I'm currently developing SkyDocs for the Internet Computer. SkyDocs now allows you to login with an Dfinity Internet Identity.

Internet Identity

With an Internet Identity, you login with cryptographically enabled devices, like a fingerprint sensor on a laptop or a YubiKey. You don't have to store a username or password. More info can be found here: https://smartcontracts.org/docs/ic-identity-guide/what-is-ic-identity.html

So you can login with your Internet Identity in SkyDocs, but SkyDocs is hosted on multiple places. It's hosted on the Internet Computer but also on Sia Skynet. No problem! That just works. You can also use login with Internet Identity in dApps that are not hosted on the Internet Computer.

Pseudonyms

So now we can login in the same dApp hosted on different locations. We should be able to access the same documents, right? The Internet Identity uses a pseudonym for every dApp. When a dApp is hosted on a different URL, it will get a different pseudonym. The dApp only has access to this pseudonym and doesn't know the real identity. So when accessing our documents, we can't access the same documents when logging in on the same dApp hosted on different URLs.

This is great from a security perspective, this way dApps can't access user data stored from another dApp. But it's not ideal from a user perspective, because the user expects the same documents, no matter which URL he uses to login.

Try it