关键词: 混合加密, 基于证书, 标准模型, 云计算, 不含双线性对

Abstract: With the rapid development of cloud computing, data security has become a critical problem of cloud security, at the same time, the amount of cloud data storage and transmission is very huge and the safety requirements are very high. On the other hand, certificate-based cryptosystems can overcome the certificate manage problem in traditional public key cryptosystems and the private key escrow problem in identity-based cryptosystems, so it provides new ways for constructing effective PKI. But there are pairing operations in most current certificate-based encryption schemes, so the efficiencies of those schemes are low. Based on judging truncated Diffie-Hellman problem, it presents a certificate-based hybrid encryption scheme without pairings, which efficiency has been analyzed, and security has been proved. Scheme is a one-time-one-key encryption scheme based on key encapsulation algorithm, symmetric encryption algorithm and message authentication code algorithm. Analysis shows that the scheme is efficient and can resist adaptive chosen ciphertext attack, so it can be used in cloud computing environment.

Key words: hybrid encryption, certificate-based cryptosystems, standard model, cloud computing, without bilinear pairing