Risk management of digital certificates in ad hoc and P2P networks

In nonhierarchical Public Key Infrastructure (PKI), any user can be a Certificate Authority (CA) to issue digital certificates to other users. As there is no single root CA, it is difficult to check the validity of certificates issued by unknown CAs. It is very risky to trust them without in-depth analysis. How users issue certificates in the real world has not been studied. Solomon Asch's conformity experiment reveals that peoples' decisions are influenced by others. To reduce the risk of trusting malicious certificate issuers, we propose two novel methods, micro method and macro method, for users to make trust decisions based on the relationships among the CAs. They will improve the security in ad hoc networks and Peer-to-Peer (P2P) communications.