Date: Thu, 02 May 2019 00:10:37 +0000
To: Aymeric Vitte <vitteaymeric@gmail.com>
From: ZmnSCPxj <ZmnSCPxj@protonmail.com>
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Cc: "bitcoin-dev@lists.linuxfoundation.org"
	<bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] IsStandard
Precedence: list

Good morning Aymeric,


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=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 Tuesday, April 30, 2019 5:43 PM, Aymeric Vitte <vitteaymeric@gmail.com> =
wrote:

> I must badly explain my point (or just wondering things that do not
> exist finally), the question is indeed whether nodes will relay non
> usual transactions or not and how to know what they will accept or not:
>
> -   my modified multisig 2 of 3: I did put OP_2 out of the usual redeem
>     script, the redeem script still matches scriptpubkey and scriptsig wi=
ll
>     execute succesfully, that's a normal legacy P2SH or segwit P2WSH
>
> -   bch segwit recovery: it's a p2sh transaction without any signature
>     verification, as far as I remember there was a story that it could no=
t
>     propagate in the network (even taking the risk to be stolen) and that
>     people had to contact a (honest) miner
>
> -   sha bounties: same as above, p2sh transactions without signatures
>
>     etc
>
>     Will all of those transactions propagate normally? And then the rule =
is
>     just that it matches the P2PKH, P2WPKH, P2SH, or P2WSH templates
>     whatever scripts you put inside?

P2PKH and P2WPKH cannot have custom script.
However, yes, any custom script can be wrapped in P2SH and P2WSH and it wil=
l be propagated.
The P2SH/P2WSH hides the details of your custom script so cannot be filtere=
d based on your custom script.
Do realize that once a claim on your modified x-of-3 is propagated your `re=
deemScript` is known and someone can attempt to RBF (or coordinate with a m=
iner) with a modified `witness` stack or `scriptSig` to claim your UTXO.
(I do not know if `OP_CHECKMULTISIG` supports 0-of-3 but at least one of yo=
ur signatories could make it a 1-of-3 and bribe a miner to get it claimed)

I cannot answer for BCH; arguably that is off-topic here.

The old SHA bounty transactions were propagated in the days before `isStand=
ard` I think.
Either that or they were put in by miners.
An SHA bounty can still be propagated today if they are wrapped in a P2SH o=
r P2WSH, but you have to publish the `redeemScript` yourself in some other =
method.
Or bribe a miner if the transaction is not time-sensitive (for an SHA bount=
y, unlikely to be time-sensitive).

Regards,
ZmnSCPxj