[bitcoin-dev] Compatibility-Oriented Omnibus Proposal

[CalvinRechner via bitcoin-dev]

This proposal is written under the assumption that the signatories to the Consensus 2017 Scaling Agreement[1] are genuinely committed to the terms of the agreement, and intend to enact the updates described therein. As such, criticisms pertaining to the chosen deployment timeline or hard fork upgrade path should be treated as out-of-scope during the initial discussion of this proposal.

Because it includes the activation of a hard fork for which community consensus does not yet exist, this proposal is not likely to be merged into Bitcoin Core in the immediate future, and must instead be maintained and reviewed in a separate downstream repository. However, it is written with the intent to remain cleanly compatible with future network updates and changes, to allow for the option of a straightforward upstream merge if community consensus for the proposal is successfully achieved in the following months.

<pre>
BIP: ?
Layer: Consensus
Title: Compatibility-oriented omnibus proposal
Author: Calvin Rechner <***@protonmail.com>
Comments-Summary: No comments yet.
Comments-URI: ?
Status: Draft
Type: Standards Track
Created: 2017-05-28
License: PD
</pre>

===Abstract===

This document describes a virtuous combination of James Hilliard’s “Reduced signalling threshold activation of existing segwit deployment”[2], Shaolin Fry’s “Mandatory activation of segwit deployment”[3], Sergio Demian Lerner’s “Segwit2Mb”[4] proposal, Luke Dashjr’s “Post-segwit 2 MB block size hardfork”[5], and hard fork safety mechanisms from Johnson Lau’s “Spoonnet”[6][7] into a single omnibus proposal and patchset.

===Motivation===

The Consensus 2017 Scaling Agreement[1] stipulated the following commitments:

• Activate Segregated Witness at an 80% threshold, signaling at bit 4
• Activate a 2 MB hard fork within six months

This proposal seeks to fulfill these criteria while retaining maximum compatibility with existing deployment approaches, thereby minimizing the risks of a destructive chain split. Additionally, subsequent indications of implied criteria and expectations of the Agreement[8][9] are satisfied.

The proposed hard fork incorporates a legacy witness discount and 2MB blocksize limit along with the enactment of Spoonnet-derived protectionary measures, to ensure the safest possible fork activation within the constraints of the requirements outlined in the Scaling Agreement.

===Rationale===

To the extent possible, this represents an effort at a best-of-all-worlds proposal, intended to provide a common foundation from which all mutually-inclusive goals can be achieved while risks are minimized.

The goal here is to minimize chain split risk and network disruption while maximizing backwards compatibility and still providing for rapid activation of segwit at the 80% threshold using bit 4.
cause the existing "segwit" deployment to activate without needing to release a new deployment.

Both of the aforementioned activation options (“fast-activation” and “flag-day activation”) serve to prevent unnecessary delays in the network upgrade process, addressing a common criticism of the Scaling Agreement and providing an opportunity for cooperation and unity instead.

Segwit2Mb combines segwit as it is today in Bitcoin 0.14+ with a 2MB block size hard-fork activated ONLY if segwit activates (95% of miners signaling ... to re-unite the Bitcoin community and avoid a cryptocurrency split.
if the community wishes to adopt (by unanimous consensus) a 2 MB block size hardfork, this is probably the best way to do it right now... Legacy Bitcoin transactions are given the witness discount, and a block size limit of 2 MB is imposed.
In a blockchain split, however, since both forks share the same historical ledger, replay attack would be possible, unless some precautions are taken.

===Copyright===

This document is placed in the public domain.

===Specification===

###Proposal Signaling###

The string “COOP” is included anywhere in the txn-input (scriptSig) of the coinbase-txn to signal compatibility and support.

###Soft Fork###

Fast-activation (segsignal): deployed by a "version bits" with an 80% activation threshold BIP9 with the name "segsignal" and using bit 4... [with a] start time of midnight June 1st, 2017 (epoch time 1496275200) and timeout on midnight November 15th 2017 (epoch time 1510704000). This BIP will cease to be active when segwit is locked-in.[2]

Flag-day activation (BIP148): While this BIP is active, all blocks must set the nVersion header top 3 bits to 001 together with bit field (1<<1) (according to the existing segwit deployment). Blocks that do not signal as required will be rejected... This BIP will be active between midnight August 1st 2017 (epoch time 1501545600) and midnight November 15th 2017 (epoch time 1510704000) if the existing segwit deployment is not locked-in or activated before epoch time 1501545600. This BIP will cease to be active when segwit is locked-in. While this BIP is active, all blocks must set the nVersion header top 3 bits to 001 together with bit field (1<<1) (according to the existing segwit deployment). Blocks that do not signal as required will be rejected.[3]

###Hard Fork###

The hard fork deployment is scheduled to occur 6 months after SegWit activates:

(HardForkHeight = SEGWIT_ACTIVE_BLOCK_HEIGHT + 26280)

For blocks equal to or higher than HardForkHeight, Luke-Jr’s legacy witness discount and 2MB limit are enacted, along with the following Spoonnet-based improvements[6][7]:

* A "hardfork signalling block" is a block with the sign bit of header nVersion is set [Clearly invalid for old nodes; easy opt-out for light wallets]

* If the median-time-past of the past 11 blocks is smaller than the HardForkHeight... a hardfork signalling block is invalid.

* Child of a hardfork signalling block MUST also be a hardfork signalling block

* Hardfork network version bit is 0x02000000. A tx is invalid if the highest nVersion byte is not zero, and the network version bit is not set.

===Deployment===

Deployment of the “fast-activation” soft fork is exactly identical to Hilliard’s segsignal proposal[2]. Deployment of the “flag-day” soft fork is exactly identical to Fry’s BIP148 proposal[3]. HardForkHeight is defined as 26280 blocks after SegWit is set to ACTIVE. All blocks with height greater than or equal to this value must adhere to the consensus rules of the 2MB hard fork.

===Backwards compatibility===

This deployment is compatible with the existing "segwit" bit 1 deployment scheduled between midnight November 15th, 2016 and midnight November 15th, 2017.

To prevent the risk of building on top of invalid blocks, miners should upgrade their nodes to support segsignal as well as BIP148.

