Certificate-Based Encryption Resilient to Continual Leakage in the Standard Model

Abstract

The security for many certificate-based encryption schemes was considered under the ideal condition, where the attackers rarely have the secret state for the solutions. However, with a side-channel attack, attackers can obtain partial secret values of the schemes. In order to make the scheme more practical, the security model for the certificate-based encryption which is resilient to continual leakage is first formalized. The attackers in the security model are permitted to get some secret information continuously through the side-channel attack. Based on the certificate-based key encapsulation scheme, a novel certificate-based encryption scheme is proposed, which is resilient to the continual leakage. In the standard model, the new scheme we propose is proved to be secure under the decisional truncated q-augmented bilinear Diffie–Hellman exponent hard problem and the decisional 1-bilinear Diffie–Hellman inversion hard problem. Additionally, the new scheme can resist the chosen-ciphertext attack. Moreover, a comparison is performed with other related schemes, where the proposed solution further considers the continual leakage-resilient property and exhibits less computation cost.