An Efficient Confidentiality Preserving Scheme Using Certificateless Encryption with High Trust Level

Certificateless public key cryptography with bilinear pairing needs costly operations, which is not appropriate for a practical application. In this paper, we present a certificateless public key encryption scheme without bilinear pairing. This encryption scheme achieves Girault’s trust Level 3 as in traditional public key infrastructure based cryptography, and which is proved to be secure in the random oracle model under the hardness assumption of computational Diffie-Hellman problem. Compared with the related schemes, the performance analysis and simulation show that our scheme is more efficient than others. It takes account of security and efficiency.