It _could_ work ...
if it were done such that one could buy a key fob or similar token from one of a dozen manufacturers, depending on your needs, which device would generate a new key whenever one fancied, and would allow you to chose between one of several such identities.
Then you take your widget to the post office, or some such, along with your passport, a gas bill and your swimming proficiency certificate, and they sign your ID using public key crypto.
I believe that one of the ex-USSR countries has something pretty close to that in their ID cards.
If you think that one of your keys is compromised, you revoke the key, create a new one and go back to the post office for it to be authenticated. No enormous central database required.
of course, since no central database is needed, there is no chance of the civil servants supporting such a scheme, because of the lack of empire building opportunities.
One could imagine having a tamper-proof module built into phones for holding these keys.
at which point this becomes something like Dave Birch's psychic paper idea:
shame it'll never happen