c#实现DES加密与解密

//DES加密
public string DESEncrypt(string  pToEncrypt,  string  sKey)
  ...{  
   DESCryptoServiceProvider  des  =  new  DESCryptoServiceProvider();  
   byte[]  inputByteArray  =  Encoding.Default.GetBytes(pToEncrypt);  
   des.Key  =  ASCIIEncoding.ASCII.GetBytes(sKey);  
   des.IV  =  ASCIIEncoding.ASCII.GetBytes(sKey);  
   MemoryStream  ms  =  new  MemoryStream();  
   CryptoStream  cs  =  new  CryptoStream(ms,  des.CreateEncryptor(),CryptoStreamMode.Write);  
   cs.Write(inputByteArray,  0,  inputByteArray.Length);  
   cs.FlushFinalBlock();  
   StringBuilder  ret  =  new  StringBuilder();  
   foreach(byte  b  in  ms.ToArray())  
   ...{  
    ret.AppendFormat("{0:X2}",  b);  
   }  
   ret.ToString();  
   return  ret.ToString();  

  }
//DES解密
  public string DESDecrypt(string  pToDecrypt,  string  sKey)
  ...{ 
   DESCryptoServiceProvider  des  =  new  DESCryptoServiceProvider();  
 
   byte[]  inputByteArray  =  new  byte[pToDecrypt.Length  /  2];  
   for(int  x  =  0;  x  <  pToDecrypt.Length  /  2;  x++)  
   ...{  
    int  i  =  (Convert.ToInt32(pToDecrypt.Substring(x  *  2,  2),  16));  
    inputByteArray[x]  =  (byte)i;  
   }  
 
   des.Key  =  ASCIIEncoding.ASCII.GetBytes(sKey);  
   des.IV  =  ASCIIEncoding.ASCII.GetBytes(sKey);  
   MemoryStream  ms  =  new  MemoryStream();  
   CryptoStream  cs  =  new  CryptoStream(ms,  des.CreateDecryptor(),CryptoStreamMode.Write);  
   cs.Write(inputByteArray,  0,  inputByteArray.Length);  
   cs.FlushFinalBlock();  
 
   StringBuilder  ret  =  new  StringBuilder();  
             
   return  System.Text.Encoding.Default.GetString(ms.ToArray());  
  }