Content pollution mitigation for Content-Centric Networking

Content-Centric Networking - CCN is a prominent architectural proposal for the future Internet. Even though CCN design includes a set of security mechanisms in order to to ensure authenticity, integrity and confidentiality of contents, some security threats still exists. One of these threats is content pollution, where malicious users cause legitimate users to retrieve incorrect contents, what, in the worst scenario, can lead to a denial of service attack. To mitigate this problem it was proposed CCNCheck, a mechanism that makes all routers in the network to check the signature of contents according to the same probability, which makes the mechanism's efficiency very topology-dependent. In this paper we propose two different deployment approaches to CCNCheck. The first one splits the network routers into two groups: border router and core routers. These two groups were associated with two different verification probabilities. In the second approach, we let the verification probability in the border routers to vary dynamically, according to the pollution level perceived by the router. We have shown through simulation experiments that these approaches reduce topology dependency, allow users to retrieve the majority of requested contents and reduces the number of polluted messages forwarded in the network core.