From: Sjors Provoost <sjors@sprovoost.nl>
Message-Id: <FF336476-DCD2-4380-83CC-584DAF7A1D72@sprovoost.nl>
Content-Type: multipart/signed;
 boundary="Apple-Mail=_E9EE833A-59BE-4767-A5C5-38E7F5165619";
 protocol="application/pgp-signature"; micalg=pgp-sha256
Mime-Version: 1.0 (Mac OS X Mail 14.0 \(3654.60.0.2.21\))
Date: Fri, 9 Apr 2021 17:33:31 +0200
In-Reply-To: <CAPKmR9u8zc3C7QmJYg-vg5jcutS07PK-0wdvpzCqMGLgnhHCBA@mail.gmail.com>
To: Bitcoin Dev <bitcoin-dev@lists.linuxfoundation.org>
References: <CAPKmR9uyY70MhmVCh=C9DeyF2Tyxibux1E_bLPo00aW_h+OjLw@mail.gmail.com>
 <CAPKmR9v=RK7byF0z0hKiLiA=Zm3ZZKbu3vEiuBuzQSXFwa+izw@mail.gmail.com>
 <DDAD27D6-57F5-4B39-AADB-B28E04E36D29@sprovoost.nl>
 <CAPKmR9u8zc3C7QmJYg-vg5jcutS07PK-0wdvpzCqMGLgnhHCBA@mail.gmail.com>
Cc: marko <marko@shiftcrypto.ch>, aarondongchen@gmail.com,
 Peter Gray <peter@coinkite.com>
Subject: Re: [bitcoin-dev] Proposal: Bitcoin Secure Multisig Setup
Precedence: list


--Apple-Mail=_E9EE833A-59BE-4767-A5C5-38E7F5165619
Content-Type: multipart/alternative;
	boundary="Apple-Mail=_2E5715EA-C69C-4FBC-BB3B-F794F8DDFC7F"


--Apple-Mail=_2E5715EA-C69C-4FBC-BB3B-F794F8DDFC7F
Content-Transfer-Encoding: quoted-printable
Content-Type: text/plain;
	charset=us-ascii

Thanks for the detailed response. Just 1 thing I needed to clarify:

> To the list of concerns at the top of the BIP, I would add one: losing =
multisig setup context. E.g. in the event of a fire where you only =
recover your steel engraved mnemonic(s), but no longer have the wallet =
descriptors.
>=20
> Good point.
>=20
>=20
> If you still have all devices and know (or guess) the threshold then =
BIP48 and sorted_multi descriptors will save you. But if you have a =
2-of-3 setup and lost 1 device then without the metadata your coins are =
lost. In a future with musig(?) and miniscript increasingly the setup =
data is just as critical as the seeds.
>=20
> How so? Each signer device should ideally have a copy of the multisig =
configuration. If you lose 1 device in a 2-of-3, you can still spend =
from the wallet? Unless I'm missing something here.

I was thinking about a scenario where all devices are destroyed. All you =
have left are the mnemonics. But indeed if at least one of your devices =
is still intact AND it has the configuration, you're also good.

But there are plenty of devices out there that can't do this. Those =
devices can still be useful, even if they can't fully check everything.

Sjors

--Apple-Mail=_2E5715EA-C69C-4FBC-BB3B-F794F8DDFC7F
Content-Transfer-Encoding: quoted-printable
Content-Type: text/html;
	charset=us-ascii

<html><head><meta http-equiv=3D"Content-Type" content=3D"text/html; =
charset=3Dus-ascii"></head><body style=3D"word-wrap: break-word; =
-webkit-nbsp-mode: space; line-break: after-white-space;" =
class=3D"">Thanks for the detailed response. Just 1 thing I needed to =
clarify:<br class=3D""><div><br class=3D""><blockquote type=3D"cite" =
class=3D""><div dir=3D"ltr" class=3D""><div =
class=3D"gmail_quote"><blockquote class=3D"gmail_quote" =
style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid =
rgb(204,204,204);padding-left:1ex">
To the list of concerns at the top of the BIP, I would add one: losing =
multisig setup context. E.g. in the event of a fire where you only =
recover your steel engraved mnemonic(s), but no longer have the wallet =
descriptors.<br class=3D""></blockquote><div class=3D""><br =
class=3D"">Good point.<br class=3D"">&nbsp;</div><blockquote =
class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px =
solid rgb(204,204,204);padding-left:1ex">
<br class=3D"">
If you still have all devices and know (or guess) the threshold then =
BIP48 and sorted_multi descriptors will save you. But if you have a =
2-of-3 setup and lost 1 device then without the metadata your coins are =
lost. In a future with musig(?) and miniscript increasingly the setup =
data is just as critical as the seeds.<br class=3D""></blockquote><div =
class=3D""><br class=3D"">How so? Each signer device should ideally have =
a copy of the multisig configuration. If you lose 1 device in a 2-of-3, =
you can still spend from the wallet? Unless I'm missing something =
here.<br class=3D""></div></div></div></blockquote><div><br =
class=3D""></div><div>I was thinking about a scenario where all devices =
are destroyed. All you have left are the mnemonics. But indeed if at =
least one of your devices is still intact AND it has the configuration, =
you're also good.</div><div><br class=3D""></div><div>But there are =
plenty of devices out there that can't do this. Those devices can still =
be useful, even if they can't fully check everything.</div><div><br =
class=3D""></div><div>Sjors</div></div></body></html>=

--Apple-Mail=_2E5715EA-C69C-4FBC-BB3B-F794F8DDFC7F--

--Apple-Mail=_E9EE833A-59BE-4767-A5C5-38E7F5165619
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment;
	filename=signature.asc
Content-Type: application/pgp-signature;
	name=signature.asc
Content-Description: Message signed with OpenPGP

-----BEGIN PGP SIGNATURE-----
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=qBk+
-----END PGP SIGNATURE-----

--Apple-Mail=_E9EE833A-59BE-4767-A5C5-38E7F5165619--