Yes, but the site has to link to the server. So either the user has accounts on every DSSID server - losing the SSO advantages - or everyone uses the same server.

If you let the users choose their own server (by putting its URL), then you've just reinvented OpenID.

The difference is that your identity is not bound to the server, it's bound to your DSSID key, which resides (encrypted) in your browser's localStorage. So you can move your (public) key to any server and retain your identity.

But the user still needs to copy the data between servers, no?And what happens if the personal clears all the cookies in FF and deletes the Local Storage?

Wouldn't it be better to use a personal cert?

> But the user still needs to copy the data between servers, no?

Yes, if you want to use multiple servers you need to get your data on multiple servers. But that's just a consequence of the laws of physics. It has nothing to do with DSSID.

> And what happens if the personal clears all the cookies in FF and deletes the Local Storage?

If they haven't made a backup copy of their key then they are screwed. You can't stop people from deliberately shooting themselves in the foot. If they have made a backup copy of their key then they can just re-import it.

> Wouldn't it be better to use a personal cert?

All else being equal yes. But the UI/UX for certs is so hopelessly bad that not even technically savvy people use them. DSSID's goal is to be secure and simple. That's a currently unoccupied point in the design space. (It's not easy to do.)