Research On Key Shares Renewal And Dynamic Expansion Of CA In Ad Hoc Network

An Ad Hoc network is a wireless, multi-hop, self-organized and infrastructureless network. Security of the network is a key point to determine whether the Ad Hoc network could be brought into full application, especially for the military and commercial applications. PKI (Public Key Infrastructure) technology, which is realized by distributed CA(Certificate Authority), is currently one of the most extensive and successful ways being used in Ad Hoc network .In the Ad Hoc networks, because of the lack of adequate protection of nodes, nodes could be easily attacked. In the environment of higher security requirements and longer life-cycle application, we should periodically renew the key shares for CA to improve the system security. At the same time, due to the condition that the nodes can join in or drop out of the Ad Hoc network at any time, the CA nodes in the network also need the ability of expansibility.Based on analyzing the existing protocol of key shares renewal, contrapose on the deficiency of the existing protocol, the thesis brings forward a kind of key shares renewal protocol on alterable threshold value, advances a key renewal protocol according to the practical instance of Ad Hoc network to ensure the system security, which combines not only the fix threshold value renewal and increase threshold value renewal, but also instantaneous renewal and periodical renewal.The thesis introduces the existing scheme of threshold expansibility, and takes a serious contrast and analysis among the existing scheme, on the basis of this, the protocol of new CA nodes joining into the Ad Hoc network is designed.Finally, the modules of CA key shares renewal and dynamic expansibility are designed and realized based on the above protocols.