Abstract: Self-certified blind signcryption (SCBSC) protocol can simultaneously fulfill public key encryption and blind signature. When disputation occurs between the sender and recipient, any third party can verify the validity of the signature. However, the existing self-certified blind signcryption protocol does not yet have universally composable (UC) security. Aiming at this problem, the UC security framework is introduced. The use of this framework can analyze and design self-certified blind signcryption protocol in modularity. Firstly, the ideal function of self-certified blind signcryption protocol is defined under the UC security framework; secondly, under the adaptive adversary model, self-certified blind signcryption protocol may achieve functionality, if and only if self-certified blind signcryption protocol satisfies the indistinguishability against adaptive chosen-ciphertext attacks (IND-CCA2)

Key words: self-certified blind signcryption, UC security, ideal function, adaptive chosen-ciphertext attacks

摘要： 自认证盲签密（self-certified blind signcryption，SCBSC）协议能够同时实现公钥加密和盲签名，并且当发送方与接收方对签名存在争议时，任何第三方都能验证签名的有效性。然而，现有的自认证盲签密协议还不具有UC（universally composable）安全性，针对这个问题，引入UC安全框架，利用该框架可以模块化分析与设计自认证盲签密协议。定义了自认证盲签密协议在UC安全框架下对应的理想函数；证明了在适应性敌手模型下，自认证盲签密协议实现该理想函数，当且仅当签密协议满足不可区分适应性选择密文攻击（indistinguishability against adaptive chosen-ciphertext attacks，IND-CCA2）。

关键词: 自认证盲签密, UC安全性, 理想函数, 适应性选择密文攻击