summaryrefslogtreecommitdiff
path: root/3e/db01f7bc35b3dcf474fce237cbc4f6e3dcc37c
blob: 9c6c09beed418f43aff8195b24c67c99d2f00568 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
Return-Path: <jaredr26@gmail.com>
Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org
	[172.17.192.35])
	by mail.linuxfoundation.org (Postfix) with ESMTPS id 2D2D1902
	for <bitcoin-dev@lists.linuxfoundation.org>;
	Wed,  7 Jun 2017 23:44:03 +0000 (UTC)
X-Greylist: whitelisted by SQLgrey-1.7.6
Received: from mail-ua0-f172.google.com (mail-ua0-f172.google.com
	[209.85.217.172])
	by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 315E7140
	for <bitcoin-dev@lists.linuxfoundation.org>;
	Wed,  7 Jun 2017 23:43:59 +0000 (UTC)
Received: by mail-ua0-f172.google.com with SMTP id h39so12935749uaa.3
	for <bitcoin-dev@lists.linuxfoundation.org>;
	Wed, 07 Jun 2017 16:43:59 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025;
	h=mime-version:in-reply-to:references:from:date:message-id:subject:to
	:cc; bh=+US7CQibQqOUJhvdwP9lYizdsSdEnGyOMKYbJlxNZO4=;
	b=Sb4cJWWmQEeHbDKlQo271XIOu6Ec8AZH9tsxuYKlr8kaUrjPHyoqfVzYF8JX1TJwR8
	3WMAhBKtqndEjggFNxu4R7ftN+BGUN7jnzXaV/BsOop7ivgsWjPoxXg6AbETWj0QM6pb
	zf24E8zbib15MN0s205ldy72gwRVfrGrz55ChKLQ4/HHgfk+XSwMQgQMDD2+5SzWcUx0
	0Ef6MIKoI5J2raWkJlIzwUa1WxGG9uBBHSJlITYawOV3Zyhp6W0FNUzCTS1YuvTiWzt1
	jSPJJTgA2FyJP7Gyb/FFqY3wQoZVh+beMdtGlZI2ghRR9EnfYx9IYiV1Mc89ofR2OWIl
	d9PQ==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
	d=1e100.net; s=20161025;
	h=x-gm-message-state:mime-version:in-reply-to:references:from:date
	:message-id:subject:to:cc;
	bh=+US7CQibQqOUJhvdwP9lYizdsSdEnGyOMKYbJlxNZO4=;
	b=peA7XcvyPzPhKHqMMRzKTaZKiH6fzsEN53KH97OKpc1ZqU3qqIXe34Y6yDx7LGSdU6
	ITvAjup+2FnOqpsNUjw/gVbv3ikgsQFDujsoaKbvVKlt8rgtyPszqQqdspf75fWU4JOm
	YWg9r/hwwOdBMBqiFa6whVj6uhU5/uI9EkxlR4758DaNsIB5oxSaQxe/2dAtL8DUM6Q7
	BmVblxtm5D36BGId8QY/WQbpcNTNAaFF8lt307iMbp4vLVFPdMc/BFDz/ocmOD4XgkSl
	/1I+/5d/fJTLEI15T+7+Ii94yhMuQ+bfkfYkhGH5JjvMrQ6okzCQRVYSQLiOAtMZ9oOo
	qRyg==
X-Gm-Message-State: AODbwcBfKnCl0UvffkBc99AU3mCw4YwjCt60/Xwh7jiEKGkD9626cunQ
	VVn2Xxjpe1a3YehvNuou/Taf0g2rnwDY
X-Received: by 10.176.93.228 with SMTP id l36mr20307696uag.55.1496879037591;
	Wed, 07 Jun 2017 16:43:57 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.31.157.215 with HTTP; Wed, 7 Jun 2017 16:43:57 -0700 (PDT)
In-Reply-To: <CADvTj4pFna4tX37XmgrP7ueZB+Yv4T9NWmp99CwKSx5mzdiJJQ@mail.gmail.com>
References: <CADvTj4qpH-t5Gx6qyn3yToyUE_GFaBE989=AWNHLKMpMNW3R+w@mail.gmail.com>
	<CAD1TkXviJouao7YoHjiDN3mTUWFEbMY9mtCqkQ8zp8JthyhT7Q@mail.gmail.com>
	<CADvTj4rz4exYMvBEmYi=bTZDgDm0drLjpRZmZUo17inzCzCRVg@mail.gmail.com>
	<CAD1TkXskei1gk_kungSvdWGmbdJMA8AG+-zK+Osz6u5vSCN8BQ@mail.gmail.com>
	<CADvTj4poO1L+Wg5J+M71sJMz-Xcg_st3MkAcQK=bfHhTJ3i8ow@mail.gmail.com>
	<CAD1TkXumetRnPO6LxhJeVoci=0=YHD7hEB0K0YH+2McRBJ-QHw@mail.gmail.com>
	<CADvTj4pFna4tX37XmgrP7ueZB+Yv4T9NWmp99CwKSx5mzdiJJQ@mail.gmail.com>
From: Jared Lee Richardson <jaredr26@gmail.com>
Date: Wed, 7 Jun 2017 16:43:57 -0700
Message-ID: <CAD1TkXtmj3H3k+k7X2DgA0cNxXBNSSrzf_o33qFO8cA9eSUTnw@mail.gmail.com>
To: James Hilliard <james.hilliard1@gmail.com>
Content-Type: multipart/alternative; boundary="f403043eb5184eb8420551674f31"
X-Spam-Status: No, score=-1.7 required=5.0 tests=BAYES_00,DKIM_SIGNED,
	DKIM_VALID,DKIM_VALID_AU,FREEMAIL_ENVFROM_END_DIGIT,FREEMAIL_FROM,
	HTML_MESSAGE, LOTS_OF_MONEY,
	RCVD_IN_DNSWL_NONE autolearn=no version=3.3.1
X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on
	smtp1.linux-foundation.org
X-Mailman-Approved-At: Wed, 07 Jun 2017 23:54:15 +0000
Cc: Bitcoin Dev <bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] User Activated Soft Fork Split Protection
X-BeenThere: bitcoin-dev@lists.linuxfoundation.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: Bitcoin Protocol Discussion <bitcoin-dev.lists.linuxfoundation.org>
List-Unsubscribe: <https://lists.linuxfoundation.org/mailman/options/bitcoin-dev>,
	<mailto:bitcoin-dev-request@lists.linuxfoundation.org?subject=unsubscribe>
List-Archive: <http://lists.linuxfoundation.org/pipermail/bitcoin-dev/>
List-Post: <mailto:bitcoin-dev@lists.linuxfoundation.org>
List-Help: <mailto:bitcoin-dev-request@lists.linuxfoundation.org?subject=help>
List-Subscribe: <https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev>,
	<mailto:bitcoin-dev-request@lists.linuxfoundation.org?subject=subscribe>
X-List-Received-Date: Wed, 07 Jun 2017 23:44:03 -0000

--f403043eb5184eb8420551674f31
Content-Type: text/plain; charset="UTF-8"

> BIP148 however is a consensus change that can
> be rectified if it gets more work, this would act as an additional
> incentive for mine the BIP148 side since there would be no wipeout
> risk there.

This statement is misleading.  Wipeout risks don't apply to any consensus
changes; It is a consensus change, it can only be abandoned.  The BIP148
chain carries just as many risks of being abandoned or even more with
segwit2x on the table.  No miner would consider "wipeout risk" an advantage
when the real threat is chain abandonment.

> Higher transaction fees on a minority chain can compensate miners for
> a lower price which would likely be enough to get the BIP148 chain to
> a difficulty reduction.

Higher transaction fees suffers the same problem as exchange support does.
Without replay protection, it is very difficult for any average user to
force transactions onto one chain or the other.  Thus, without replay
protection, the UASF chain is unlikely to develop any viable fee market;
Its few miners 99% of the time will simply choose from the highest fees
that were already available to the other chain, which is basically no
advantage at all.

>  ETC replay protection was done after the fork on an as
> needed basis(there are multiple reliable techniques that can be used
> to split UTXO's), the same can happen with BIP148 and it is easier to
> do with Bitcoin than with the ETH/ETC split IMO.

ETC replay protection was added because they were already a hardfork and
without it they would not have had a viable chain.  BIP148 is not supposed
to be a hardfork, and if it added replay protection to remain viable it
would lose the frequently touted "wipeout advantage" as well as the ability
to call itself a softfork.  And are you seriously suggesting that what
happened with ETC and ETH is a desirable and good situation for Bitcoin,
and that UASF is ETC?

