Research On Group Signatures And Its Application In Electronic Cash

Information and network techniques are rapidly developing in nowadays; information security becomes a research hotspot in computer and network application organizations both at home and abroad. As a main method of authentication, digital signature can solve problems such as identity authentication, data integrity, and undeniability. Group signature is an important embranchment of digital signature, and it can provide some special authentication. Group signatures have some favorable properties, especially; their anonymity can hide the structure of a group and protect its privacy, so they can be used to design protocols which demand anonymity, such as E-cash and E-vote schemes etc. In this paper we studied group signature and its applications in E-cash. The main works are as follows:1. The development trend and the research status of group signature are summarized, the concept and security properties of group signature are described, and some variants of group signature are briefly introduced.2. An ID-based member classified group signature scheme is proposed, the users are classified into small groups in the new scheme, there is a manager in every small group, and a user can sign a message on behalf of his group, but he can't transcend his right and sign a message on behalf of other groups, the verifiers can verify a signature according to the group's public keys. Such signatures are well arranged so that they can be efficient managed, so they are suitable for large groups especially.3. The basic knowledge of E-cash and its development are introduced, and the problems in E-cash are discussed. A new E-cash system based on group signature is proposed and its efficiency is analyzed. The new scheme satisfies most of the requirements in E-cash; it has high security and efficiency.