[at612]

> So distribute keys on smart cards that don't allow you to export the key

That's what I covered in the second paragraph. :-)

The thing is, both those implementations were a disaster from either a technological or a security point of view. We're not even getting into whether a central source of trust is a good idea or not (you will look at the state of HTTPS and make up your own mind on that). So, to repeat, proper security is hard.