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The Evil — and Beauty — of Peer to Peer File Sharing

July 2005

I am not a criminal. And I don’t encourage criminal behavior. Nevertheless . . .  this month we’re going to talk about peer-to-peer file sharing. Which to many people means one thing: downloading music and movies from the Internet — for free.

If you’re already doing the deed, no need to read this column. Go directly to jail, do not pass Go, do not collect $100.

If you’re not already doing it, this column won’t encourage you to do so. But you need to know about this phenomenon because peer-to-peer is becoming mainstream. And simply, the latest incarnation — BitTorrent — is wonderfully elegant and an important new direction for the Internet.

You must by now be aware of the infamy of file sharing. The latest Star Wars movie, for example, was available online for free downloading even before it was in theaters. It’s theft. People are getting things for free that they would ordinarily have to purchase. And you’ve probably heard the stories about the kids who’ve been arrested in the last couple years for doing this.

Peer-to-peer file sharing, which originated with Napster in 1999, is based on a simple idea: if you’ve “ripped” the latest CD, that is, copied the music to your computer in MP3 format, why not share it across the Internet with others? Software like Napster lets other people access your computer to download you shared songs and movies, and in turn lets you access other people’s computers to download theirs. That’s peer to peer: you’re not downloading from a central server, but from some other individual.

As you can imagine, interest exploded. Napster eventually had 70 million users in its heyday, and nearly 3 billion songs were downloaded. Everybody shares, and everybody gains. That itself was yet another elegant illustration of what makes the Internet so powerful. It was also illegal.

About six months after the appearance of Naptster, the Recording Industry Association of America sued. And in July of 2001, a judge ruled that Napster must not allow the sharing of copyrighted files, effectively shutting down the service.

The problem officials face with peer to peer is that it’s so distributed. It’s difficult to go after 70 million people who are sharing files. However, the way Napster worked is that a central server kept track of where everything was. It would be difficult to shut down 70 million computers, but was a simple matter to shut down the central index.

However, even as the authorities were pursuing Napster, the genie was out of the bottle, and many more peer-to-peer programs were being born. But with a difference: they typically avoided having a central server. Today there’s BitTorrent, Limewire, Gnutella, OpenNap, KaZaA, Morpheus, WinMX, FastTrack, and many more.

The largest may be KaZaA. And it may be among the most dangerous. All these people happily downloading free songs, movies, and more have also discovered to their chagrin that their computers no longer work because they’re so overloaded with spyware and viruses.

So why am I writing about this? I promised not to encourage criminal behavior. The reason is that with the arrival of BitTorrent, peer-to-peer is going mainstream.

Like Napster, which was created by 18-year-old college dropout Shawn Fanning, BitTorrent comes with a legend, a twentysomething computer expert with a mild form of autism and a brilliant mind: Bram Cohen.

Individuals and software companies are increasingly using BitTorrent to distribute their products. This is because of the obvious advantage that you don’t need a powerful central server to handle the download traffic. Rather, it can be better handled by the distributed power of the Internet.

And BitTorrent uses that power more efficiently than any other program. One reason is that BitTorrent divides files into many tiny parts. If someone is downloading a movie from your computer (God forbid), it doesn’t bog down your computer by downloading the whole thing from you. Rather it takes bits and pieces from you and perhaps 50 other computers and then reassembles the file. As soon as you start downloading the pieces, those pieces become available to others.

This torrent of pieces or “bits” flows around the Internet, evenly distributing the work. If you want fast downloads, you must participate in the torrent, making your pieces available. Otherwise, your request to the torrent receives a low priority.

BitTorrent downloads files considerably faster than other services, and may be less prone to spyware and viruses.

BitTorrent is the future of the Internet. But please use it legally.

Related Links:

You can find legal BitTorrent downloads at www.legaltorrents.com. Also, there's a great intro to peer to peer on About.com.

© 2005 by Jim Karpen, Ph.D

E-mail Jim Karpen