ago, a senior White House official had been receiving E-mail threats from someone with an anonymous E-mail address. The NSA had been asked to locate the individual. Although the NSA had the clout to demand the remailing company reveal the user's identity, it opted for a more subtle method-a "tracer."
Susan had created, in effect, a directional beacon disguised as a piece of E-mail. She could send it to the user's phony address, and the remailing company, performing the duty for which it had been contracted, would forward it to the user's real address. Once there, the program would record its Internet location and send word back to the NSA. Then the program would disintegrate without a trace. From that day on, as far as the NSA was concerned, anonymous remailers were nothing more than a minor annoyance.
"Can you find him?" Strathmore asked.
"Sure. Why did you wait so long to call me?"
"Actually"-he frowned-"I hadn't planned on calling you at all. I didn't want anyone else in the loop. I tried to send a copy of your tracer myself, but you wrote the damn thing in one of those new hybrid languages; I couldn't get it to work. It kept returning nonsensical data. I finally had to bite the bullet and bring you in."
Susan chuckled. Strathmore was a brilliant cryptographic programmer, but his repertoire was limited primarily to algorithmic work; the nuts and bolts of less lofty "secular" programming often escaped him. What was more, Susan had written her tracer in a new, crossbreed programming language called LIMBO; it was understandable that Strathmore had encountered problems. "I'll take care of it." She smiled, turning to leave. "I'll be at my terminal."
"Any idea on a time frame?"
Susan paused. "Well… it depends on how efficiently ARA forwards their mail. If he's here in the States and uses something like AOL or CompuServe, I'll snoop his credit card and get a billing address within the hour. If he's with a university or corporation, it'll take a little longer." She smiled uneasily. "After that, the rest is up to you."
Susan knew that "the rest" would be an NSA strike team, cutting power to the guy's house and crashing through his windows with stun guns. The team would probably think it was on a drug bust. Strathmore would undoubtedly stride through the rubble himself and locate the sixty-four-character pass-key. Then he would destroy it. Digital Fortress would languish forever on the Internet, locked for all eternity.
"Send the tracer carefully," Strathmore urged. "If North Dakota sees we're onto him, he'll panic, and I'll never get a team there before he disappears with the key."
"Hit and run," she assured. "The moment this thing finds his account, it'll dissolve. He'll never know we were there."
The commander nodded tiredly. "Thanks."
Susan gave him a soft smile. She was always amazed how even in the face of disaster Strathmore could muster a quiet calm. She was convinced it was this ability that had defined his career and lifted him to the upper echelons of power.
As Susan headed for the door, she took a long look down at TRANSLTR. The existence of an unbreakable algorithm was a concept she was still struggling to grasp. She prayed they'd find North Dakota in time.
"Make it quick," Strathmore called, "and you'll be in the Smoky Mountains by nightfall."
Susan froze in her tracks. She knew she had never mentioned her trip to Strathmore. She wheeled. Is the NSA tapping my phone?
Strathmore smiled guiltily. "David told me about your trip this morning. He said you'd be pretty ticked about postponing it."
Susan was lost. "You talked to David this morning?"
"Of course." Strathmore seemed puzzled by Susan's reaction. "I had to brief him."
"Brief him?" she demanded. "For what?"
"For his trip. I sent David to Spain."
Chapter 11
Spain. I sent David to Spain. The commander's words stung.
"David's in Spain?" Susan was incredulous. "You sent him to Spain?" Her tone turned angry. "Why?"
Strathmore looked dumbfounded. He was apparently not accustomed to being yelled at, even by his head cryptographer. He gave Susan a confused look. She was flexed like a mother tiger defending her cub.
"Susan," he said. "You spoke to him, didn't you? David did explain?"
She was too shocked to speak. Spain? That's why David postponed our Stone Manor trip?
"I sent a car for him this morning. He said he was going to call you before he left. I'm sorry. I thought-"
"Why would you send David to Spain?"
Strathmore paused and gave her an obvious look. "To get the other pass-key."
"What other pass-key?"
"Tankado's copy."
Susan was lost. "What are you talking about?"
Strathmore sighed. "Tankado surely would have had a copy of the pass-key on him when he died. I sure as hell didn't want it floating around the Seville morgue."
"So you sent David Becker?" Susan was beyond shock. Nothing was making sense. "David doesn't even work for you!"
Strathmore looked startled. No one ever spoke to the deputy director of the NSA that way. "Susan," he said, keeping his cool, "that's the point. I needed-"
The tiger lashed out. "You've got twenty thousand employees at your command! What gives you the right to send my fiance?"
