Anonymous Multicast Routing Protocol In Mobile Ad Hoc Networks

Mobile Ad Hoc Network(MANET)is a special peer-to-peer network which is self-organizing, dynamically reconfiguration and mobile. In recent years, anonymity security has become more and more important for ad hoc networks. This paper mainly analyzes and researches anonymity technology in MANET, proposes two anonymous multicast routing protocols in MANET.The paper introduces anonymity technology and anonymity demand of MANET, analyzes typical anonymous unicast routing protocols and multicast routing protocols in ad hoc networks. Based on the research of ad hoc multicast routing protocols, this paper proposes two anonymous multicast routing protocols: AODMRP and AMAODV.AODMRP is based on ODMRP, a typical protocol of mesh-based multicast routing protocols. Aiming at the problem that ODMRP can not ensure the anonymity of sender and communication relationship, we adopt encryption, decryption and pseudonym mechanism, change the format of packet, so that packets have no relation in content and their length is consistent, attacker can't trace packets by their content or length.Aiming at the problem that MAODV can't ensure the anonymity of sender, group leader, and transmission route, we propose tree-based anonymous multicast routing protocol: AMAODV, which is based on MAODV, and we analyze the anonymity of AMAODV detailedly. AMAODV also adopts encryption, decryption and pseudonym mechanism to protect important routing information, abolishes the symbols in RREQs and RREPs, so that attacker can't find senders, group leaders, or trace the transmission route through tracing particular routing packets.We simulate AMAODV and MAODV in NS2, the results indicate that the packet delivery ratio of AMAODV decreases distinctly in high-speed mobile environment. After analysis, we find it mainly results from adoption of encryption and decryption mechanism. Nodes in AMAODV with anonymous mechanism have to decrypt and encrypt messages, which greatly increases transmission latency and consequently causes transmission routes more easily to break in AMAODV, thus less packets are received. So anonymous transmission mechanism based on encryption and decryption is not fit for high-speed MANET.