SHORT GROUP SIGNATURE APPARATUS AND SCHEMES WITH CONTROLLABLE LINKABILITY

摘要

PURPOSE: A group signature system and method for providing controllable connectivity are provided to systematically control anonymity by providing not only unforgeability, traceability, non-frameability, and controllable anonymity but also additional controllable linkability. CONSTITUTION: User equipment provides a subscription request message and user information to an issuer server(S300). The issuer server verifies the validity of the subscription request message. The issuer server transmits a partial parameter necessary for generating a secret key from the user equipment which is generated by using a master issuing key(S302). The user equipment verifies the validity of the received partial parameter. The user equipment stores the secret key for the user equipment(S304). The issuer server verifies the validity of a received signature. The issuer server approves the effective registration of the user equipment. The issuer server stores partial secret key information(S306).