基于混沌序列的DES算法研究与实现

Study and Implementation of DES Algorithm Based on Chaotic Sequences

针对DES算法使用短密钥的不足,提出利用混沌理论拓展DES密钥空间的设想,设计了一种基于混沌序列的DES算法.即用Logistic映射产生混沌序列,从中构造DES的轮密钥,轮密钥间具有相互独立性,密钥空间具有无限性.通过改进的DES算法进行图像数据的加/解密试验,结果表明改进的DES算法较改进前的算法在安全性和抗破译性方面具有更强的抗攻击能力.

In view of the deficient application of short cryptographic keys in DES algorithm, this paper presents the conception of developing DES key space by the chaotic theory and designs a new DES algorithm based on logistic chaotic sequences. That is, generated by logistic maps are chaotic sequences, from which composed are DES round cryptographic keys with reciprocal independence and infinite key space. Experiments are carried out on the encryption and decryption of image data by means of the improved DES algorithm. The results show that, as compared with the original algorithm, the betterment possesses stronger resistance to attacks in security and anti-decryption.