一个扩展的基于身份的签密方案

在基于身份的签密方案，公钥可以通过用户的身份直接得到，简化了证书管理，但在传统的签密方案中，密钥产生中心很容易知道用户的私钥．不适合方案在开放式环境中的应用。文章利用椭圆曲线上双线性映射的特性．提出了一个扩展的基于身份的签密方案，并且对其安全性进行了证明。该方案具有多个密钥产生中心，能够同时实现数字签名和消息加密两项功能，能够应用于开放环境中，实现了向前安全性。

An Extended Identity-based Signcryption Scheme

In Identity-based Signcryption scheme, public key can be directly gained through the user' identity, simplifying the management of certificates, but in traditional signcryption scheme, Public Key Generator can know the users' private key easily, which is not fit for the application of the scheme in the open circumstance. This paper proposed an extended Identity-based Signcryption scheme using the characterisrics of bilinear map, and proved the security of the scheme. This scheme had multi Public Key Generation, can sign and encrypt message at the same time , can be used in open circumstance, and achieved forward security.