A minor mistake: You say "An identity provider (ISP): the centralized service your user will use to authenticate". You mean "IDP", not "ISP".
(That happens to me w/ using uncommon initialisms that are one letter off from the ones I use more commonly. My muscle memory inevitably makes me type some fraction of the more common one even when I mean otherwise.)
(That happens to me w/ using uncommon initialisms that are one letter off from the ones I use more commonly. My muscle memory inevitably makes me type some fraction of the more common one even when I mean otherwise.)