对称密码算法专用描述语言算符优先级的设计

Designing for the Operator Priority of the Special Description Language for the Symmetric Cryptographic Algorithm

对称密码算法专用描述语言以类似专业语言的思维方式描述算法的设计思想。密码算法具有很强的严密性和逻辑性,为了提高算法描述语言的逻辑性和准确性,本文在算法描述语言的语法体制中增加了算符优先级的机制。本文基于ANTLR来实现表达式的语法规则,并根据表达式的语法规则,采用LL分析法创建表达式语法树实现表达式的语法和语义分析,同时为了存储表达式的信息,设计了专门的存储结构来实现算符的优先级。最后通过严格测试验证了算符优先级设计的合理性与实现的正确性。实践结果表明,应用优先级可以更加准确描述密码算法,为SDLSCA推广应用打下了坚实的理论和实际基础。

In this paper, on the basis of the analysis of designing rules and features of a large number of public cryptographic algorithms and according to the thinking patterns and habits of experts in crypto- graphic and with reference to general procedure priority, the operator priority of SDLSCA is designed and implemented. By describing the expression storage structure, grammar rules and the grammar tree, a detailed introduction is given on the implementation principles and methods of tice shows that applying operator priority can make it more precise to describe ope the rator priority. Praccryptographic algo- rithm, which has laid a solid theory and practice foundation for application and dissemination of SDLSCA.