The intent of this proposal is to maintain full legacy consensus compatibility for users up until the HardForkHeight block height, after which backwards compatibility is waived as enforcement of the hard fork consensus ruleset begins.

===References===

[1] https://medium.com/@DCGco/bitcoin-scaling-agreement-at-consensus-2017-133521fe9a77
[2] https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2017-May/014380.html
[3] https://github.com/bitcoin/bips/blob/master/bip-0148.mediawiki
[4] https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2017-March/013921.html
[5] https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2017-May/014399.html
[6] https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2017-February/013542.html
[7] https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2017-January/013473.html
[8] https://twitter.com/sysmannet/status/867124645279006720
[9] https://twitter.com/JihanWu/status/867139046786465792

[James Hilliard via bitcoin-dev]

For the reasons listed
here(https://github.com/bitcoin/bips/blob/master/bip-0091.mediawiki#Motivation)
you should have it so that the HF can not lock in unless the existing
BIP141 segwit deployment is activated.

The biggest issue is that a safe HF is very unlikely to be able to be
coded and tested within 6 months.

On Sun, May 28, 2017 at 8:18 PM, CalvinRechner via bitcoin-dev

Post by CalvinRechner via bitcoin-dev
This proposal is written under the assumption that the signatories to the
Consensus 2017 Scaling Agreement[1] are genuinely committed to the terms of
the agreement, and intend to enact the updates described therein. As such,
criticisms pertaining to the chosen deployment timeline or hard fork upgrade
path should be treated as out-of-scope during the initial discussion of this
proposal.
Because it includes the activation of a hard fork for which community
consensus does not yet exist, this proposal is not likely to be merged into
Bitcoin Core in the immediate future, and must instead be maintained and
reviewed in a separate downstream repository. However, it is written with
the intent to remain cleanly compatible with future network updates and
changes, to allow for the option of a straightforward upstream merge if
community consensus for the proposal is successfully achieved in the
following months.
<pre>
BIP: ?
Layer: Consensus
Title: Compatibility-oriented omnibus proposal
Comments-Summary: No comments yet.
Comments-URI: ?
Status: Draft
Type: Standards Track
Created: 2017-05-28
License: PD
</pre>
===Abstract===
This document describes a virtuous combination of James Hilliard’s “Reduced
signalling threshold activation of existing segwit deployment”[2], Shaolin
Fry’s “Mandatory activation of segwit deployment”[3], Sergio Demian Lerner’s
“Segwit2Mb”[4] proposal, Luke Dashjr’s “Post-segwit 2 MB block size
hardfork”[5], and hard fork safety mechanisms from Johnson Lau’s
“Spoonnet”[6][7] into a single omnibus proposal and patchset.
===Motivation===
• Activate Segregated Witness at an 80% threshold, signaling at bit 4
• Activate a 2 MB hard fork within six months
This proposal seeks to fulfill these criteria while retaining maximum
compatibility with existing deployment approaches, thereby minimizing the
risks of a destructive chain split. Additionally, subsequent indications of
implied criteria and expectations of the Agreement[8][9] are satisfied.
The proposed hard fork incorporates a legacy witness discount and 2MB
blocksize limit along with the enactment of Spoonnet-derived protectionary
measures, to ensure the safest possible fork activation within the
constraints of the requirements outlined in the Scaling Agreement.
===Rationale===
To the extent possible, this represents an effort at a best-of-all-worlds
proposal, intended to provide a common foundation from which all
mutually-inclusive goals can be achieved while risks are minimized.
James Hilliard’s “Reduced signalling threshold activation of existing segwit

The goal here is to minimize chain split risk and network disruption while
maximizing backwards compatibility and still providing for rapid activation
of segwit at the 80% threshold using bit 4.
cause the existing "segwit" deployment to activate without needing to
release a new deployment.

Both of the aforementioned activation options (“fast-activation” and
“flag-day activation”) serve to prevent unnecessary delays in the network
upgrade process, addressing a common criticism of the Scaling Agreement and
providing an opportunity for cooperation and unity instead.
Sergio Demian Lerner’s “Segwit2Mb”[4] proposal explains the reasoning behind
linking SegWit’s activation with that of a later hard fork block size

Segwit2Mb combines segwit as it is today in Bitcoin 0.14+ with a 2MB block
size hard-fork activated ONLY if segwit activates (95% of miners signaling
... to re-unite the Bitcoin community and avoid a cryptocurrency split.

Luke Dashjr’s “Post-segwit 2 MB block size hardfork”[5] suggestions are
included to reduce the marginal risks that such an increase in the block

if the community wishes to adopt (by unanimous consensus) a 2 MB block
size hardfork, this is probably the best way to do it right now... Legacy
Bitcoin transactions are given the witness discount, and a block size limit
of 2 MB is imposed.

Johnson Lau’s anti-replay and network version updates[6][7] are included as

In a blockchain split, however, since both forks share the same historical
ledger, replay attack would be possible, unless some precautions are taken.

