Random encryption of string in C#

public string EncryptString(string inputString)
       {
           MemoryStream memStream = null;
           try
           {
               byte[] key = { };
               byte[] IV = { 12, 21, 43, 17, 57, 35, 67, 27 };
               string encryptKey = "aXb2uy4z";
               key = Encoding.UTF8.GetBytes(encryptKey);
               byte[] byteInput = Encoding.UTF8.GetBytes(inputString);
               DESCryptoServiceProvider provider = new DESCryptoServiceProvider();
               memStream = new MemoryStream();
               ICryptoTransform transform = provider.CreateEncryptor(key, IV);
               CryptoStream cryptoStream = new CryptoStream(memStream, transform, CryptoStreamMode.Write);
               cryptoStream.Write(byteInput, 0, byteInput.Length);
               cryptoStream.FlushFinalBlock();

           }
           catch (Exception ex)
           {
               Response.Write(ex.Message);
           }
           return Convert.ToBase64String(memStream.ToArray());
       }