Can parties sign locally?

[xygdys]

Does the following protocol work?

For 10 parties and 5 is the threshold,

1. Every party compute it's share locally (without communicate with others), then broadcast it's to others.
2. Any party who recieved 5 shares recover a valid signature

[yycen]

You may need a one round signing scheme. For ecdsa, you could find gg20 branch that has such features, but in order to sign in one round, the parties needs to have several rounds of communication to get a preSig for use when message to be sign comes. If you are not stick to ecdsa scheme, you could find signature schemes like BLS that is pretty straight forward to make such one round threshold signing feature work.

[wanghao-bianjie]

You may need a one round signing scheme. For ecdsa, you could find gg20 branch that has such features, but in order to sign in one round, the parties needs to have several rounds of communication to get a preSig for use when message to be sign comes. If you are not stick to ecdsa scheme, you could find signature schemes like BLS that is pretty straight forward to make such one round threshold signing feature work.

If it is 1-2, both parties need to sign. Can preSig be calculated and saved in advance, and used for offline signature in the future? Is this feasible and are there any safety issues?