Abstract:A hybrid signcryption scheme should withstand various leakage attacks when applied in practical applications. This paper presents a new leakage-resilient certificateless hybrid signcryption (LR-CLHS) scheme without bilinear pairing. The security of this scheme is based on the computational Diffie-Hellman (CDH) assumption and discrete logarithm (DL) problem. Considering the computational costs, the proposal is more efficient than traditional certificateless hybrid signcryption schemes and has a short ciphertext length and high security. In the random oracle model, it is also indistinguishability against adaptive posteriori key-leakage chosenciphertext attacks (IND-KL-CCA2) according to the hardness of the CDH assumption, existentially unforgeable against key-leakage chosen-message attacks (EUF-KL-CMA) according to the hardness of the DL problem, and maintains the original security under the condition that the adversary learns a small amount of leakage about the secret key by the leakage attacks (e.g., side-channel attacks, etc).