利用MD5加密数据库中的密码

NET提供了进行数据加密类，下面就用例子进行说明如何使用MD5进行数据加密。
首先，创建一个UserAccount表，字段两个：UserName和Password，类型分别为varchar(25)和binary(16)，下面的ASP.NET代码就是创建用户时的具体实现：
<%@ Import Namespace="System.Security.Cryptography" %>
<%@ Import Namespace="System.Text" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<script runat="server" language="VB">
Sub CreateAccount(sender as Object, e as EventArgs)
'1. 创建连接
Const strConnString as String
strConnString= "Data Source=.;Initial Catalog=test;User Id=sa;Password=;"
Dim objConn as New SqlConnection(strConnString)
'2. 创建Command对象
Dim strSQL as String = _
"INSERT INTO UserAccount(Username,Password) " & _
"VALUES(@Username, @Password)"
Dim objCmd as New SqlCommand(strSQL, objConn)
'3. 创建参数
Dim paramUsername as SqlParameter
paramUsername = New SqlParameter("@Username", SqlDbType.VarChar, 25)
paramUsername.Value = txtUsername.Text
objCmd.Parameters.Add(paramUsername)

'加密密码字段
Dim md5Hasher as New MD5CryptoServiceProvider()

Dim hashedBytes as Byte()
Dim encoder as New UTF8Encoding()
hashedBytes = md5Hasher.ComputeHash(encoder.GetBytes(txtPwd.Text))