> A big reason BIP148 still has support is because up until SegWit
> actually activates there's no guarantee segwit2mb will actually have
> the necessary support to activate SegWit.

For a miners blowing through six million dollars a day in mining
operational costs, that's a pretty crappy reason.  Serious miners can't
afford to prop up a non-viable chain based on philosophy or maybes.  BIP148
is based entirely upon people who aren't putting anything on the line
trying to convince others to take the huge risks for them.  With
deceptively fallacious logic, in my opinion.

Even segwit2x is based on the assumption that all miners can reach
consensus.  Break that assumption and segwit2x will have the same problems
as UASF.

> This is largely an issue due to segwit2x's bundling, if the SW and HF
> part of segwit2x were unbundled then there would be no reason to delay
> BIP91 activation

They are bundled.  Segwit alone doesn't have the desired overwhelming
consensus, unless core wishes to fork 71% to 29%, and maybe not even that
high.  That's the technical reason, and they can't be unbundled without
breaking that consensus.

Jared


On Wed, Jun 7, 2017 at 4:11 PM, James Hilliard <james.hilliard1@gmail.com>
wrote:

> On Wed, Jun 7, 2017 at 5:53 PM, Jared Lee Richardson <jaredr26@gmail.com>
> wrote:
> >> There are 2 primary factors involved here, economic support and
> > hashpower either of which is enough to make a permanent chain split
> > unlikely, miners will mine whichever chain is most profitable(see
> > ETH/ETC hashpower profitability equilibrium for an example of how this
> > works in practice)
> >
> > That's not a comparable example.  ETC did not face potentially years of
> slow
> > blocktimes before it normalized, whereas BIP148 is on track to do exactly
> > that.  Moreover, ETC represented a fundamental break from the majority
> > consensus that could not be rectified, whereas BIP148 represents only a
> > minority attempt to accelerate something that an overwhelming majority of
> > miners have already agreed to activate under segwit2x.  Lastly ETC was
> > required to add replay protection, just like any minority fork proposed
> by
> > any crypto-currency has been, something that BIP148 both lacks and
> refuses
> > to add or even acknowledge the necessity of.  Without replay protection,
> ETC
> > could not have become profitable enough to be a viable minority chain.
> If
> > BIP148's chain is not the majority chain and it does not have replay
> > protection, it will face the same problems, but that required replay
> > protection will turn it into a hardfork.  This will be a very bad
> position
> > for UASF supporters to find themselves in - Either hardfork and hope the
> > price is higher and the majority converts, or die as the minority chain
> with
> > no reliable methods of economic conversion.
> Higher transaction fees on a minority chain can compensate miners for
> a lower price which would likely be enough to get the BIP148 chain to
> a difficulty reduction. BIP148 however is a consensus change that can
> be rectified if it gets more work, this would act as an additional
> incentive for mine the BIP148 side since there would be no wipeout
> risk there. ETC replay protection was done after the fork on an as
> needed basis(there are multiple reliable techniques that can be used
> to split UTXO's), the same can happen with BIP148 and it is easier to
> do with Bitcoin than with the ETH/ETC split IMO.
> >
> > I believe, but don't have data to back this, that most of the BIP148
> > insistence comes not from a legitimate attempt to gain consensus (or else
> > they would either outright oppose segwit2mb for its hardfork, or they
> would
> > outright support it), but rather from an attempt for BIP148 supporters to
> > save face for BIP148 being a failure.  If I'm correct, that's a terrible
> and
> > highly non-technical reason for segwit2mb to bend over backwards
> attempting
> > to support BIP148's attempt to save face.
> A big reason BIP148 still has support is because up until SegWit
> actually activates there's no guarantee segwit2mb will actually have
> the necessary support to activate SegWit.
> >
> >> The main issue is just one of activation timelines, BIP91 as
> > is takes too long to activate unless started ahead of the existing
> > segwit2x schedule and it's unlikely that BIP148 will get pushed back
> > any further.
> >
> > Even if I'm not correct on the above, I and others find it hard to accept
> > that this timeline conflict is segwit2x's fault.  Segwit2x has both some
> > flexibility and broad support that crosses contentious pro-segwit and
> > pro-blocksize-increase divisions that have existed for two years.
> BIP148 is
> > attempting to hold segwit2x's timelines and code hostage by claiming
> > inflexibility and claiming broad support, and not only are neither of
> those
> > assertions are backed by real data, BIP148 (by being so inflexible) is
> > pushing a position that deepens the divides between those groups.  For
> there
> > to be technical reasons for compatibility (so long as there are
> tradeoffs,
> > which there are), there needs to be hard data showing that BIP148 is a
> > viable minority fork that won't simply die off on its own.
> This is largely an issue due to segwit2x's bundling, if the SW and HF
> part of segwit2x were unbundled then there would be no reason to delay
> BIP91 activation, this is especially a problem since it takes a good
> deal of time to properly code and test a HF. Unfortunately segwit2x
> has been quite inflexible in regards to the bundling aspect even
> though there are clearly no technical reasons for it to be there.
> >
> > Jared
> >
> >
> > On Wed, Jun 7, 2017 at 3:23 PM, James Hilliard <
> james.hilliard1@gmail.com>
> > wrote:
> >>
> >> On Wed, Jun 7, 2017 at 4:50 PM, Jared Lee Richardson <
> jaredr26@gmail.com>
> >> wrote:
> >> > Could this risk mitigation measure be an optional flag?  And if so,
> >> > could it+BIP91 signal on a different bit than bit4?
> >> It's fairly trivial for miners to signal for BIP91 on bit4 or a
> >> different bit at the same time as the code is trivial enough to
> >> combine
> >> >
> >> > The reason being, if for some reason the segwit2x activation cannot
> >> > take place in time, it would be preferable for miners to have a more
> >> > standard approach to activation that requires stronger consensus and
> >> > may be more forgiving than BIP148.  If the segwit2x activation is on
> >> > time to cooperate with BIP148, it could be signaled through the
> >> > non-bit4 approach and everything could go smoothly.  Thoughts on that
> >> > idea?  It may add more complexity and more developer time, but may
> >> > also address your concerns among others.
> >> This does give miners another approach to activate segwit ahead of
> >> BIP148, if segwit2x activation is rolled out and activated immediately
> >> then this would not be needed however based on the timeline here
> >> https://segwit2x.github.io/ it would not be possible for BIP91 to
> >> enforce mandatory signalling ahead of BIP148. Maybe that can be
> >> changed though, I've suggested an immediate rollout with a placeholder
> >> client timeout instead of the HF code initially in order to accelerate
> >> that.
> >> >
> >> >> Since this BIP
> >> >> only activates with a clear miner majority it should not increase the
> >> >> risk of an extended chain split.
> >> >
> >> > The concern I'm raising is more about the psychology of giving BIP148
> >> > a sense of safety that may not be valid.  Without several more steps,
> >> > BIP148 is definitely on track to be a risky chainsplit, and without
> >> > segwit2x it will almost certainly be a small minority chain. (Unless
> >> > the segwit2x compromise falls apart before then, and even in that case
> >> > it is likely to be a minority chain)
> >> There are 2 primary factors involved here, economic support and
> >> hashpower either of which is enough to make a permanent chain split
> >> unlikely, miners will mine whichever chain is most profitable(see
> >> ETH/ETC hashpower profitability equilibrium for an example of how this
> >> works in practice) however there may be lag time immediately after the
> >> split if there is an economic majority but not a hashpower majority
> >> initially. This is risk mitigation that only requires miners support
> >> however. The main issue is just one of activation timelines, BIP91 as
> >> is takes too long to activate unless started ahead of the existing
> >> segwit2x schedule and it's unlikely that BIP148 will get pushed back
> >> any further.
> >> >
> >> > Jared
> >> >
> >> >
> >> > On Wed, Jun 7, 2017 at 2:42 PM, James Hilliard
> >> > <james.hilliard1@gmail.com> wrote:
> >> >> I don't really see how this would increase the likelihood of an
> >> >> extended chain split assuming BIP148 is going to have
> >> >> non-insignificant economic backing. This BIP is designed to provide a
