1 /// <summary> 
 2         /// DES加密，密钥为8位字符 
 3         /// </summary> 
 4         /// <param name="strEncrypt">需要加密的字符串</param> 
 5         /// <param name="strKey">8位的密钥</param> 
 6         /// <returns></returns> 
 7         public static string DesEncrypt(string strEncrypt, string strKey) 
 8         { 
 9             if (string.IsNullOrEmpty(strEncrypt)) return null; 
10             try 
11             { 
12                 DESCryptoServiceProvider des = new DESCryptoServiceProvider(); 
13                 byte[] inputByteArray = Encoding.Default.GetBytes(strEncrypt); 
14                 des.Key = ASCIIEncoding.ASCII.GetBytes(strKey); 
15                 des.IV = ASCIIEncoding.ASCII.GetBytes(strKey); 
16                 MemoryStream ms = new MemoryStream(); 
17                 CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write); 
18                 cs.Write(inputByteArray, 0, inputByteArray.Length); 
19                 cs.FlushFinalBlock(); 
20                 StringBuilder ret = new StringBuilder(); 
21                 foreach (byte b in ms.ToArray()) 
22                 { 
23                     ret.AppendFormat("{0:X2}", b); 
24                 } 
25                 ret.ToString(); 
26                 return ret.ToString(); 
27             } 
28             catch 
29             { 
30                 return null; 
31             } 
32         } 

 1 /// <summary> 
 2         /// DES解密，密钥为8为字符 
 3         /// </summary> 
 4         /// <param name="strDecrypt">需要加密的字符串</param> 
 5         /// <param name="strKey">8位的密钥</param> 
 6         /// <returns></returns> 
 7         public string DesDecrypt(string strDecrypt, string strKey) 
 8         { 
 9             if (string.IsNullOrEmpty(strDecrypt)) return null; 
10             try 
11             { 
12                 DESCryptoServiceProvider des = new DESCryptoServiceProvider(); 
13                 byte[] inputByteArray = new byte[strDecrypt.Length / 2]; 
14                 for (int x = 0; x < strDecrypt.Length / 2; x++) 
15                 { 
16                     int i = (Convert.ToInt32(strDecrypt.Substring(x * 2, 2), 16)); 
17                     inputByteArray[x] = (byte)i; 
18                 } 
19                 des.Key = ASCIIEncoding.ASCII.GetBytes(strKey); 
20                 des.IV = ASCIIEncoding.ASCII.GetBytes(strKey); 
21                 MemoryStream ms = new MemoryStream(); 
22                 CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write); 
23                 cs.Write(inputByteArray, 0, inputByteArray.Length); 
24                 cs.FlushFinalBlock(); 
25                 return System.Text.Encoding.Default.GetString(ms.ToArray()); 
26             } 
27             catch 
28             { 
29                 return null; 
30             } 
31         }