[DecoySalamander]

You will need to implement some very invasive issuing mechanism to ensure that only those with a pulse can procure new keys. Even then, keys will still be bought or stolen - as was the case with pre-Elon Twitter checkmarks.

[kreetx]

In Europe some countries have ID cards which have a private key on it. If you report it stolen it goes into the revocation list and they issue a new ID card to you.