Date: Sun, 24 Jun 2018 04:19:00 -0400
To: Andrew Chow <achow101-lists@achow101.com>,
	Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
From: Andrea <a.raspitzu@protonmail.com>
Reply-To: Andrea <a.raspitzu@protonmail.com>
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Subject: Re: [bitcoin-dev] BIP 174 thoughts
Precedence: list

Hi,=20

I think in the revised spec we can remove completely the "global types" as =
a map or even as typed record. Since there is only one type (the transactio=
n) and it's compulsory to have one (and only one) we could just drop the de=
finition of global type and the key associated with it, simply after the he=
ader + separator there must be a transaction.=E2=80=8B=E2=80=8B Having read=
 all the discussion i also agree having per-input key derivation and per-ou=
tput data is a lot more handy for signers, no special feeling regarding the=
 encoding.Looking forward for the test vectors and the new spec.

Cheers, Andrea.

=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90 Original Me=
ssage =E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90

On June 23, 2018 10:33 PM, Andrew Chow via bitcoin-dev <bitcoin-dev@lists.l=
inuxfoundation.org> wrote:

> =E2=80=8B=E2=80=8B
>=20
> On 06/23/2018 10:00 AM, William Casarin wrote:
>=20
> > Since we're still considering the encoding, I wonder if it would be a
> >=20
> > good idea to have a human-readible part like lightning invoices[1]?
>=20
> I don't think that is necessary.
>=20
> > Then perhaps you could drop the magic code as well?
>=20
> The magic is still necessary for the binary format in order to prevent
>=20
> normal transaction deserializers from accidentally deserializing a psbt.
>=20
> > Also we could do a base encoding that excludes + and / characters, such
> >=20
> > as base62 (gmp-style). It's easier to copy/paste (double clicking a
> >=20
> > string stops at / or + in base64 encodings).
>=20
> While that would be ideal, I think it is better to use an encoding that
>=20
> most wallets already support. Most wallets already have Base64 decoding
>=20
> available so that they can decode signed messages which also use Base64
>=20
> encoding. I think it is unnecessary to introduce another encoding.
>=20
> On 06/23/2018 11:27 AM, Peter D. Gray wrote:
>=20
> > Personally, I don't think you should spec an encoding. It should be bin=
ary only and hex for developers and JSON interfaces. My thinking is that PS=
BT's are not user-visible things. They have a short lifetime and are nothin=
g something that is "stored" or referenced much later. Hex is good enough a=
nd has no downsides as an excoding except for density.
>=20
> I think what will end up happening though is that, at least in the
>=20
> beginning, PSBTs will primarily be strings that people end up copy and
>=20
> pasting. Since a PSBT can get pretty large, the strings are rather
>=20
> cumbersome to move around, especially as hex. At least with Base64 the
>=20
> strings will be smaller.
>=20
> > On the other hand, suggesting a filename extension (probably .PSBT?) an=
d a mime-type to match, are helpful since wallets and such will want to reg=
ister with their operating systems to become handlers of those mimetypes. R=
eally that's a lot more important for interoperability at this point, than =
an encoding.
>=20
> Agreed. I will include those in the BIP.
>=20
> > Looking forward to test vectors, and I might have more to say once my c=
ode can handle them (again).
> >=20
> > Feedback on the BIP as it stands now:
> >=20
> > -   Appendix A needs an update, and I suggest defining symbols (PK_PART=
IAL_SIG =3D=3D 0x02) for the numeric key values. This helps implementers as=
 we don't all define our own symbols and/or use numeric constants in our co=
de.
>=20
> Okay.
>=20
> > -   Those tables are just not working. Might want to reformat as descri=
ptive lists, point form, or generally anything else... sorry.
>=20
> I will try my best to fix that. Mediawiki sucks...
>=20
> Andrew
>=20
> bitcoin-dev mailing list
>=20
> bitcoin-dev@lists.linuxfoundation.org
>=20
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev