摘要： 为增强流密码算法泄露提取(LEX)抵抗滑动攻击的能力,通过提取高级加密标准(AES)密钥扩展环节的16字节的中间变量作为下一轮AES加密密钥K,对LEX的密钥体系进行改进。在此基础上,分析改进算法的安全性和运算速度,并通过C++编程测试检验改进算法的密钥流随机性。结果表明,改进后的LEX算法能够抵抗滑动攻击,并保持与LEX算法相同的运算速度和密钥流随机性。

关键词: 流密码, 密钥流, 泄露提取算法, 安全性, 滑动攻击, 随机性

Abstract: In order to enhance the ability of the stream cipher algorithm for Leak Extraction(LEX) in resisting slide attack,16 bytes from the intermediate variable are extracted at each key expansion of Advanced Encryption Standard(AES),and they are used as the secret key K in the next AES.The key system of LEX is improved.On this basis,the safety and operating speed of the improved LEX algorithm is analyzed.The simulation based on C++ is also conducted to test the key stream randomness of the improved LEX algorithm.The results show that the improved algorithm can resist slide attack with the same computing speed and key stream randomness in the LEX algorithm.

Key words: stream cipher, key stream, Leak Extraction(LEX) algorithm, security, slide attack, randomness

中图分类号: 

• TP301.6