Research On Hybrid Authentication Schemes In Mobile Ad-hoc Networks

With the rapid development of communication technologies, network technologies, and the increase of people's need in mobile communications, wireless networks have become one of the most important branches of networks. Mobile Ad-hoc NETworks (MANETs) emerge as a new kind of mobile wireless communication networks. It doesn't rely on any fixed infrastructure and central controller, which is self-organized. However, compared with traditional networks, MANETs are more vulnerable to various attacks due to dynamic topology and so on. Security is one of the most important issues in MANETs, and it is also a hot research topic in this field.This thesis investigates the issue of authentication and key management in MANETs. We find that existing mechanisms usually utilize encryption and threshold to achieve authentication, which can't guarantee security and scalability at the same time.Against this question, a hybrid authentication scheme suitable to large-scale MANETs is proposed. The hybrid authentication scheme integrates the idea of trust chain into authentication. Distributed authentication and chained authentication are combined seamlessly in this scheme. The former is used to do certificate management; the latter takes charge of identity authentication. The proposed scheme can take advantage of high security of the distributed authentication scheme, and hide the mobility of nodes effectively, then achieve high success ratio of authentication with the trust chain.We compare the proposed protocol and distributed authentication scheme with theoretical analysis and simulations. The analysis results show that, when node in sparse area can't finds enough signatures to form a valid certificate, it can utilize trust chain to enlarge the search range to find more CA nodes. In addition, the simulation results show that the proposed protocol enhances the successful ratio of authentication compared with the distributed authentication scheme. It improves expansibility and flexibility of the networks, which can be used as a reference to the related works.