Author: James O'Beirne 2022-03-08 19:46:03
Published on: 2022-03-08T19:46:03+00:00
The conversation between Antoine and James revolves around the discussion of pre-signed transactions as a security measure for Bitcoin wallets. James argues that bugs can affect the output amount or relative-timelock setting correctness in any sufficiently involved uses of bitcoin script, including lightning scripts or DLCs or tapscript use. He also notes that the immutability of the flow paths is inherent to the idea of covenants and that it's possible to lock coins up for an arbitrary amount of time and then have advance notice of an attempted spend only with some kind of covenant technique. Antoine raises concerns about trusted hardware in the vault design, which might lead one to ask what's the security advantage of vaults compared to classic multisig setup. James clarifies that the cold key in the vault structure could have been generated by performing SHA rounds with the pebbles in your neighbor's zen garden. He also notes that keeping an actively used multi-sig setup secure isn't easy and that if there's a known scheme that doesn't require covenants but has similar usage and security characteristics, he'd love to know it. Antoine suggests introducing an intermediary, out-of-chain protocol step where the unvault broadcast is formally authorized by the vault stakeholders. James agrees and notes that it's pretty straightforward to send such a process (whether it's a program or a collection of humans) an authenticated signal that says "hey, expect a withdrawal." They also discuss the critical data persistence requirement and reducing surface area.Antoine raises concerns about the usage of anchor output being safe for any vault deployment where the funds stakeholders do not trust each other or where the watchtowers are not trusted. James explains that he's thinking of individual users and custodians, each of which functions as a single trusted entity. He also notes that better fee-bumping needs a la SIGHASH_GROUP or transaction sponsors are needed.Finally, they discuss the space efficiency and James notes that if every major custodian ends up implementing some type of vault scheme, this might be a lot of space. However, he's all for facilitating the flow of bitcoin from major custodians to miners.
Updated on: 2023-06-15T17:42:53.031169+00:00