===Copyright===
This document is placed in the public domain.
===Specification===
###Proposal Signaling###
The string “COOP” is included anywhere in the txn-input (scriptSig) of the
coinbase-txn to signal compatibility and support.
###Soft Fork###
Fast-activation (segsignal): deployed by a "version bits" with an 80%
activation threshold BIP9 with the name "segsignal" and using bit 4... [with
a] start time of midnight June 1st, 2017 (epoch time 1496275200) and timeout
on midnight November 15th 2017 (epoch time 1510704000). This BIP will cease
to be active when segwit is locked-in.[2]
Flag-day activation (BIP148): While this BIP is active, all blocks must set
the nVersion header top 3 bits to 001 together with bit field (1<<1)
(according to the existing segwit deployment). Blocks that do not signal as
required will be rejected... This BIP will be active between midnight August
1st 2017 (epoch time 1501545600) and midnight November 15th 2017 (epoch time
1510704000) if the existing segwit deployment is not locked-in or activated
before epoch time 1501545600. This BIP will cease to be active when segwit
is locked-in. While this BIP is active, all blocks must set the nVersion
header top 3 bits to 001 together with bit field (1<<1) (according to the
existing segwit deployment). Blocks that do not signal as required will be
rejected.[3]
###Hard Fork###
(HardForkHeight = SEGWIT_ACTIVE_BLOCK_HEIGHT + 26280)
For blocks equal to or higher than HardForkHeight, Luke-Jr’s legacy witness
discount and 2MB limit are enacted, along with the following Spoonnet-based
* A "hardfork signalling block" is a block with the sign bit of header
nVersion is set [Clearly invalid for old nodes; easy opt-out for light
wallets]
* If the median-time-past of the past 11 blocks is smaller than the
HardForkHeight... a hardfork signalling block is invalid.
* Child of a hardfork signalling block MUST also be a hardfork signalling block
* Hardfork network version bit is 0x02000000. A tx is invalid if the highest
nVersion byte is not zero, and the network version bit is not set.
===Deployment===
Deployment of the “fast-activation” soft fork is exactly identical to
Hilliard’s segsignal proposal[2]. Deployment of the “flag-day” soft fork is
exactly identical to Fry’s BIP148 proposal[3]. HardForkHeight is defined as
26280 blocks after SegWit is set to ACTIVE. All blocks with height greater
than or equal to this value must adhere to the consensus rules of the 2MB
hard fork.
===Backwards compatibility===
This deployment is compatible with the existing "segwit" bit 1 deployment
scheduled between midnight November 15th, 2016 and midnight November 15th,
2017.
To prevent the risk of building on top of invalid blocks, miners should
upgrade their nodes to support segsignal as well as BIP148.
The intent of this proposal is to maintain full legacy consensus
compatibility for users up until the HardForkHeight block height, after
which backwards compatibility is waived as enforcement of the hard fork
consensus ruleset begins.
===References===
[1]
[2]
https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2017-May/014380.html
[3] https://github.com/bitcoin/bips/blob/master/bip-0148.mediawiki
[4]
https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2017-March/013921.html
[5]
https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2017-May/014399.html
[6]
https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2017-February/013542.html
[7]
https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2017-January/013473.html
[8] https://twitter.com/sysmannet/status/867124645279006720
[9] https://twitter.com/JihanWu/status/867139046786465792
_______________________________________________
bitcoin-dev mailing list
https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev

[Erik Aronesty via bitcoin-dev]

I can't think of any resistance to this, but the code, on a tight timeline,
isn't going to be easy. Is anyone volunteering for this?

On May 29, 2017 6:19 AM, "James Hilliard via bitcoin-dev" <

Post by James Hilliard via bitcoin-dev
For the reasons listed
here(https://github.com/bitcoin/bips/blob/master/bip-
0091.mediawiki#Motivation)
you should have it so that the HF can not lock in unless the existing
BIP141 segwit deployment is activated.
The biggest issue is that a safe HF is very unlikely to be able to be
coded and tested within 6 months.
On Sun, May 28, 2017 at 8:18 PM, CalvinRechner via bitcoin-dev

Post by CalvinRechner via bitcoin-dev
This proposal is written under the assumption that the signatories to the
Consensus 2017 Scaling Agreement[1] are genuinely committed to the terms

of

Post by CalvinRechner via bitcoin-dev
the agreement, and intend to enact the updates described therein. As

such,

Post by CalvinRechner via bitcoin-dev
criticisms pertaining to the chosen deployment timeline or hard fork

upgrade

Post by CalvinRechner via bitcoin-dev
path should be treated as out-of-scope during the initial discussion of

this

Post by CalvinRechner via bitcoin-dev
proposal.
Because it includes the activation of a hard fork for which community
consensus does not yet exist, this proposal is not likely to be merged

into

Post by CalvinRechner via bitcoin-dev
Bitcoin Core in the immediate future, and must instead be maintained and
reviewed in a separate downstream repository. However, it is written with
the intent to remain cleanly compatible with future network updates and
changes, to allow for the option of a straightforward upstream merge if
community consensus for the proposal is successfully achieved in the
following months.
<pre>
BIP: ?
Layer: Consensus
Title: Compatibility-oriented omnibus proposal
Comments-Summary: No comments yet.
Comments-URI: ?
Status: Draft
Type: Standards Track
Created: 2017-05-28
License: PD
</pre>
===Abstract===
This document describes a virtuous combination of James Hilliard’s

“Reduced

Post by CalvinRechner via bitcoin-dev
signalling threshold activation of existing segwit deployment”[2],

Shaolin

Post by CalvinRechner via bitcoin-dev
Fry’s “Mandatory activation of segwit deployment”[3], Sergio Demian

Lerner’s

Post by CalvinRechner via bitcoin-dev
“Segwit2Mb”[4] proposal, Luke Dashjr’s “Post-segwit 2 MB block size
hardfork”[5], and hard fork safety mechanisms from Johnson Lau’s
“Spoonnet”[6][7] into a single omnibus proposal and patchset.
===Motivation===
• Activate Segregated Witness at an 80% threshold, signaling at bit 4
• Activate a 2 MB hard fork within six months
This proposal seeks to fulfill these criteria while retaining maximum
compatibility with existing deployment approaches, thereby minimizing the
risks of a destructive chain split. Additionally, subsequent indications

of

Post by CalvinRechner via bitcoin-dev
implied criteria and expectations of the Agreement[8][9] are satisfied.
The proposed hard fork incorporates a legacy witness discount and 2MB
blocksize limit along with the enactment of Spoonnet-derived

protectionary

Post by CalvinRechner via bitcoin-dev
measures, to ensure the safest possible fork activation within the
constraints of the requirements outlined in the Scaling Agreement.
===Rationale===
To the extent possible, this represents an effort at a best-of-all-worlds
proposal, intended to provide a common foundation from which all
mutually-inclusive goals can be achieved while risks are minimized.
James Hilliard’s “Reduced signalling threshold activation of existing

segwit

Post by CalvinRechner via bitcoin-dev

The goal here is to minimize chain split risk and network disruption

while

Post by CalvinRechner via bitcoin-dev

maximizing backwards compatibility and still providing for rapid

activation

Post by CalvinRechner via bitcoin-dev

of segwit at the 80% threshold using bit 4.

