The process works like this:
1. Register on SITE.
2. Forwarded to 3RD PARTY.
3. Data uploaded to 3RD PARTY.
4. Data processed, stored, handled, exclusively by 3RD PARTY.
5. 3RD PARTY asks you for consent to send specific information to SITE (in this instance, only Gender).
6. SITE stores an API token (looks like 'b594e335-ea8d-4a6f-969a-ab167a56eef5').
- This token means nothing on its own.
- This token has value to the 3RD PARTY.
- SITE can check this token against 3RD PARTY to ensure that no one registers twice.
7. In the event of total data breach, hackers get meaningless tokens, F/M.
I'm not settled on an account system yet. You'd basically log in with this token.