Certificate-Based Key Encapsulation Mechanism Secure in the Standard Model

A hybrid construction is a formal method of combining asymmetric encryption and symmetric encryption.By introducing key encapsulation mechanism into certificate-based encryption scheme,we propose a formal definition and security model of the certificate-based key encapsulation mechanism.Furthermore,we present a construction of the certificate-based key encapsulation scheme.Based on decision bilinear Diffie-Hellman difficulty assumption,the proposed scheme is provably secure against indistinguishability under adaptive chosen-ciphertext attack in the standard model.