本例是用md5做为数据校验的算法防止自己的程序被篡改的小例子。有些可执行程序，当被改了资源时再运行会有文件已损坏的提示，这就是使用了数据校验。当然你可以使用个性化的,比如des作为数字签名，那样安全性更高。具体请见代码及注释.-cases is the use of data as md5 checksum algorithm to prevent their own procedures be tampered with small examples. Some of the executable, when resources were diverted when the operation will damage the document has suggested that this is the use of calibration data. Of course, you can use the personalized, such as des as digital signatures, as higher security. See specific code and the Notes.