Dynamic k-Times Anonymous Authentication

k-times anonymous authentication (k-TAA) schemes allow members of a group to be anonymously authenticated by application providers for a bounded number of times. k-TAA has application in e-voting, e-cash, electronic coupons and anonymous trial browsing of content. In this paper, we extend k-TAA model to dynamick-TAA in which application providers can independently grant or revoke users from their own groups and so have the required control on their clients. We give a formal model for dynamic k-TAA, propose a dynamic k-times anonymous authentication scheme from bilinear pairing, and prove its security. We also construct an ordinary k-TAA from the dynamic scheme and show communication efficiency of the schemes compared to the previously proposed schemes.