From: Jimmy Song <jaejoon@gmail•com>
To: bitcoin-dev@lists•linuxfoundation.org
Subject: Re: [bitcoin-dev] A Small Modification to Segwit
Date: Fri, 7 Apr 2017 19:05:16 -0500 [thread overview]
Message-ID: <CAJR7vkri7UX2Mqsdp0y21FapQBeg49oHFM_eLUd=ZBarzGc3-A@mail.gmail.com> (raw)
In-Reply-To: <CAJR7vkpRhNsQsem-nFkeubX04xx1y7aHwCENfg0d1266oOsXMw@mail.gmail.com>
[-- Attachment #1: Type: text/plain, Size: 2763 bytes --]
I've gotten feedback from Adam Back that you actually don't need all 32
bits in the header for overt ASICBoost, so I'm modifying my proposal. Of
the 32-bit version field, bits 16 to 23 are reserved for miners, the
witness commitment stays as defined in BIP-141 except that it's now
required. BIP9 then is modified so that bits 16 to 23 are now no longer
usable.
On Fri, Apr 7, 2017 at 3:06 PM, Jimmy Song <jaejoon@gmail•com> wrote:
> Hey everyone, This is an idea that I had about Segwit and Gregory's
> proposal from yesterday that I wanted to run by everyone on this list. I'm
> not at all sure what this would mean for non-upgraded nodes on the network
> and would like feedback on that. This is not a formal BIP as it's a
> modification to a previously submitted one, but I'm happy to formalize it
> if it would help.
> ----------------------------------------
> MotivationOne of the interesting aspects of Gregory Maxwell’s proposal is
> that it only precludes the covert version of ASICBoost. He specifically
> left the overt version alone.
>
> Overt ASICBoost requires grinding on the version bits of the Block header
> instead of the Merkle Root. This is likely more efficient than the Merkle
> Root grinding (aka covert ASICBoost) and requires way less resources
> (much less RAM, SHA256 calculations, no tx shuffling, etc).
>
> If we combine Gregory Maxwell’s proposal with BIP-141 (Segwit) and add a
> slight modification, this should, in theory, make ASICBoost a lot more
> useful to miners and appeal to their financial interests.
> The Modification
>
> Currently, the version bits (currently 4 bytes, or 32 bits) in the header
> are used for BIP9 signaling. We change the version bits to a nonce-space so
> the miners can use it for overt ASICBoost. The 32-bits are now moved over
> to the Coinbase transaction as part of the witness commitment. The witness
> commitment goes from 38 bytes to 42 bytes, with the last 4 bytes being used
> as the version bits in the block header previously. The witness commitment
> becomes required as per Gregory Maxwell’s proposal.
> Reasoning
>
> First, this brings ASICBoost out into the open. Covert ASICBoost becomes
> much more costly and overt ASICBoost is now encouraged.
>
> Second, we can make this change relatively quickly. Most of the Segwit
> testing stays valid and this change can be deployed relatively quickly.
>
> Note on SPV clients
>
> Currently Segwit stores the witness commitment in the Coinbase tx, so
> lightweight clients will need to get the Coinbase tx + Merkle proof to
> validate segwit transactions anyway. Putting block version information in
> the Coinbase tx will not impose an extra burden on upgraded light clients.
>
[-- Attachment #2: Type: text/html, Size: 5368 bytes --]
next prev parent reply other threads:[~2017-04-08 0:05 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-07 20:06 Jimmy Song
2017-04-08 0:05 ` Jimmy Song [this message]
2017-04-08 14:59 ` Luke Dashjr
2017-04-08 15:17 ` Jimmy Song
2017-04-08 16:05 ` Luke Dashjr
2017-04-08 16:16 ` Jimmy Song
2017-04-08 16:19 ` Timo Hanke
2017-04-08 1:48 ` praxeology_guy
2017-04-08 2:46 ` Jimmy Song
2017-04-08 8:33 ` Pavel Moravec
2017-04-08 14:35 ` Jimmy Song
2017-04-08 16:38 ` Pavel Moravec
2017-04-08 22:19 ` Jimmy Song
2017-04-08 18:15 ` praxeology_guy
2017-04-08 18:51 ` Eric Voskuil
2017-04-08 20:38 ` praxeology_guy
2017-04-09 11:46 ` Jorge Timón
2017-04-08 16:27 ` Jorge Timón
2017-04-08 17:22 ` Jorge Timón
2017-04-08 22:26 ` Jimmy Song
2017-04-09 11:48 ` Jorge Timón
2017-04-09 14:01 ` Jimmy Song
[not found] ` <CABm2gDqfsBREj2x5Uz9hxwt-Y6m=KHd2-hRw4gV0CbO+-8B0dg@mail.gmail.com>
2017-04-10 9:16 ` Jorge Timón
2017-04-09 18:44 ` Erik Aronesty
2017-04-09 21:16 ` Jared Lee Richardson
2017-04-09 23:51 ` David Vorick
2017-04-10 0:20 ` Erik Aronesty
2017-04-10 1:45 ` Thomas Daede
2017-04-10 14:34 ` Bram Cohen
2017-04-10 14:46 ` Bram Cohen
2017-04-10 15:25 ` g
2017-04-10 18:17 ` Erik Aronesty
2017-04-11 2:39 ` g
2017-04-11 18:39 ` Staf Verhaegen
2017-04-11 9:31 ` Sancho Panza
2017-04-11 13:00 ` Jorge Timón
2017-04-11 7:59 ` Tom Zander
2017-04-11 13:25 ` Sancho Panza
2017-04-11 14:40 ` Jimmy Song
2017-04-11 21:25 ` Jorge Timón
2017-04-11 23:42 ` Jimmy Song
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='CAJR7vkri7UX2Mqsdp0y21FapQBeg49oHFM_eLUd=ZBarzGc3-A@mail.gmail.com' \
--to=jaejoon@gmail$(echo .)com \
--cc=bitcoin-dev@lists$(echo .)linuxfoundation.org \
/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