Study On Ad Hoc Trust Mechanism And Key Management

Ad hoc is a new wireless, multi-top network without central distributed control and it hasunique properties in composition structure. The main character of Ad hoc is lack of basicarchitecture predefined and with dynamic topology structure, which makes it more vulnerablewhile suffering some attacks and threats from itself than fixed wired networks. However, withthe development of Internet, the applications of wireless Ad hoc network are more and moreextensive. But the security problem is always one of the biggest challenges of Ad hoc andconcerned by more and more researchers. So, how to solve the security problem is the key ifthe Ad hoc network can be widely applied. Main reasons are as follow:(1)Mobile Ad hoc network uses wireless signal as the transmission medium, and themessage is transmitted in the air so that anyone can receive and it can be easily eavesdroppedby enemy. At the same time, wireless channel are easier to appear enemy interference andfalse message injection.(2)While Ad hoc is arranged on the battlefield, the security of node itself is very fragileand may fall into the adversary so that the key and packets of node will be cracked and thenode will re-join the network as the normal node which can be used to obtain secret anddestroy the normal function of the network.(3)The trust relationship between network nodes is related to the system security. Oncethere are some malicious nodes in the network without being known by the adjacent nodes,the behavior of these malicious nodes may lead to disturbance of the entire mobile networkorder, which will make a certification center destroyed and the entire network losing security.Therefore, the mobile Ad hoc network should not only need to prevent external invasion,but also need to deal with the attacks of internal nodes. So, trust is the central issue. Wecannot trust any media, so we must use the key. The same as other distributed system, thecorrect use of key management system is very import for ad hoc security.While carrying out key management, to ensure security is the basic communicationrequirements and the computation should be as small as possible. So how to design a reliable,secure, practical and proper key management is the development of ad hoc. Though there area lot of scholars have published their research results in key management technology ofwireless network, these researches are still lack of important technical innovation ideas.The so-called trust mechanism and key management solution is to study how todistribute and manage keys in the case lack of a fixed underlying structure.At present, the research results of ad hoc trust management include: traditional trustedthird party trust model, local distributed trust model, fully distributed trust model, identity-based distributed trust model and fully distributed self-organization trust model.However, it is still in the exploratory stage and many researches of trust model have their ownshortcomings. The existed research of key management is mainly focused on: the localdistributed CA certificate scheme, polynomial-based secret sharing scheme, PGP-basedself-organized and identity-based key management scheme.The work of this paper is to summarize trust model and key management applied tovarious fields. By comparing these trust models and key management features, such as theadvantages and disadvantages and the improvement of these schemes, we summarize thefeasibility of the application of these schemes in ad hoc network so that we can implement thetrust mechanism and key management better.Then, according to the research results of ad hoc network trust mechanism and keymanagement scheme home and abroad, a new trust model and key management scheme ispresented.The trust model designed in this paper is secure, reliable and proper of ad hoc networkwhich is a combination of identity-based encryption and elliptic curve technology. In thisscheme, we construct a unique cluster structure, that is, in the cluster; there are a primarycluster head and some secondary cluster heads. We use the identity of identity-basedencryption to identity the user ID and use the elliptic curve to realize the shorter key lengthand higher message confidentiality in user interaction. Currently this scheme is still in theresearch stage and has not put into practical application.In this paper, a new identity-based trust management mechanism and key managementscheme is given which makes the mobile ad hoc network more flexibility. It mainly displaysin:(1)The collaboration between primary cluster head and secondary cluster heads and theprivate key distribution of primary cluster head make the system more practical, that is, thesystem is redundant and without accounting into the communication problems caused byprimary cluster head.(2)It is easier to implement the message interaction between nodes.(3)It use elliptic curve algorithm with short key but high security which makes theinteraction message between nodes shorter and more suitable for mobile ad hoc network.To measure the feasibility of a wireless network key management protocol, we cananalyze from the communication traffic and computational complexity. The scheme of thispaper which uses the identity concept of IBE scheme makes the node public key binding withnode identity without another map of name and identity. Also, the scheme is implemented byECC algorithm which can reduce the communicate traffic and computational complexity andmore proper to mobile network.At last, according to the simulator results, the trust model and key management functionsproposed in this paper provide the reliable security and practicality. However, the premisecondition of these schemes is that there must be a credible and secure route protocol. Therefore, there are heavy responsibilities to put ad hoc network into large global use.