Research On The Secure Multicast In MANET

Mobile Ad Hoc Network(MANET) is a kind of self-adapted and self-organized information network characterized by lack of infrastructure,mobile nodes and distributed network protocols. The property of distributed processing and mobility gives MANET some good application features, such as high survivability,robustness and quick deployment.And now MANET is a hot topic in the network research.The typical application of MANET includes that mobile nodes achieve a certain job in groups. So multicast plays an important role in MANET.The development and perfection of multicast techniques is an important power to promote the wide spread of MANET.Security is critical to the application of MANET multicast.The security threat to MANET multicast is more severe due to the poor physical security,more attack chances by the broadcast communication mode,etc.With the limitation of mobility and self-organization and limited resource of MANET,providing secure multicast communication becomes a hard problem.The secure multicast protocol and group key management suitable to the character of MANET has not been sufficiently studied yet.Studying and eventually solving the security problem of MANET multicast has important practical meaning and great research significance.Considering the challenge of MANET multicast security and the deficiency of current work,this dissertation works on the key techniques of MANET multicast,such as public key management,group key management and secure multicast routing protocols,etc.,hoping to provide security mechanism to the multicast communication in military MANET applications.The main contribution of this dissertation includes:First,we present an ID-based public key management scheme using the basic ideas of secret sharing of threshold cryptography and the partially distributed CA under the assumption of managed hostile application environment.The scheme decreases the computation and storage of mobile nodes with reduced commutation overhead.The security is also improved for the initially existence of the off-line trued third party.The scheme provides high availability and security due to the distributed public key management model and gives a good solution to the problem of public key revocation dependent on the localized trust model.The server nodes of public key management can be dynamically adjusted to adapt to the dynamic nature of MANET.The simulation proves that the key refresh mechanism has little effect on MANET communication.Second,we put forward an ID-based authenticated group key management protocol CEAGKP. The algorithm introduces the key tree of STR protocol that has minimum traffic in fixed network environment combined with the ID-based public key cryptography.The protocol executes in constant round with small traffic and well suits the wireless communication mechanism of MANET. While group members increase,new member's secret contribution will be an argument to calculate the new group key with no change to the original members' share.And while the group member exits,the departed member's secret contribution will not be involved in the new group key.The forward secrecy and backward secrecy property of the group key is kept.The protocol provides the explicit authenticity of the group key and is advisable to applications that have high security requirements.The simulation proves that CEAGKP scales well in MANET but the computation will be relatively large for the reason of authentication.Considering the security provided by CEAGKP,the computation is reasonable.Third,we introduces the principle of scale and energy to the network clustering and put forward a clustering algorithm named Scale-Energy Cognitive Clustering Algorithm(SECC ).It is an improvement to Warning Energy Aware Clusterhead by introducing the conception of scale to constrain the cluster's size in order to reduce the change of clusterhead.The simulation proves the validity and feasibility of SECC by comparing the network survivability when using SECC and WEAC algorithm.SECC is more suitable to large MANET and can effectively avoid the problem of frequent changing clusterhead.Forth and the last one,we put forward a secure multicast routing protocol BCSMR.Considering the effects of clustering over node's energy,BCSMR protocol builds on the base of SECC and the HiM-TORA routing mechanism,and introduces the TELSA authentication scheme which using the symmetry encryption algorithm that has low computation cost.BCSMR can securely build the multicast tree covering all group members and effectively prevent various attacks over multicast routing by means of authentication of the member's identity and other information during the phase of route establishment.We give a thorough and detailed research on the key techniques of MANET multicast security in this dissertation and present effective solutions which exhibit excellent application futures under the assumption of military application environment.