Multi-receiver Certificate-Based Encryption and Application to Public Key Broadcast Encryption

In this paper we firstly introduce the notion of multi- receiver certificate-based encryption that avoids the inherent key escrow problem while preserving the implicit certification of multi-receiver identity-based encryption. We also construct a highly efficient multi-receiver certificate-based encryption scheme which eliminates pairing computation to encrypt a message for multiple receivers. Moreover, the proposed scheme only needs one pairing computation for decrypting the ciphertext. We compare our scheme with the most efficient multi-receiver identity-based encryption scheme[2] in terms of the computational point of view, and show that our scheme provides better efficiency than [2]. Finally, we discuss how to properly transform our scheme into a new public key broadcast encryption scheme based on subset-cover framework, which enjoys the advantages of certificate-based encryption.