One of the technologies I am waiting for would allow me to effect transactions without giving over vast quantities of personal data. After all, what companies really need to know are: can I pay, and do I have the necessary qualities (age, residence) I claim to have. They don't need to know a vast range of irrelevant *details* about me.

Such a system exists; it's called U-Prove.

This is absolutely brilliant. There's just one problem: you can't use it in practical situations, because it's not widely deployed. And because it's not widely deployed, nobody uses it...

So, how do you break that vicious circle? Easy - you make it freely available to encourage uptake - and that's just what Microsoft has done.

rest here