KadCache: Employing Kad to Mitigate Flash Crowds and Application Layer DDoS Attacks Against Web Servers

Flash crowds or application layer DDoS attacks can severely degrade the availability of websites. Peer-to-peer (P2P) networks have been exploited to amplify DDoS attacks, but we believe their available resource, such as distributed storage and network bandwidth, can be used to mitigate both flash crowds and DDoS attacks. In this poster, we propose a server initiated approach to employing the P2P network as a distributed web cache, so that the workload directed to web servers can be reduced. The experiment using Kad demonstrates the feasibility and robustness of our approach. The latency is comparable to normal direct access to web servers, and the web contents cached in Kad remain reachable despite of the dynamic departure of peers.