A General and Secure Certification-based Encryption Construction

The certificate-based encryption is a new PKC paradigm which combines public-key encryption (PKE) and identity based encryption (IBE) while preserving their features. CBE provides an efficient implicit certification mechanism for a PKI and allows a form of automatic certificate revocation, while it is not subjected to the private key escrow problem and secret key distribution problem inherent in IBE. In this paper, we propose a generic construction of CBE from PKE and IBE, and prove it to be secure in the random oracle model. Compared to previous generic constructions, the security requirement of the primitive encryption schemes in our construction is much weaker. This result shows that CBE can be constructed in a more general way.