Research On Path Compression And Security Technologies For Mobile Ad Hoc Networks

With the gradual promotion of the scope of MANET applications, performance optimization and security issues of MANET are more and more concerned. This paper focuses on some key problems in this field and proposes some solutions from the point of adaptability, expansibility, anonymity and authentication.The main achievements of this paper are listed below:(1) We proposed a dynamic model for analyzing path compression algorithm in MANET. Based on the analysis to the probability distribution of time-t relevant movement vector of two MANET nodes, this model constructs the quantitative relationship between network parameters and path compression probability. The model takes the mobility and expansibility of MANET into account and provides the theoretic basis for developing and analyzing path compression algorithm. The simulation results of SHORT and PCA show that it is a correct and efficient dynamic model for path compression.(2) To overcome the shortcomings of traditional path compression techniques, a node staying probability based path compression algorithm (NSP-PCA) is proposed. In NSP-PCA, the stability of new path is predicted by computing the probability that one node keeps staying in another node's transmission range and the compressing operation is performed based on the prediction to reduce the blindness of compression. Simulation results show that NSP-PCA lessens the ephemeral and multiple short-cuts observably and achieves lower end-to-end delay, lower routing overhead and higher packet delivery rate compared with both SHORT and PCA.(3) Existing anonymous routing protocols for MANET are vulnerable to attacks based on forged packets. We present an anonymous and authenticated routing protocols (ANAR) to solve this problem. By anonymous neighborhood authentications using bilinear paring, shared keys are established between legal neighboring nodes in ANAR. In route discovery procedure, control packets are hop-by-hop authenticated and processed. ANAR ensures the forged packets are correctly distinguished and the nodes en route process control packets by symmetric key which decrease computing overhead. Analysis and simulation show that ANAR can resist attacks based on forged packets and has lower route construction delay than traditional protocols.(4) To solve the security problem of traditional onion routing protocol in MANET, we propose an onion routing schemes with forward secrecy (FSAR).In FSAR, the communicating nodes construct the anonymous route through an forward secure key agreement scheme, which ensure the forward secrecy of the onion packets. Compared with traditional onion routing protocol, FSAR can efficiently eliminate the security shortage and also has lower route construction overhead.(5) We present an efficient traceback scheme (WETS) to locate DDoS attack sources in WSN. In WETS, every node in attack paths marks packets probabilistically and the victim reconstructs attack paths by collecting those marked packets. WETS is adaptive to DDoS traffic distribution, which means the sampling probability of the marking nodes keeps increasing along with the distance to the victim. Thus, the farer node where the DDoS traffic is lower can be sampled more easily. Simulation results show that WETS is much more efficient than other traditional schemes.