Re: [bitcoin-dev] Signature and Script Independent Hierarchy for Deterministic Wallets.

[Robert Spigler <RobertSpigler@protonmail.ch>]

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Hi Craig,

For multisignature wallets, you need to back up the descriptor anyway, especially for secure multisignature schemes (https://github.com/nunchuk-io/bips/pull/1).

To restore, the user needs M private key data, and all public keys. The descriptor provides the required public key data, with the benefit of key origin information and error detection, and tells the wallet which script to watch.

So I see this proposal as a clear gain for multisignature wallets, as it (1) gets rid of redundant data in the key record, (2) separates keys/scripts, (3) makes full use of descriptors, and (4) prevents key reuse.

>>If one has the threshold and all the cosigner seeds, the funds in a multisig wallet can very likely be discovered by checking one of a handful of standard derivation paths/script types

Old scenario: You have BIP39 words (I assume). You try BIP 45 - search 20 addresses on the first 5 accounts. Then try BIP 48 - search 20 addresses on the first 5 accounts with script type 1 (P2SH-P2WSH); then search 20 addresses on the first 5 accounts with script type 2 (P2WSH).

New scenario: Should have a descriptor, and you just do what it says.

If you don't, you have to search the `address_index` for each script. The moment funds are found, you know that script type is the only script type used for that `account'` level. Increment `account'`, and repeat.

Robert

Personal Fingerprint: BF0D 3C08 A439 5AC6 11C1 5395 B70B 4A77 F850 548F

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Friday, March 19, 2021 3:54 AM, Craig Raw <craigraw@gmail.com> wrote:

> Hi Robert,
>
> I believe many of the same concerns apply in multisig. If one has the threshold and all the cosigner seeds, the funds in a multisig wallet can very likely be discovered by checking one of a handful of standard derivation paths/script types. Is the motivation of this BIP proposal strong enough to lose this capability?
>
> Craig

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