> >> >> risk mitigation measure that miners can safely deploy. Since this BIP
> >> >> only activates with a clear miner majority it should not increase the
> >> >> risk of an extended chain split. At this point it is not completely
> >> >> clear how much economic support there is for BIP148 but support
> >> >> certainly seems to be growing and we have nearly 2 months until
> BIP148
> >> >> activation. I intentionally used a shorter activation period here so
> >> >> that decisions by miners can be made close to the BIP148 activation
> >> >> date.
> >> >>
> >> >> On Wed, Jun 7, 2017 at 4:29 PM, Jared Lee Richardson
> >> >> <jaredr26@gmail.com> wrote:
> >> >>> I think this BIP represents a gamble, and the gamble may not be a
> good
> >> >>> one.  The gamble here is that if the segwit2x changes are rolled out
> >> >>> on time, and if the signatories accept the bit4 + bit1 signaling
> >> >>> proposals within BIP91, the launch will go smoother, as intended.
> But
> >> >>> conversely, if either the segwit2x signatories balk about the Bit1
> >> >>> signaling OR if the timelines for segwit2mb are missed even by a
> bit,
> >> >>> it may cause the BIP148 chainsplit to be worse than it would be
> >> >>> without.  Given the frequent concerns raised in multiple places
> about
> >> >>> the aggressiveness of the segwit2x timelines, including the
> >> >>> non-hardfork timelines, this does not seem like a great gamble to be
> >> >>> making.
> >> >>>
> >> >>> The reason I say it may make the chainsplit be worse than it would
> >> >>> otherwise be is that it may provide a false sense of safety for
> BIP148
> >> >>> that currently does not currently exist(and should not, as it is a
> >> >>> chainsplit).  That sense of safety would only be legitimate if the
> >> >>> segwit2x signatories were on board, and the segwit2x code
> effectively
> >> >>> enforced BIP148 simultaneously, neither of which are guaranteed.  If
> >> >>> users and more miners had a false sense that BIP148 was *not* going
> to
> >> >>> chainsplit from default / segwit2x, they might not follow the news
> if
> >> >>> suddenly the segwit2x plan were delayed for a few days.  While any
> >> >>> additional support would definitely be cheered on by BIP148
> >> >>> supporters, the practical reality might be that this proposal would
> >> >>> take BIP148 from the "unlikely to have any viable chain after flag
> day
> >> >>> without segwit2x" category into the "small but viable minority
> chain"
> >> >>> category, and even worse, it might strengthen the chainsplit just
> days
> >> >>> before segwit is activated on BOTH chains, putting the BIP148
> >> >>> supporters on the wrong pro-segwit, but still-viable chain.
> >> >>>
> >> >>> If Core had taken a strong stance to include BIP148 into the client,
> >> >>> and if BIP148 support were much much broader, I would feel
> differently
> >> >>> as the gamble would be more likely to discourage a chainsplit (By
> >> >>> forcing the acceleration of segwit2x) rather than encourage it (by
> >> >>> strengthening an extreme minority chainsplit that may wind up on the
> >> >>> wrong side of two segwit-activated chains).  As it stands now, this
> >> >>> seems like a very dangerous attempt to compromise with a small but
> >> >>> vocal group that are the ones creating the threat to begin with.
> >> >>>
> >> >>> Jared
> >> >>>
> >> >>> On Tue, Jun 6, 2017 at 5:56 PM, James Hilliard via bitcoin-dev
> >> >>> <bitcoin-dev@lists.linuxfoundation.org> wrote:
> >> >>>> Due to the proposed calendar(https://segwit2x.github.io/) for the
> >> >>>> SegWit2x agreement being too slow to activate SegWit mandatory
> >> >>>> signalling ahead of BIP148 using BIP91 I would like to propose
> >> >>>> another
> >> >>>> option that miners can use to prevent a chain split ahead of the
> Aug
> >> >>>> 1st BIP148 activation date.
> >> >>>>
> >> >>>> The splitprotection soft fork is essentially BIP91 but using BIP8
> >> >>>> instead of BIP9 with a lower activation threshold and immediate
> >> >>>> mandatory signalling lock-in. This allows for a majority of miners
> to
> >> >>>> activate mandatory SegWit signalling and prevent a potential chain
> >> >>>> split ahead of BIP148 activation.
> >> >>>>
> >> >>>> This BIP allows for miners to respond to market forces quickly
> ahead
> >> >>>> of BIP148 activation by signalling for splitprotection. Any miners
> >> >>>> already running BIP148 should be encouraged to use splitprotection.
> >> >>>>
> >> >>>> <pre>
> >> >>>>   BIP: splitprotection
> >> >>>>   Layer: Consensus (soft fork)
> >> >>>>   Title: User Activated Soft Fork Split Protection
> >> >>>>   Author: James Hilliard <james.hilliard1@gmail.com>
> >> >>>>   Comments-Summary: No comments yet.
> >> >>>>   Comments-URI:
> >> >>>>   Status: Draft
> >> >>>>   Type: Standards Track
> >> >>>>   Created: 2017-05-22
> >> >>>>   License: BSD-3-Clause
> >> >>>>            CC0-1.0
> >> >>>> </pre>
> >> >>>>
> >> >>>> ==Abstract==
> >> >>>>
> >> >>>> This document specifies a coordination mechanism for a simple
> >> >>>> majority
> >> >>>> of miners to prevent a chain split ahead of BIP148 activation.
> >> >>>>
> >> >>>> ==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==
> >> >>>>
> >> >>>> The biggest risk of BIP148 is an extended chain split, this BIP
> >> >>>> provides a way for a simple majority of miners to eliminate that
> >> >>>> risk.
> >> >>>>
> >> >>>> This BIP provides a way for a simple majority of miners to
> coordinate
> >> >>>> activation of the existing segwit deployment with less than 95%
> >> >>>> hashpower before BIP148 activation. Due to time constraints unless
> >> >>>> immediately deployed BIP91 will likely not be able to enforce
> >> >>>> mandatory signalling of segwit before the Aug 1st activation of
> >> >>>> BIP148. This BIP provides a method for rapid miner activation of
> >> >>>> SegWit mandatory signalling ahead of the BIP148 activation date.
> >> >>>> Since
> >> >>>> the primary goal of this BIP is to reduce the chance of an extended
> >> >>>> chain split as much as possible we activate using a simple miner
> >> >>>> majority of 65% over a 504 block interval rather than a higher
> >> >>>> percentage. This BIP also allows miners to signal their intention
> to
> >> >>>> run BIP148 in order to prevent a chain split.
> >> >>>>
> >> >>>> ==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 "version bits" with a 65%(this can be
> >> >>>> adjusted if desired) activation threshold BIP9 with the name
> >> >>>> "splitprotecion" and using bit 2.
> >> >>>>
> >> >>>> This BIP starts immediately and is a BIP8 style soft fork since
> >> >>>> mandatory signalling will start on midnight August 1st 2017 (epoch
> >> >>>> time 1501545600) regardless of whether or not this BIP has reached
> >> >>>> its
> >> >>>> own signalling threshold. 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);
> >> >>>> }
> >> >>>>
> >> >>>> // SPLITPROTECTION mandatory segwit signalling.
> >> >>>> if ( VersionBitsState(pindex->pprev, chainparams.GetConsensus(),
> >> >>>> Consensus::DEPLOYMENT_SPLITPROTECTION, versionbitscache) ==
> >> >>>> THRESHOLD_LOCKED_IN &&
> >> >>>>      !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");
> >> >>>>     }
> >> >>>> }
> >> >>>>
> >> >>>> // BIP148 mandatory segwit signalling.
> >> >>>> int64_t nMedianTimePast = pindex->GetMedianTimePast();
> >> >>>> if ( (nMedianTimePast >= 1501545600) &&  // Tue 01 Aug 2017
> 00:00:00
> >> >>>> UTC
> >> >>>>      (nMedianTimePast <= 1510704000) &&  // Wed 15 Nov 2017
> 00:00:00
> >> >>>> UTC
> >> >>>>      (!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:splitprotection-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. This deployment is also compatible with the
> >> >>>> existing BIP148 deployment. This BIP is compatible with BIP91 only
> if
> >> >>>> BIP91 activates before it and before BIP148. Miners will need to
> >> >>>> upgrade their nodes to support splitprotection otherwise they may
> >> >>>> build on top of an invalid block. While this bip is active users
> >> >>>> should either upgrade to splitprotection 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. We also use a BIP8 style timeout to
> >> >>>> ensure that this BIP is compatible with BIP148 and that BIP148
> >> >>>> compatible mandatory signalling activates regardless of miner
> >> >>>> signalling levels.
> >> >>>>
> >> >>>> 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. As we
> approach
> >> >>>> BIP148 activation it may be desirable for a majority of miners to
> >> >>>> have
> >> >>>> a method that will ensure that there is no chain split.
> >> >>>>
> >> >>>> ==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-0091.mediawiki|BIP91 Reduced threshold Segwit MASF]]
> >> >>>> *[[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@lists.linuxfoundation.org
> >> >>>> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
> >
> >
>

