To me, identity is not something one has, like InfoCard or a key, but something one does, a verb if you will. Identity is like the equal sign of an equation. For identity to happen, you need both sides of the equation.
In the real world, identity happens when I see someone I met before. I compare the face in front of me with the face I remember and, voila, identity happens. Identity stops happening as soon as the person walks away or the person hits me hard enough to faint.
Likewise, online identity happens when a website and I agree on some piece of secret and then I later show it. Yup, the website would say, you showed us what we saw before. As soon as that is done, the website has to give me something else because identity is an event and the website will forget who I am otherwise. Usually, they give me a ticket which I have to show everytime I say something. When I am done with the website, the ticket is thrown away.
But does the website know who I am? Nope. If I tell them that I am the Don Ho who sang Tiny Bubbles, they'll accept that so, when online identity happens later, they'll be able to say Yup, you showed us what we saw before from a guy who claimed to be Don Ho.
At this point, I forgot what I was going to say. It's too bad that, like identity, enlightment is a verb.