Privacy Protection Routing and a Self-organized Key Management Scheme in Opportunistic Networks

The opportunistic network adopts the disconnected store-and-forward architecture to provide communication support for the nodes without an infrastructure. As there is no stable communication link between the nodes, so that forwarding messages is via any encountered nodes. Social networks based on such opportunistic networks will have privacy challenges. In this paper, we propose a privacy protection scheme routing based on the utility value. We exploit the Bloom filter to obfuscate the friends lists and the corresponding utility values of nodes in order to make the routing decisions. This is easy to implement with high performance. Considering no infrastructure and stable link in opportunistic networks, this paper presents a self-organized key management system consisting of an identity authentication scheme based on the zero-knowledge proof of the elliptic curve and a key agreement scheme based on the threshold cryptography. The nodes prove their identities by themselves, and each node carries a certificate library to improve the authentication efficiency and success rate. In order to ensure the forward security and improve the session key agreement rate and the success rate, we exploit threshold cryptography to divide the session key, which could reduce the communication consumption of the traditional Diffie-Hellman (DH) algorithm. The experimental simulation results show that the proposed schemes are much better than the existing schemes for opportunistic networks.