The Cipher (9 page)

43

“SPILL IT,” SMILES
said.

He snatched up his duffel bag and commandeered the far bed. The morning's drama had worn his nerves thin, and part of him wanted to slump over for a nap. But first, he really needed to hear this.

Ben trailed him inside, pulling a chair out from one of those completely useless tables they put in the corner of hotel rooms. “Okay, okay. But . . . well . . . you're not going to like this.”

Smiles couldn't imagine how Ben's formulas—whatever they amounted to—could possibly affect him. “Try me.”

Ben heaved a sigh. “I figured out something about prime numbers this morning.”

“Umm, yeah, I got that much.”

Ben extracted his notebook from the backpack like he was defusing a bomb. He gripped it tight to his chest. “The thing I figured out—it's more dangerous, in a way, than a nuclear weapon. It could cause all kinds of trouble.”

“No joke, dude, you've got to stop talking in riddles.”

“Just listen. I told you about the Riemann Hypothesis, right?”

“But that's not what you figured out?”

“No,” Ben said.

Even hearing this a second time, it was still a buzzkill.

Smiles was still stuck on the idea of a million-dollar score—probably because it was exactly the kind of thing he wanted for himself someday. When he dared to, he imagined what it would be like to tell his dad that he'd started his own company, that he'd made his first sale, that he was succeeding at something. He just had to find the something, and it had to be relatively easy. Maybe he should go back to that idea he'd had to make a beer pong app for smartphones for when you were drinking but didn't have a Ping-Pong table around. It was pretty brilliant. You could make one for Quarters, too. Spin the Bottle. All kinds of stuff. There had to be tons of cash in those things, and Ben could probably do the programming with his eyes closed.

“Anyway,” Ben said, “I was working on the Riemann Hypothesis, and I got to thinking about the shape of elliptical curves in space and how they—”

Smiles made a rapid rolling movement with his index finger.

“Yeah, fine. I figured out
how to fast-factor the product of two primes
.” Ben said this as if he had just made the Statue of Liberty disappear.

Smiles let the silence hang for a second. He didn't have the first clue what it meant to factor the whatever of blah blah blah. Ben must have seen his confusion, because he grabbed a pad of hotel stationery and a pen. “It's like this,” he said, writing:

3 × 7 = 21

“Three and seven are both prime numbers. You multiply them and get 21, right?”

“Yepper.”

“Okay, well, going this way is easy . . .” He wrote it with an arrow:

3 × 7
21

“Simple. But there's no good way to go backward, to start with 21 and get the 3 and the 7.” He wrote:

21
3 × 7

“Or, there wasn't until today. Now I have an algorithm that can do it in a snap.”

Smiles considered the page. “I take it this means something important,” he said, “besides the fact that you're a math geek?”

Ben wilted with frustration. “Smiles . . . it's, like, revolutionary.”

Something about Ben's disappointed reaction stabbed at him the way it would coming from his dad. “Just kidding you, man.” He straightened up. “Congrats, seriously. But why'd you freak out down there? Saying you weren't safe and everything.”

Ben leaned forward, elbows on his knees. “You should know, Smiles.”

Was he joking? “Well, I don't.”

“All computer encryption—like, your dad's whole company—is built on the premise that you can't factor the product of two prime numbers. But I can do that now.”

Smiles squinted at him. “What are you saying?”

The air-conditioning was blasting into the room's heavy curtains. The air pushed ripples across the fabric, as if ghosts were gathering for a mixer back there. Smiles felt the tingle of goose bumps on his arms.

“I'm saying that if you gave me a halfway decent computer hacker, in about a half hour I could decode any message that Alyce encrypts.”

“Hold up. Really?”

“Any of them,” Ben said. “Anything encrypted by Alyce, or any other company that uses public-key cryptography, I could get.”

Alyce encrypted messages for all kinds of businesses. Smiles didn't really know what they were, but he knew they were big ones. His blood was pumping now in a way that was different from his excitement over the beer pong app.

“So, you could get all the credit card numbers from Amazon?”

Ben let out a hard-edged laugh. “It's like the guy said this morning. Encryption doesn't just protect credit card numbers. It's how they keep
everything
on computer networks secure. People buying stocks. Wire transfers. It's how they control water systems. Airplanes and missiles. Nuclear power plants, for all I know.”

Water systems.

Nuclear power plants.

The stock market.

Smiles was getting a bigger picture now, and as he did, something heavy settled over his body.

“You could see all those things?” Smiles said. “How?”

“'Cause I can generate private keys.”

Smiles closed his eyes, trying to catch up.

