The CLEFIA is one of the two international standardized lightweight block cipher,which has important application value under the condition of resource constrain.In view of the problems that CLEFIA-128 need 5 round to realize the avalanche effect,and the diffu-sion effect is not obvious,and the design of round function in each round makes the efficiency of software and hardware lower,the CLE-FIA-128 is improved from the structure and round function.The test demonstrates the improved algorithm only need 4 rounds to realize the avalanche effect,its DC,LC and IDC indicates that the security is improved,while the software and hardware performance also increa-ses a lot.%CLEFIA算法是两种国际标准化的轻量级分组密码之一，它在资源受限环境下具有重要的应用价值。文中针对CLEFIA-128算法需要5轮才能基本实现雪崩效应、扩散效果并不明显的问题，以及每一轮中两个轮函数的设计方式导致的软、硬件实现效率降低的问题，从加密结构和轮函数上对该算法进行了改进。测试表明改进后的算法只要4轮就能基本实现雪崩效应，差分、线性和不可能差分分析表明改进后算法的安全性有了提高，而且算法的软、硬件实现效率也有了明显提高。
展开▼