Shaolin Fry’s “Mandatory activation of segwit deployment”[3] is included

cause the existing "segwit" deployment to activate without needing to
release a new deployment.

Both of the aforementioned activation options (“fast-activation” and
“flag-day activation”) serve to prevent unnecessary delays in the network
upgrade process, addressing a common criticism of the Scaling Agreement

and

Post by CalvinRechner via bitcoin-dev
providing an opportunity for cooperation and unity instead.
Sergio Demian Lerner’s “Segwit2Mb”[4] proposal explains the reasoning

behind

Post by CalvinRechner via bitcoin-dev
linking SegWit’s activation with that of a later hard fork block size

Segwit2Mb combines segwit as it is today in Bitcoin 0.14+ with a 2MB

block

Post by CalvinRechner via bitcoin-dev

size hard-fork activated ONLY if segwit activates (95% of miners

signaling

Post by CalvinRechner via bitcoin-dev

... to re-unite the Bitcoin community and avoid a cryptocurrency split.

Luke Dashjr’s “Post-segwit 2 MB block size hardfork”[5] suggestions are
included to reduce the marginal risks that such an increase in the block

if the community wishes to adopt (by unanimous consensus) a 2 MB block
size hardfork, this is probably the best way to do it right now...

Legacy

Post by CalvinRechner via bitcoin-dev

Bitcoin transactions are given the witness discount, and a block size

limit

Post by CalvinRechner via bitcoin-dev

of 2 MB is imposed.

Johnson Lau’s anti-replay and network version updates[6][7] are included

as

Post by CalvinRechner via bitcoin-dev

In a blockchain split, however, since both forks share the same

historical

Post by CalvinRechner via bitcoin-dev

ledger, replay attack would be possible, unless some precautions are

taken.

Post by CalvinRechner via bitcoin-dev
===Copyright===
This document is placed in the public domain.
===Specification===
###Proposal Signaling###
The string “COOP” is included anywhere in the txn-input (scriptSig) of

the

Post by CalvinRechner via bitcoin-dev
coinbase-txn to signal compatibility and support.
###Soft Fork###
Fast-activation (segsignal): deployed by a "version bits" with an 80%
activation threshold BIP9 with the name "segsignal" and using bit 4...

[with

Post by CalvinRechner via bitcoin-dev
a] start time of midnight June 1st, 2017 (epoch time 1496275200) and

timeout

Post by CalvinRechner via bitcoin-dev
on midnight November 15th 2017 (epoch time 1510704000). This BIP will

cease

Post by CalvinRechner via bitcoin-dev
to be active when segwit is locked-in.[2]
Flag-day activation (BIP148): While this BIP is active, all blocks must

set

Post by CalvinRechner via bitcoin-dev
the nVersion header top 3 bits to 001 together with bit field (1<<1)
(according to the existing segwit deployment). Blocks that do not signal

as

Post by CalvinRechner via bitcoin-dev
required will be rejected... This BIP will be active between midnight

August

Post by CalvinRechner via bitcoin-dev
1st 2017 (epoch time 1501545600) and midnight November 15th 2017 (epoch

time

Post by CalvinRechner via bitcoin-dev
1510704000) if the existing segwit deployment is not locked-in or

activated

Post by CalvinRechner via bitcoin-dev
before epoch time 1501545600. This BIP will cease to be active when

segwit

Post by CalvinRechner via bitcoin-dev
is locked-in. While this BIP is active, all blocks must set the nVersion
header top 3 bits to 001 together with bit field (1<<1) (according to the
existing segwit deployment). Blocks that do not signal as required will

be

Post by CalvinRechner via bitcoin-dev
rejected.[3]
###Hard Fork###
(HardForkHeight = SEGWIT_ACTIVE_BLOCK_HEIGHT + 26280)
For blocks equal to or higher than HardForkHeight, Luke-Jr’s legacy

witness

Post by CalvinRechner via bitcoin-dev
discount and 2MB limit are enacted, along with the following

Spoonnet-based

Post by CalvinRechner via bitcoin-dev
* A "hardfork signalling block" is a block with the sign bit of header
nVersion is set [Clearly invalid for old nodes; easy opt-out for light
wallets]
* If the median-time-past of the past 11 blocks is smaller than the
HardForkHeight... a hardfork signalling block is invalid.
* Child of a hardfork signalling block MUST also be a hardfork signalling block
* Hardfork network version bit is 0x02000000. A tx is invalid if the

highest

Post by CalvinRechner via bitcoin-dev
nVersion byte is not zero, and the network version bit is not set.
===Deployment===
Deployment of the “fast-activation” soft fork is exactly identical to
Hilliard’s segsignal proposal[2]. Deployment of the “flag-day” soft fork

is

Post by CalvinRechner via bitcoin-dev
exactly identical to Fry’s BIP148 proposal[3]. HardForkHeight is defined

as

Post by CalvinRechner via bitcoin-dev
26280 blocks after SegWit is set to ACTIVE. All blocks with height

greater

Post by CalvinRechner via bitcoin-dev
than or equal to this value must adhere to the consensus rules of the 2MB
hard fork.
===Backwards compatibility===
This deployment is compatible with the existing "segwit" bit 1 deployment
scheduled between midnight November 15th, 2016 and midnight November

15th,

Post by CalvinRechner via bitcoin-dev
2017.
To prevent the risk of building on top of invalid blocks, miners should
upgrade their nodes to support segsignal as well as BIP148.
The intent of this proposal is to maintain full legacy consensus
compatibility for users up until the HardForkHeight block height, after
which backwards compatibility is waived as enforcement of the hard fork
consensus ruleset begins.
===References===
[1]

consensus-2017-133521fe9a77

Post by CalvinRechner via bitcoin-dev
[2]
https://lists.linuxfoundation.org/pipermail/bitcoin-dev/

2017-May/014380.html

Post by CalvinRechner via bitcoin-dev
[3] https://github.com/bitcoin/bips/blob/master/bip-0148.mediawiki
[4]
https://lists.linuxfoundation.org/pipermail/bitcoin-dev/

