Broadcast Encryption with Sender Authentication and its Duality

In this paper, we study the duality of two primitives between broadcast encryption with sender authentication (BESA) and 1-out-of-n designated verifier signature ((1,n)- DVS). In our study, we first construct the model of both BESA and (1,n)-DVS strictly. Then we point out the existence of duality. This paper provides not only the model and discussions on the duality, but also two practical schemes. Our schemes have the remarkable properties: In BESA scheme, the transmitted data size is not proportional to the size of the group. In the same way, (1,n)-DVS scheme has the constant size of signature. The performance evaluations for the schemes are also estimated rigorously. We believe that our approach contributes to the cryptographic community from both theoretical and practical point of view.