Large-scale Mobile Ad Hoc Key Management Scheme

Mobile ad hoc networks is a multi-hop and temporary autonomous network system with a group of wireless mobile terminals. Compared with traditional networks, mobile ad hoc networks faces much more security risk, especially in large-scale ad hoc networks, because of its special characteristics including the dynamic of topology, non-center and no infrastructure and the open and instable of wireless channels. As the foundation of secure communication and secure route, key management has become one of the research focuses in network security.In this paper, two key managements suitable for large-scale network are presented. The first scheme is based on tactical environments. It is used three-layer model in tactical environment, which entirely consistent with realistic battlefield management systems. By means of proxy signature the trust relationship is clear, so the scheme avoids cross authentication between different CAs, thereby reducing the number of cross authentication and the overhead of communication and computation, and at the same time it has a good scalability. Aiming at the conspiracy attack in distributed certification signature, a verification threshold group signature is used in this scheme, which is relied on the difficulty in computing the discrete logarithm and the factorization of RSA large integer. Part of members inside a group can not get any system secret parameters in collusion, thus the conspiracy attack is withstood. Simulation results demonstrate that it is better than traditional threshold cryptosystem with respect to the average signature of time and successful signature rate.The other scheme is based on the ring CA trust model. It using traditional threshold digital signature has a strong security, the CA only has cross authentication with its adjacent other two CA, thereby reducing the number of cross authentication. Between the CA is absolute trust chain, and effective to prevent the malicious signature. At the same time it has a good scalability and robustness, better applied to large-scale ad hoc networks. Simulation results show that it is much improved in communication cost.