Strongly secure group signature scheme

Group signature schemes are fundamental cryptographic tools, in which messages are allowed to be signed anonymously. Full-traceability and full anonymity are two important security requirements for group signatures. Response to the misapplication, the group manager is able to revoke the full anonymity. The group joining protocol is a crucial ingredient of a group signature scheme, if devised carefully, group manager´s forgery would be prevented. This paper presents a new efficient group signature scheme with a simple joining protocol which possesses the properties of full-traceability and full anonymity. The security of our new construction is based on the DCR assumption, strong RSA assumption, and collision resistant hash functions, which is proved in the random oracle model. Moreover, the signature length of our scheme is very short. Hence it is an efficient short group signature scheme with efficient concurrent join.