📅 Original date posted:2017-05-22
📝 Original message:Given the overwhelming support for SegWit across the ecosystem of businesses and users, this seems reasonable to me.
On May 22, 2017 6:40:13 PM EDT, James Hilliard via bitcoin-dev <bitcoin-dev at lists.linuxfoundation.org> wrote:
>I would like to propose an implementation that accomplishes the first
>part of the Barry Silbert proposal independently from the second:
>
>"Activate Segregated Witness at an 80% threshold, signaling at bit 4"
>in a way that
>
>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.
>
>By activating segwit immediately and separately from any HF we can
>scale quickly without risking a rushed combined segwit+HF that would
>almost certainly cause widespread issues.
>
>Draft proposal:
>https://github.com/jameshilliard/bips/blob/bip-segsignal/bip-segsignal.mediawiki
>
>Proposal text:
><pre>
> BIP: segsignal
> Layer: Consensus (soft fork)
>Title: Reduced signalling threshold activation of existing segwit
>deployment
> Author: James Hilliard <james.hilliard1 at gmail.com>
> Status: Draft
> Type: Standards Track
> Created: 2017-05-22
> License: BSD-3-Clause
> CC0-1.0
></pre>
>
>==Abstract==
>
>This document specifies a method to activate the existing BIP9 segwit
>deployment with a majority hashpower less than 95%.
>
>==Definitions==
>
>"existing segwit deployment" refer to the BIP9 "segwit" deployment
>using bit 1, between November 15th 2016 and November 15th 2017 to
>activate BIP141, BIP143 and BIP147.
>
>==Motivation==
>
>Segwit increases the blocksize, fixes transaction malleability, and
>makes scripting easier to upgrade as well as bringing many other
>[https://bitcoincore.org/en/2016/01/26/segwit-benefits/ benefits].
>
>This BIP provides a way for a simple majority of miners to coordinate
>activation of the existing segwit deployment with less than 95%
>hashpower. For a number of reasons a complete redeployment of segwit
>is difficulty to do until the existing deployment expires. This is due
>to 0.13.1+ having many segwit related features active already,
>including all the P2P components, the new network service flag, the
>witness-tx and block messages, compact blocks v2 and preferential
>peering. A redeployment of segwit will need to redefine all these
>things and doing so before expiry would greatly complicate testing.
>
>==Specification==
>
>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.
>
>==Deployment==
>
>This BIP will be deployed by a "version bits" with an 80%(this can be
>adjusted if desired) activation threshold BIP9 with the name
>"segsignal" and using bit 4.
>
>This BIP will have 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.
>
>=== Reference implementation ===
>
><pre>
>// Check if Segregated Witness is Locked In
>bool IsWitnessLockedIn(const CBlockIndex* pindexPrev, const
>Consensus::Params& params)
>{
> LOCK(cs_main);
> return (VersionBitsState(pindexPrev, params,
>Consensus::DEPLOYMENT_SEGWIT, versionbitscache) ==
>THRESHOLD_LOCKED_IN);
>}
>
>// SEGSIGNAL mandatory segwit signalling.
>if ( VersionBitsState(pindex->pprev, chainparams.GetConsensus(),
>Consensus::DEPLOYMENT_SEGSIGNAL, versionbitscache) == THRESHOLD_ACTIVE
>&&
> !IsWitnessLockedIn(pindex->pprev, chainparams.GetConsensus()) &&
>// Segwit is not locked in
> !IsWitnessEnabled(pindex->pprev, chainparams.GetConsensus()) ) //
>and is not active.
