Abstract: This article proposed a checking mechanism, named as probabilistic checking before storing based on content popularity (PCS-CP). The design of PCS-CP includes two aspects, one is the node which should check the received content randomly according to its popularity, and the other is the node only stores the legitimate content. On the one hand, PCS-CP can ensure the limited computing resource of node to serve the high popularity content as much as possible. On the other hand, PCS-CP guarantees the authenticity of cached content, and then reduces the computation overhead of node. Because only cooperating with certain caching policy, PCS-CP can maximize its effectiveness. The in-network caching strategy based on cache update time (ICS-CUT) was further proposed to optimize the copy redundancy in network. It is shown that, comparing with checking on hit mechanism, PCS-CP can effectively reduce the average amount of checking in network and well defense the content pollution attack.

Key words: name data networking, content pollution, content checking, checking overhead