密码学的ppt，里面详细说明了DES算法，以及各个置换盒的数据。-Cryptography ppt, which details the DES algorithm, as well as various replacement cartridge data.

。该法根据所研 究的问题构造检验统计量，并利用手头样本，按排列组合的原理导出检验统计量的理论抽样分布； 若难以导出确切的理论分布，则采用抽样模拟的方法估计其近似分布，然后求出从该分布中获得 手头样本及更极端样本的概率(P值)，并界定此概率值，作出推论。-It is sample．based distribution-free method，which makes use of“permutation or combination”to get the theo． retical

ecent advances in electrical engineering and computer science, esp ecially in micro- electro-mechanical systems (MEMS), very-large-scale integration (VLSI) and op erating system theory, have made wireless sensor network (WSN) technologies an imp