流密码算法，可用于文件加密和实

代码说明：

流密码算法,可用于文件加密和实时通信 ,设计者是著名的密码学家Rivest.该算法效率远高于一般分组密码,并且很适合用于随机数生成-Stream cipher algorithm, can be used for file encryption and real-time communication, the designer is well-known cryptographer Rivest. The algorithm efficiency is much higher than the general block cipher, and is suitable for random number generator