基于时序逻辑的加密协议分析

Analyzing Encryption Protocols Based on Temporal Logic

形式化方法由于其精炼、简洁和无二义性 ,逐步成为分析加密协议的一条可靠和准确的途径 ,但是加密协议的形式化分析研究目前还不够深入 ,至今仍没有统一的加密协议验证体系 .针对这一现状 ,该文从加密协议可能面临的最强大的攻击着手 ,提出了一种基于时序逻辑的加密协议描述方法 ,在该模型下 ,对协议行为、入侵者行为、安全需求等特性的描述均用时序逻辑公式表达 ,从而利用现有的统一的时序逻辑框架分析密码协议的性质 .特别地 ,作者描述和检测了一个系统入侵者不能用任何代数和逻辑的办法获得消息的实例 .通过对比 ,作者认为该方法具有形式化程度较高的特点 .

In order to develope a unified theory to verify encryption protocols. This paper provided a way to describe encryption protocols based on temporal logic from the main weakness and threats to encryption protocols. The protocol's actions,the intruder's actions and correctness requirements can be specified using temporal formulas under this model. All this analysis is specified according to standard safety properties,for which standard temporal logic proof techniques apply. In particular, authors model an encryption protocol where the intruder cannot obtain plaintexts by any logical or algebraic techniques. Comparing with relevant ones, it is a better formal way to describe encryption protocols. This scheme can be used widely,not only in analyzing traditional cryptosystem's,but also in describing public key cryptosystem's. In addition,it can also analyze other characteristics,such as the characteristics of fault-tolerance and no key to be reused.