>{
> bool fVersionBits = (pindex->nVersion & VERSIONBITS_TOP_MASK) ==
>VERSIONBITS_TOP_BITS;
> bool fSegbit = (pindex->nVersion &
>VersionBitsMask(chainparams.GetConsensus(),
>Consensus::DEPLOYMENT_SEGWIT)) != 0;
> if (!(fVersionBits && fSegbit)) {
> return state.DoS(0, error("ConnectBlock(): relayed block must
>signal for segwit, please upgrade"), REJECT_INVALID, "bad-no-segwit");
> }
>}
></pre>
>
>https://github.com/bitcoin/bitcoin/compare/0.14...jameshilliard:segsignal-v0.14.1
>
>==Backwards Compatibility==
>
>This deployment is compatible with the existing "segwit" bit 1
>deployment scheduled between midnight November 15th, 2016 and midnight
>November 15th, 2017. Miners will need to upgrade their nodes to
>support segsignal otherwise they may build on top of an invalid block.
>While this bip is active users should either upgrade to segsignal or
>wait for additional confirmations when accepting payments.
>
>==Rationale==
>
>Historically we have used IsSuperMajority() to activate soft forks
>such as BIP66 which has a mandatory signalling requirement for miners
>once activated, this ensures that miners are aware of new rules being
>enforced. This technique can be leveraged to lower the signalling
>threshold of a soft fork while it is in the process of being deployed
>in a backwards compatible way.
>
>By orphaning non-signalling blocks during the BIP9 bit 1 "segwit"
>deployment, this BIP can cause the existing "segwit" deployment to
>activate without needing to release a new deployment.
>
>==References==
>
>*[https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2017-March/013714.html
>Mailing list discussion]
>*[https://github.com/bitcoin/bitcoin/blob/v0.6.0/src/main.cpp#L1281-L1283
>P2SH flag day activation]
>*[[bip-0009.mediawiki|BIP9 Version bits with timeout and delay]]
>*[[bip-0016.mediawiki|BIP16 Pay to Script Hash]]
>*[[bip-0141.mediawiki|BIP141 Segregated Witness (Consensus layer)]]
>*[[bip-0143.mediawiki|BIP143 Transaction Signature Verification for
>Version 0 Witness Program]]
>*[[bip-0147.mediawiki|BIP147 Dealing with dummy stack element
>malleability]]
>*[[bip-0148.mediawiki|BIP148 Mandatory activation of segwit
>deployment]]
>*[[bip-0149.mediawiki|BIP149 Segregated Witness (second deployment)]]
>*[https://bitcoincore.org/en/2016/01/26/segwit-benefits/ Segwit
>benefits]
>
>==Copyright==
>
>This document is dual licensed as BSD 3-clause, and Creative Commons
>CC0 1.0 Universal.
>_______________________________________________
>bitcoin-dev mailing list
>bitcoin-dev at lists.linuxfoundation.org
>https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
Matt Corallo [ARCHIVE] /
npub1e4…jxmcu
2023-06-07 18:01:39
in reply to nevent1q…n88l
Author Public Key
npub1e46n428mcyfwznl7nlsf6d3s7rhlwm9x3cmkuqzt3emmdpadmkaqqjxmcuSeen on
wss://relay.noswhere.comPublished at
2023-06-07 18:01:39Event JSON
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"content": "📅 Original date posted:2017-05-22\n📝 Original message:Given the overwhelming support for SegWit across the ecosystem of businesses and users, this seems reasonable to me.\n\nOn May 22, 2017 6:40:13 PM EDT, James Hilliard via bitcoin-dev \u003cbitcoin-dev at lists.linuxfoundation.org\u003e wrote:\n\u003eI would like to propose an implementation that accomplishes the first\n\u003epart of the Barry Silbert proposal independently from the second:\n\u003e\n\u003e\"Activate Segregated Witness at an 80% threshold, signaling at bit 4\"\n\u003ein a way that\n\u003e\n\u003eThe goal here is to minimize chain split risk and network disruption\n\u003ewhile maximizing backwards compatibility and still providing for rapid\n\u003eactivation of segwit at the 80% threshold using bit 4.