to understand how Nostr is able to function without signing up for accounts anywhere, it's really useful to understand public key cryptography, a.k.a. asymmetric cryptography. the main way of doing that is the RSA algorithm. Bitcoin uses secp256k1 elliptic curve cryptography instead, which is considered to be more future-proof since it's more resilient to quantum computer attacks.
Discussion
Hmm ok but you didn’t really explain anything.
because the idea is to google the keywords i gave you.
knowing what to google is the real superpower. knowing just a few key phrases and then you go walking the search engines and the wikis to learn.
the idea of that post was "this is something to research" rather than "i am going to give you a dissertation on this topic on a medium that is not at all appropriate for long-form texts"