The Cipher (12 page)

67

A CRYSTAL CHANDELIER
hung from the ceiling of the cozy ballroom. It was big enough to hold maybe a hundred people, but there were fewer than that inside it now: a clump of twenty professors, an equal-sized huddle of students, and a few brave souls from each group daring to network with the other. Most of the professors had plastic stemware in their hands, courtesy of the bar in the corner. A few students were doing damage to the buffet of mini quiches and barbecue sliders. The food sat in silver trays on white-clothed tables under the chandelier, bisecting the room. A single row of chairs lined the walls, a last resort for the socially hopeless.

Smiles didn't belong here at all, but no one had looked twice at him on the way in. He had smiled generously to the girl at the door, wearing the orange lanyard he'd swiped from one of the cardboard boxes behind the registration table. He'd turned the blank name tag around the wrong way.

His plan was officially in motion, and it felt good. Tonight was the first step: identifying the NSA agent, and getting him—or her—interested.

By now, they were thirty minutes into the hour-long reception for the best and brightest math minds in the country. A bunch of universities were hosting the event, looking to woo high school whizzes into their math programs and college kids to their graduate schools. Apparently the NSA did some recruiting here, too—though they did it quietly, the way they liked to do everything else.

Ben had given Smiles this background while they'd scrambled to prepare for this moment. Ben's role here would be easy enough. He'd gone into the reception ahead of Smiles, fifteen minutes ago. All he had to do was give the NSA agent his article as planned, and then hang around long enough to ensure Smiles knew who the agent was. They had placed the article in a bright red folder to make it stand out, but Smiles didn't see anyone carrying a red folder, and he didn't see Ben.

Smiles used a healthy portion of his available willpower to refrain from heading to the bar. He sauntered toward the food instead, checking every face he could on the way. The sliders were soggy, and there was no such thing as a good mini quiche. What was wrong with good old pizza rolls? Smiles shook his head as he slapped a few shrimp tarts on his plate and reminded himself he wasn't there for the food.

Luckily, a few of the students hadn't dressed up. He didn't look quite as out of place as he could have in his plain white T-shirt, the classiest piece of clothing he'd brought on the trip. He was bobbing his head for a better angle into the collection of students when he heard a voice at his back.

“Aren't those delectable?”

Smiles wheeled to find a tall bald man with thin-frame glasses and a name tag with an intimidating number of colored ribbons hanging from it. It said:
PETER WELSH, P
H.D., CRYPTCON CHAIRMAN
.

Oh, great. Smiles was talking to the head honcho of the entire conference.

“Peter,” he said, extending a bony hand.

Smiles shook it and forced himself at ease. “Like I don't know who
you
are, Dr. Welsh.”

The chairman guffawed and picked up a slider, taking it down in a bite. All the while, Smiles made a half-circle maneuver to get a better look at the attendees. The event was going to be breaking up soon, and Smiles needed to find the NSA agent fast.

“Well, you've got the advantage on me, then,” the chairman said. “Tell me a little about yourself. I love hearing about our talented students. You're all so impressive.”

“I'm Harold,” Smiles said. “I just flew in, actually, but the conference looks great. Per usual. You put on such a great show.”

Smiles was pretty pleased with himself. The chairman seemed to be eating out of his hand. The ribbons on his name tag fluttered as he leaned in conspiratorially, like they were old friends. “What's your area of interest, Harold?”

“Excuse me?”

Smiles had just spied Ben in the corner of the room. When their eyes met, Ben's went wide. Apparently, he knew who Smiles was talking to. His lips read:
What the . . . ?

Smiles shrugged helplessly, then saw Ben direct his eyes to the far wall. There, in the same blue suit they'd seen him in earlier, was the guy they'd hidden from in the hallway. The copier salesman. He was holding a bright red folder in his hands, tossing his empty food plate away. Ben hadn't been paranoid after all—the guy was, in fact, the NSA agent. And now he was shaking hands with people, ready to leave.

“Your niche,” the chairman said, demanding Smiles's attention. “Tell me what you're working on. I love to hear what you students are up to.”

“Careful there. I could bore you all night with that one.” Smiles hoped for a laugh that would get him off the hook, but the chairman only raised his eyebrows in anticipation as he polished off another slider. Smiles gulped. He summoned every bit of jargon he'd ever heard from Ben. “Well . . . there are these zeta functions, I'm sure you've heard about them. And I've also been dabbling in elliptical curves, those are good. I can't get enough of those, actually. It's a little complicated to explain, but—”

“Tell me where you're from, son.” The chairman reached out and turned his name tag around, finding nothing.

“Like I said, fresh off the plane.” In the distance, Smiles saw the NSA agent leaving the reception. If he got away, they'd lose any chance of making this work. Their plan hadn't even gotten started, and already it was crumbling around him. “Haven't gotten a proper name tag yet, but—”

“What school?” Something had definitely changed in the chairman's tone.

Smiles took a step toward the door. “I, uh . . . Berkeley.” His mother's school was the first to pop into his mind. “But look, I should probably—”

“No, no, hold it right there,” the chairman said, and Smiles had no choice but to stay put. “Berkeley, you say?” Skepticism dripped from his voice, and Smiles had a terrible premonition of what was coming next. “You must be one of Professor Taft's favorites. Alice?”

Oh no. Smiles hadn't seen her, but there she was, emerging from a group of professors. Her dollish cheeks had been flush with wine, but they went pale at the sight of Smiles.

He did the only thing he could. He thrust his plate of shrimp tarts into the chairman's hand and said, “Sorry, Pete, I think I have food poisoning.”

He dashed to the exit, never looking back.

