采用VB6.0编程的MD5加密算法。MD5就是采用单向加密的加密算法，对于MD5而言，有两个特性是很重要的，第一是任意两段明文数据，加密以后的密文不能是相同的；第二是任意一段明文数据，经过加密以后，其结果必须永远是不变的。前者的意思是不可能有任意两段明文加密以后得到相同的密文，后者的意思是如果我们加密特定的数据，得到的密文一定是相同的。-Using VB6.0 programming of MD5 encryption algorithm. MD5 is the use of one-way encryption algorithm, for MD5, there are two characteristics is very important, the first is any two plaintext data encrypted ciphertext, later not to be the same　second is an arbitrary piece of plaintext encrypted data, then, the results must always be the same. The meaning of the former is unlikely to have any two plaintext after getting the same ciphertext, which means if we encrypt specific data, the encryption must be the same.