From 0e0fbb40360ac4f1febbc967a5d08ad3bac19abc Mon Sep 17 00:00:00 2001 From: James Hilliard Date: Tue, 23 May 2017 16:51:27 -0400 Subject: Rename to BIP91 --- bip-0091.mediawiki | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) create mode 100644 bip-0091.mediawiki (limited to 'bip-0091.mediawiki') diff --git a/bip-0091.mediawiki b/bip-0091.mediawiki new file mode 100644 index 0000000..a28a412 --- /dev/null +++ b/bip-0091.mediawiki @@ -0,0 +1,88 @@ +
+  BIP: 91
+  Layer: Consensus (soft fork)
+  Title: Reduced signalling threshold activation of existing segwit deployment
+  Author: James Hilliard 
+  Status: Draft
+  Type: Standards Track
+  Created: 2017-05-22
+  License: BSD-3-Clause
+           CC0-1.0
+
+ +==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 === + +
+// 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");
+    }
+}
+
+ +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. + -- cgit v1.2.3 From 31bda2f033e975c55fcbb74e2c06ef3516698ec4 Mon Sep 17 00:00:00 2001 From: James Hilliard Date: Tue, 23 May 2017 16:52:41 -0400 Subject: =?UTF-8?q?Rename=20BIP=20to=20to=20=E2=80=9CReduced=20threshold?= =?UTF-8?q?=20Segwit=20MASF=E2=80=9D?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- bip-0091.mediawiki | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'bip-0091.mediawiki') diff --git a/bip-0091.mediawiki b/bip-0091.mediawiki index a28a412..1654d0c 100644 --- a/bip-0091.mediawiki +++ b/bip-0091.mediawiki @@ -1,7 +1,7 @@ 
   BIP: 91
   Layer: Consensus (soft fork)
-  Title: Reduced signalling threshold activation of existing segwit deployment
+  Title: Reduced threshold Segwit MASF
   Author: James Hilliard 
   Status: Draft
   Type: Standards Track
-- 
cgit v1.2.3


From 0295dbb760b20683ecc86353d486dd4c24ee8c1e Mon Sep 17 00:00:00 2001
From: James Hilliard 
Date: Tue, 23 May 2017 17:35:44 -0400
Subject: Add BIP91 comments section

---
 bip-0091.mediawiki | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'bip-0091.mediawiki')

diff --git a/bip-0091.mediawiki b/bip-0091.mediawiki
index 1654d0c..2a4d489 100644
--- a/bip-0091.mediawiki
+++ b/bip-0091.mediawiki
@@ -3,6 +3,8 @@
   Layer: Consensus (soft fork)
   Title: Reduced threshold Segwit MASF
   Author: James Hilliard 
+  Comments-Summary: No comments yet.
+  Comments-URI: https://github.com/bitcoin/bips/wiki/Comments:BIP-0091
   Status: Draft
   Type: Standards Track
   Created: 2017-05-22
-- 
cgit v1.2.3