基于椭圆曲线离散对数的无证书混合加密

基于椭圆曲线离散对数困难问题，结合KEM-DEM混合加密结构，提出一个新的无证书混合加密方案。采用椭圆曲线签名算法保证用户自主生成公钥的不可伪造性，利用用户公钥生成的会话密钥以对称加密算法加密明文，保证明文的机密性，对明文空间的大小没有严格限制。该方案主要涉及椭圆曲线上的点运算，与原有无证书加密方案中采用双线性对计算相比具有更高的执行效率。

Certificateless Hybrid Encryption Based on Elliptic Curve Discrete Logarithm

Based on elliptic curve discrete logarithm problem and KEM-DEM hybrid encryption construction, a novel certificateless hybrid encryption scheme is proposed. Elliptic Curve Signature Algorithm(ECSA) is used to provide unforgeability of user public key. Owing to KEM-DEM construction user public key is used to generate session key and session key encapsulation. Plaintext is encrypted by symmetry encryption scheme with session key, which provides the confidentiality of plaintext without the strict limitation for plaintext message space. The main operations is point operation in elliptic curve. Compared with previous certificateless encryption schemes related to bilinear pairing operation the scheme is more efficient on computation.