Provably secure certificate-based encryption with leakage resilience

Abstract

The security of encryption schemes, in general, has been considered in an ideal environment, where the adversary cannot obtain the secret internal state of the scheme. However, in the real world, an adversary can gain partial information on the secret key through a key leakage attack. To avoid this attack, it is crucial to construct an encryption scheme with leakage resilience. In this paper, we first define a secure leakage-resilient model of certificate-based encryption. In this model, the adversary is permitted to get some information on the secret value through a side-channel attack. Moreover, we put forward a new leakage-resilient certificate-based encryption scheme. This scheme is secure against chosen ciphertext attack under the decisional 3-party Diffie–Hellman assumption in the standard model. Compared with the existing two certificate-based encryption schemes, our scheme enhances the security property, and the execution time of the proposed scheme is less than that of the two certificate-based encryption schemes.