Re: [bitcoin-dev] IsStandard

[ZmnSCPxj <ZmnSCPxj@protonmail.com>]

Good morning Aymeric,


Sent with ProtonMail Secure Email.

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Monday, April 29, 2019 5:30 PM, Aymeric Vitte <vitteaymeric@gmail.com> wrote:

> ZmnSCPxj, OK, but you can put whatever you like in the different
> standard output script you mention (my example below whether legacy or
> segwit)
>

I am uncertain what you mean by this.

For P2PKH and P2WPKH, you must present a hash of a public key.
You cannot present a hash of anything else.

The P2PKH template can be interpreted as a script, but is actually recognized as a template by most current nodes (in a way that is consistent with interpreting it as a script).

For P2SH and P2WSH, you must present a hash of a script.

It is more helpful to consider that *today* nodes recognize particular patterns (P2PKH, P2WPKH, P2SH, P2WSH) as templates and not as scripts to be executed.

In any case, if you want to make anything more complicated than "single signer" you should use P2SH or P2WSH regardless, and give your script.
If you want to assure somebody that a particular P2SH or P2WSH commits to a particular policy, just expose the policy script to them and have them (i.e. their client software) verify that the policy is what the user wants and that when hashed it matches the P2SH/P2WSH.

As Luke said, nodes can have any policy for propagating transactions.
However it is generally expected that P2PKH, P2WPKH, P2SH, and P2WSH will be propagated by a majority of nodes, if only because those are reliably "passed" by `isStandard` in the default latest Bitcoin Core and most people will not modify the Core code.

Generally, anything that isn't P2PKH, P2WPKH, P2SH, or P2WSH will not likely be propagated by the network.
You *could* still coordinate with one or more miners to get it mined: you can put anything in the block, it is simply that most nodes will not inform miners about transactions that do not pay out to P2PKH, P2WPKH, P2SH, or P2WSH.

Regards,
ZmnSCPxj