How does wa work?

Question

PHP

Hello, this is the question. I have a wa account linked to an old SIM card (number) at the moment this number is not used by me (operators resold due to inactivity). But the wa account still works without problems. If I give someone my old number, then they write to me (although someone else is already using the number) how does this happen? And the second question, if I change the phone, how can people write to my account?

Answer 1

No.
The hash cannot be rolled back.

Answer 2

In fact, the hash is needed so that it cannot be recognized. If only to look for holes in the algorithm or brute force.

Answer 3

I suspect that wa is not aware that you have changed the number, and the new owner of the number is not aware that an account in some messenger is linked to his number.
We drag something, another reason why instant messengers with a link to a mobile phone are evil.