Client side caches form a large space for web caching that, if properly utilized, can significantly improve the hit ratio. Conventional peer-to-peer web caching schemes fail to consider several critical issues. Some rely on a centralized proxy server for coordination. Most do not consider the frequent arrival and departure of client platforms. In this paper, we propose a decentralized, peer-to-peer web caching scheme in a corporate network. Without proxy servers, each client shares its local cache contents with the others via structured peer-to-peer routing protocols. We design a new replacement policy specific to peer-to-peer systems and consider security and fault tolerance in our approach. Trace-driven simulations show that our scheme is more efficient, secure, and reliable than the existing approaches.