Title: libsecp256k1 schnorr sigs - how to determine the number of signers Post by: jl777 on June 06, 2016, 10:40:19 AM 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 Title: Re: libsecp256k1 schnorr sigs - how to determine the number of signers Post by: tonytumble on June 08, 2016, 10:46:07 PM 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. Title: Re: libsecp256k1 schnorr sigs - how to determine the number of signers Post by: jl777 on June 10, 2016, 03:17:01 AM 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. 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 |