New application methods for word-oriented cryptographic primitives  

作　　者：YANG Yang ZENG Guang JIN ChengHui QU YunYing 

机构地区：[1]Zhengzhou Information Science and Technology Institute,Zhengzhou 450002,China [2]State Key Laboratory of Information Security,Institute of Software,Chinese Academy of Sciences,Beijing 100190,China

出　　处：《Science China(Information Sciences)》2012年第9期2149-2160,共12页中国科学（信息科学）（英文版）

基　　金：supported by National Natural Science Foundation of China (Grant No. 61003291);National High Technology Research and Development Program of China (Grant No. 2011AA010803);Foundation for the Author of National Excellent Doctoral Dissertation of China (Grant No. FANEDD-2007B74)

摘　　要：Modern software oriented symmetric ciphers have become a key feature in utilizing word-oriented cryptographic primitives. Using the output sequence, in the order of its generation, of a word-oriented crypto- graphic primitive in the same way as traditional bit-oriented primitives, we can expose the intrinsic weakness of these primitives, especially for word-oriented linear feedback shift registers, T-functions, and so on. Two new methods for using word-oriented cryptographic primitives are presented in this paper, that is, the extracted state method and cascading extracted coordinate method. Using a T-function as an example, we research the different cryptographic properties of the output sequences of the original method and the two proposed methods, focusing mainly on period, linear complexity, and k-error linear complexity. Our conclusions show that the proposed methods could enhance at low cost the cryptographic properties of the output sequence. As a result, since the new methods are simple and easy to implement, they could be used to design new word-oriented cryptographic primitives.Modern software oriented symmetric ciphers have become a key feature in utilizing word-oriented cryptographic primitives. Using the output sequence, in the order of its generation, of a word-oriented crypto- graphic primitive in the same way as traditional bit-oriented primitives, we can expose the intrinsic weakness of these primitives, especially for word-oriented linear feedback shift registers, T-functions, and so on. Two new methods for using word-oriented cryptographic primitives are presented in this paper, that is, the extracted state method and cascading extracted coordinate method. Using a T-function as an example, we research the different cryptographic properties of the output sequences of the original method and the two proposed methods, focusing mainly on period, linear complexity, and k-error linear complexity. Our conclusions show that the proposed methods could enhance at low cost the cryptographic properties of the output sequence. As a result, since the new methods are simple and easy to implement, they could be used to design new word-oriented cryptographic primitives.

关 键 词：stream cipher single cycle T-function linear complexity k-error linear complexity 

分 类 号：TP301.6[自动化与计算机技术—计算机系统结构] TP309[自动化与计算机技术—计算机科学与技术]