There are three major types of security concerns in any file distribution system - denial of service, attacker corrupting the file, and opening up of a remote exploit. This talk will go over how even HTTP-based file distribution is susceptible to all three, and how Napster-style p2p distribution makes the possibilities of all three worse. However, it will encouraging new results in the security implications of using BitTorrent, and show how BitTorrent results in a modest increase in susceptibility to denial of service without significantly changing the other risks when compared to HTTP. Bram Cohen is the author of the highly successful BitTorrent file distribution system, and formerly worked on Mojo Nation. He has extensive experience with both cryptography and networking protocols.