Research On Group Digital Signature

Digital signatures provide solutions for problems in the Internet such as identity authentication, data integrity and nonrepudiation. So digital signature technique has been studied widely, and various digital signature schemes suit for special cases have been proposed. Group signature is studied in this paper, the main work and results are as follows:1. The overview of group signature history and researching state are presented; two valuable group signature schemes are descrribed and analyzed, and several variety of group signature are introducted.2. The notion of rank group signature is proposed for the first time, and a concrete scheme is given as well. Different group members have different signing ability in the scheme, and no one can sign a message out of his purview. The signature can be verified by a public message rank flag.3. Making a primary research on member deletion. Three kinds of member deletion schemes are annlyzed, including schemes based on witness, accumulator and Chinese Remainder Theorem.