The Research On Design And Application Of Signature Schemes In Mobile Wireless Networks

With the continuous updating and development of computer network and communication technology, the traditional wired networks have been unable to meet demands for new applications, and furthermore, it becomes gradually the epoch of mobile wireless networks. In the past, the communication between people was limited by place, time and object. The mobile wireless networks have not only eliminated these limitations, but also greatly improved the quality of human life, study and work.Compared with wired networks, wireless networks have its own unique properties, such as the openness of the transmission medium, the dynamic network topology, the mobility of the wireless terminal, the limited resources and so on. Because of the above characteristics, however, the wireless networks will be confronted with serious security threatens and network attacks (e.g., tampering, hacking, identity forgery, and denial of service attacks). In addition, most security protocols in wired networks cannot be directily realized under the wireless networks environment. We need to consider more secure issues, when we design and implement the wireless network-oriented protocols. In fact, it is very important to ensure the security of the mobile networks, not only for the personal privacy, but also for the social stability and development.As one of the key technologies of information security, the digital signature has some good secure properties, such as Authentication, Non-repudiation, Data Integrity and so on. There are important and wide applications of digital signatures in mobile wireless networks, as an important privacy-preserving method. This dissertation systematically studied the digital signature in terms of definition, classification and function. Especially we utilized digital signature technology to construct novel digital signature schemes, which could solve related security issues under the mobile wireless networks.Our research on the security issues for the mobile wireless networks can be roughly divided into two aspects, where the first one is the privacy-preserving identity authentication in vehicular ad hoc networks and the second one is to solve the problem of privacy protection in the wireless mobile networks. In order to overcome the shortcomings of the existing schemes, we put forward new solutions. The main results are as follows:(1) A conditional privacy-preserving authentication scheme was proposed. Firstly, we introduced the short signature technology and then constructed a new identity-based short signature scheme. Compared with current well-known schemes, the proposed scheme can reduce the computation costs of both the signature and verification process, and improve the communication efficiency. Secondly, we simply split the private signing key into two correlative sub-keys, so that it can effectively solve the issue of key escrow. Therefore, the scheme is especially adapted to the applications of vehicular ad hoc networks. Based on the proposed signature scheme, we further presented a conditional privacy-preserving authentication scheme, which can achieve identity authentication with conditional privacy preservation. The theoretical and efficiency analysis shows that the scheme reduces the computation costs. Especially, we used batch verification by adding the small coefficient test to accelerate the authentication speed and reduce the error rate.(2) A novel roaming authentication scheme with anonymity was presented. A certificateless aggregate signature scheme was constructed, by introducing the online/offline signature and combining the aggregate signature. Compared with the related schemes, the proposed scheme has higher efficiency in computations of both signature and verification, and also improves the efficiency in communications. Furthermore, based on the proposed signature scheme, a novel roaming authentication scheme with anonymity was presented, in which we simplifid the traditional three-party authentication model. The theoretical analysis shows that this scheme is secure and effective, and especially suitable for large-scale wireless mobile networks.