Dynamic Authenticated Asymmetric Group Key Agreement With Sender Non-Repudiation and Privacy for Group-Oriented Applications

Abstract

Group-oriented applications generally support communications for multiple entities (e.g., users and/or devices) through open networks. Typical requirements of group communications include secrecy, authentication, sender non-repudiation, and sender privacy. However, conventional approaches such as group key agreement and broadcast encryption are generally not designed to achieve all these requirements simultaneously or efficiently. In this article, we propose a one-round dynamic authenticated asymmetric group key agreement with sender non-repudiation and privacy (DAAGKAwSNP) protocol. A key building block of our DAAGKAwSNP protocol is our proposed batch multi-signature scheme with strong unforgeability. We prove that the DAAGKAwSNP protocol achieves secrecy under chosen ciphertext attacks – CCA, assuming the intractability of the computational Diffie-Hellman and k-Bilinear Diffie-Hellman exponent problem. We also evaluate DAAGKAwSNP’s performance to demonstrate its utility.