\n\u003e\n\u003eBy activating segwit immediately and separately from any HF we can\n\u003escale quickly without risking a rushed combined segwit+HF that would\n\u003ealmost certainly cause widespread issues.\n\u003e\n\u003eDraft proposal:\n\u003ehttps://github.com/jameshilliard/bips/blob/bip-segsignal/bip-segsignal.mediawiki\n\u003e\n\u003eProposal text:\n\u003e\u003cpre\u003e\n\u003e BIP: segsignal\n\u003e Layer: Consensus (soft fork)\n\u003eTitle: Reduced signalling threshold activation of existing segwit\n\u003edeployment\n\u003e Author: James Hilliard \u003cjames.hilliard1 at gmail.com\u003e\n\u003e Status: Draft\n\u003e Type: Standards Track\n\u003e Created: 2017-05-22\n\u003e License: BSD-3-Clause\n\u003e CC0-1.0\n\u003e\u003c/pre\u003e\n\u003e\n\u003e==Abstract==\n\u003e\n\u003eThis document specifies a method to activate the existing BIP9 segwit\n\u003edeployment with a majority hashpower less than 95%.\n\u003e\n\u003e==Definitions==\n\u003e\n\u003e\"existing segwit deployment\" refer to the BIP9 \"segwit\" deployment\n\u003eusing bit 1, between November 15th 2016 and November 15th 2017 to\n\u003eactivate BIP141, BIP143 and BIP147.\n\u003e\n\u003e==Motivation==\n\u003e\n\u003eSegwit increases the blocksize, fixes transaction malleability, and\n\u003emakes scripting easier to upgrade as well as bringing many other\n\u003e[https://bitcoincore.org/en/2016/01/26/segwit-benefits/ benefits].\n\u003e\n\u003eThis BIP provides a way for a simple majority of miners to coordinate\n\u003eactivation of the existing segwit deployment with less than 95%\n\u003ehashpower. For a number of reasons a complete redeployment of segwit\n\u003eis difficulty to do until the existing deployment expires. This is due\n\u003eto 0.13.1+ having many segwit related features active already,\n\u003eincluding all the P2P components, the new network service flag, the\n\u003ewitness-tx and block messages, compact blocks v2 and preferential\n\u003epeering. A redeployment of segwit will need to redefine all these\n\u003ethings and doing so before expiry would greatly complicate testing.\n\u003e\n\u003e==Specification==\n\u003e\n\u003eWhile this BIP is active, all blocks must set the nVersion header top\n\u003e3 bits to 001 together with bit field (1\u003c\u003c1) (according to the\n\u003eexisting segwit deployment). Blocks that do not signal as required\n\u003ewill be rejected.\n\u003e\n\u003e==Deployment==\n\u003e\n\u003eThis BIP will be deployed by a \"version bits\" with an 80%(this can be\n\u003eadjusted if desired) activation threshold BIP9 with the name\n\u003e\"segsignal\" and using bit 4.\n\u003e\n\u003eThis BIP will have a start time of midnight June 1st, 2017 (epoch time\n\u003e1496275200) and timeout on midnight November 15th 2017 (epoch time\n\u003e1510704000). This BIP will cease to be active when segwit is\n\u003elocked-in.\n\u003e\n\u003e=== Reference implementation ===\n\u003e\n\u003e\u003cpre\u003e\n\u003e// Check if Segregated Witness is Locked In\n\u003ebool IsWitnessLockedIn(const CBlockIndex* pindexPrev, const\n\u003eConsensus::Params\u0026 params)\n\u003e{\n\u003e LOCK(cs_main);\n\u003e return (VersionBitsState(pindexPrev, params,\n\u003eConsensus::DEPLOYMENT_SEGWIT, versionbitscache) ==\n\u003eTHRESHOLD_LOCKED_IN);\n\u003e}\n\u003e\n\u003e// SEGSIGNAL mandatory segwit signalling.