If the authentication was successful, then you know that you are really talking to your friend. Any imposter should have a hard time guessing what you're typing in, so you'll be able to catch them in the act.
Si l' autenticació ha estat correcta, llavors sabreu que realment esteu parlant amb el vostre amic. Qualsevol impostor tindria moltes dificultats per a saber què hi escriviu, de manera que l' enganxaríeu a l' acte.