I am using encryt function to encrypt a xml file,how can w e decrypt a file at runtime and convert it to xml document in memeory to use without creating a document at s eperate location

  private void Encrypt(string inputFilePath, string outputfilePath)
    {
        string EncryptionKey = "MAKV2SPBNI99212";
        using (Aes encryptor = Aes.Create())
        {
            Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(EncryptionKey, new byte[] { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 });
            encryptor.Key = pdb.GetBytes(32);
            encryptor.IV = pdb.GetBytes(16);
            using (FileStream fsOutput = new FileStream(outputfilePath, FileMode.Create))
            {
                using (CryptoStream cs = new CryptoStream(fsOutput, encryptor.CreateEncryptor(), CryptoStreamMode.Write))
                {
                    using (FileStream fsInput = new FileStream(inputFilePath, FileMode.Open))
                    {
                        int data;
                        while ((data = fsInput.ReadByte()) != -1)
                        {
                            cs.WriteByte((byte)data);
                        }
                    }
                }
            }
        }
    }


    private void Decrypt(string inputFilePath, string outputfilePath)
    {
        string EncryptionKey = "MAKV2SPBNI99212";
        using (Aes encryptor = Aes.Create())
        {
            Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(EncryptionKey, new byte[] { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 });
            encryptor.Key = pdb.GetBytes(32);
            encryptor.IV = pdb.GetBytes(16);
            using (FileStream fsInput = new FileStream(inputFilePath, FileMode.Open))
            {
                using (CryptoStream cs = new CryptoStream(fsInput, encryptor.CreateDecryptor(), CryptoStreamMode.Read))
                {
                    using (FileStream fsOutput = new FileStream(outputfilePath, FileMode.Create))
                    {
                        int data;
                        while ((data = cs.ReadByte()) != -1)
                        {
                            fsOutput.WriteByte((byte)data);
                        }
                    }
                }
            }
        }
    }