--f403043eb5184eb8420551674f31
Content-Type: text/html; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr">&gt;=C2=A0<span style=3D"font-size:12.8px">BIP148 however =
is a consensus change that can</span><br style=3D"font-size:12.8px"><span s=
tyle=3D"font-size:12.8px">&gt; be rectified if it gets more work, this woul=
d act as an additional</span><br style=3D"font-size:12.8px"><span style=3D"=
font-size:12.8px">&gt; incentive for mine the BIP148 side since there would=
 be no wipeout</span><br style=3D"font-size:12.8px"><span style=3D"font-siz=
e:12.8px">&gt; risk there.=C2=A0<br><br>This statement is misleading.=C2=A0=
 Wipeout risks don&#39;t apply to any consensus changes; It is a consensus =
change, it can only be abandoned.=C2=A0 The BIP148 chain carries just as ma=
ny risks of being abandoned or even more with segwit2x on the table.=C2=A0 =
No miner would consider &quot;wipeout risk&quot; an advantage when the real=
 threat is chain abandonment.<br><br></span><span style=3D"font-size:12.8px=
">&gt;=C2=A0</span><span style=3D"font-size:12.8px">Higher transaction fees=
 on a minority chain can compensate miners for</span><br style=3D"font-size=
:12.8px"><span style=3D"font-size:12.8px">&gt; a lower price which would li=
kely be enough to get the BIP148 chain to</span><br style=3D"font-size:12.8=
px"><span style=3D"font-size:12.8px">&gt; a difficulty reduction.=C2=A0</sp=
an><span style=3D"font-size:12.8px"><br><br>Higher transaction fees suffers=
 the same problem as exchange support does.=C2=A0 Without replay protection=
, it is very difficult for any average user to force transactions onto one =
chain or the other.=C2=A0 Thus, without replay protection, the UASF chain i=
s unlikely to develop any viable fee market; Its few miners 99% of the time=
 will simply choose from the highest fees that were already available to th=
e other chain, which is basically no advantage at all.<br><br>&gt;=C2=A0</s=
pan><span style=3D"font-size:12.8px">=C2=A0ETC replay protection was done a=
fter the fork on an as</span><br style=3D"font-size:12.8px"><span style=3D"=
font-size:12.8px">&gt; needed basis(there are multiple reliable techniques =
that can be used</span><br style=3D"font-size:12.8px"><span style=3D"font-s=
ize:12.8px">&gt; to split UTXO&#39;s), the same can happen with BIP148 and =
it is easier to</span><br style=3D"font-size:12.8px"><span style=3D"font-si=
ze:12.8px">&gt; do with Bitcoin than with the ETH/ETC split IMO.</span><spa=
n style=3D"font-size:12.8px"><br><br>ETC replay protection was added becaus=
e they were already a hardfork and without it they would not have had a via=
ble chain.=C2=A0 BIP148 is not supposed to be a hardfork, and if it added r=
eplay protection to remain viable it would lose the frequently touted &quot=
;wipeout advantage&quot; as well as the ability to call itself a softfork.=
=C2=A0 And are you seriously suggesting that what happened with ETC and ETH=
 is a desirable and good situation for Bitcoin, and that UASF is ETC?<br><b=
r>&gt;=C2=A0</span><span style=3D"font-size:12.8px">A big reason BIP148 sti=
ll has support is because up until SegWit</span><br style=3D"font-size:12.8=
px"><span style=3D"font-size:12.8px">&gt; actually activates there&#39;s no=
 guarantee segwit2mb will actually have</span><br style=3D"font-size:12.8px=
"><span style=3D"font-size:12.8px">&gt; the necessary support to activate S=
egWit.<br></span><span style=3D"font-size:12.8px"><br>For a miners blowing =
through six million dollars a day in mining operational costs, that&#39;s a=
 pretty crappy reason.=C2=A0 Serious miners can&#39;t afford to prop up a n=
on-viable chain based on philosophy or maybes.=C2=A0 BIP148 is based entire=
ly upon people who aren&#39;t putting anything on the line trying to convin=
ce others to take the huge risks for them.=C2=A0 With deceptively fallaciou=
s logic, in my opinion.<br><br>Even segwit2x is based on the assumption tha=
t all miners can reach consensus.=C2=A0 Break that assumption and segwit2x =
will have the same problems as UASF.<br><br>&gt;=C2=A0</span><span style=3D=
"font-size:12.8px">This is largely an issue due to segwit2x&#39;s bundling,=
 if the SW and HF</span><br style=3D"font-size:12.8px"><span style=3D"font-=
size:12.8px">&gt; part of segwit2x were unbundled then there would be no re=
ason to delay</span><br style=3D"font-size:12.8px"><span style=3D"font-size=
:12.8px">&gt; BIP91 activation<br></span><span style=3D"font-size:12.8px"><=
br>They are bundled.=C2=A0 Segwit alone doesn&#39;t have the desired overwh=
elming consensus, unless core wishes to fork 71% to 29%, and maybe not even=
 that high.=C2=A0 That&#39;s the technical reason, and they can&#39;t be un=
bundled without breaking that consensus.</span><div><span style=3D"font-siz=
e:12.8px"><br></span></div><div><span style=3D"font-size:12.8px">Jared<br><=
br></span></div></div><div class=3D"gmail_extra"><br><div class=3D"gmail_qu=
ote">On Wed, Jun 7, 2017 at 4:11 PM, James Hilliard <span dir=3D"ltr">&lt;<=
a href=3D"mailto:james.hilliard1@gmail.com" target=3D"_blank">james.hilliar=
d1@gmail.com</a>&gt;</span> wrote:<br><blockquote class=3D"gmail_quote" sty=
le=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span =
class=3D"">On Wed, Jun 7, 2017 at 5:53 PM, Jared Lee Richardson &lt;<a href=
=3D"mailto:jaredr26@gmail.com">jaredr26@gmail.com</a>&gt; wrote:<br>
&gt;&gt; There are 2 primary factors involved here, economic support and<br=
>
&gt; hashpower either of which is enough to make a permanent chain split<br=
>
&gt; unlikely, miners will mine whichever chain is most profitable(see<br>
&gt; ETH/ETC hashpower profitability equilibrium for an example of how this=
<br>
&gt; works in practice)<br>
&gt;<br>
&gt; That&#39;s not a comparable example.=C2=A0 ETC did not face potentiall=
y years of slow<br>
&gt; blocktimes before it normalized, whereas BIP148 is on track to do exac=
tly<br>
&gt; that.=C2=A0 Moreover, ETC represented a fundamental break from the maj=
ority<br>
&gt; consensus that could not be rectified, whereas BIP148 represents only =
a<br>
&gt; minority attempt to accelerate something that an overwhelming majority=
 of<br>
&gt; miners have already agreed to activate under segwit2x.=C2=A0 Lastly ET=
C was<br>
&gt; required to add replay protection, just like any minority fork propose=
d by<br>
&gt; any crypto-currency has been, something that BIP148 both lacks and ref=
uses<br>
&gt; to add or even acknowledge the necessity of.=C2=A0 Without replay prot=
ection, ETC<br>
&gt; could not have become profitable enough to be a viable minority chain.=
=C2=A0 If<br>
&gt; BIP148&#39;s chain is not the majority chain and it does not have repl=
ay<br>
&gt; protection, it will face the same problems, but that required replay<b=
r>
&gt; protection will turn it into a hardfork.=C2=A0 This will be a very bad=
 position<br>
&gt; for UASF supporters to find themselves in - Either hardfork and hope t=
he<br>
&gt; price is higher and the majority converts, or die as the minority chai=
n with<br>
