基于Camellia算法的快速流密码算法设计与特性研究

摘要

As the encryption standard of the block cipher of NESSIE,Camellia algorithm has the same security and applicability as AES algorithm.In this paper,a novel fast stream cipher algorithm was proposed based on Camellia algorithm.The idea is to extract parts of the internal state at certain round function F and give them as the output key-stream.We analyzed the relative characteristics of the new algorithm.The result shows that the new algorithm achieves almost the same performance as the optimal performance obtained in LEX,in terms of keystream generation speed and randomness.Besides,it can resist slide attack,with both input and key changing in each Camellia module.%Camellia算法作为欧洲分组密码加密标准,与AES算法具有一致的安全性与适用性.以Camellia算法为核心部件,从部分轮函数F中提取4个字节的中间状态作为密钥流输出,设计了一种新的快速流密码算法,并分析了它的相关特性.分析结果表明,该算法的密钥流生成速度和密钥流随机性与同类型的LEX算法大致相当,但由于每个Camellia模块的输入与密钥均发生了改变,因此该算法可以有效地抵抗LEX算法所不能抵抗的滑动攻击.