A significant challenge for Peer-to-Peer (P2P) systems is maintaining the correctness and consistency of their global data structures and shared contents as peers independently and unpredictably join and leave the system. In such networks, it is necessary that some security mechanisms will be applied with the aim of avoiding attacks based on nonauthorized content modifications. In this paper, we propose a content authentication protocol for pure P2P networks. The scheme also incorporates a rational content access procedure based on proofs of computational effort. Our proposal relies on a set of peers playing the role of a certification authority, since it is unrealistic to assume that appropriate trusted third parties can be deployed in such environments.
Esther Palomar, Juan M. Estévez-Tapiador, J