Napsters Nine Lives

While observers were quick to predict the demise of Napster after last weeks preliminary injunction, the terms could have been a lot worse for the music swapping service.

Unlike the initial injunction issued in July and stayed on appeal, the new order doesnt hold Napster solely responsible for stopping all unauthorized trading of copyrighted files. Rather, the responsibility for policing the network is shared between Napster and the record companies that filed suit. Napster only must show that it is making every effort, within the limits of its technology, to stop trading specific recordings on lists provided by the plaintiffs.

Companies such as Audible Magic and Cantametrix are offering to help Napster do its policing. They provide sophisticated technology for identifying music files. Both use digital signal processing to measure essential parts of the music itself. That information provides a small fingerprint, on the order of a few hundred to a few thousand bytes, which cannot be altered without significantly changing the sound of the song, executives from both companies said.

Max Wells, chief technology officer and co-founder of Cantametrix, said each identification takes, on the average, less than a half-second.

Napster is in the rather unusual position of hoping that such technology isnt so effective, allowing songs to slip through its security nets.

David Wagner, a professor of computer science at the University of California, Berkeley, said Napsters hopes would likely be borne out. "You can make it annoying enough that the average person on the street is not so likely to use Napster, but its going to be very hard to prevent slightly more savvy people from bypassing these schemes," he said.