This seems just like regular auth, just using a trusted 3P to re-anonymize. Maybe I’m missing something, though. It seems likely it won’t provide much value if it’s unbreakably anonymous (because it only takes a few stolen credentials to give an attacker access to fake-humanity), and doesn’t provide sufficient anonymity for important uses if it’s escrowed (such that the issuer CAN track identity and individual usage, even if they currently choose not to).
Yeah I appreciate the engagement, I don’t think either of those is a knock-down objection though:
The ability to illicitly gain a few credentials —> >1 account is still meaningfully different from being able to create ~unbounded accounts. It is true this means a PHC doesn’t 100% ensure a distinct person, but it can still be a pretty high assurance and significantly increase the cost of doing attacks that depend on scale.
Re: the second point, I’m not sure I fully understand—say more? By our paper’s definitions, issuers wouldn’t be able to merely choose to identify individuals. In fact, even if an issuer and service-provider colluded, PHCs are meant to be robust to this. (Devil is in the details of course.)
This seems just like regular auth, just using a trusted 3P to re-anonymize. Maybe I’m missing something, though. It seems likely it won’t provide much value if it’s unbreakably anonymous (because it only takes a few stolen credentials to give an attacker access to fake-humanity), and doesn’t provide sufficient anonymity for important uses if it’s escrowed (such that the issuer CAN track identity and individual usage, even if they currently choose not to).
Yeah I appreciate the engagement, I don’t think either of those is a knock-down objection though:
The ability to illicitly gain a few credentials —> >1 account is still meaningfully different from being able to create ~unbounded accounts. It is true this means a PHC doesn’t 100% ensure a distinct person, but it can still be a pretty high assurance and significantly increase the cost of doing attacks that depend on scale.
Re: the second point, I’m not sure I fully understand—say more? By our paper’s definitions, issuers wouldn’t be able to merely choose to identify individuals. In fact, even if an issuer and service-provider colluded, PHCs are meant to be robust to this. (Devil is in the details of course.)