On peer-to-peer client web cache sharing

Conventional web caching systems based on client-server model often suffer from the limited cache space and the single point of failure. In this paper, we present a novel peer-to-peer client web caching system, in which end-hosts collectively share their web cache contents. Aggregating these individual web caches, a huge virtual cache space is formed, and the burden on web servers can be greatly lightened. We design an efficient algorithm for managing and searching in the aggregated cache. We also implement consistency control to prevent sharing stale web objects in peers' caches. Finally and most importantly, considering that end-hosts are generally not trustworthy as servers or proxies, we employ an opinion-based sampling technique to minimize the chance of distributing forged copies from malicious nodes. We have built a prototype of the proposed system, and our experimental results demonstrate that it has fast response time with low overhead, and can effectively identify and block malicious peers.