The way it would work with blind signatures is that the server will know the device that comes to it to request a blinded signature and will be able to rate limit how often that device asks it.

But once you get the response you can unblind the signed signature and obtain the token (which is just the unblinded signature). This token can then be used once either because its blacklisted after use (and it expires before the next day starts for example).

The desired property of blind signatures is that given a token it's information theoretically impossible to determine which blinded signature it came from (because it could have come from any of them) even if the cryptographic primitive is broken by a mathematical breakthrough or a quantum computer. There is technically the danger that if the anonymity set is too small and all the other participants collude you can be singled out.

Correlating times is a threat vector that needs to be managed either by delaying actions (not tolerable by normal users) or by acquiring tokens automatically and storing them in expectation. Or something other I haven't thought of probably. There is also a networking aspect to this, you will need a decentralized relay server network that masks origin of requests.

> But once you get the response you can unblind the signed signature and obtain the token (which is just the unblinded signature).

The premise of this is to keep the person issuing the tokens and the person accepting them from correlating you.

The issue is when you have more than one service accepting them. You go to use Facebook and WhatsApp but they're both Meta so you present the same unblinded signature to both services and now your Facebook and WhatsApp accounts are correlated against your will. And they have a network that does the same thing, so you go to use a third party service and they require you to submit your unblinded signature to Meta which allows them to correlate you everywhere.