Author

Topic: libsecp256k1 schnorr sigs - how to determine the number of signers (Read 828 times)

legendary
Activity: 1176
Merit: 1134
I have been experimenting with the schnorr combined signatures and I cant figure out how to directly determine the number of signers.

From what I am seeing, the combined pubkey will say any combined pubkey with any subset of signers is valid.

I dont see a clean way to get a specific threshold validation. Is the process to iterate through all the pubkeys from each signer to see which ones validate against the combined signature? Otherwise it seems that some sort of combinatorial explosion of combined pubkey needs to be made to find the exact set of signers.

but I only need the number of signers, not the exact ones, so I am hoping there is a simple way

James

i would determine it by iterating through every users pubkey and validating them against the sig. I don"t think there is a easier way as its not known how many users combined their sigs into the merged "unified signature" which from my understanding does not reveal who nor how many people signed. but with their pubkeys you could validate their participation incrementaly.
thanks, I guess this requires every node sharing the pubkeys globally... But if that is the case then how would this save space on the blockchain as these are temporary keypairs each multisig would need all the pubkeys, which is essentially the same as now.

Not exactly the behaviour I was expecting.

I had thought using schnorr partial sigs allowed for space efficient threshold sigs, ie MofN
If iterating through the pubkeys is required, that seems to not allow any space savings
newbie
Activity: 16
Merit: 0
I have been experimenting with the schnorr combined signatures and I cant figure out how to directly determine the number of signers.

From what I am seeing, the combined pubkey will say any combined pubkey with any subset of signers is valid.

I dont see a clean way to get a specific threshold validation. Is the process to iterate through all the pubkeys from each signer to see which ones validate against the combined signature? Otherwise it seems that some sort of combinatorial explosion of combined pubkey needs to be made to find the exact set of signers.

but I only need the number of signers, not the exact ones, so I am hoping there is a simple way

James

i would determine it by iterating through every users pubkey and validating them against the sig. I don"t think there is a easier way as its not known how many users combined their sigs into the merged "unified signature" which from my understanding does not reveal who nor how many people signed. but with their pubkeys you could validate their participation incrementaly.
legendary
Activity: 1176
Merit: 1134
I have been experimenting with the schnorr combined signatures and I cant figure out how to directly determine the number of signers.

From what I am seeing, the combined pubkey will say any combined pubkey with any subset of signers is valid.

I dont see a clean way to get a specific threshold validation. Is the process to iterate through all the pubkeys from each signer to see which ones validate against the combined signature? Otherwise it seems that some sort of combinatorial explosion of combined pubkey needs to be made to find the exact set of signers.

but I only need the number of signers, not the exact ones, so I am hoping there is a simple way

James
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