Probably something involving smart cards, each with a display so you can confirm on the card itself every time you sign something. I would also add another lay

Probably something involving smart cards, each with a display so you can confirm on the card itself every time you sign something. I would also add another layer of signing, so that you have a master key that you keep locked up in a secure location at home (wherever you keep your Social Security card today), and use that key very infrequently to sign and endorse another key you keep in your wallet. If you lose your wallet, then it's a simple matter to take your master key out of storage and revoke the previous wallet key and sign a new one. If you lose your master key, it's a more complicated process of going down to the DMV and proving your identity again to create a new master key. But it's not going to happen because the costs of fraud in the current system are less than the costs of rejigging the whole whole thing.