“The gate and the door, remember that? That's how public-key cryptography works, but it's just an analogy. Your dad's the one who actually made it work electronically. Without his system, you couldn't exchange secret messages over the Internet with people you didn't trust completely. It was a total revolution, and it's all based on primes.”

Smiles nodded, more to calm Ben down than anything. “So instead of keys, they use prime numbers somehow,” he ventured.

“
Yes, exactly!
”

“Chill. Just break it down.”

Ben pointed to what he'd written before:

3 × 7 = 21

“Three and seven are primes. Because they're primes, they're the
only
two numbers that you can multiply together to get 21.”

“Okay.”

“So 21 is my public key—it opens my gate. And 3 and 7 are my private keys. They open my door.”

“Okay,” Smiles said, feeling a foreign twinge of pride within himself for keeping up.

“So say you want to send me your credit card number. You type it in the computer, and then the encryption program scrambles it up using a formula based on my public key, 21. The way the encryption is written, the only way to undo it is to know the two numbers that when multiplied together equal 21. Which only I know, 'cause they're my private keys.”

“And even though people know that your public key is 21, it's hard to figure out that your private keys are 3 and 7?”

“Right! But that's what I figured out today, how to do this . . .” He underlined:

21
3 × 7

“It's always been impossible to do in a short time with really huge numbers. It's called factoring. The only way that people can do it is to basically try random combinations to see if you get the public key when you multiply them together. With the big numbers they use, it takes forever to try all the possible combinations.”

“Forever? Even with computers?”

Ben nodded. “The sun would burn out before you would get the private keys to a really long public key. Literally. It'll be faster when quantum computing gets here, but for now it takes forever. When your dad started Alyce, he did this thing to prove how good his system was. He put a number out there, the product of two prime numbers. He challenged anyone to find the two prime factors within ten years. Somebody actually figured it out, but it took them twelve years. Now, with my algorithm, I can do it in under a second.”

“Which means you can unscramble the messages.”

“Yeah.” Ben sat back in his chair, spent. “With my algorithm, I can figure out all the private keys in the world.”

Smiles really needed to stretch his legs, but he was glued to the bed. “If somebody got your formula, they could, like, wreck the stock market, couldn't they?”

“They could do anything,” Ben said. “Smiles, this algorithm—the government would consider it an instrument of war. They would actually consider it illegal to possess. Didn't you hear that guy talking about the NSA?”

Smiles nodded.

“They don't even want people talking about little research discoveries. But this is on a different level. This is
everything
. Do you see how badly people would want this algorithm? You see what terrorists could do with this? People would die for—”

“Slow down, slow down. I get it.”

Ben was reentering meltdown mode, but Smiles couldn't blame him. He wasn't kidding about having a nuclear bomb in that backpack.

The whole thing reminded him of when he'd gotten kicked out of Kingsley, just because he'd agreed to keep Darby Fisher's weed in his closet and they happened to find it there. The problem was so huge, there was nothing to do about it.

Ben was looking at Smiles with a deep sadness in his eyes. “Honestly, I was just trying to think of a solution to the Riemann Hypothesis. I was never trying to do this.” He crushed the page from the stationery and flung it to the dresser. “I'm sorry.”

“Sorry?” Smiles didn't understand the apology until it hit him. “Because your algorithm could make my dad's whole company irrelevant.”

“You're not mad at me?”

“No,” he said quickly, though he saw the problem clearly enough. He lifted off the bed with a syrupy weight in his legs and shut off the air-conditioning. After that, he didn't know what to do. Ben took his place on the bed, staring up at the ceiling in a semicatatonic way, and the weighty silence of the room was making Smiles edgy. He felt an urgent desire to play some
Call of Duty
, to shoot some pool, to watch his fish. He could spend hours staring at them, envying their bubbled lives. No intrusions, no pressures, no expectations to meet. Eat your food, play in the rocks, waggle your tail—as far as lifestyles went, it was hard to beat.

Smiles opened the curtains just to do something. Their fifth-floor room looked out on an impossibly big parking lot, and the sun glanced back at Smiles from a thousand windshields. He would have let some fresh air into the room, but he knew they always rigged the windows shut in casino hotels so gamblers couldn't commit suicide after a bad night at the tables.

“I had a pretty strange experience myself this morning,” he said suddenly, surprising himself. “You know that big-shot professor? The special guest? That was my mother. She left when I was two.” He spoke slowly, talking to the view. Ben didn't answer, but it was better that way. He just needed to speak it out loud to someone, and in the silence left by Ben he could imagine Melanie listening to his words. “It was so weird seeing her up there. I thought I'd never see her again in my life. Maybe this morning was the last time, I don't know.”