I think each identity is going to need multiple keys too. The key in the secure element on my smartphone may well be different to the key on my Yubikey. There w

I think each identity is going to need multiple keys too. The key in the secure element on my smartphone may well be different to the key on my Yubikey. There will also need to be a robust mechanism for revoking keys, if/when they are compromised/lost. Key management is tough. OAuth and tokenisation are great solutions for authentication but applications like GPG and crypto-currencies will likely still require "proper" crypto. Smartcards feel like the now-old'n'clunky prototype/PoC implementation of something better. I can't help feeling like the banks and telcos could contribute to a solution if they could work more collaboratively. I don't think the end solution is a proprietary, for-profit one. It needs to be open and accessible to everyone, instead of fragmented into competing walled gardens.