"I needed a civilian courier, someone totally removed from government. If I went through regular channels and someone caught wind-"
"And David Becker is the only civilian you know?"
"No! David Becker is not the only civilian I know! But at six this morning, things were happening quickly! David speaks the language, he's smart, I trust him, and I thought I'd do him a favor!"
"A favor?" Susan sputtered. "Sending him to Spain is a favor?"
"Yes! I'm paying him ten thousand for one day's work. He'll pick up Tankado's belongings, and he'll fly home. That's a favor!"
Susan fell silent. She understood. It was all about money.
Her thoughts wheeled back five months to the night the president of Georgetown University had offered David a promotion to the language department chair. The president had warned him that his teaching hours would be cut back and that there would be increased paperwork, but
there was also a substantial raise in salary. Susan had wanted to cry out David, don't do it! You'll be miserable. We have plenty of money-who cares which one of us earns it? But it was not her place. In the end, she stood by his decision to accept. As they fell asleep that night, Susan tried to be happy for him, but something inside kept telling her it would be a disaster. She'd been right-but she'd never counted on being so right.
"You paid him ten thousand dollars?" she demanded. "That's a dirty trick!"
Strathmore was fuming now. "Trick? It wasn't any goddamn trick! I didn't even tell him about the money. I asked him as a personal favor. He agreed to go."
"Of course he agreed! You're my boss! You're the deputy director of the NSA! He couldn't say no!"
"You're right," Strathmore snapped. "Which is why I called him. I didn't have the luxury of-"
"Does the director know you sent a civilian?"
"Susan," Strathmore said, his patience obviously wearing thin, "the director is not involved. He knows nothing about this."
Susan stared at Strathmore in disbelief. It was as if she no longer knew the man she was talking to. He had sent her fiance-a teacher-on an NSA mission and then failed to notify the director about the biggest crisis in the history of the organization.
"Leland Fontaine hasn't been notified?"
Strathmore had reached the end of his rope. He exploded. "Susan, now listen here! I called you in here because I need an ally, not an inquiry! I've had one hell of morning. I downloaded Tankado's file last night and sat here by the output printer for hours praying TRANSLTR could break it. At dawn I swallowed my pride and dialed the director-and let me tell you, that was a conversation I was really looking forward to. Good morning, sir. I'm sorry to wake you. Why am I calling? I just found out TRANSLTR is obsolete. It's because of an algorithm my entire top-dollar Crypto team couldn't come close to writing!" Strathmore slammed his fist on the desk.
Susan stood frozen. She didn't make a sound. In ten years, she had seen Strathmore lose his cool only a handful of times, and never once with her.
Ten seconds later neither one of them had spoken. Finally Strathmore sat back down, and Susan could hear his breathing slowing to normal. When he finally spoke, his voice was eerily calm and controlled.
"Unfortunately," Strathmore said quietly, "it turns out the director is in South America meeting with the President of Colombia. Because there's absolutely nothing he could do from down there, I had two options-request he cut his meeting short and return, or handle this myself." There was along silence. Strathmore finally looked up, and his tired eyes met Susan's. His expression softened immediately. "Susan, I'm sorry. I'm exhausted. This is a nightmare come true. I know you're upset about David. I didn't mean for you to find out this way. I thought you knew."
Susan felt a wave of guilt. "I overreacted. I'm sorry. David is a good choice."
Strathmore nodded absently. "He'll be back tonight."
Susan thought about everything the commander was going through-the pressure of overseeing TRANSLTR, the endless hours and meetings. It was rumored his wife of thirty years was leaving him. Then on top of it, there was Digital Fortress-the biggest intelligence threat in the history of the NSA, and the poor guy was flying solo. No wonder he looked about to crack.
"Considering the circumstances," Susan said, "I think you should probably call the director."
Strathmore shook his head, a bead of sweat dripping on his desk. "I'm not about to compromise the director's safety or risk a leak by contacting him about a major crisis he can do nothing about."
Susan knew he was right. Even in moments like these, Strathmore was clear-headed. "Have you considered calling the President?"
Strathmore nodded. "Yes. I've decided against it."
Susan had figured as much. Senior NSA officials had the right to handle verifiable intelligence emergencies without executive knowledge. The NSA was the only U.S. intelligence organization that enjoyed total immunity from federal accountability of any sort. Strathmore often availed himself of this right; he preferred to work his magic in isolation.
"Commander," she argued, "this is too big to be handled alone. You've got to let somebody else in on it."