一种基于身份的广播签密方案

为了使保密信息能够通过不安全的广播信道安全地发送给已授权接收的用户集，对Selvi IBBSC方案进行研究，提出了一个改进的基于身份的广播签密方案。方案建立基于身份的广播签密方案构架，利用椭圆曲线上的双线性对，形成了具有安全性和高效性的广播签密方案。先分析了方案的正确性，然后基于判定双线性Diffie-Hellman假定在随机预言模型下分析了密文的不可区分性以及基于计算性Diffie-Hellman假定分析了签名的不可伪造性，最后简要分析了方案的有效性。结果表明，提出的方案能够对保密和认证的双重问题提供有

An ID-based Broadcast Signcryption Scheme

In order to securely transmit the privacy information to authorized users’ set through the unsafe channel,an identity-based broadcast signcryption scheme(IBSC) based on Selvi IBBSC scheme was proposed.In the IBSC,the ID-based signcryption scheme for broadcast communication’ schema was put up,and using bilinear pairing on elliptic curves,a new secure,efficiently identity-based broadcast signcryption scheme was proposed.Firstly the correction was analyzed,and then signcryption schemes were proven to be secure against adaptive chosen ciphertext attacks and adaptive chosen message attacks under decisional bilinear Diffie-Hellman assumption and computational Diffie-Hellman assumption respectively.Lastly the efficiency of IBSC was analyzed simply.The results showed that the proposed scheme,which provids the efficient solution to the dual problem of confidentiality and authentication,is secure in the random oracle model and could efficiently improve the security of Broadcast network,and more efficient in reducing the broadcasting parameter and the computing consumption of Designcypt.