From: Anthony Towns <aj@erisian•com.au>
To: Keagan McClelland <keagan.mcclelland@gmail•com>,
Bitcoin Protocol Discussion
<bitcoin-dev@lists•linuxfoundation.org>
Subject: Re: [bitcoin-dev] Speedy Trial
Date: Tue, 26 Apr 2022 03:00:12 +1000 [thread overview]
Message-ID: <20220425170012.GA7453@erisian.com.au> (raw)
In-Reply-To: <CALeFGL19G7eLdM7J9dQrumdVTgo1OyoK6UbzF3oJMkGG55qLzg@mail.gmail.com>
On Mon, Apr 25, 2022 at 10:11:45AM -0600, Keagan McClelland via bitcoin-dev wrote:
> > Under *any* other circumstance, when they're used to activate a bad soft
> > fork, speedy trial and bip8 are the same. If a resistance method works
> > against bip8, it works against speedy trial; if it fails against speedy
> > trial, it fails against bip8.
> IIRC one essential difference between ST (which is a variant of BIP9) and
> BIP8 is that since there is no mandatory signaling during the lockin
> period,
BIP8 doesn't have mandatory signaling during the lockin period, it has
semi-mandatory [0] signalling during the must_signal period.
> you can't do a counter soft fork as easily.
The "counter" for bip8 activation is to reject any block during either
the started or must_signal phases that would meet the threshold. In that
case someone running bip8 might see blocks:
[elapsed=2010, count=1813, signal=yes]
[elapsed=2011, count=1813, signal=no]
[elapsed=2012, count=1814, signal=yes]
[elapsed=2013, count=1815, signal=yes, will-lockin!]
[elapsed=2014, count=1816, signal=yes]
[elapsed=2015, count=1816, signal=no]
[elapsed=2016, count=1816, signal=no]
[locked in!]
But running software to reject the soft fork, you would reject the
elapsed=2013 block, and any blocks that build on it. You would wait for
someone else to mine a chain that looked like:
[elapsed=2013, count=1814, signal=no]
[elapsed=2014, count=1814, signal=no]
[elapsed=2015, count=1814, signal=no]
[elapsed=2016, count=1814, signal=no]
[failed!]
That approach works *exactly* the same with speedy trial.
Jeremy's written code that does exactly this using the getdeploymentinfo
rpc to check the deployment status, and the invalidateblock rpc to
reject a block. See: https://github.com/JeremyRubin/forkd
The difference to bip8 with lot=true is that nodes running speedy trial
will reorg to follow the resisting chain if it has the most work. bip8
with lot=true nodes will not reorg to a failing chain, potentially
creating an ongoing chain split, unless one group or the other gives up,
and changes their software.
Cheers,
aj
[0] Semi-mandatory in that only "threshold" blocks must signal, so if
only 4% or 9% of miners aren't signalling and the threshold is set
at 95% or 90%, no blocks will be orphaned.
next prev parent reply other threads:[~2022-04-25 17:00 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-11 0:12 Russell O'Connor
2022-03-11 0:28 ` Luke Dashjr
2022-03-11 5:41 ` Billy Tetrud
2022-03-11 12:19 ` Jorge Timón
2022-03-11 13:47 ` Russell O'Connor
2022-03-11 14:04 ` Jorge Timón
2022-03-12 13:34 ` Russell O'Connor
2022-03-12 17:52 ` Billy Tetrud
2022-03-17 12:18 ` Jorge Timón
2022-03-23 22:34 ` Kate Salazar
2022-03-15 17:21 ` Jeremy Rubin
2022-03-17 4:17 ` Billy Tetrud
2022-03-18 18:36 ` Jorge Timón
2022-03-17 12:08 ` Jorge Timón
2022-03-17 15:38 ` Billy Tetrud
2022-03-18 23:01 ` ZmnSCPxj
2022-03-21 3:41 ` Billy Tetrud
2022-03-21 15:56 ` vjudeu
2022-03-22 15:19 ` Billy Tetrud
2022-03-22 15:45 ` Eric Voskuil
2022-03-22 16:37 ` vjudeu
2022-03-19 16:43 ` vjudeu
2022-03-15 15:45 ` Anthony Towns
2022-03-17 14:04 ` Jorge Timón
2022-03-22 23:49 ` Anthony Towns
2022-03-24 18:30 ` Jorge Timón
2022-03-26 1:45 ` Anthony Towns
2022-03-28 8:31 ` Jorge Timón
2022-03-30 4:21 ` Anthony Towns
2022-04-08 9:58 ` Jorge Timón
2022-04-11 13:05 ` Anthony Towns
2022-04-24 11:13 ` Jorge Timón
2022-04-24 12:14 ` Anthony Towns
2022-04-24 12:44 ` Jorge Timón
2022-04-25 16:11 ` Keagan McClelland
2022-04-25 17:00 ` Anthony Towns [this message]
2022-04-25 17:26 ` Keagan McClelland
2022-04-26 5:42 ` Anthony Towns
2022-04-26 13:05 ` Erik Aronesty
2022-04-27 2:35 ` Billy Tetrud
2022-03-11 16:26 ` Billy Tetrud
2022-03-17 11:32 ` Jorge Timón
2022-03-11 11:14 pushd
2022-03-12 17:11 pushd
2022-03-17 14:34 pushd
2022-03-26 12:59 pushd
2022-03-30 10:34 pushd
2022-03-30 20:10 ` Billy Tetrud
2022-03-30 21:14 ` pushd
2022-03-31 4:31 ` Billy Tetrud
2022-03-31 14:19 ` pushd
2022-03-31 15:34 ` Billy Tetrud
2022-03-31 15:55 ` pushd
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