Flow-Cookies: Using Bandwidth Amplification to Defend Against DDoS Flooding Attacks

This paper describes flow-cookies which defend against DDoS flooding attacks using bandwidth amplification. "Flow-cookies" is a mechanism in which a Website can reliably send filtering requests to a cooperating node in the network, leveraging its protection bandwidth. In this approach, a third party provider installs a flow-cookies enabled middlebox called the cookie box, in the network at a high bandwidth link. All traffic to or from the protected Web server must traverse the cookie box. The cookie box guarantees that all packets that pass between it and the server belong to a legitimate TCP flow with a valid sender. This implementation is able to operate at gigabit speeds including per-packet IP filtering of millions of addresses. This approach is also very effective against high volume SYN flooding attacks