Architectural Design And Implementation Of OLSR Based Fully Distributed Certificate Authority In MANET

As the mobile computing technique developing, people are able to share information and able to communicate with each other easily through the mobile networks. Security becomes an obstacle of sharing information in MANET because nodes of MANET log in and check out frequently. A high powered Certificate Authority is needed to solve the problem of security. This paper follows the security request of MANET, analyses the Optimized Link State Routing protocol, designs an OLSR based Fully Distributed Certificate Authority in MANET for providing the certificate service.In this paper, we first analyze the factor which threaten the security of MANET, such as radio channel can be interfered easily, attacks to the routing protocol and attacks to the key management system, wiretapping and playback attack.Through the analyses to the security of MANET, combines peculiarity of OLSR protocol, se design the scheme of FDCA. We combine the RSA's certificate service with Shamir's secret sharing, distribute the certificate of CA into certificate shares, issue the shares to some certain functional nodes. When a node need apply a certificate, it could be aware of the information of the functional nodes through the HELLO message and the TC message. Then the node requires a certificate, those functional nodes who receive the request reply a certificate share and the requiring node collects k pieces and combines them together to compose a whole CA's certificate. To solve the problem that many nodes often log in and check out the network, we specially designs the algorithm, we use the HELLO message and TC message to select functional nodes to provide certificate service.Finally, we test the antetype of FDCA in the lab. The result of our test shows that the FDCA can fit the mobility of MANET and the certificate service is robust enough although the nodes are moving or the topology of the network change regularly.