A Classified Credential Selection Scheme with Disclosure-minimizing Privacy

In this paper, we propose a classified credential selection scheme with disclosure-minimizing privacy and give protocols for realizing it in point-based management model. The client has two or more classes of credentials, and defines a quantitative privacy score for each credential, while the server defines a point value for each credential disclosed by the client and a minimum access threshold of point values to access a resource. When the server requires the client to disclose at least one credential in each class, the proposed scheme allows the server and client to jointly compute an optimal subset of credentials without revealing their private information such that the total private scores of disclosed credentials is minimal while the server’s access threshold is satisfied. We also prove the security of the protocols in our scheme in the semi-honest model.