Smiles had three choices: left, right, or straight ahead to the casino lobby. The NSA agent didn't appear in any of the hallways before him. Smiles quickly wrote off the one to the right. It led only to more conference rooms, and CRYPTCON had to be wrapping up for the day. Straight ahead was a good possibility. The shops, Starbucks, and casino all lay in that direction. But the hallway to the left led to an elevator bank—the same one the agent had appeared from that morning. His room was up there, and maybe he was headed back to it now.

Smiles bolted to his left. If it wasn't the right choice, the plan was already up in smoke. There would be no chance of catching him, and even if Ben had a number for the guy, it wasn't likely Smiles could pull this off over the phone. He sprinted forward to the elevators. His ankle gave way as he made a ninety-degree turn at the elevator bank. As he hobbled forward, it appeared useless. There wasn't a soul waiting for the six elevators, three on each side of the small area. Just Smiles, a bowl of artificial flowers, and another confirmation that he was generally useless.

But then Smiles saw the green light ignited above one of the far elevators. Preparing to go up. The doors of the elevator began sliding closed. Quickly. Smiles stumbled forward and blindly thrust his hand between the door panels, just inches apart. They crunched together on his right hand, pinching his knuckles. After an excruciating moment, they pulled lazily apart.

From inside the elevator, the copier salesman eyed him with concern. His eyes were set deep into a hawklike face, and he wore a squared-off crew cut with edges much sharper than those of his travel-worn suit. For a moment, Smiles was too relieved to speak. But then he had to, because the doors were closing again. He jammed his hand against the doorstop and said, “Could I talk to you for a sec?”

It wasn't the best introduction. He was still out of breath from the run, and the guy was tense with suspicion.

“Talk to me?”

“If you would. Just a sec?” Smiles threw out his left hand to the little elevator area, like he was welcoming the guy into his home. “I just came from the student reception. I was hoping to catch you there.”

The agent exited the elevator but wasn't happy about it. “Well, you missed me,” he said, checking his watch, “and I actually have some things—”

“How much would a fast-factoring algorithm be worth to you?” The aggressive approach was a gamble, but it felt right. Smiles had to seize control of this conversation, and quick.

The agent took a moment to absorb what he'd just heard, then laughed. “A lot. So would the Loch Ness monster and Santa Claus's home address. Unfortunately they don't exist.” He circled around Smiles and pressed the call button for the elevator.

“It does exist, and I've got it. Can I prove it to you, or do you want to be the NSA agent who tried to turn away the most valuable information your agency will ever have?”

That last part got to him. Smiles had annoyed the guy, but also gotten his interest. “Two minutes,” he said, holding up fingers in case the words didn't get through. “Where do you want to talk?”

“C'mon.” Smiles led him back the way he'd come, praying that neither the chairman nor his mother would appear down the hallway. He opened the door inside the alcove that he and Ben had hidden in earlier. It led to a classroom-sized space with more chairs lining the walls. Smiles flicked the lights and closed the door behind them.

“Two minutes is all this will take,” he said.

He and Ben had drawn up a script for this discussion, and so far Smiles had followed exactly none of it. But it was coming back to him now. From his back pocket, Smiles pulled some pages he and Ben had printed off the Internet at the business center. They listed the first five hundred prime numbers.

Smiles passed it over to the guy. “Could I ask your name?”

“Ken Gary. And yours?”

“Pick any two of those numbers, Mr. Gary. And don't show me.”

Agent Gary squinted at him. “What is this, a magic trick?”

Ben said the agent would see the logic of the demonstration right away, and despite the guy's moaning, Ben was right. His interest was piqued.

“Pick the two numbers, multiply them together, and tell me what you get.”

Multiplying the two numbers would create a public key—a gate key. If Ben's algorithm worked, using that public key alone he'd be able to identify the two prime numbers the agent had picked—the private key, the house key. It would be solid proof that they could defeat public-key encryption.

Smiles didn't even have to explain it to him. The agent pulled out his phone and opened a calculator app. Smiles turned away till the guy coughed, ready to show him the display.

Smiles copied the number into a text message on his own phone and prayed. Ben had written a quick program that would execute the algorithm on his computer. He called it a cipher. When he received the text, he was going to use the cipher and text back the two primes that the agent had picked. It was all in Ben's hands now, and if he was somehow wrong about his discovery, Smiles was going to look like the biggest ass in the world.

He pressed send and waited. The only delay, Ben told him, would be typing the number into his computer. Once he did that, the prime factors would spit right out.

The agent barely had time to check his watch before an incoming text bleeped onto Smiles's screen. It had two numbers in it.

“17 and 2203,” Smiles said.

The agent crossed his arms, and Smiles knew that Ben had gotten it right. “Is this some parlor game? You have these memorized or something? You have them written down somewhere?”

“There are five hundred numbers on that page. That's two hundred and fifty thousand combinations. That's a lot to memorize, or write down.”

“Who's on the other end of the phone?”

“My associate. He's just keeping the cipher safe.” Smiles liked that.
Associate.
Pretty badass.

The agent inspected the pages, like there might be invisible ink on them or something. Smiles had his full attention now.

“Here's what's going to happen,” Smiles said. “You're going to give me a line where I can reach you. Keep it open at eleven a.m. tomorrow. I'll tell you where to meet me.”

“What happens when I meet you?” The guy was trying to sound amused, but it wasn't working.

“Bring ten public keys with you,” Smiles said, getting back on script. “They can be a hundred digits, two hundred digits, however long you like. No parlor games, no magic. You choose the numbers. I'll produce the private keys for you in seconds.”