if you're rolling your own authentication system for anything other than learning purposes (so god forbid production), you really should NOT be rolling an authentication system from scratch.
With that, I mean write one yourself.
Use libraries that are well established by people who know security.
Security is hard, and one mistake can open up all your users to being hacked, never mind the legal trouble YOU are going to be in when that happens (especially since OP wants to build a social network and those generally end up keeping sensitive information about their users).
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if you're rolling your own authentication system for anything other than learning purposes (so god forbid production), you really should NOT be rolling an authentication system from scratch.
With that, I mean write one yourself.
Use libraries that are well established by people who know security.
Security is hard, and one mistake can open up all your users to being hacked, never mind the legal trouble YOU are going to be in when that happens (especially since OP wants to build a social network and those generally end up keeping sensitive information about their users).