Author: Billy Tetrud 2021-07-28 17:57:09
Published on: 2021-07-28T17:57:09+00:00
In a Bitcoin development mailing list, a user named Billy suggested a wallet vault design that uses an opcode called OP_CD to create secure wallets. This approach would allow normal people to hold self-custody of their keys without fear of loss or theft. The discussion revolves around the idea of limiting the amount that can be sent from an address, especially in a wallet vault. While it would be difficult to do this in Bitcoin's output-based system, the proposal suggests combining coins into a single output and encumbering it with a script that allows limited amounts to be sent to a destination address. It requires all other bitcoins to be returned to the sender in a new change output. The proposal also suggests setting up and maintaining multiple rate-limited addresses that meet any rate-limiting parameters as desired by the user. This approach could alleviate privacy concerns since the wallet would be able to mix outputs. The proposal further discusses different rate-limiting parameters and how such user-enabled rate-limiting is superior to one that requires a third party. Regarding the use case of wallet vaults, the proposal mentions that the op_code could be used to create a 2-key wallet vault where the user only needs to use one key to spend funds, but the attacker must steal two or more keys to spend funds. However, a question arises on how a vault solution could prevent an attacker who is in possession of the vault's private key from sabotaging the user by replacing the user transaction with one having a higher fee every time the user attempts to transact. A possible solution proposed is to have multiple keys, and if one key is stolen, the user can use additional keys to override the attacker's transaction.James MacWhyte, another user on the mailing list, questioned the usefulness of this opcode compared to a 2-of-2 multisig setup. The proposal suggests that the OP_CD opcode is better suited for rate-limiting and providing additional security measures for wallet vaults.
Updated on: 2023-06-15T00:21:23.242112+00:00