多种CRC的算法解释和原理分析，并有原程序。可以在通讯和文件加密中使用-CRC algorithm multiple interpretations and principles of analysis, and the original procedure. The communications and the use of file encryption

ET199加密狗内部文件读取模块，用于写入加密狗的程序，可以通过外部程序调用，不是在电脑上运行的。-ET199 dog internal file reading module, the procedure used to write the dog, can be invoked through the external program is not running on the computer.