I'm thinking about creating a central login system for all my websites, where you get redirected to and then login/sign up and then be redirect back. A bit like oAuth.

I have a few websites (and more in development) that use a login system, so that could be really useful to have... Especially because all of them are built from scratch and have their pros and cons. And security wise it's easier to concentrate on one system instead of all of them.

Another benefit is that you save some DB space, if you have lots of users!
And of course the users benefit from it as they'll be able to use all my websites with a single account.

What do you think about it?
I'll still need to do a bit of research on security but other than that, I only see benefits!