&gt; no reliable methods of economic conversion.<br>
</span>Higher transaction fees on a minority chain can compensate miners fo=
r<br>
a lower price which would likely be enough to get the BIP148 chain to<br>
a difficulty reduction. BIP148 however is a consensus change that can<br>
be rectified if it gets more work, this would act as an additional<br>
incentive for mine the BIP148 side since there would be no wipeout<br>
risk there. ETC replay protection was done after the fork on an as<br>
needed basis(there are multiple reliable techniques that can be used<br>
to split UTXO&#39;s), the same can happen with BIP148 and it is easier to<b=
r>
do with Bitcoin than with the ETH/ETC split IMO.<br>
<span class=3D"">&gt;<br>
&gt; I believe, but don&#39;t have data to back this, that most of the BIP1=
48<br>
&gt; insistence comes not from a legitimate attempt to gain consensus (or e=
lse<br>
&gt; they would either outright oppose segwit2mb for its hardfork, or they =
would<br>
&gt; outright support it), but rather from an attempt for BIP148 supporters=
 to<br>
&gt; save face for BIP148 being a failure.=C2=A0 If I&#39;m correct, that&#=
39;s a terrible and<br>
&gt; highly non-technical reason for segwit2mb to bend over backwards attem=
pting<br>
&gt; to support BIP148&#39;s attempt to save face.<br>
</span>A big reason BIP148 still has support is because up until SegWit<br>
actually activates there&#39;s no guarantee segwit2mb will actually have<br=
>
the necessary support to activate SegWit.<br>
<span class=3D"">&gt;<br>
&gt;&gt; The main issue is just one of activation timelines, BIP91 as<br>
&gt; is takes too long to activate unless started ahead of the existing<br>
&gt; segwit2x schedule and it&#39;s unlikely that BIP148 will get pushed ba=
ck<br>
&gt; any further.<br>
&gt;<br>
&gt; Even if I&#39;m not correct on the above, I and others find it hard to=
 accept<br>
&gt; that this timeline conflict is segwit2x&#39;s fault.=C2=A0 Segwit2x ha=
s both some<br>
&gt; flexibility and broad support that crosses contentious pro-segwit and<=
br>
&gt; pro-blocksize-increase divisions that have existed for two years.=C2=
=A0 BIP148 is<br>
&gt; attempting to hold segwit2x&#39;s timelines and code hostage by claimi=
ng<br>
&gt; inflexibility and claiming broad support, and not only are neither of =
those<br>
&gt; assertions are backed by real data, BIP148 (by being so inflexible) is=
<br>
&gt; pushing a position that deepens the divides between those groups.=C2=
=A0 For there<br>
&gt; to be technical reasons for compatibility (so long as there are tradeo=
ffs,<br>
&gt; which there are), there needs to be hard data showing that BIP148 is a=
<br>
&gt; viable minority fork that won&#39;t simply die off on its own.<br>
</span>This is largely an issue due to segwit2x&#39;s bundling, if the SW a=
nd HF<br>
part of segwit2x were unbundled then there would be no reason to delay<br>
BIP91 activation, this is especially a problem since it takes a good<br>
deal of time to properly code and test a HF. Unfortunately segwit2x<br>
has been quite inflexible in regards to the bundling aspect even<br>
though there are clearly no technical reasons for it to be there.<br>
<div class=3D"HOEnZb"><div class=3D"h5">&gt;<br>
&gt; Jared<br>
&gt;<br>
&gt;<br>
&gt; On Wed, Jun 7, 2017 at 3:23 PM, James Hilliard &lt;<a href=3D"mailto:j=
ames.hilliard1@gmail.com">james.hilliard1@gmail.com</a>&gt;<br>
&gt; wrote:<br>
&gt;&gt;<br>
&gt;&gt; On Wed, Jun 7, 2017 at 4:50 PM, Jared Lee Richardson &lt;<a href=
=3D"mailto:jaredr26@gmail.com">jaredr26@gmail.com</a>&gt;<br>
&gt;&gt; wrote:<br>
&gt;&gt; &gt; Could this risk mitigation measure be an optional flag?=C2=A0=
 And if so,<br>
&gt;&gt; &gt; could it+BIP91 signal on a different bit than bit4?<br>
&gt;&gt; It&#39;s fairly trivial for miners to signal for BIP91 on bit4 or =
a<br>
&gt;&gt; different bit at the same time as the code is trivial enough to<br=
>
&gt;&gt; combine<br>
&gt;&gt; &gt;<br>
&gt;&gt; &gt; The reason being, if for some reason the segwit2x activation =
cannot<br>
&gt;&gt; &gt; take place in time, it would be preferable for miners to have=
 a more<br>
&gt;&gt; &gt; standard approach to activation that requires stronger consen=
sus and<br>
&gt;&gt; &gt; may be more forgiving than BIP148.=C2=A0 If the segwit2x acti=
vation is on<br>
&gt;&gt; &gt; time to cooperate with BIP148, it could be signaled through t=
he<br>
&gt;&gt; &gt; non-bit4 approach and everything could go smoothly.=C2=A0 Tho=
ughts on that<br>
&gt;&gt; &gt; idea?=C2=A0 It may add more complexity and more developer tim=
e, but may<br>
&gt;&gt; &gt; also address your concerns among others.<br>
&gt;&gt; This does give miners another approach to activate segwit ahead of=
<br>
&gt;&gt; BIP148, if segwit2x activation is rolled out and activated immedia=
tely<br>
&gt;&gt; then this would not be needed however based on the timeline here<b=
r>
&gt;&gt; <a href=3D"https://segwit2x.github.io/" rel=3D"noreferrer" target=
=3D"_blank">https://segwit2x.github.io/</a> it would not be possible for BI=
P91 to<br>
&gt;&gt; enforce mandatory signalling ahead of BIP148. Maybe that can be<br=
>
&gt;&gt; changed though, I&#39;ve suggested an immediate rollout with a pla=
ceholder<br>
&gt;&gt; client timeout instead of the HF code initially in order to accele=
rate<br>
&gt;&gt; that.<br>
&gt;&gt; &gt;<br>
&gt;&gt; &gt;&gt; Since this BIP<br>
&gt;&gt; &gt;&gt; only activates with a clear miner majority it should not =
increase the<br>
&gt;&gt; &gt;&gt; risk of an extended chain split.<br>
&gt;&gt; &gt;<br>
&gt;&gt; &gt; The concern I&#39;m raising is more about the psychology of g=
iving BIP148<br>
&gt;&gt; &gt; a sense of safety that may not be valid.=C2=A0 Without severa=
l more steps,<br>
&gt;&gt; &gt; BIP148 is definitely on track to be a risky chainsplit, and w=
ithout<br>
&gt;&gt; &gt; segwit2x it will almost certainly be a small minority chain. =
(Unless<br>
&gt;&gt; &gt; the segwit2x compromise falls apart before then, and even in =
that case<br>
&gt;&gt; &gt; it is likely to be a minority chain)<br>
&gt;&gt; There are 2 primary factors involved here, economic support and<br=
>
&gt;&gt; hashpower either of which is enough to make a permanent chain spli=
t<br>
&gt;&gt; unlikely, miners will mine whichever chain is most profitable(see<=
br>
&gt;&gt; ETH/ETC hashpower profitability equilibrium for an example of how =
this<br>
&gt;&gt; works in practice) however there may be lag time immediately after=
 the<br>
&gt;&gt; split if there is an economic majority but not a hashpower majorit=
y<br>
&gt;&gt; initially. This is risk mitigation that only requires miners suppo=
rt<br>
&gt;&gt; however. The main issue is just one of activation timelines, BIP91=
 as<br>
&gt;&gt; is takes too long to activate unless started ahead of the existing=
<br>
&gt;&gt; segwit2x schedule and it&#39;s unlikely that BIP148 will get pushe=
d back<br>
&gt;&gt; any further.<br>
&gt;&gt; &gt;<br>
&gt;&gt; &gt; Jared<br>
&gt;&gt; &gt;<br>
&gt;&gt; &gt;<br>
&gt;&gt; &gt; On Wed, Jun 7, 2017 at 2:42 PM, James Hilliard<br>
