中文摘要：

分组密码一直是解决信息系统安全问题的常用加密方法。分组密码的典型代表数据加密标准DES（Data Encryption Standard）被广泛应用于软件加密和硬件加密,其中所体现的设计思想和设计原则依然值得研究和借鉴。S盒作为DES算法的一个关键环节,它的设计好坏直接影响DES的加密性能。通过对分组密码安全性设计的分析,立足于DES算法框架,提出了一种轻量级安全加密算法LEA（Light weight Encryption Algorithm）,通过增加位选逻辑陷阱来对S盒中的元素进行选取和重新优化设计,最后从S盒统计特性角度对其安全性进行分析。该算法能有效解决低成本系统的安全问题。

英文摘要：

Block cipher is always a general technique for solving the problem of information system security.Data Encryption Standard（DES） is widely applied in software encryption and hardware encryption.It is worthwhile to study and make reference of the design ideas and rules in DES.S-box is a key module in the DES algorithm,and its design has a direct affection on the performance of DES encryption.In this paper,a lightweight encryption algorithm（LEA） based on analysis of block cipher security design and the framework of DES,is proposed.And by increasing the bit selection logic traps,the S-box design is optimized,and finally the security of S-box is analyzed from the angle of the statistical characteristics.The proposed algorithm could effectively solve the security problem of low-cost systems.