A Digital Gift Certificate Scheme with Conditional Anonymity

Abstract

The digital gift certificate, a special substitute for digital cash, is a practical tool in e-commerce. Digital gift certificates are released by stores, departments or other similar business entities, and users can use digital gift certificates to consume specific commodities at corresponding sites. The advantages of using digital gift certificates are transferability and simple verification. Hence, they are especially compatible in some commercial aspects during advertising or promotions. In this paper, we particularly regard the rights of privacy to users and the equity protection of stores. We not only propose a novel digital gift certificate scheme, but also resolve the two important problems, i.e., preventing dishonest buyers from duplicating digital gift certificates and preventing dishonest users from using digital gift certificates more than once. When some buyers or users illegally use their digital gift certificates, the proposed scheme allows the sources to trace the identities of the dishonest buyers or users. Therefore, the anonymity of our scheme is conditional, that is, it only protects the privacy of buyers or users when they legally use digital gift certificates.