&gt;&gt; &gt; &lt;<a href=3D"mailto:james.hilliard1@gmail.com">james.hillia=
rd1@gmail.com</a>&gt; wrote:<br>
&gt;&gt; &gt;&gt; I don&#39;t really see how this would increase the likeli=
hood of an<br>
&gt;&gt; &gt;&gt; extended chain split assuming BIP148 is going to have<br>
&gt;&gt; &gt;&gt; non-insignificant economic backing. This BIP is designed =
to provide a<br>
&gt;&gt; &gt;&gt; risk mitigation measure that miners can safely deploy. Si=
nce this BIP<br>
&gt;&gt; &gt;&gt; only activates with a clear miner majority it should not =
increase the<br>
&gt;&gt; &gt;&gt; risk of an extended chain split. At this point it is not =
completely<br>
&gt;&gt; &gt;&gt; clear how much economic support there is for BIP148 but s=
upport<br>
&gt;&gt; &gt;&gt; certainly seems to be growing and we have nearly 2 months=
 until BIP148<br>
&gt;&gt; &gt;&gt; activation. I intentionally used a shorter activation per=
iod here so<br>
&gt;&gt; &gt;&gt; that decisions by miners can be made close to the BIP148 =
activation<br>
&gt;&gt; &gt;&gt; date.<br>
&gt;&gt; &gt;&gt;<br>
&gt;&gt; &gt;&gt; On Wed, Jun 7, 2017 at 4:29 PM, Jared Lee Richardson<br>
&gt;&gt; &gt;&gt; &lt;<a href=3D"mailto:jaredr26@gmail.com">jaredr26@gmail.=
com</a>&gt; wrote:<br>
&gt;&gt; &gt;&gt;&gt; I think this BIP represents a gamble, and the gamble =
may not be a good<br>
&gt;&gt; &gt;&gt;&gt; one.=C2=A0 The gamble here is that if the segwit2x ch=
anges are rolled out<br>
&gt;&gt; &gt;&gt;&gt; on time, and if the signatories accept the bit4 + bit=
1 signaling<br>
&gt;&gt; &gt;&gt;&gt; proposals within BIP91, the launch will go smoother, =
as intended.=C2=A0 But<br>
&gt;&gt; &gt;&gt;&gt; conversely, if either the segwit2x signatories balk a=
bout the Bit1<br>
&gt;&gt; &gt;&gt;&gt; signaling OR if the timelines for segwit2mb are misse=
d even by a bit,<br>
&gt;&gt; &gt;&gt;&gt; it may cause the BIP148 chainsplit to be worse than i=
t would be<br>
&gt;&gt; &gt;&gt;&gt; without.=C2=A0 Given the frequent concerns raised in =
multiple places about<br>
&gt;&gt; &gt;&gt;&gt; the aggressiveness of the segwit2x timelines, includi=
ng the<br>
&gt;&gt; &gt;&gt;&gt; non-hardfork timelines, this does not seem like a gre=
at gamble to be<br>
&gt;&gt; &gt;&gt;&gt; making.<br>
&gt;&gt; &gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt; The reason I say it may make the chainsplit be worse =
than it would<br>
&gt;&gt; &gt;&gt;&gt; otherwise be is that it may provide a false sense of =
safety for BIP148<br>
&gt;&gt; &gt;&gt;&gt; that currently does not currently exist(and should no=
t, as it is a<br>
&gt;&gt; &gt;&gt;&gt; chainsplit).=C2=A0 That sense of safety would only be=
 legitimate if the<br>
&gt;&gt; &gt;&gt;&gt; segwit2x signatories were on board, and the segwit2x =
code effectively<br>
&gt;&gt; &gt;&gt;&gt; enforced BIP148 simultaneously, neither of which are =
guaranteed.=C2=A0 If<br>
&gt;&gt; &gt;&gt;&gt; users and more miners had a false sense that BIP148 w=
as *not* going to<br>
&gt;&gt; &gt;&gt;&gt; chainsplit from default / segwit2x, they might not fo=
llow the news if<br>
&gt;&gt; &gt;&gt;&gt; suddenly the segwit2x plan were delayed for a few day=
s.=C2=A0 While any<br>
&gt;&gt; &gt;&gt;&gt; additional support would definitely be cheered on by =
BIP148<br>
&gt;&gt; &gt;&gt;&gt; supporters, the practical reality might be that this =
proposal would<br>
&gt;&gt; &gt;&gt;&gt; take BIP148 from the &quot;unlikely to have any viabl=
e chain after flag day<br>
&gt;&gt; &gt;&gt;&gt; without segwit2x&quot; category into the &quot;small =
but viable minority chain&quot;<br>
&gt;&gt; &gt;&gt;&gt; category, and even worse, it might strengthen the cha=
insplit just days<br>
&gt;&gt; &gt;&gt;&gt; before segwit is activated on BOTH chains, putting th=
e BIP148<br>
&gt;&gt; &gt;&gt;&gt; supporters on the wrong pro-segwit, but still-viable =
chain.<br>
&gt;&gt; &gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt; If Core had taken a strong stance to include BIP148 i=
nto the client,<br>
&gt;&gt; &gt;&gt;&gt; and if BIP148 support were much much broader, I would=
 feel differently<br>
&gt;&gt; &gt;&gt;&gt; as the gamble would be more likely to discourage a ch=
ainsplit (By<br>
&gt;&gt; &gt;&gt;&gt; forcing the acceleration of segwit2x) rather than enc=
ourage it (by<br>
&gt;&gt; &gt;&gt;&gt; strengthening an extreme minority chainsplit that may=
 wind up on the<br>
&gt;&gt; &gt;&gt;&gt; wrong side of two segwit-activated chains).=C2=A0 As =
it stands now, this<br>
&gt;&gt; &gt;&gt;&gt; seems like a very dangerous attempt to compromise wit=
h a small but<br>
&gt;&gt; &gt;&gt;&gt; vocal group that are the ones creating the threat to =
begin with.<br>
&gt;&gt; &gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt; Jared<br>
&gt;&gt; &gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt; On Tue, Jun 6, 2017 at 5:56 PM, James Hilliard via bi=
tcoin-dev<br>
&gt;&gt; &gt;&gt;&gt; &lt;<a href=3D"mailto:bitcoin-dev@lists.linuxfoundati=
on.org">bitcoin-dev@lists.<wbr>linuxfoundation.org</a>&gt; wrote:<br>
&gt;&gt; &gt;&gt;&gt;&gt; Due to the proposed calendar(<a href=3D"https://s=
egwit2x.github.io/" rel=3D"noreferrer" target=3D"_blank">https://segwit2x.<=
wbr>github.io/</a>) for the<br>
&gt;&gt; &gt;&gt;&gt;&gt; SegWit2x agreement being too slow to activate Seg=
Wit mandatory<br>
&gt;&gt; &gt;&gt;&gt;&gt; signalling ahead of BIP148 using BIP91 I would li=
ke to propose<br>
&gt;&gt; &gt;&gt;&gt;&gt; another<br>
&gt;&gt; &gt;&gt;&gt;&gt; option that miners can use to prevent a chain spl=
it ahead of the Aug<br>
&gt;&gt; &gt;&gt;&gt;&gt; 1st BIP148 activation date.<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; The splitprotection soft fork is essentially BIP9=
1 but using BIP8<br>
&gt;&gt; &gt;&gt;&gt;&gt; instead of BIP9 with a lower activation threshold=
 and immediate<br>
&gt;&gt; &gt;&gt;&gt;&gt; mandatory signalling lock-in. This allows for a m=
ajority of miners to<br>
&gt;&gt; &gt;&gt;&gt;&gt; activate mandatory SegWit signalling and prevent =
a potential chain<br>
&gt;&gt; &gt;&gt;&gt;&gt; split ahead of BIP148 activation.<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; This BIP allows for miners to respond to market f=
orces quickly ahead<br>
&gt;&gt; &gt;&gt;&gt;&gt; of BIP148 activation by signalling for splitprote=
ction. Any miners<br>
&gt;&gt; &gt;&gt;&gt;&gt; already running BIP148 should be encouraged to us=
e splitprotection.<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; &lt;pre&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0BIP: splitprotection<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0Layer: Consensus (soft fork)<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0Title: User Activated Soft Fork Split=
 Protection<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0Author: James Hilliard &lt;<a href=3D=
"mailto:james.hilliard1@gmail.com">james.hilliard1@gmail.com</a>&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0Comments-Summary: No comments yet.<br=
