Quote from: Pieter Wuille on Today at 06:09:35 PM

The Bitcoin script system *is* a (programmable) digital signature

No!
It is just an invention, a bad one: Programmable digital signature. There was no such thing in the world before you guys made it up, right? No problem, as super devs you are entitled to do inventions, but as an observer I have all rights to review and to resist.

Quote from: Pieter Wuille on Today at 06:09:35 PM

The "messages" of this scheme are the spending transactions, excluding witness data.[/li][/list]
{-snip-}
BIP322 is taking this script signature system, and transposing it to a different context: messages that aren't transactions.

So, BIP322 is hijacking (taking) your invention and landing it where it was not supposed to (transposing).
I understand how it feels, getting high by doing abstractions and generalizations, but it needs to pass some review and criticisn. I'm afraid the vague and loose terminology is a bad sign.

Bitcoin scripting system is not electronic signature, it may use this technology. Using a technology doesn't make a system identical with that technology.
Why should anybody do it? Ruining established terminology. What's the catch? Proof-of -ownership or something? Why should it be considered an act of signing? Why don't we simply open a BIP for this one with an appropriate terminology? It is not "message signing" per se, it is "virtual transacting", whatever.

Quote from: Pieter Wuille on Today at 06:09:35 PM

I don't understand any of the concerns brought up here. AFAICT, the only thing necessary to move BIP322 forward is finalizing the last details of the specification, and implementing it (which may mean bring the Bitcoin Core implementation up-to-date, if BIP changes are made, and/or implementations for other software, which may be template based).

Then how is it possible to have both, template based and interpreter based implementations in one world?
Above thread, I've already discussed it, for now let's check just one issue (there are more, believe me):

For a p2sh where the script is well-formed and can be supported by both, either the message produced by interpreter friendly style is not compatible with template based verification and fails, or it is compatible, the only way for this to happen is preparing and signing a message conventionally and template based the putting this message (including signatures) in the virtual txn and signing it AGAIN! A total mess of a design.

My Suggestions: (I want to be constructive)

1- First and foremost, stop scrambling the terminology, I know, we all know, Greg is genius, you are genious, ..., no doubts, but we are all humans, sometimes we go too far.

2- Ripping this sign-by-script concept off from BIP322, let it focus on true signing with support for references to standard txns (with well-formed scripts).

3- Make another BIP Just for proof-by-interpretation thing. Find a proper label.

Do not mix signing-with-reference-to-txo with proof-by-interpretation/ or whatever you may call it.