Mayday: Distributed Filtering for Internet Services

Mayday is an architecture that combines overlay networks with lightweight packet filtering to defend against denial of service attacks. The overlay nodes perform client authentication and protocol verification, and then relay the requests to a protected server. The server is protected from outside attack by simple packet filtering rules that can be efficiently deployed even in backbone routers. Mayday generalizes earlier work on Secure Overlay Services. Mayday improves upon this prior work by separating the overlay routing and the filtering, and providing a more powerful set of choices for each. Through this generalization, Mayday supports several different schemes that provide different balances of security and performance, continuum, and supports mechanisms that achieve better security or better performance than earlier systems. To evaluate both Mayday and previous work, we also present several practical attacks, two of them novel, that are effective against filtering-based systems.