零知识的理想功能和零知识的序列组合

为了降低零知识的错误概率,通常采用协议的组合操作,独立运行安全的协议,在组合情形,其安全性却并非平凡的。利用UC安全密码元件可以在协议组合过程中作为一个模块安全调用的特性,在UC框架下,通过定义理想功能Fwzk,在Fwzk-混合模型下,讨论零知识协议的组合安全性问题。得到结果:基本Blum协议在序列合成时零知识性具有封闭性。

Ideal Functionality and Sequential Composition of Zero-knowledge

UC security is the framework in treating a stand-alone protocol and guaranteeing the secure composition. This means that a protocol may run concurrently with many other protocols, on arbitrary inputs and in adversarial controlled way, if it is UC security in the sense that it emulates an ideal functionality, it can be treated as a piece of that ideal functionality in overall system security analysis. In this paper, ZK under UC framework is studied, and the study proves that Blum protocol is closed under sequential composition in the Fwzk-hybrid model.