Problem: Efficient weighted threshold signatures
We want to construct a signature scheme that allow a quorum to sign. Each participant has a weight , and we want a signature to be accepted if the sum of weights of the signing participants is at least some threshold .
Notes:
- There is good progress in eprint.iacr.org/2023/1609.pdf by Garg, Goel, and Wang, but this paper uses FRI. Can we do better?
- The “cheap” approach is just to use regular threshold signatures, where each participant signs times.
- If we have a big hammer like a SNARK, this is easy:
- Everybody generates a signature, and then the aggregator generates a proof that it saw valid signatures from (say) five people, and the sum of their weights is greater than the threshold.
- The witness would be the signatures from the individual participants and the weights of the participants.
- Is there a simple algebraic scheme?
- Maybe there’s a way to generalize BLS signatures: https://en.wikipedia.org/wiki/BLS_digital_signature