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From: Rusty Russell <rusty@rustcorp•com.au>
To: Russell O'Connor <roconnor@blockstream•io>,
	Luke Dashjr <luke@dashjr•org>
Cc: Bitcoin Protocol Discussion <bitcoin-dev@lists•linuxfoundation.org>
Subject: Re: [bitcoin-dev] BIP: Block signal enforcement via tx fees
Date: Mon, 15 May 2017 10:44:13 +0930	[thread overview]
Message-ID: <87tw4mly56.fsf@rustcorp.com.au> (raw)
In-Reply-To: <CAMZUoKnjc4ezVm4FeMFA-+=g13E5ZwZCAoAjd_yL89v7qf1gEA@mail.gmail.com>

Russell O'Connor via bitcoin-dev <bitcoin-dev@lists•linuxfoundation.org>
writes:
> On Sat, May 13, 2017 at 1:26 AM, Luke Dashjr <luke@dashjr•org> wrote:
>
>> Versionbits change/lose their meaning after the deployment timeout. For
>> this
>> reason, the timeout must be specified so the check is skipped when that
>> occurs.
>>
>
> To add a timeout a user can optionally bundle a pair of similar
> transactions.  One with the transaction version bits set and a second with
> a locktime set.  The effect is the same.

I have a similar proposal to Russell; use tx nVersion.  However, my
subset is simpler, and uses fewer precious nVersion bits:

1. Top version 26 bits must be 1 (say)
2. Next bit indicates positive (must have bit set) or negative (must NOT
   have bit set).
3. Bottom 5 bits refer to which BIP8/9 bit we're talking about.

This only allows specifying a single bit, and only support BIP8/9-style
signalling.

I believe we can skip the timeout: miners don't signal 100% either way
anyway.  If a BIP is in LOCKIN, wallets shouldn't set positive on that
bit (this gives them two weeks).  Similarly, if a BIP is close to
FAILED, don't set positive on your tx.  Wallets shouldn't signal until
any bit until see some minimal chance it's accepted (eg. 1 in 20 blocks).

> I recall chatting about this idea recently and my conclusion was the same
> as Peter Todd's conclusion: this will just encourage miners to false signal
> readiness with undermines both BIP 9 and BIP 8.

This is gentler on miners than a UASF flag day, and does offer some
harder-to-game signalling from bitcoin users.

False signalling miners still have the 2 week LOCKIN period to upgrade,
otherwise they can already lose money.  You could argue they're *more*
likely to upgrade with a signal that significant parts of the economy
have done so.

Cheers,
Rusty.


  reply	other threads:[~2017-05-15  1:15 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-12 19:22 Luke Dashjr
2017-05-12 22:17 ` ZmnSCPxj
2017-05-12 22:22 ` Peter Todd
2017-05-13  0:49   ` Luke Dashjr
2017-05-13  3:26     ` Eric Voskuil
2017-05-13  3:54       ` ZmnSCPxj
2017-05-13  5:36         ` Eric Voskuil
2017-05-13  5:45       ` Luke Dashjr
2017-05-13  6:43         ` Eric Voskuil
2017-05-13 12:48     ` Peter Todd
2017-05-13 16:42       ` Luke Dashjr
2017-05-13  4:23 ` Russell O'Connor
2017-05-13  5:26   ` Luke Dashjr
2017-05-13 17:11     ` Russell O'Connor
2017-05-15  1:14       ` Rusty Russell [this message]
2017-05-20  5:05       ` Anthony Towns
2017-05-14 12:18 ` ZmnSCPxj

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