一种基于动态S-盒P-盒的快速分组密码算法--DSP  

Novel Software Block Cipher Using Dynamic S-box and P-box

作　　者：陈利科[1] 张润彤[1,2] 

机构地区：[1]大连海事大学信息科学技术学院,大连116029 [2]北京交通大学经济管理学院,北京100044

出　　处：《计算机科学》2009年第2期78-81,共4页Computer Science

基　　金：国家自然资金项目(60773033)资助

摘　　要：密钥相关加密结构作为一种较安全的密码结构受到密码工作者的广泛关注,然而现有该类算法的安全缺陷和十分复杂的算法初始化过程,严重地限制了算法的使用。因此,提出一种基于密钥相关Feistel结构的快速分组加密算法,算法通过结合密钥相关的动态S-盒和密钥相关动态P-盒两种基本密码组件,设计一种更加安全的Feistel轮加密结构,可以使算法在较少的轮数内达到安全。同时,该算法通过采用快速置乱算法生成S-盒、P-盒,改进了现有该类算法子密钥生成算法效率极低的缺点。为了得到更好的兼容性,算法仅选用基于字节的密码操作,使得算法广泛适用现有的大多数处理器。算法的最大特点就是使用了密钥相关的动态S-盒(DS)和动态P-盒(DP),因此该密码结构命名为DSP结构,该算法为DSP分组密码算法。分别用C和Java在不同Pentium PC上实现了该算法;实验结果表明,该算法有着较好的加密解密效率,以及相对快速的算法初始化过程。Block ciphers based on key-dependent cipher structures have been investigated for years, however, their over- all performance in terms of security and speed has not been sufficiently addressed. We proposed a 128-bit Feistel block cipher,which engages both dynamic S-box and dynamic P-boxes that are all key-depen-dent. With these two key-dependent transformations, the internal structure of this cipher algorithm was secured, so as to resist the linear and differential cryptanalysis in a few round encryptions. Hence, the encryption and decryption functions are very efficient. We named this key-dependent structure the DSP structure, and the cipher DSP. A fast permutation algorithm was used to generate both the dynamic S-box and dynamic P-boxes. This greatly compensates the performance penalty of complex key schedule. The basic operations selected in DSP are all efficient bytewise operations, so the algorithm will have a reasonable fast speed on recent processors, 16-bit processors and smart cards as well as 8-bit processors. We implemented the algorithm with C and Java on two different PCs with Pentium processors, and estimated the optimized assembly performance. The experimental results and the estimation show that DSP has a very fast encryption/decryption speed and a reasonable fast key scheduling implementation.

关 键 词：DSP结构 动态S-盒 动态P-盒 分组密码算法 

分 类 号：TP336[自动化与计算机技术—计算机系统结构] TN918.1[自动化与计算机技术—计算机科学与技术]