RC4密码的改进方法及其性能分析

针对RC4密码技术在工程应用中存在的弱密钥和相关密钥攻击、不变性弱点、数据流偏向性弱点等安全问题，提出一种将ECC技术与RC4技术相结合的方法。对改进后的RC4的数据处理效率、密钥管理、安全性能进行研究和分析。改进后的RC4技术在保证与RC4数据处理效率相近的同时，对当前针对RC4流密码的密码分析方法具有一定的抗攻击性。该技术较好地解决了密钥的共享和更新问题，具有重要的工程应用意义。

Improved RC4 Cipher Method and Its Performance Analysis

When used in application, RC4 cipher technology has some problems, such as weak keys and related key attacks, invariance weakness,, byte bias and so on. This paper presents an improved RC4 cipher technology, which combines the ECC cipher and the RC4 stream cipher. The emphasis is analyzing the efficiency, the management of keys, and the capability of the improved RC4 cipher. The result indicates that the efficiency of the improved RC4 is just a litter lower than RC4 stream cipher while the security is much better than RC4. It has good repellency of the current attacks which aim at RC4 stream cipher. What is more, the improved RC4 cipher has a good way to solve the problems about key management and key update, which is very significant in application.