实现了三种古典密码学体制和DES体制及其分析。affine(仿射)读入文件11.txt中内容（小写字母，明文）加密并把内容写入12.txt，还可以解密生成文件13.txt。vigenere,hill体制类似。DES体制包括加密解密雪崩效应差分分析等内容。由于本人还是刚学习程序设计语言及密码学的在校本科生，水平很低，第一次上传只是为了试一下。可以考虑少给几点，呵呵。-achieve three classical cryptography system and DES system and its analysis. P14 (affine) read into the document 11. Txt contents (lowercase letters, expressly) encryption and written 12. txt, can also generate documents declassified 13. txt. Vigenere, hill similar system. DES encryption and decryption system, including avalanche effect Differential analysis of the contents. Because I still just learning programming language and Cryptography in undergraduate school, the low level Uploading is the first to try. Consider a smaller number of points-huh.