2017-March/013921.html

Post by CalvinRechner via bitcoin-dev
[5]
https://lists.linuxfoundation.org/pipermail/bitcoin-dev/

2017-May/014399.html

Post by CalvinRechner via bitcoin-dev
[6]
https://lists.linuxfoundation.org/pipermail/bitcoin-dev/

2017-February/013542.html

Post by CalvinRechner via bitcoin-dev
[7]
https://lists.linuxfoundation.org/pipermail/bitcoin-dev/

2017-January/013473.html

Post by CalvinRechner via bitcoin-dev
[8] https://twitter.com/sysmannet/status/867124645279006720
[9] https://twitter.com/JihanWu/status/867139046786465792
_______________________________________________
bitcoin-dev mailing list
https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev

_______________________________________________
bitcoin-dev mailing list
https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev

[Oliver Petruzel via bitcoin-dev]

if the community wishes to adopt (by unanimous consensus) a 2 MB block

size hardfork, this is probably the best way to do it right now... Legacy
Bitcoin transactions are given the witness discount, and a block size limit
of 2 MB is imposed.<<


The above decision may quickly become very controversial. I don't think it's
what most users had/have in mind when they discuss a "2MB+SegWit" solution.

With the current 1MB+SegWit, testing has shown us that normal usage results
in ~2 or 2.1MB blocks.

I think most users will expect a linear increase when Base Size is
increased to 2000000 bytes and Total Weight is increased to 8000000 bytes.
With normal usage, the expected results would then be ~4 or 4.2MB blocks.

Am I missing something here, or does Luke's suggested 2MB cap completely
nullify that expected linear increase? If so, why? What's the logic behind
this decision?

I'd love to be armed with a good answer should my colleagues ask me the
same obvious question, so thank you ahead of time!

Respectfully,
Oliver Petruzel

[Erik Aronesty via bitcoin-dev]

- We now are witnessing this... COOP vs LukeJr COOP, vs BIP148 vs BIP149 vs
BIP91 ... how many are there?:

https://xkcd.com/927

- If some miners and exchanges collude to enact a rapid 2MB+Segwit hard
fork coin... and calling it "bitcoin" on major exchanges this could swiftly
fragment the network.

- If this fork fails to contain an ASICBOOST defense, then this is
essentially an example of core failing to appropriately respond to the CVE
security vulnerability in time.

- A swift BIP148 release in core seems necessary to defend against this.
I am no longer in favor of adding a BIP148 option with default "false"..
I think it should be merged in...enabled, and released ASAP to defend
against these attacks.


On Mon, May 29, 2017 at 7:49 PM, Oliver Petruzel via bitcoin-dev <

if the community wishes to adopt (by unanimous consensus) a 2 MB block

size hardfork, this is probably the best way to do it right now... Legacy
Bitcoin transactions are given the witness discount, and a block size limit
of 2 MB is imposed.<<
The above decision may quickly become very controversial. I don't think it's
what most users had/have in mind when they discuss a "2MB+SegWit" solution.
With the current 1MB+SegWit, testing has shown us that normal usage
results in ~2 or 2.1MB blocks.
I think most users will expect a linear increase when Base Size is
increased to 2000000 bytes and Total Weight is increased to 8000000 bytes.
With normal usage, the expected results would then be ~4 or 4.2MB blocks.
Am I missing something here, or does Luke's suggested 2MB cap completely
nullify that expected linear increase? If so, why? What's the logic behind
this decision?
I'd love to be armed with a good answer should my colleagues ask me the
same obvious question, so thank you ahead of time!
Respectfully,
Oliver Petruzel
_______________________________________________
bitcoin-dev mailing list
https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev

[CalvinRechner via bitcoin-dev]

In principle, there is complete flexibility when it comes to the specific consensus details of the hard fork. One common suggestion has been to phase in a gradual blocksize increase beyond the initial 2MB cap included in Luke-Jr's proposal (a la BIP103); this would certainly be a welcome inclusion in the Omnibus Proposal, provided that is what we want. The reasoning behind incorporating Luke-Jr's 2MB limit and discount-rebalancing was to satisfy the conditions of the Scaling Agreement while ensuring maximum safety, minimum code discrepancies, and minimum controversy among the community; these priorities seem imperative, considering the extreme timeline constraints we are working under and the goals of the proposal. To put it more simply, the intent of the proposal was to serve as a template for the minimum viable fork that can achieve true consensus. A gradual increase to a larger size cap, especially if it were reasonably conservative, would be wholly in accordance with the Omnibus Proposal if that is what it takes to achieve the cooperation between community, industry, and developers in this critical moment of Bitcoin's history.

The purpose of the Omnibus Proposal is singlefold: to achieve the goals of the Consensus 2017 Scaling Agreement in the most maximally-compatible way. We can minimize disruption and loss potential all around by solving these problems in a compatibility-oriented manner. It is possible to fulfill both the letter and the spirit of the Scaling Agreement, to the complete satisfaction of all involved, while preventing chain-split risks in the meantime.

There is no justification for incompatibility with existing deployment approaches, when there is the possibility to work together towards our mutual goals instead. The most rational option is to join forces and avoid any chain-split potential for as long as possible. Under the Omnibus Proposal, once SegWit is activated, the terms of the hard fork are locked in automatically, set to activate 6 months later. The proposal guarantees that a successful SegWit activation is followed by a hard fork. Beyond enforcing the hard fork rules beginning at block height HardForkHeight, the Omnibus Proposal simply represents compatibility with the existing SegWit-activation deployment approaches.

By committing to this proposal, we can ensure unity, at least for now. There do not appear to be any arguments to the contrary. Why squander this opportunity for consensus and harmony? We can leverage the momentum of several disparate movements, and perhaps enjoy some much-needed social solidarity. In a way, everyone can get what they want, and through cooperation, we avoid the risk of a costly fracture.

The Segwit2x Team has begun work on an implementation of the Consensus Scaling Agreement, their operational timeline including the publication of a BIP on June 16, 2017.[1] I call upon the developers and maintainers of this initiative to consider and honor the Omnibus Proposal, extended or modified as needed, as the guiding approach to your development effort. Almost every component of the code exists, in some form or fashion, in the various constituent proposals' reference implementations, most of which have already undergone a significant degree of peer review.

