Aethernal McAwesome on Nostr: Thanks for the explanation, brother. Still there are so many questions in my mind if ...

Thanks for the explanation, brother. Still there are so many questions in my mind if you don't mind me asking. How can I be sure the user logging in my platform is the same one that registered? I mean, what if someone uses someone else's npub to login? My understanding of nostr protocol is small, from what I've read, if someone has your npub he can load all your posts, but can't post as you if he doesn't have your nsec. How can I certify it without asking for nsec? Does your code allow npub:password pair or only a nostr "signer" app? Regarding NIP-98, I see it was only a draft, none of the relays I use for example support it. Will I need to host a nostr relay that support NIP-98 for the users?