>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0Comments-URI:<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0Status: Draft<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0Type: Standards Track<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0Created: 2017-05-22<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0License: BSD-3-Clause<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 CC0-1.0<=
br>
&gt;&gt; &gt;&gt;&gt;&gt; &lt;/pre&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; =3D=3DAbstract=3D=3D<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; This document specifies a coordination mechanism =
for a simple<br>
&gt;&gt; &gt;&gt;&gt;&gt; majority<br>
&gt;&gt; &gt;&gt;&gt;&gt; of miners to prevent a chain split ahead of BIP14=
8 activation.<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; =3D=3DDefinitions=3D=3D<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; &quot;existing segwit deployment&quot; refer to t=
he BIP9 &quot;segwit&quot; deployment<br>
&gt;&gt; &gt;&gt;&gt;&gt; using bit 1, between November 15th 2016 and Novem=
ber 15th 2017 to<br>
&gt;&gt; &gt;&gt;&gt;&gt; activate BIP141, BIP143 and BIP147.<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; =3D=3DMotivation=3D=3D<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; The biggest risk of BIP148 is an extended chain s=
plit, this BIP<br>
&gt;&gt; &gt;&gt;&gt;&gt; provides a way for a simple majority of miners to=
 eliminate that<br>
&gt;&gt; &gt;&gt;&gt;&gt; risk.<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; This BIP provides a way for a simple majority of =
miners to coordinate<br>
&gt;&gt; &gt;&gt;&gt;&gt; activation of the existing segwit deployment with=
 less than 95%<br>
&gt;&gt; &gt;&gt;&gt;&gt; hashpower before BIP148 activation. Due to time c=
onstraints unless<br>
&gt;&gt; &gt;&gt;&gt;&gt; immediately deployed BIP91 will likely not be abl=
e to enforce<br>
&gt;&gt; &gt;&gt;&gt;&gt; mandatory signalling of segwit before the Aug 1st=
 activation of<br>
&gt;&gt; &gt;&gt;&gt;&gt; BIP148. This BIP provides a method for rapid mine=
r activation of<br>
&gt;&gt; &gt;&gt;&gt;&gt; SegWit mandatory signalling ahead of the BIP148 a=
ctivation date.<br>
&gt;&gt; &gt;&gt;&gt;&gt; Since<br>
&gt;&gt; &gt;&gt;&gt;&gt; the primary goal of this BIP is to reduce the cha=
nce of an extended<br>
&gt;&gt; &gt;&gt;&gt;&gt; chain split as much as possible we activate using=
 a simple miner<br>
&gt;&gt; &gt;&gt;&gt;&gt; majority of 65% over a 504 block interval rather =
than a higher<br>
&gt;&gt; &gt;&gt;&gt;&gt; percentage. This BIP also allows miners to signal=
 their intention to<br>
&gt;&gt; &gt;&gt;&gt;&gt; run BIP148 in order to prevent a chain split.<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; =3D=3DSpecification=3D=3D<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; While this BIP is active, all blocks must set the=
 nVersion header top<br>
&gt;&gt; &gt;&gt;&gt;&gt; 3 bits to 001 together with bit field (1&lt;&lt;1=
) (according to the<br>
&gt;&gt; &gt;&gt;&gt;&gt; existing segwit deployment). Blocks that do not s=
ignal as required<br>
&gt;&gt; &gt;&gt;&gt;&gt; will be rejected.<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; =3D=3DDeployment=3D=3D<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; This BIP will be deployed by &quot;version bits&q=
uot; with a 65%(this can be<br>
&gt;&gt; &gt;&gt;&gt;&gt; adjusted if desired) activation threshold BIP9 wi=
th the name<br>
&gt;&gt; &gt;&gt;&gt;&gt; &quot;splitprotecion&quot; and using bit 2.<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; This BIP starts immediately and is a BIP8 style s=
oft fork since<br>
&gt;&gt; &gt;&gt;&gt;&gt; mandatory signalling will start on midnight Augus=
t 1st 2017 (epoch<br>
&gt;&gt; &gt;&gt;&gt;&gt; time 1501545600) regardless of whether or not thi=
s BIP has reached<br>
&gt;&gt; &gt;&gt;&gt;&gt; its<br>
&gt;&gt; &gt;&gt;&gt;&gt; own signalling threshold. This BIP will cease to =
be active when<br>
&gt;&gt; &gt;&gt;&gt;&gt; segwit<br>
&gt;&gt; &gt;&gt;&gt;&gt; is locked-in.<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; =3D=3D=3D Reference implementation =3D=3D=3D<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; &lt;pre&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; // Check if Segregated Witness is Locked In<br>
&gt;&gt; &gt;&gt;&gt;&gt; bool IsWitnessLockedIn(const CBlockIndex* pindexP=
rev, const<br>
&gt;&gt; &gt;&gt;&gt;&gt; Consensus::Params&amp; params)<br>
&gt;&gt; &gt;&gt;&gt;&gt; {<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0 =C2=A0LOCK(cs_main);<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0 =C2=A0return (VersionBitsState(pinde=
xPrev, params,<br>
&gt;&gt; &gt;&gt;&gt;&gt; Consensus::DEPLOYMENT_SEGWIT, versionbitscache) =
=3D=3D<br>
&gt;&gt; &gt;&gt;&gt;&gt; THRESHOLD_LOCKED_IN);<br>
&gt;&gt; &gt;&gt;&gt;&gt; }<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; // SPLITPROTECTION mandatory segwit signalling.<b=
r>
&gt;&gt; &gt;&gt;&gt;&gt; if ( VersionBitsState(pindex-&gt;<wbr>pprev, chai=
nparams.GetConsensus(),<br>
&gt;&gt; &gt;&gt;&gt;&gt; Consensus::DEPLOYMENT_<wbr>SPLITPROTECTION, versi=
onbitscache) =3D=3D<br>
&gt;&gt; &gt;&gt;&gt;&gt; THRESHOLD_LOCKED_IN &amp;&amp;<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0 =C2=A0 !IsWitnessLockedIn(pindex-&gt=
;<wbr>pprev, chainparams.GetConsensus()) &amp;&amp;<br>
&gt;&gt; &gt;&gt;&gt;&gt; // Segwit is not locked in<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0 =C2=A0 !IsWitnessEnabled(pindex-&gt;=
<wbr>pprev, chainparams.GetConsensus()) )<br>
&gt;&gt; &gt;&gt;&gt;&gt; //<br>
&gt;&gt; &gt;&gt;&gt;&gt; and is not active.<br>
&gt;&gt; &gt;&gt;&gt;&gt; {<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0 =C2=A0bool fVersionBits =3D (pindex-=
&gt;nVersion &amp; VERSIONBITS_TOP_MASK) =3D=3D<br>
&gt;&gt; &gt;&gt;&gt;&gt; VERSIONBITS_TOP_BITS;<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0 =C2=A0bool fSegbit =3D (pindex-&gt;n=
Version &amp;<br>
&gt;&gt; &gt;&gt;&gt;&gt; VersionBitsMask(chainparams.<wbr>GetConsensus(),<=
br>
&gt;&gt; &gt;&gt;&gt;&gt; Consensus::DEPLOYMENT_SEGWIT)) !=3D 0;<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0 =C2=A0if (!(fVersionBits &amp;&amp; =
fSegbit)) {<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0return state.DoS=
(0, error(&quot;ConnectBlock(): relayed block must<br>
&gt;&gt; &gt;&gt;&gt;&gt; signal for segwit, please upgrade&quot;), REJECT_=
INVALID,<br>
&gt;&gt; &gt;&gt;&gt;&gt; &quot;bad-no-segwit&quot;);<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0 =C2=A0}<br>
&gt;&gt; &gt;&gt;&gt;&gt; }<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; // BIP148 mandatory segwit signalling.<br>
&gt;&gt; &gt;&gt;&gt;&gt; int64_t nMedianTimePast =3D pindex-&gt;GetMedianT=
imePast();<br>
&gt;&gt; &gt;&gt;&gt;&gt; if ( (nMedianTimePast &gt;=3D 1501545600) &amp;&a=
mp;=C2=A0 // Tue 01 Aug 2017 00:00:00<br>
&gt;&gt; &gt;&gt;&gt;&gt; UTC<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0 =C2=A0 (nMedianTimePast &lt;=3D 1510=
704000) &amp;&amp;=C2=A0 // Wed 15 Nov 2017 00:00:00<br>
