Publicly Traceable Attribute-Based Anonymous Authentication and Its Application to Voting

Numerous anonymous authentication schemes are designed to provide efficient authentication services while preserving privacy. Such schemes may easily neglect access control and accountability, which are two requirements that play an important role in some particular environments and applications. Prior designs of attribute-based anonymous authentication schemes did not concentrate on providing full anonymity while at the same time holding public traceability. To address this problem, we formally define and present a new primitive called traceable attribute-based anonymous authentication (TABAA) which achieves (i) full anonymity, i.e., both registration and authentication cannot reveal user's privacy; (ii) reusable credential, i.e., a registered credential can be repeatedly used without being linked; (iii) access control, i.e., only when the user's attribute satisfies the access policy can the user be involved in authentication; and (iv) public traceability, i.e., anyone, without help from the trusted third party, can trace a misbehaving user who has authenticated two messages corresponding to a common address. Then, we formally define the security requirements of TABAA, including unforgeability, anonymity, and accountability, and give a generic construction satisfying the security requirements. Furthermore, based on TABAA, we propose the first attribute-based, decentralized, fully anonymous, publicly traceable e-voting, which enables voters to engage in a number of different voting activities without repeated registration.