Little Brother

people, and the paper had tiny stories about little groups of people that had protested at the BART stations.
    I used the Xnet for almost everything now. I'd set up a fake email address through the Pirate Party, a Swedish political party that hated Internet surveillance and promised to keep their mail accounts a secret from everyone, even the cops. I accessed it strictly via Xnet, hopping from one neighbor's Internet connection to the next, staying anonymous — I hoped — all the way to Sweden. I wasn't using w1n5ton anymore. If Benson could figure it out, anyone could. My new handle, come up with on the spur of the moment, was M1k3y, and I got a lot of email from people who heard in chat rooms and message boards that I could help them troubleshoot their Xnet configurations and connections.
    I missed Harajuku Fun Madness. The company had suspended the game indefinitely. They said that for "security reasons" they didn't think it would be a good idea to hide things and then send people off to find them. What if someone thought it was a bomb? What if someone put a bomb in the same spot?
    What if I got hit by lightning while walking with an umbrella? Ban umbrellas! Fight the menace of lightning!
    I kept on using my laptop, though I got a skin-crawly feeling when I used it. Whoever had wiretapped it would wonder why I didn't use it. I figured I'd just do some random surfing with it every day, a little less each day, so that anyone watching would see me slowly changing my habits, not doing a sudden reversal. Mostly I read those creepy obits — all those thousands of my friends and neighbors dead at the bottom of the Bay.
    Truth be told, I was doing less and less homework every day. I had business elsewhere. I burned new stacks of ParanoidXbox every day, fifty or sixty, and took them around the city to people I'd heard were willing to burn sixty of their own and hand them out to their friends.
    I wasn't too worried about getting caught doing this, because I had good crypto on my side. Crypto is cryptography, or "secret writing," and it's been around since Roman times (literally: Augustus Caesar was a big fan and liked to invent his own codes, some of which we use today for scrambling joke punchlines in email).
    Crypto is math. Hard math. I'm not going to try to explain it in detail because I don't have the math to really get my head around it, either — look it up on Wikipedia if you really want.
    But here's the Cliff's Notes version: Some kinds of mathematical functions are really easy to do in one direction and really hard to do in the other direction. It's easy to multiply two big prime numbers together and make a giant number. It's really, really hard to take any given giant number and figure out which primes multiply together to give you that number.
    That means that if you can come up with a way of scrambling something based on multiplying large primes, unscrambling it without knowing those primes will be hard. Wicked hard. Like, a trillion years of all the computers ever invented working 24/7 won't be able to do it.
    There are four parts to any crypto message: the original message, called the "cleartext." The scrambled message, called the "ciphertext." The scrambling system, called the "cipher." And finally there's the key: secret stuff you feed into the cipher along with the cleartext to make ciphertext.
    It used to be that crypto people tried to keep all of this a secret. Every agency and government had its own ciphers and its own keys. The Nazis and the Allies didn't want the other guys to know how they scrambled their messages, let alone the keys that they could use to descramble them. That sounds like a good idea, right?
    Wrong.
    The first time anyone told me about all this prime factoring stuff, I immediately said, "No way, that's BS. I mean, sure it's hard to do this prime factorization stuff, whatever you say it is. But it used to be impossible to fly or go to the moon or get a hard-drive with more than a few kilobytes of storage. Someone must have invented a way of descrambling the messages." I had visions of a hollow mountain full of National Security Agency mathematicians reading every email in the world and snickering.
    In fact, that's pretty much what happened during World War II. That's the reason that life isn't more like Castle Wolfenstein, where I've spent many days hunting Nazis.
    The thing is, ciphers are hard to keep secret. There's a lot of math that goes into one, and if they're widely used,