Simple Genius (Sean King & Michelle Maxwell 3)

“Yes, but it would have taken her about a full day to do it. 18,313 is the 2,000th prime number, meaning she would have to have gone through all those that preceded it to see if it divided into 408,508,091 without leaving a remainder. She just saw it in her head, like she said.”

“And tell me why this is so important?”

“Sean—”

“Damn it, Alicia, people are dying here. I’ve agreed to protect Viggie because you think she’s in danger. The least you can do is start telling me why.”

“All right. The world runs on information sent electronically. How to move it from A to B safely is the key to civilization. Using your credit card to buy things, getting cash from an ATM, sending an e-mail, paying bills or purchasing things online. Encryption these days is strictly about numbers and their length. The strongest system is based on asymmetric public key cryptography. It’s the only thing that makes electronic transmissions, from government to commercial to private citizens, safe and thus viable.”

“I think I’ve heard of it. RSA or something?”

“Right. Now, the standard public key is typically a very large number hundreds of digits long that would take a hundred million PCs, working in parallel several thousand years, to figure out the two factors. However, while everyone knows the public key number, or at least your computer does, the only way to read what’s being sent is by unlocking the public key using the two private keys. Those keys are the two factors of the public key and only your computer software knows what they are. To use a simple example, the number thirty-five might be the public key and seven and five would be the private keys. If you know the numbers seven and five you can read the transmission.”

“Like the numbers that Viggie gave you?”

“Yes. With computers getting faster all the time and the practice of running hundreds of millions of computers in massive parallel assaults the encryption standards keep getting ratcheted upward. But, still, all you have to do is add a few more digits to the public key and the time required to break it goes up thousands, if not millions of years.”

“But your research might just throw a monkey wrench in all that.”

“The encryption community is betting on the fact that there is no shortcut to factoring because in 2,000 years of searching no one’s found one. And yet Viggie is able to do it from time to time. Can she do it for bigger numbers? If so, as I said, no electronic transmission is safe and the world as we know it would be drastically different.”

“Back to typewriters, couriers and tin cans strung with wire?”

“It would shut down business and government; the poor consumer would have no idea how to function. And generals could no longer safely communicate with their armies. I doubt most people realize that as late as the Seventies, before public key cryptography was invented, private businesses and governments had to send thousands of couriers out constantly with new codebooks and passwords. No one wants to go back to those days.”

He said, “It’s incredible how our entire civilization is based on not being able to factor huge numbers quickly.”

“We made the bed, now we have to lie in it.”

“Obviously the public isn’t aware of any of this?”

“It would scare the public to death.”

“So do you think there’s a shortcut?”

“Viggie makes me think there might be one. But despite that, my biggest worry right now isn’t about numbers, it’s about Viggie. I can’t let anything happen to her.”

“You think someone knows Viggie might be the key to stopping the world in its tracks?”

“You said Len thought there were spies here. Her father knew about her ability and he’s dead. I don’t know. I just don’t know.”

Sean once more put a comforting hand on her shoulder. “Nothing’s going to happen to her. The FBI and police are around; the place is crawling with guards.”

“That was true before Len was killed,” she pointed out.

“But now I’m on the case.”

“And how exactly do you propose to protect Viggie?”

“How many bedrooms do you have in your bungalow?”

“Four. Why?”

“One for Viggie, one for you and one for me and one left over.”

“You, moving in with me?”

“If I stay in the main house, there’s no way I could get to her in time in case something happened.”