中文摘要：

环签名是一种匿名签名技术，能保证签名用户的无条件匿名性．针对目前环签名协议只考虑单一协议执行时的安全性这一问题，定义了环签名在通用可组合框架下的安全模型，证明其等价于基于游戏的安全模型，并以前向安全环签名协议为例描述了如何应用环签名的通用可组合安全模型来设计复杂协议，为签名协议的模块化设计提供了理论依据．

英文摘要：

Ring signature is a new kind of anonymous signature which can provide unconditional anonymity for the signer. Aiming at the problem that the security of ring signature was only considered in a single instance, the security model of ring signature under the universally composable （ UC ） framework is defined which is proved to be equivalent to the game-based model in the standard model. Taking forward secure ring signature for example, how to apply the security model under the UC framework in design of complex protocols is described, which provides a modular approach for the design of signature protocols.