I am wondering if a digital voting scheme would be possible by combining ring signatures, blind signatures and nostr.

With ring signatures a voter can sign their vote anonymously, and anybody can verify that "someone" that is registered as a voter has cast a valid vote.

The problem with this is that a voter can cast multiple valid votes, while we'd want to constrain that to one.

If everybody votes the cheating can be spotted, because the votes would surpass the number of voters. But even then, it would not possible to distinguish which votes are duplicate.

If we introduce and authority figure, then we can use blind signatures.

A voter creates their vote, turns it into a number, blinds that number and then communicates it to the authority.

The authority only signs that blinded vote if it can confirm the identity of the voter and that it hasn't already cast a vote.

The voter can then unblind the vote (only they can do that) and create a ring signature of the vote with the public keys of other plausible voters.

Now I am thinking: could we split that authority amongst nostr relays and have it collaboratively blindly sign something?