From: Sjors Provoost <sjors@sprovoost•nl>
To: Matt Corallo <lf-lists@mattcorallo•com>,
Russell O'Connor <roconnor@blockstream•io>,
Bitcoin Protocol Discussion
<bitcoin-dev@lists•linuxfoundation.org>
Subject: Re: [bitcoin-dev] OP_CODESEPARATOR Re: BIP Proposal: The Great Consensus Cleanup
Date: Fri, 8 Mar 2019 20:12:29 +0100 [thread overview]
Message-ID: <D2014BB7-1EFC-4604-ACF6-3C5AC74B6FC0@sprovoost.nl> (raw)
In-Reply-To: <6bb308f5-f478-d5ec-064f-e4972709f29c@mattcorallo.com>
> (1) It has been well documented again and again that there is desire to remove OP_CODESEPARATOR, (2) it is well-documented OP_CODESEPARATOR in non-segwit scripts represents a rather significant vulnerability in Bitcoin today, and (3) lots of effort has gone into attempting to find practical use-cases for OP_CODESEPARATOR's specific construction, with no successes as of yet. I strongly, strongly disagree that the highly-unlikely remote possibility that someone created something before which could be rendered unspendable is sufficient reason to not fix a vulnerability in Bitcoin today.
>
>> I suggest an alternative whereby the execution of OP_CODESEPARATOR increases the transactions weight suitably as to temper the vulnerability caused by it. Alternatively there could be some sort of limit (maybe 1) on the maximum number of OP_CODESEPARATORs allowed to be executed per script, but that would require an argument as to why exceeding that limit isn't reasonable.
>
> You could equally argue, however, that any such limit could render some moderately-large transaction unspendable, so I'm somewhat skeptical of this argument. Note that OP_CODESEPARATOR is non-standard, so getting them mined is rather difficult in any case.
Although I'm not a fan of extra complicity, just to explore these two ideas a bit further.
What if such a transaction:
1. must have one input; and
2. must be smaller than 400 vbytes; and
3. must spend from a UTXO older than fork activation
Adding such a contextual check seems rather painful, perhaps comparable to nLockTime. Anything more specific than the above, e.g. counting the number of OP_CODESEPARATOR calls, seems like guess work.
Transaction weight currently doesn't consider OP codes, it only considers if bytes are part of the witness. Changing that to something more akin to Ethereums gas pricing sounds too complicated to even consider.
I would also like to believe that whoever went through the trouble of using OP_CODESEPARATOR reads this list.
Sjors
next prev parent reply other threads:[~2019-03-08 19:12 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-06 21:39 [bitcoin-dev] " Matt Corallo
2019-03-07 10:44 ` Luke Dashjr
2019-03-07 19:44 ` Matt Corallo
2019-03-07 15:03 ` [bitcoin-dev] OP_CODESEPARATOR " Russell O'Connor
2019-03-07 19:50 ` Matt Corallo
2019-03-08 15:57 ` Russell O'Connor
2019-03-08 18:35 ` Matt Corallo
2019-03-09 18:29 ` Russell O'Connor
2019-03-10 3:25 ` Jacob Eliosoff
2019-03-11 17:49 ` Russell O'Connor
2019-03-12 21:08 ` Matt Corallo
2019-03-12 22:39 ` Jacob Eliosoff
2019-03-13 0:54 ` Gregory Maxwell
2019-03-13 1:34 ` Russell O'Connor
2019-03-08 19:12 ` Sjors Provoost [this message]
2019-03-08 20:14 ` Matt Corallo
2019-03-10 14:25 ` LORD HIS EXCELLENCY JAMES HRMH
2019-03-10 18:24 ` Moral Agent
2019-03-12 7:34 ` LORD HIS EXCELLENCY JAMES HRMH
2019-03-10 18:28 ` Dustin Dettmer
2019-03-11 19:15 ` Russell O'Connor
2019-03-12 2:23 ` Matt Corallo
2019-03-13 1:38 ` Russell O'Connor
2019-03-09 18:29 ` Russell O'Connor
[not found] ` <PS2P216MB0179EFBEF7BEEE1C3F251F719D4E0@PS2P216MB0179.KORP216.PROD.OUTLOOK.COM>
2019-03-10 15:22 ` Russell O'Connor
2019-03-07 15:16 ` [bitcoin-dev] Sighash Type Byte; " Russell O'Connor
2019-03-07 19:57 ` Matt Corallo
2019-03-08 15:57 ` Russell O'Connor
2019-03-13 1:34 ` Russell O'Connor
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=D2014BB7-1EFC-4604-ACF6-3C5AC74B6FC0@sprovoost.nl \
--to=sjors@sprovoost$(echo .)nl \
--cc=bitcoin-dev@lists$(echo .)linuxfoundation.org \
--cc=lf-lists@mattcorallo$(echo .)com \
--cc=roconnor@blockstream$(echo .)io \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox