Pseudorandomness on the Round-Structure of Skipjack  

作　　者：WU Wenling WEI Hongru 

机构地区：[1]State Key Laboratory of Information Security, Institute of Software, Chinese Academy of Sciences, Beijing 100080, China [2]School of Applied Science, Beijing University of Science and Technology, Beijing 100083, China

出　　处：《Chinese Journal of Electronics》2006年第3期378-383,共6页电子学报（英文版）

基　　金：This work （No.60373047, 90304007）; the National Basic Research 973 Program Development 863 Program of China （No.2003AA144030）. is supported by the National Natural Science Foundation of China of China （No.2004CB318004） and the National High-Technology

摘　　要：Skipjack is a simple cipher, and one interesting feature is the use of two different types of rounds. These are referred to as A and B-rounds. Earlier researchers have studied the security of Skipjack against some attack methods, but they did not focus on pseudorandomness of the round-structure of Skipjack. In this paper, we discuss the pseudorandomness on the round-structure of Skipjack. We first point out six rounds A-Skipjack is not pseudorandom, and then prove seven rounds A-Skipjack is pseudorandom for any adversaries. Next we point out twelve rounds B-Skipjack is not pseudorandom, and prove fourteen rounds B-Skipjack is pseudorandom for any adversaries.

关 键 词：Block cipher Skipjack Random function PSEUDORANDOMNESS Round structure. 

分 类 号：TN918.2[电子电信—通信与信息系统]