&gt;&gt; &gt;&gt;&gt;&gt; UTC<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0 =C2=A0 (!IsWitnessLockedIn(pindex-&g=
t;<wbr>pprev, chainparams.GetConsensus())<br>
&gt;&gt; &gt;&gt;&gt;&gt; &amp;&amp;<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 // Segwit is not locked in<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0 =C2=A0 =C2=A0!IsWitnessEnabled(pinde=
x-&gt;<wbr>pprev, chainparams.GetConsensus())) )<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 // and is not active.<br>
&gt;&gt; &gt;&gt;&gt;&gt; {<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0 =C2=A0bool fVersionBits =3D (pindex-=
&gt;nVersion &amp; VERSIONBITS_TOP_MASK) =3D=3D<br>
&gt;&gt; &gt;&gt;&gt;&gt; VERSIONBITS_TOP_BITS;<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0 =C2=A0bool fSegbit =3D (pindex-&gt;n=
Version &amp;<br>
&gt;&gt; &gt;&gt;&gt;&gt; VersionBitsMask(chainparams.<wbr>GetConsensus(),<=
br>
&gt;&gt; &gt;&gt;&gt;&gt; Consensus::DEPLOYMENT_SEGWIT)) !=3D 0;<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0 =C2=A0if (!(fVersionBits &amp;&amp; =
fSegbit)) {<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0return state.DoS=
(0, error(&quot;ConnectBlock(): relayed block must<br>
&gt;&gt; &gt;&gt;&gt;&gt; signal for segwit, please upgrade&quot;), REJECT_=
INVALID,<br>
&gt;&gt; &gt;&gt;&gt;&gt; &quot;bad-no-segwit&quot;);<br>
&gt;&gt; &gt;&gt;&gt;&gt;=C2=A0 =C2=A0 =C2=A0}<br>
&gt;&gt; &gt;&gt;&gt;&gt; }<br>
&gt;&gt; &gt;&gt;&gt;&gt; &lt;/pre&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; <a href=3D"https://github.com/bitcoin/bitcoin/com=
pare/0.14...jameshilliard:splitprotection-v0.14.1" rel=3D"noreferrer" targe=
t=3D"_blank">https://github.com/bitcoin/<wbr>bitcoin/compare/0.14...<wbr>ja=
meshilliard:splitprotection-<wbr>v0.14.1</a><br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; =3D=3DBackwards Compatibility=3D=3D<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; This deployment is compatible with the existing &=
quot;segwit&quot; bit 1<br>
&gt;&gt; &gt;&gt;&gt;&gt; deployment scheduled between midnight November 15=
th, 2016 and<br>
&gt;&gt; &gt;&gt;&gt;&gt; midnight<br>
&gt;&gt; &gt;&gt;&gt;&gt; November 15th, 2017. This deployment is also comp=
atible with the<br>
&gt;&gt; &gt;&gt;&gt;&gt; existing BIP148 deployment. This BIP is compatibl=
e with BIP91 only if<br>
&gt;&gt; &gt;&gt;&gt;&gt; BIP91 activates before it and before BIP148. Mine=
rs will need to<br>
&gt;&gt; &gt;&gt;&gt;&gt; upgrade their nodes to support splitprotection ot=
herwise they may<br>
&gt;&gt; &gt;&gt;&gt;&gt; build on top of an invalid block. While this bip =
is active users<br>
&gt;&gt; &gt;&gt;&gt;&gt; should either upgrade to splitprotection or wait =
for additional<br>
&gt;&gt; &gt;&gt;&gt;&gt; confirmations when accepting payments.<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; =3D=3DRationale=3D=3D<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; Historically we have used IsSuperMajority() to ac=
tivate soft forks<br>
&gt;&gt; &gt;&gt;&gt;&gt; such as BIP66 which has a mandatory signalling re=
quirement for miners<br>
&gt;&gt; &gt;&gt;&gt;&gt; once activated, this ensures that miners are awar=
e of new rules being<br>
&gt;&gt; &gt;&gt;&gt;&gt; enforced. This technique can be leveraged to lowe=
r the signalling<br>
&gt;&gt; &gt;&gt;&gt;&gt; threshold of a soft fork while it is in the proce=
ss of being deployed<br>
&gt;&gt; &gt;&gt;&gt;&gt; in a backwards compatible way. We also use a BIP8=
 style timeout to<br>
&gt;&gt; &gt;&gt;&gt;&gt; ensure that this BIP is compatible with BIP148 an=
d that BIP148<br>
&gt;&gt; &gt;&gt;&gt;&gt; compatible mandatory signalling activates regardl=
ess of miner<br>
&gt;&gt; &gt;&gt;&gt;&gt; signalling levels.<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; By orphaning non-signalling blocks during the BIP=
9 bit 1 &quot;segwit&quot;<br>
&gt;&gt; &gt;&gt;&gt;&gt; deployment, this BIP can cause the existing &quot=
;segwit&quot; deployment to<br>
&gt;&gt; &gt;&gt;&gt;&gt; activate without needing to release a new deploym=
ent. As we approach<br>
&gt;&gt; &gt;&gt;&gt;&gt; BIP148 activation it may be desirable for a major=
ity of miners to<br>
&gt;&gt; &gt;&gt;&gt;&gt; have<br>
&gt;&gt; &gt;&gt;&gt;&gt; a method that will ensure that there is no chain =
split.<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; =3D=3DReferences=3D=3D<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; *[<a href=3D"https://lists.linuxfoundation.org/pi=
permail/bitcoin-dev/2017-March/013714.html" rel=3D"noreferrer" target=3D"_b=
lank">https://lists.<wbr>linuxfoundation.org/pipermail/<wbr>bitcoin-dev/201=
7-March/013714.<wbr>html</a><br>
&gt;&gt; &gt;&gt;&gt;&gt; Mailing list discussion]<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; *[<a href=3D"https://github.com/bitcoin/bitcoin/b=
lob/v0.6.0/src/main.cpp#L1281-L1283" rel=3D"noreferrer" target=3D"_blank">h=
ttps://github.com/bitcoin/<wbr>bitcoin/blob/v0.6.0/src/main.<wbr>cpp#L1281-=
L1283</a><br>
&gt;&gt; &gt;&gt;&gt;&gt; P2SH flag day activation]<br>
&gt;&gt; &gt;&gt;&gt;&gt; *[[bip-0009.mediawiki|BIP9 Version bits with time=
out and delay]]<br>
&gt;&gt; &gt;&gt;&gt;&gt; *[[bip-0016.mediawiki|BIP16 Pay to Script Hash]]<=
br>
&gt;&gt; &gt;&gt;&gt;&gt; *[[bip-0091.mediawiki|BIP91 Reduced threshold Seg=
wit MASF]]<br>
&gt;&gt; &gt;&gt;&gt;&gt; *[[bip-0141.mediawiki|BIP141 Segregated Witness (=
Consensus layer)]]<br>
&gt;&gt; &gt;&gt;&gt;&gt; *[[bip-0143.mediawiki|BIP143 Transaction Signatur=
e Verification for<br>
&gt;&gt; &gt;&gt;&gt;&gt; Version 0 Witness Program]]<br>
&gt;&gt; &gt;&gt;&gt;&gt; *[[bip-0147.mediawiki|BIP147 Dealing with dummy s=
tack element<br>
&gt;&gt; &gt;&gt;&gt;&gt; malleability]]<br>
&gt;&gt; &gt;&gt;&gt;&gt; *[[bip-0148.mediawiki|BIP148 Mandatory activation=
 of segwit<br>
&gt;&gt; &gt;&gt;&gt;&gt; deployment]]<br>
&gt;&gt; &gt;&gt;&gt;&gt; *[[bip-0149.mediawiki|BIP149 Segregated Witness (=
second deployment)]]<br>
&gt;&gt; &gt;&gt;&gt;&gt; *[<a href=3D"https://bitcoincore.org/en/2016/01/2=
6/segwit-benefits/" rel=3D"noreferrer" target=3D"_blank">https://bitcoincor=
e.org/en/<wbr>2016/01/26/segwit-benefits/</a> Segwit<br>
&gt;&gt; &gt;&gt;&gt;&gt; benefits]<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; =3D=3DCopyright=3D=3D<br>
&gt;&gt; &gt;&gt;&gt;&gt;<br>
&gt;&gt; &gt;&gt;&gt;&gt; This document is dual licensed as BSD 3-clause, a=
nd Creative Commons<br>
&gt;&gt; &gt;&gt;&gt;&gt; CC0 1.0 Universal.<br>
&gt;&gt; &gt;&gt;&gt;&gt; ______________________________<wbr>______________=
___<br>
&gt;&gt; &gt;&gt;&gt;&gt; bitcoin-dev mailing list<br>
&gt;&gt; &gt;&gt;&gt;&gt; <a href=3D"mailto:bitcoin-dev@lists.linuxfoundati=
on.org">bitcoin-dev@lists.<wbr>linuxfoundation.org</a><br>
&gt;&gt; &gt;&gt;&gt;&gt; <a href=3D"https://lists.linuxfoundation.org/mail=
man/listinfo/bitcoin-dev" rel=3D"noreferrer" target=3D"_blank">https://list=
s.linuxfoundation.<wbr>org/mailman/listinfo/bitcoin-<wbr>dev</a><br>
&gt;<br>
&gt;<br>
</div></div></blockquote></div><br></div>

--f403043eb5184eb8420551674f31--