\n\u003eif ( VersionBitsState(pindex-\u003epprev, chainparams.GetConsensus(),\n\u003eConsensus::DEPLOYMENT_SEGSIGNAL, versionbitscache) == THRESHOLD_ACTIVE\n\u003e\u0026\u0026\n\u003e !IsWitnessLockedIn(pindex-\u003epprev, chainparams.GetConsensus()) \u0026\u0026\n\u003e// Segwit is not locked in\n\u003e !IsWitnessEnabled(pindex-\u003epprev, chainparams.GetConsensus()) ) //\n\u003eand is not active.\n\u003e{\n\u003e bool fVersionBits = (pindex-\u003enVersion \u0026 VERSIONBITS_TOP_MASK) ==\n\u003eVERSIONBITS_TOP_BITS;\n\u003e bool fSegbit = (pindex-\u003enVersion \u0026\n\u003eVersionBitsMask(chainparams.GetConsensus(),\n\u003eConsensus::DEPLOYMENT_SEGWIT)) != 0;\n\u003e if (!(fVersionBits \u0026\u0026 fSegbit)) {\n\u003e return state.DoS(0, error(\"ConnectBlock(): relayed block must\n\u003esignal for segwit, please upgrade\"), REJECT_INVALID, \"bad-no-segwit\");\n\u003e }\n\u003e}\n\u003e\u003c/pre\u003e\n\u003e\n\u003ehttps://github.com/bitcoin/bitcoin/compare/0.14...jameshilliard:segsignal-v0.14.1\n\u003e\n\u003e==Backwards Compatibility==\n\u003e\n\u003eThis deployment is compatible with the existing \"segwit\" bit 1\n\u003edeployment scheduled between midnight November 15th, 2016 and midnight\n\u003eNovember 15th, 2017. Miners will need to upgrade their nodes to\n\u003esupport segsignal otherwise they may build on top of an invalid block.\n\u003eWhile this bip is active users should either upgrade to segsignal or\n\u003ewait for additional confirmations when accepting payments.\n\u003e\n\u003e==Rationale==\n\u003e\n\u003eHistorically we have used IsSuperMajority() to activate soft forks\n\u003esuch as BIP66 which has a mandatory signalling requirement for miners\n\u003eonce activated, this ensures that miners are aware of new rules being\n\u003eenforced. This technique can be leveraged to lower the signalling\n\u003ethreshold of a soft fork while it is in the process of being deployed\n\u003ein a backwards compatible way.\n\u003e\n\u003eBy orphaning non-signalling blocks during the BIP9 bit 1 \"segwit\"\n\u003edeployment, this BIP can cause the existing \"segwit\" deployment to\n\u003eactivate without needing to release a new deployment.\n\u003e\n\u003e==References==\n\u003e\n\u003e*[https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2017-March/013714.html\n\u003eMailing list discussion]\n\u003e*[https://github.com/bitcoin/bitcoin/blob/v0.6.0/src/main.cpp#L1281-L1283\n\u003eP2SH flag day activation]\n\u003e*[[bip-0009.mediawiki|BIP9 Version bits with timeout and delay]]\n\u003e*[[bip-0016.mediawiki|BIP16 Pay to Script Hash]]\n\u003e*[[bip-0141.mediawiki|BIP141 Segregated Witness (Consensus layer)]]\n\u003e*[[bip-0143.mediawiki|BIP143 Transaction Signature Verification for\n\u003eVersion 0 Witness Program]]\n\u003e*[[bip-0147.mediawiki|BIP147 Dealing with dummy stack element\n\u003emalleability]]\n\u003e*[[bip-0148.mediawiki|BIP148 Mandatory activation of segwit\n\u003edeployment]]\n\u003e*[[bip-0149.mediawiki|BIP149 Segregated Witness (second deployment)]]\n\u003e*[https://bitcoincore.org/en/2016/01/26/segwit-benefits/ Segwit\n\u003ebenefits]\n\u003e\n\u003e==Copyright==\n\u003e\n\u003eThis document is dual licensed as BSD 3-clause, and Creative Commons\n\u003eCC0 1.0 Universal.\n\u003e_______________________________________________\n\u003ebitcoin-dev mailing list\n\u003ebitcoin-dev at lists.linuxfoundation.org\n\u003ehttps://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev",
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