We cannot afford to delay, nor to reimplement; the launch timeline is aggressively optimistic as it is. The quickest and safest approach to achieving the goals set forth at Consensus 2017 is to leverage the existing tools and proposals for the job. We can solve our problems properly, cooperatively.

I humbly ask that Jeff Garzik, Barry Silbert, Mike Belshe, and all of the other wonderful, intelligent collaborators on this project step forward and support the cooperative, compatibility-oriented approach of the Omnibus Proposal.

This is the best way to maximize value for everyone. We have a real opportunity to collaborate and work together on the same team. The Omnibus Proposal, designed in exact accordance with a powerful industry agreement and incorporating the feedback and suggestions provided from within both the developer community and the community-at-large, stands the best chance of uniting everyone under a common front.

Please, for the love of Bitcoin, let us do our best to cooperate.

[1] https://imgur.com/a/a2oPs

Sent with [ProtonMail](https://protonmail.com) Secure Email.

-------- Original Message --------
Subject: Re: [bitcoin-dev] Compatibility-Oriented Omnibus Proposal
Local Time: May 29, 2017 6:49 PM
UTC Time: May 29, 2017 11:49 PM

if the community wishes to adopt (by unanimous consensus) a 2 MB block size hardfork, this is probably the best way to do it right now... Legacy Bitcoin transactions are given the witness discount, and a block size limit of 2 MB is imposed.<<

The above decision may quickly become very controversial. I don't think it's what most users had/have in mind when they discuss a "2MB+SegWit" solution.

With the current 1MB+SegWit, testing has shown us that normal usage results in ~2 or 2.1MB blocks.

I think most users will expect a linear increase when Base Size is increased to 2000000 bytes and Total Weight is increased to 8000000 bytes. With normal usage, the expected results would then be ~4 or 4.2MB blocks.

Am I missing something here, or does Luke's suggested 2MB cap completely nullify that expected linear increase? If so, why? What's the logic behind this decision?

I'd love to be armed with a good answer should my colleagues ask me the same obvious question, so thank you ahead of time!

Respectfully,
Oliver Petruzel

[Jared Lee Richardson via bitcoin-dev]

Post by Oliver Petruzel via bitcoin-dev
The above decision may quickly become very controversial. I don't think

it's what most users had/have in mind when they discuss a "2MB+SegWit"
solution.

Post by Oliver Petruzel via bitcoin-dev
With the current 1MB+SegWit, testing has shown us that normal usage

results in ~2 or 2.1MB blocks.

Post by Oliver Petruzel via bitcoin-dev
I think most users will expect a linear increase when Base Size is

increased to 2000000 bytes and Total Weight is increased to 8000000 bytes.
With normal usage, the expected results would then be ~4 or 4.2MB blocks.

I think Calvin is correct here, the secondary limit is not what people
anticipated with the segwit + 2mb agreement. It would not kill the
agreement for me, but it might for others.

What is the justification for the secondary limitation? Is there hard data
to back this? The quadratic hashing problem is frequently brought up, but
that is trivially handled with a hard 1mb transaction limit and on the
other thread there's talk/suggestions of an even lower limit. Are there
any other reasons for this limitation, and is there data to justify those
concerns? If not, this should be left out in favor of a transaction size
limit. If so, hard data would go a long way to dealing with the conversy
this will create.

Post by Oliver Petruzel via bitcoin-dev

cause the existing "segwit" deployment to activate without needing to

release a new deployment.

Post by Oliver Petruzel via bitcoin-dev
Both of the aforementioned activation options (“fast-activation” and

“flag-day activation”) serve to prevent unnecessary delays in the network
upgrade process, addressing a common criticism of the Scaling Agreement and
providing an opportunity for cooperation and unity instead.

This is likely to cause more controversy and unfortunately has the tightest
timelines. Unlike the SW2mb working group's timelines, a hard-coded
timeline couldn't be changed with mutual agreement from the signers.

Given the chance of bit1 accidental activation without clear signaling for
the required bit4 2mb hard fork, I don't think the fair or acceptable
tradeoff is for flag day to require bit1 signaling only. *Flag day should
be modified to accept either bit1 signaling, OR to accept bit4 signaling IF
the 80% threshold hasn't been met.* In this way the anti-segwit working
group members are not in danger of an activated bit1 segwit without also
getting their portion of the compromise, the bit4 signaled HF. If flag day
accepts bit4 OR bit1, AND bit4 requires both bit1 and bit4 once 80% is
reached, flag day is nearly guaranteed to get its stated desire within 1750
blocks (bit4 accepted until block 800; bit4+bit1 signaled afterwards until
95%), but without the chance that the WG signers won't get what they agreed
to.

*That seems like a minor compromise for BIP148. Thoughts on this change to
flag day / BIP148?*

In addition, the aggressiveness of the timelines and the complexity of the
merged COOP proposal may require the BIP148 flag day to be pushed back. I
would think some day in September is achievable, but I'm not sure if August
1st will be.

