Blockchain: user authorization and registration?

Question

Python

Tell me how to organize the registration and authorization of users in some application that organizes blockchain technology.
I understand that it is necessary to allocate a pair of keys (public and private) to the user, but how can I later check that this pair was generated by my program, and not forged?

Answer 1

And what's the difference what it is generated?
Any keys created by the correct algorithm should be working, you never know, I already have my own key.
What does fake mean? Is there a key? He is a worker? What problems?

Answer 2

You simply cannot open (decrypt) content protected by another pair of keys in your program.