Abstract:

In order to solve the different authority between the signers of group signature, a lot of threshold group signature schemes with privilege sets are proposed. This paper analyzes and studies a threshold group signature scheme which is based on the ElGamal type, and the shortages of this scheme are found which do not satisfy the property of group signature and do not distinguish the single signatures. Aiming at these shortages, an improved threshold group signature scheme with a privilege set based on ECC is proposed. The ability of this scheme to prevent the forgery of KDC and the Clerk is enhanced by adding an authentication key and using an interactive identity verification method under the public environment. The group members prevent the forgery of KDC by using the Pedersen VSS validation methods. The improved scheme can not only achieve the discoveries and revocation of group members, but also have the properties of threshold group signature.