Chapter 16 Page 7 of 7

The two NSA men and Templemeyer listened to Jonny’s carefully scripted presentation without interruption. When he was finished Little said, “yes, well it looks like you have the criminal investigation under control. As you said Agnes, the FBI is in their element there and while the NSA would be happy to help, I doubt that there is much we can do for you there.

“On the other hand, perhaps more can be done on the technical side…”

I wasn’t going to let this opportunity slip by a second time. I said, “One area where we can use some immediate help is CPU cycles.”

Little turned in my direction. “We can certainly let you have some cycles. Just give us your source code,” Little replied. He seemed relieved to be discussing the technical issues again.

“What does your program do?” Dr. Thomas asked.

“We have two programs,” Lisa answered. “The first is a more-or-less futile attempt to trace the bogus EFT’s through the full graph. The program simply tests paths haphazardly. We recognize, of course, that there is an exponential number of paths, but we’re desperate enough to try anything. Who knows, maybe we can stumble upon one of the millwright’s bank accounts.” She paused briefly and smiled sheepishly toward Dr. Thomas. I doubt that his response helped ease her embarrassment.

“Yeah, I’d say that’s a long shot. What’s the other program?”

Anxious to re-establish her credibility, Lisa told him about BIF. “The other program uses a statistical approach to try to identify suspect bank accounts. We analyze each bank account in isolation. We are hoping to be able to sift through all of the accounts in the system for suspicious accounts and then analyze those by hand. We are looking for any accounts with unusual activity. Of course writing programs to automate the search requires that we define what we mean by `unusual’.

“We’ve designed and implemented a small rule-based language that allows us to write simple rules to characterize unusual account activity. This makes it possible to change the rules easily and thereby redefine the profiles for suspicious accounts.”

I picked up the explanation at this point. “We have several rule sets that we have developed already,” I explained, “and we have been experimenting with them. The trouble is that the program is extremely slow. Testing a single bank account is order n2 where n is the number of rules. On top of that, some of the individual rules take a long time to run against a single account. When you consider that there are millions of bank accounts in the EFT network you can appreciate just how big the problem is. Even for our current rule sets, which are still much smaller than the profiles we anticipate we’ll want to use soon, it takes us about a week to run through all the data we have.”

“What are you running it on now?”

Lisa answered. “We are using a couple of Pentiums running Linux. I think they are 150 MHz and 90 MHz,” she said, as she glanced toward me for confirmation. I nodded and added that the code was written in C. Dr. Thomas nodded his head, apparently satisfied with this answer.

“That should be easy to port,” he said. “Would you be upset if we tinkered with the source a bit? We have some people that are quite skilled at optimizing programs for performance. In fact, it sounds like this problem may lend itself quite nicely to a parallel algorithm.”

“Absolutely!” exclaimed Lisa. “This is an excellent opportunity for parallelism. Not only do we test each bank account independently, but even within the tests for a single account there are opportunities for parallel testing of rules.”

“How soon can you get the source to us?” asked Little.

“We can give you a tape before you leave here today,” Lisa replied.

Both Mr. Little and Dr. Thomas seemed pleased with this and Mr. Little stood up as if to go. Agnes still had some matters she apparently wanted to discuss, but seemed reluctant to do so with the rest of us in the room. Sensing this, I suggested that Lisa and I go prepare the tape. Jonny said he’d join us, and the three of us left. As we closed the door behind us I heard Agnes saying once again that the Bureau was pleased to have the assistance of the NSA but that the criminal investigation was well under control and that they really didn’t need help.

“Turf wars,” muttered Jonny. I wasn’t sure whether I should feel sorry for Agnes or disgusted. I decided to feel sorry; I liked Agnes.