Jared


On Tue, May 30, 2017 at 3:20 PM, CalvinRechner via bitcoin-dev <

Post by Oliver Petruzel via bitcoin-dev
In principle, there is complete flexibility when it comes to the specific
consensus details of the hard fork. One common suggestion has been to phase
in a gradual blocksize increase beyond the initial 2MB cap included in
Luke-Jr's proposal (a la BIP103); this would certainly be a welcome
inclusion in the Omnibus Proposal, provided that is what we want. The
reasoning behind incorporating Luke-Jr's 2MB limit and discount-rebalancing
was to satisfy the conditions of the Scaling Agreement while ensuring
maximum safety, minimum code discrepancies, and minimum controversy among
the community; these priorities seem imperative, considering the extreme
timeline constraints we are working under and the goals of the proposal. To
put it more simply, the intent of the proposal was to serve as a template
for the minimum viable fork that can achieve true consensus. A gradual
increase to a larger size cap, especially if it were reasonably
conservative, would be wholly in accordance with the Omnibus Proposal if
that is what it takes to achieve the cooperation between community,
industry, and developers in this critical moment of Bitcoin's history.
The purpose of the Omnibus Proposal is singlefold: to achieve the goals of
the Consensus 2017 Scaling Agreement in the most maximally-compatible way.
We can minimize disruption and loss potential all around by solving these
problems in a compatibility-oriented manner. It is possible to fulfill both
the letter and the spirit of the Scaling Agreement, to the complete
satisfaction of all involved, while preventing chain-split risks in the
meantime.
There is no justification for incompatibility with existing deployment
approaches, when there is the possibility to work together towards our
mutual goals instead. The most rational option is to join forces and avoid
any chain-split potential for as long as possible. Under the Omnibus
Proposal, once SegWit is activated, the terms of the hard fork are locked
in automatically, set to activate 6 months later. The proposal guarantees
that a successful SegWit activation is followed by a hard fork. Beyond
enforcing the hard fork rules beginning at block height HardForkHeight, the
Omnibus Proposal simply represents compatibility with the existing
SegWit-activation deployment approaches.
By committing to this proposal, we can ensure unity, at least for now.
There do not appear to be any arguments to the contrary. Why squander this
opportunity for consensus and harmony? We can leverage the momentum of
several disparate movements, and perhaps enjoy some much-needed social
solidarity. In a way, everyone can get what they want, and through
cooperation, we avoid the risk of a costly fracture.
The Segwit2x Team has begun work on an implementation of the Consensus
Scaling Agreement, their operational timeline including the publication of
a BIP on June 16, 2017.[1] I call upon the developers and maintainers of
this initiative to consider and honor the Omnibus Proposal, extended or
modified as needed, as the guiding approach to your development effort.
Almost every component of the code exists, in some form or fashion, in the
various constituent proposals' reference implementations, most of which
have already undergone a significant degree of peer review.
We cannot afford to delay, nor to reimplement; the launch timeline is
aggressively optimistic as it is. The quickest and safest approach to
achieving the goals set forth at Consensus 2017 is to leverage the existing
tools and proposals for the job. We can solve our problems properly,
cooperatively.
I humbly ask that Jeff Garzik, Barry Silbert, Mike Belshe, and all of the
other wonderful, intelligent collaborators on this project step forward and
support the cooperative, compatibility-oriented approach of the Omnibus
Proposal.
This is the best way to maximize value for everyone. We have a real
opportunity to collaborate and work together on the same team. The Omnibus
Proposal, designed in exact accordance with a powerful industry agreement
and incorporating the feedback and suggestions provided from within both
the developer community and the community-at-large, stands the best chance
of uniting everyone under a common front.
Please, for the love of Bitcoin, let us do our best to cooperate.
[1] https://imgur.com/a/a2oPs
Sent with ProtonMail <https://protonmail.com> Secure Email.
-------- Original Message --------
Subject: Re: [bitcoin-dev] Compatibility-Oriented Omnibus Proposal
Local Time: May 29, 2017 6:49 PM
UTC Time: May 29, 2017 11:49 PM

if the community wishes to adopt (by unanimous consensus) a 2 MB block

size hardfork, this is probably the best way to do it right now... Legacy
Bitcoin transactions are given the witness discount, and a block size limit
of 2 MB is imposed.<<
The above decision may quickly become very controversial. I don't think it's
what most users had/have in mind when they discuss a "2MB+SegWit" solution.
With the current 1MB+SegWit, testing has shown us that normal usage
results in ~2 or 2.1MB blocks.
I think most users will expect a linear increase when Base Size is
increased to 2000000 bytes and Total Weight is increased to 8000000 bytes.
With normal usage, the expected results would then be ~4 or 4.2MB blocks.
Am I missing something here, or does Luke's suggested 2MB cap completely
nullify that expected linear increase? If so, why? What's the logic behind
this decision?
I'd love to be armed with a good answer should my colleagues ask me the
same obvious question, so thank you ahead of time!
Respectfully,
Oliver Petruzel
_______________________________________________
bitcoin-dev mailing list
https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev

[Sergio Demian Lerner via bitcoin-dev]

I don't see LukeJr 2MB limit to be compatible with the NY agreement. For
the rest, seems fine for me.



On Fri, Jun 2, 2017 at 4:13 PM, Jared Lee Richardson via bitcoin-dev <

Post by CalvinRechner via bitcoin-dev

Post by Oliver Petruzel via bitcoin-dev
The above decision may quickly become very controversial. I don't think

it's what most users had/have in mind when they discuss a "2MB+SegWit"
solution.

Post by Oliver Petruzel via bitcoin-dev
With the current 1MB+SegWit, testing has shown us that normal usage

results in ~2 or 2.1MB blocks.

Post by Oliver Petruzel via bitcoin-dev
I think most users will expect a linear increase when Base Size is

increased to 2000000 bytes and Total Weight is increased to 8000000 bytes.
With normal usage, the expected results would then be ~4 or 4.2MB blocks.
I think Calvin is correct here, the secondary limit is not what people
anticipated with the segwit + 2mb agreement. It would not kill the
agreement for me, but it might for others.
What is the justification for the secondary limitation? Is there hard
data to back this? The quadratic hashing problem is frequently brought up,
but that is trivially handled with a hard 1mb transaction limit and on the
other thread there's talk/suggestions of an even lower limit. Are there
any other reasons for this limitation, and is there data to justify those
concerns? If not, this should be left out in favor of a transaction size
limit. If so, hard data would go a long way to dealing with the conversy
this will create.

Post by Oliver Petruzel via bitcoin-dev
Shaolin Fry’s “Mandatory activation of segwit deployment”[3] is included

cause the existing "segwit" deployment to activate without needing to

release a new deployment.

