MD5的具体实现，大致分为以下几步。补位，消息填充，移位，进入四轮循环，输出。代码有详细注释。-MD5 practical implementation, roughly divided into the following a few steps. Fill a, message filled, shift, into the fourth cycle, output. The code is detailed notes.

信道编码中的循环码编码和译码，有效达到加密效果，解密速度快-Channel coding loop coding and decoding, encryption effectively achieve results faster decryption