private void createkeybutton_ontap(object sender, Windows.UI.Xaml.Input.TappedRoutedEventArgs e)
{
PgpPublicKeyRing publicKey;
PgpSecretKeyRing privateKey;
PGP.GenerateKeyPair(userid_box.Text, password_box.Text, out publicKey, out privateKey);
KeyStore.Instance.StoreKeyPair(privateKey, publicKey);
// todo: some key-generating loading animation
// navigate to next tutorial slide
this.Frame.Navigate(typeof(TutorialPage));
}