Summary

• We propose CoinPool, a covenant-based payment pool construction, which takes the idea of sharing UTXO ownership to the next level.
• In CoinPool, Bitcoin users lock funds in many accounts within a single UTXO to instantly transact across the pool without much on-chain footprint...or use their accounts inside the pool for advanced protocols (e.g. payment channels), possible even connect to other CoinPools to the Lightning Network.
• CoinPool users can withdraw their funds from the pool at anytime.
• Once a user withdraws from the pool, the remaining participants can either continue withdrawing non-cooperatively or return to off-chain pool operations.
• CoinPool introduces an alternative set of trade-offs: users get increased funds velocity and use Bitcoin throughput more efficiently, at the cost of high interactivity required by pool participants.
• e.g. A CoinPool instance can represent a corporation, with stakeholders having different balances and voting rights to implement corporate governance and distribute dividends. A special balance could be used as a corporate account and controlled by the majority of the participants.
• CoinPool requires modifications to the Bitcoin protocol.
• Similar to CoinPool, mixers provide confidentiality against an outside, but not against an in-protocol spy. "Confidentiality boost "is a secondary feature for CoinPool.