Efficient Multi-receiver Identity-Based Encryption and Its Application to Broadcast Encryption

In this paper, we construct an efficient “multi-receiver identity-based encryption scheme”. Our scheme only needs one (or none if precomputed and provided as a public parameter) pairing computation to encrypt a single message for n receivers, in contrast to the simple construction that re-encrypts a message n times using Boneh and Franklin’s identity-based encryption scheme, considered previously in the literature. We extend our scheme to give adaptive chosen ciphertext security. We support both schemes with security proofs under precisely defined formal security model. Finally, we discuss how our scheme can lead to a highly efficient public key broadcast encryption scheme based on the “subset-cover” framework. Disciplines Physical Sciences and Mathematics Publication Details Baek, J., Safavi-Naini, R. & Susilo, W. (2005). Efficient Multi-receiver identity-based encryption and its application to broadcast encryption. In S. Vaudenay (Eds.), International Workshop on Practice and Theory in Public Key Cryptography (pp. 380-397). Germany: Springer. This conference paper is available at Research Online: http://ro.uow.edu.au/infopapers/2799 Efficient Multi-Receiver Identity-Based Encryption and Its Application to Broadcast Encryption Joonsang Baek Reihaneh Safavi-Naini Willy Susilo Centre for Information Security Research School of Information Technology and Computer Science University of Wollongong Wollongong NSW 2522, Australia {baek, rei, wsusilo}@uow.edu.au