安全的无双线性映射的无证书签密机制

无证书签密是能够同时提供无证书加密和无证书签名的一种非常重要的密码学原语.近年来，多个无证书签密方案相继被提出，并声称他们的方案是可证明安全的.但是，通过给出具体的攻击方法，指出现有的一些无证书签密机制并不具备其所声称的安全性.针对上述问题，提出一种无双线性映射的高效无证书签密方案，并在随机谕言机模型下，基于计算性Diffie-Hellman问题和离散对数问题对所提方案的安全性进行了证明.同时，该方案还具有不可否认性和公开验证性等安全属性.与其他传统无证书签密方案相比，由于未使用双线性映射运算，在具有更高计算效率的同时，该方案的安全性更优.

Secure Certificateless Signcryption Scheme without Bilinear Pairing

Certificateless signcryption is a useful cryptographic primitive which simultaneously provides the functionalities of certificateless encryption and certificateless signature.In the past few years, some certificateless signcryption schemes have been proposed, and claimed to be provably secure.Unfortunately, concrete attacks can be made that indicate that some existing certificateless signcryption schemes are not secure.To overcome these disadvantages, an efficient certificateless signcryption scheme without bilinear pairings is proposed.The proposal is provably secure in the random oracle model based on the computational Diffie-Hellman problem and discrete logarithm problem, and also has the security properties such as non-repudiation and public verifiability.Additionally, compared with other existing certificateless signcryption schemes in the computational complexity, the proposed method is more efficient and secure due to the lack of bilinear pairings.