alt Hacker NewsI don't quite get your point. The signer is blind to what it signs, but that does not mean there is no identity per se.
A signed key is still unique.
- You can still check that user 1 and user 2 don't use the same key.
- You can still issue a challenge to the user every 10 days to make sure he has indeed access to his key and not just borrowed it.
- You can still enforce TPM use of said keys, so that they cannot be extracted or distributed online, but require a physical ID card.
- You can still do whatever revocation system you want for the cases when a key is stolen or lost.
Really the "blind" nature of the signature changes nothing to what you would normally do with a PKI.
You're only describing a half-blind system.
If the site you send your information to gets a uniquely identifying piece of information, that's not blind to your identity.
> - You can still check that user 1 and user 2 don't use the same key.
The systems described elsewhere in the thread give people a set of signatures that can't be traced back to their source.