Post by Oliver Petruzel via bitcoin-dev
Both of the aforementioned activation options (“fast-activation” and

“flag-day activation”) serve to prevent unnecessary delays in the network
upgrade process, addressing a common criticism of the Scaling Agreement and
providing an opportunity for cooperation and unity instead.
This is likely to cause more controversy and unfortunately has the
tightest timelines. Unlike the SW2mb working group's timelines, a
hard-coded timeline couldn't be changed with mutual agreement from the
signers.
Given the chance of bit1 accidental activation without clear signaling for
the required bit4 2mb hard fork, I don't think the fair or acceptable
tradeoff is for flag day to require bit1 signaling only. *Flag day
should be modified to accept either bit1 signaling, OR to accept bit4
signaling IF the 80% threshold hasn't been met.* In this way the
anti-segwit working group members are not in danger of an activated bit1
segwit without also getting their portion of the compromise, the bit4
signaled HF. If flag day accepts bit4 OR bit1, AND bit4 requires both bit1
and bit4 once 80% is reached, flag day is nearly guaranteed to get its
stated desire within 1750 blocks (bit4 accepted until block 800; bit4+bit1
signaled afterwards until 95%), but without the chance that the WG signers
won't get what they agreed to.
*That seems like a minor compromise for BIP148. Thoughts on this change
to flag day / BIP148?*
In addition, the aggressiveness of the timelines and the complexity of the
merged COOP proposal may require the BIP148 flag day to be pushed back. I
would think some day in September is achievable, but I'm not sure if August
1st will be.
Jared
On Tue, May 30, 2017 at 3:20 PM, CalvinRechner via bitcoin-dev <

Post by Oliver Petruzel via bitcoin-dev
In principle, there is complete flexibility when it comes to the specific
consensus details of the hard fork. One common suggestion has been to phase
in a gradual blocksize increase beyond the initial 2MB cap included in
Luke-Jr's proposal (a la BIP103); this would certainly be a welcome
inclusion in the Omnibus Proposal, provided that is what we want. The
reasoning behind incorporating Luke-Jr's 2MB limit and discount-rebalancing
was to satisfy the conditions of the Scaling Agreement while ensuring
maximum safety, minimum code discrepancies, and minimum controversy among
the community; these priorities seem imperative, considering the extreme
timeline constraints we are working under and the goals of the proposal. To
put it more simply, the intent of the proposal was to serve as a template
for the minimum viable fork that can achieve true consensus. A gradual
increase to a larger size cap, especially if it were reasonably
conservative, would be wholly in accordance with the Omnibus Proposal if
that is what it takes to achieve the cooperation between community,
industry, and developers in this critical moment of Bitcoin's history.
The purpose of the Omnibus Proposal is singlefold: to achieve the goals
of the Consensus 2017 Scaling Agreement in the most maximally-compatible
way. We can minimize disruption and loss potential all around by solving
these problems in a compatibility-oriented manner. It is possible to
fulfill both the letter and the spirit of the Scaling Agreement, to the
complete satisfaction of all involved, while preventing chain-split risks
in the meantime.
There is no justification for incompatibility with existing deployment
approaches, when there is the possibility to work together towards our
mutual goals instead. The most rational option is to join forces and avoid
any chain-split potential for as long as possible. Under the Omnibus
Proposal, once SegWit is activated, the terms of the hard fork are locked
in automatically, set to activate 6 months later. The proposal guarantees
that a successful SegWit activation is followed by a hard fork. Beyond
enforcing the hard fork rules beginning at block height HardForkHeight, the
Omnibus Proposal simply represents compatibility with the existing
SegWit-activation deployment approaches.
By committing to this proposal, we can ensure unity, at least for now.
There do not appear to be any arguments to the contrary. Why squander this
opportunity for consensus and harmony? We can leverage the momentum of
several disparate movements, and perhaps enjoy some much-needed social
solidarity. In a way, everyone can get what they want, and through
cooperation, we avoid the risk of a costly fracture.
The Segwit2x Team has begun work on an implementation of the Consensus
Scaling Agreement, their operational timeline including the publication of
a BIP on June 16, 2017.[1] I call upon the developers and maintainers of
this initiative to consider and honor the Omnibus Proposal, extended or
modified as needed, as the guiding approach to your development effort.
Almost every component of the code exists, in some form or fashion, in the
various constituent proposals' reference implementations, most of which
have already undergone a significant degree of peer review.
We cannot afford to delay, nor to reimplement; the launch timeline is
aggressively optimistic as it is. The quickest and safest approach to
achieving the goals set forth at Consensus 2017 is to leverage the existing
tools and proposals for the job. We can solve our problems properly,
cooperatively.
I humbly ask that Jeff Garzik, Barry Silbert, Mike Belshe, and all of the
other wonderful, intelligent collaborators on this project step forward and
support the cooperative, compatibility-oriented approach of the Omnibus
Proposal.
This is the best way to maximize value for everyone. We have a real
opportunity to collaborate and work together on the same team. The Omnibus
Proposal, designed in exact accordance with a powerful industry agreement
and incorporating the feedback and suggestions provided from within both
the developer community and the community-at-large, stands the best chance
of uniting everyone under a common front.
Please, for the love of Bitcoin, let us do our best to cooperate.
[1] https://imgur.com/a/a2oPs
Sent with ProtonMail <https://protonmail.com> Secure Email.
-------- Original Message --------
Subject: Re: [bitcoin-dev] Compatibility-Oriented Omnibus Proposal
Local Time: May 29, 2017 6:49 PM
UTC Time: May 29, 2017 11:49 PM

if the community wishes to adopt (by unanimous consensus) a 2 MB block

size hardfork, this is probably the best way to do it right now... Legacy
Bitcoin transactions are given the witness discount, and a block size limit
of 2 MB is imposed.<<
The above decision may quickly become very controversial. I don't think it's
what most users had/have in mind when they discuss a "2MB+SegWit" solution.
With the current 1MB+SegWit, testing has shown us that normal usage
results in ~2 or 2.1MB blocks.
I think most users will expect a linear increase when Base Size is
increased to 2000000 bytes and Total Weight is increased to 8000000 bytes.
With normal usage, the expected results would then be ~4 or 4.2MB blocks.
Am I missing something here, or does Luke's suggested 2MB cap completely
nullify that expected linear increase? If so, why? What's the logic behind
this decision?
I'd love to be armed with a good answer should my colleagues ask me the
same obvious question, so thank you ahead of time!
Respectfully,
Oliver Petruzel
_______________________________________________
bitcoin-dev mailing list
https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev

_______________________________________________
bitcoin-dev mailing list
https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev