From: Rusty Russell <rusty@rustcorp.com.au>
To: Jeremy Rubin <jeremy.l.rubin@gmail.com>
Cc: Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] TXHASH + CHECKSIGFROMSTACKVERIFY in lieu of CTV and ANYPREVOUT
Date: Wed, 16 Feb 2022 12:56:14 +1030 [thread overview]
Message-ID: <87a6err1h5.fsf@rustcorp.com.au> (raw)
In-Reply-To: <CAD5xwhi4y1NiZ__c1WY-rCV3XBzN5yxY1Zox6Mc1FTjxUhXK9A@mail.gmail.com>
Jeremy Rubin <jeremy.l.rubin@gmail.com> writes:
> Hi Rusty,
>
> Please see my post in the other email thread
> https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2022-February/019886.html
>
> The differences in this regard are several, and worth understanding beyond
> "you can iterate CTV". I'd note a few clear examples for showing that "CTV
> is just as powerful" is not a valid claim:
>
> 1) CTV requires the contract to be fully enumerated and is non-recursive.
> For example, a simple contract that allows n participants to take an action
> in any order requires factorially many pre-computations, not just linear or
> constant. For reference, 24! is about 2**80. Whereas for a more
> interpretive covenant -- which is often introduced with the features for
> recursion -- you can compute the programs for these addresses in constant
> time.
> 2) CTV requires the contract to be fully enumerated: For example, a simple
> contract one could write is "Output 0 script matches Output 1", and the set
> of outcomes is again unbounded a-priori. With CTV you need to know the set
> of pairs you'd like to be able to expand to a-priori
> 3) Combining 1 and 2, you could imagine recursing on an open-ended thing
> like creating many identical outputs over time but not constraining what
> those outputs are. E.g., Output 0 matches Input 0, Output 1 matches Output
> 2.
Oh agreed. It was distinction of "recursive" vs "not recursive" which
was less useful in this context.
"limited to complete enumeration" is the more useful distinction: it's a
bright line between CTV and TXHASH IMHO.
> I'll close by repeating : Whether that [the recursive/open ended
> properties] is an issue or not precluding this sort of design or not, I
> defer to others.
Yeah. There's been some feeling that complex scripting is bad, because
people can lose money (see the various attempts to defang
SIGHASH_NOINPUT). I reject that; since script exists, we've crossed the
Rubicon, so let's make the tools as clean and clear as we can.
Cheers!
Rusty.
next prev parent reply other threads:[~2022-02-16 3:45 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-26 17:20 [bitcoin-dev] TXHASH + CHECKSIGFROMSTACKVERIFY in lieu of CTV and ANYPREVOUT Russell O'Connor
2022-01-26 22:16 ` Jeremy
2022-01-27 4:20 ` James Lu
2022-01-27 19:16 ` Russell O'Connor
2022-01-28 0:18 ` James O'Beirne
2022-01-28 13:14 ` Michael Folkson
2022-01-28 14:17 ` Anthony Towns
2022-01-28 16:38 ` Jeremy
2022-01-28 14:13 ` Russell O'Connor
2022-01-28 15:14 ` James O'Beirne
2022-01-29 15:43 ` Russell O'Connor
2022-01-29 17:02 ` Jeremy Rubin
[not found] ` <CAD5xwhjHv2EGYb33p2MRS=VSz=ciGwAsiafX1yRHjxQEXfykSA@mail.gmail.com>
2022-01-29 17:14 ` Russell O'Connor
2022-01-31 2:18 ` Anthony Towns
2022-01-28 1:34 ` Anthony Towns
2022-01-28 13:56 ` Russell O'Connor
2022-02-01 1:16 ` Anthony Towns
2022-02-08 2:16 ` Russell O'Connor
2022-02-17 14:27 ` Anthony Towns
2022-02-17 14:50 ` Russell O'Connor
2022-02-08 3:40 ` Rusty Russell
2022-02-08 4:34 ` Jeremy Rubin
2022-02-11 0:55 ` [bitcoin-dev] Recursive covenant opposition, or the absence thereof, was " David A. Harding
2022-02-11 3:42 ` Jeremy Rubin
2022-02-11 17:42 ` James O'Beirne
2022-02-11 18:12 ` digital vagabond
2022-02-12 10:54 ` darosior
2022-02-12 15:59 ` Billy Tetrud
2022-02-17 15:15 ` Anthony Towns
2022-02-18 7:34 ` ZmnSCPxj
2022-02-23 11:28 ` ZmnSCPxj
2022-02-23 18:14 ` Paul Sztorc
2022-02-24 2:20 ` ZmnSCPxj
2022-02-24 6:53 ` Anthony Towns
2022-02-24 12:03 ` ZmnSCPxj
2022-02-26 5:38 ` Billy Tetrud
2022-02-26 6:43 ` ZmnSCPxj
2022-02-27 0:58 ` Paul Sztorc
2022-02-27 2:00 ` ZmnSCPxj
2022-02-27 7:25 ` ZmnSCPxj
2022-02-27 16:59 ` Billy Tetrud
2022-02-27 23:50 ` Paul Sztorc
2022-02-28 0:20 ` Paul Sztorc
2022-02-28 6:49 ` ZmnSCPxj
2022-02-28 7:55 ` vjudeu
2022-03-04 8:42 ` ZmnSCPxj
2022-03-04 13:43 ` vjudeu
2022-02-28 22:54 ` Paul Sztorc
2022-03-01 5:39 ` Billy Tetrud
2022-03-02 0:00 ` Paul Sztorc
2022-03-04 12:35 ` Billy Tetrud
2022-03-04 20:06 ` Paul Sztorc
2022-02-26 6:00 ` Anthony Towns
2022-02-15 8:45 ` [bitcoin-dev] " Rusty Russell
2022-02-15 18:57 ` Jeremy Rubin
2022-02-15 19:12 ` Russell O'Connor
2022-02-16 2:26 ` Rusty Russell [this message]
2022-02-16 4:10 ` Russell O'Connor
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