The Design And Implementation Of Distributed Certification Authority System Based On Ad Hoc Network

In recent years, Mobile Ad hoc Network (MANET) technologies have been a research focus in the international academy. Along the in-depth research, its security problems have attracted more attention from researchers. Public Key Infrastructure(PKI)is the best security system for wired networks, but it can not be directly applied into MANET, because there is not a fixed infrastructure in MANET. According to the vulnerable features of Ad Hoc network such as wireless Link, Dynamic topology and no fixed infrastructure, etc. the paper focuses on the distributed CA system in MANET.The main contents discussed in this thesis are as follows. Firstly, some problems were analyzed about MANET such as architecture, Clustering, typical threat and security scheme. Secondly, the paper studies the principles and technologies of Ad Hoc network security, such as symmetric key algorithm ,public key algorithm, threshold theory, PKI-based authentication model, etc; Thirdly, some typical distributed authentication model are studied, a improved Power Control Clustering Algorithm based on MIN-ID Clustering Algorithm is proposed; studies the CA location scheme based on cluster head; a distributed signature scheme is proposed based on no-inverse signature scheme; a proactive secret sharing scheme based on the Elliptic Curve Cryptosystem(ECC) is studied, Key exchange using certificate makes the communication confidentially, integrated and non-repudiation. Finally, design and implement PDCA prototype system based on Elliptic Curve Cryptosystem. The performances of secret key initialization,signature efficiency and so on is tested.Power Control Clustering Algorithm can avoid redundant nodes in a cluster. Secret key shares are refreshed periodically in the proactive secret sharing scheme, thus the adversary is challenged to compromise a certain number of CA nodes between periodic refreshing. Share refreshing is transparent to all nodes.