public inbox for bitcoindev@googlegroups.com
 help / color / mirror / Atom feed
From: Peter Todd <pete@petertodd•org>
To: Alex Morcos <morcos@gmail•com>,
	Bitcoin Protocol Discussion
	<bitcoin-dev@lists•linuxfoundation.org>
Subject: Re: [bitcoin-dev] [BIP Proposal] Buried Deployments
Date: Wed, 16 Nov 2016 16:01:00 -0500	[thread overview]
Message-ID: <20161116210100.GC5639@savin.petertodd.org> (raw)
In-Reply-To: <CAPWm=eUQjpELFB2A9vJ8j6Y5Zvts9YqkZYNCO0aDnNSb+VwFvg@mail.gmail.com>

[-- Attachment #1: Type: text/plain, Size: 1791 bytes --]

On Wed, Nov 16, 2016 at 09:32:24AM -0500, Alex Morcos via bitcoin-dev wrote:
> I think we are misunderstanding the effect of this change.
> It's still "OK" for a 50k re-org to happen.
> We're just saying that if it does, we will now have potentially introduced
> a hard fork between new client and old clients if the reorg contains
> earlier signaling for the most recent ISM soft fork and then blocks which
> do not conform to that soft fork before the block height encoded activation.
> 
> I think the argument is this doesn't substantially add to the confusion or
> usability of the system as its likely that old software won't even handle
> 50k block reorgs cleanly anyway and there will clearly have to be human
> coordination at the time of the event.  In the unlikely event that the new
> chain does cause such a hard fork, that coordination can result in everyone
> upgrading to software that supports the new rules anyway.
> 
> So no, I don't think we should add a checkpoint.  I think we should all
> just agree to a hard fork that only has a very very slim chance of any
> practical effect.

So, conceptually, another way to deal with this is to hardcode a blockhash
where we allow blocks in a chain ending with that blockhash to _not_ follow
BIP65, up until that blockhash, and any blockchain without that blockhash must
respect BIP65 for all blocks in the chain.

This is a softfork: we've only added rules that made otherwise valid chains
invalid, and at the same time we are still accepting large reorgs (albeit under
stricter rules than before).

I'd suggest we call this a exemption hash - we've exempted a particular
blockchains from a soft-forked rule that we would otherwise enforce.

-- 
https://petertodd.org 'peter'[:-1]@petertodd.org

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 455 bytes --]

  reply	other threads:[~2016-11-16 21:01 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-14 18:17 Suhas Daftuar
2016-11-14 18:47 ` Eric Voskuil
2016-11-15 14:42   ` Suhas Daftuar
2016-11-15 17:45   ` Btc Drak
2016-11-15 22:42     ` Eric Voskuil
2016-11-16 13:29       ` Jameson Lopp
2016-11-16 13:58         ` Eric Voskuil
2016-11-16 14:18           ` Tier Nolan
2016-11-16 14:32             ` Alex Morcos
2016-11-16 21:01               ` Peter Todd [this message]
2016-11-16 22:21                 ` Eric Voskuil
2016-11-17  3:06                 ` Luke Dashjr
2016-11-16 14:18           ` Thomas Kerin
2016-11-16 23:58             ` Jorge Timón
2016-11-17  0:00               ` Eric Voskuil
2016-11-17  1:24                 ` Alex Morcos
2016-11-17  1:41                   ` Eric Voskuil
2016-11-17  0:13             ` Eric Voskuil
2016-11-16 23:48           ` Jorge Timón
2016-11-17  1:50           ` Pieter Wuille
2016-11-17  2:16             ` Eric Voskuil
2016-11-17  2:47               ` Pieter Wuille
2016-11-17 10:10                 ` Eric Voskuil
2016-11-16 14:38   ` Tom Zander

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=20161116210100.GC5639@savin.petertodd.org \
    --to=pete@petertodd$(echo .)org \
    --cc=bitcoin-dev@lists$(echo .)linuxfoundation.org \
    --cc=morcos@gmail$(echo .)com \
    /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