[sBTC] Open Design Questions

[jcnelson]

• Stacker-controlled Bitcoin wallet script design
• Best way to add support for existing Bitcoin wallets for peg-ins
• Paying for Stacks transactions with sBTC
• Stacking with sBTC, or other forms of BTC yield on sBTC? Needs an economist's attention
• Who pays the Bitcoin tx fee for peg-out fulfillment? How do we set this fee?
• Multiple hard-forks to speed up deployment?
• Stacker peg hand-off concerns, especially w.r.t. TOCTTOU issues with client wallets sending to a freshly-stale peg wallet address
• Delegating Stacker signing authority to a custodian?
• How might we make the signer process more accessible?

[JoseSK999]

I think the Stacker Bitcoin wallet needs to be P2TR to allow up to 11,759 signing keys. Something similar to this degrading multisig setup could be used, but I don't know if the MuSig key aggregation is suitable (it's interactive and a spend from it requires all the keys to participate).

[jcnelson]

We're using a variation of FROST [1] to have the Stackers collectively produce a single signature. It doesn't matter how many signers there are; the resulting transaction takes the same amount of block space.

[1] https://github.com/Trust-Machines/frost