A Study On The Security Technology Of Mobile Ad Hoc Network

Mobile Ad Hoc network is a collection of mobile computing devices that communicate using wireless links. It is a dynamical multihop network which has a topology structure. Such networks are useful in emergency rescue, exploration missions and other tactical applications, where cellular infrastructure is unavailable or unusable. And it's also an important branch of 4G network in future. A mobile Ad Hoc network doesn't need the use of any static network infrastructure such as base stations. Each node in this network is equal and has two roles: router and host. So they form a multihop distributed network through middle nodes as repeaters.Due to the characteristic of itself, mobile Ad Hoc network is easily under attack and faces various security challenges. So the security problem has been an important question for study in the field of Ad Hoc network. And key management is a very important part of network security.In this paper, we study Ad Hoc network security mechanism, discuss the threats to Ad Hoc network and related research branches, probe into secret sharing and key agreement and their application in Ad Hoc network as an emphases. The current schemes are analyzed, and a new multi-secret sharing scheme, group key agreement protocol, distributed security scheme in Ad Hoc network are proposed.The major contributions of this thesis are listed as follows:1. Introduced the concept, characteristic, applications and history of mobile Ad Hoc network. Then attempted to analyze the secure problem in Ad Hoc network such as security threats, security requirement and so on2. Introduced some basic technology of key management like encryption technique, secret sharing and key agreement. Then probed into several typical researches of key management.3. To against some weakness of most current multi-secret sharing scheme like Chien's, Yang's. We proposed a new multi-secret sharing scheme based on pairings. This scheme can sharing freewill secrets in one distributing, and only need three broadcast massages for adding one secret. It overcomes the weakness which is referred to in this paper like too many massages, no verified, rely on secure channel and static secret-publisher and so on.4. Based on the multi-secret sharing scheme this paper proposed and the identify-based key management, an effective key-update scheme in Ad Hoc network is designed. We simulate it using OPNET tools, and the result shows it runs well when the bandwidth is low.5. We designed a simple two-side key management protocol, then extended it to group and proposed an ID-based group key agreement protocol. Because of its advantage such as identify-based and only one round needed, it is adapted to Ad Hoc network.