c# 几种常见的加密方法的实现

//ACSII码加密
    private static string ACSIIPWd(string rpwd)
    {
      string Ret;
      byte[] array = System.Text.Encoding.ASCII.GetBytes(rpwd);
      byte[] byteArray = new byte[array.Length];

      for (int i = 0; i < array.Length; i++)
      {
        int asciicode = (int)(array[i]);
        asciicode = asciicode + 1;
        byteArray[i] = (byte)asciicode;
      }
      System.Text.ASCIIEncoding asciiEncoding = new System.Text.ASCIIEncoding();
      string strCharacter = asciiEncoding.GetString(byteArray);
      Ret = strCharacter;
      return Ret;
    }

//MD5加密
    private static string MD5PWd(string rpwd)
    {
      string Ret;

      MD5 md5 = new MD5CryptoServiceProvider();
      byte[] palindata = Encoding.Default.GetBytes(rpwd);//将要加密的字符串转换为字节数组
      byte[] encryptdata = md5.ComputeHash(palindata);//将字符串加密后也转换为字符数组
      Ret = Convert.ToBase64String(encryptdata);
      return Ret;
    }

//RSA加密
    private static string RSAPWD1(string myKeyContainerName)
    {
      string ret = "";     
      CspParameters cp = new CspParameters();
      cp.KeyContainerName = myKeyContainerName;
      RSACryptoServiceProvider rsa = new RSACryptoServiceProvider(cp);
      
      ret = rsa.ToXmlString(true);
      Console.WriteLine("Key is : \n" + rsa.ToXmlString(true));
      return ret;

    }

//DES加密 
    private static string DESPWD(string ciphertext)
    {
      string desPWD = ""; 
      byte[] buffer;
      DESCryptoServiceProvider DesCSP = new DESCryptoServiceProvider();

      MemoryStream ms = new MemoryStream();//先创建 一个内存流
      CryptoStream cryStream = new CryptoStream(ms, DesCSP.CreateEncryptor(), CryptoStreamMode.Write);//将内存流连接到加密转换流
      StreamWriter sw = new StreamWriter(cryStream);
      sw.WriteLine(ciphertext);//将要加密的字符串写入加密转换流
      sw.Close();
      cryStream.Close();
      buffer = ms.ToArray();//将加密后的流转换为字节数组
      desPWD = Convert.ToBase64String(buffer);//将加密后的字节数组转换为字符串

      return desPWD;
    }