summaryrefslogtreecommitdiff
path: root/ac/adbf5b6694619e544fabc87a6f46745308a7e4
blob: 800846adb4f225cbfbc1b34a40e7febbf7b22a41 (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
Return-Path: <sergej@bitrefill.com>
Received: from smtp1.osuosl.org (smtp1.osuosl.org [IPv6:2605:bc80:3010::138])
 by lists.linuxfoundation.org (Postfix) with ESMTP id 07280C002D
 for <bitcoin-dev@lists.linuxfoundation.org>;
 Fri, 21 Oct 2022 14:19:49 +0000 (UTC)
Received: from localhost (localhost [127.0.0.1])
 by smtp1.osuosl.org (Postfix) with ESMTP id D6257842B9
 for <bitcoin-dev@lists.linuxfoundation.org>;
 Fri, 21 Oct 2022 14:19:48 +0000 (UTC)
DKIM-Filter: OpenDKIM Filter v2.11.0 smtp1.osuosl.org D6257842B9
Authentication-Results: smtp1.osuosl.org;
 dkim=pass (2048-bit key) header.d=bitrefill.com header.i=@bitrefill.com
 header.a=rsa-sha256 header.s=b header.b=PJ/RLW3m
X-Virus-Scanned: amavisd-new at osuosl.org
X-Spam-Flag: NO
X-Spam-Score: -2.089
X-Spam-Level: 
X-Spam-Status: No, score=-2.089 tagged_above=-999 required=5
 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1,
 DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, HTML_MESSAGE=0.001,
 RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001,
 T_KAM_HTML_FONT_INVALID=0.01] autolearn=ham autolearn_force=no
Received: from smtp1.osuosl.org ([127.0.0.1])
 by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024)
 with ESMTP id f6HOHkIu0E0W
 for <bitcoin-dev@lists.linuxfoundation.org>;
 Fri, 21 Oct 2022 14:19:46 +0000 (UTC)
X-Greylist: whitelisted by SQLgrey-1.8.0
DKIM-Filter: OpenDKIM Filter v2.11.0 smtp1.osuosl.org 1E2B783F8C
Received: from mail-lj1-x231.google.com (mail-lj1-x231.google.com
 [IPv6:2a00:1450:4864:20::231])
 by smtp1.osuosl.org (Postfix) with ESMTPS id 1E2B783F8C
 for <bitcoin-dev@lists.linuxfoundation.org>;
 Fri, 21 Oct 2022 14:19:46 +0000 (UTC)
Received: by mail-lj1-x231.google.com with SMTP id r22so3850448ljn.10
 for <bitcoin-dev@lists.linuxfoundation.org>;
 Fri, 21 Oct 2022 07:19:45 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bitrefill.com; s=b;
 h=cc:to:subject:message-id:date:from:in-reply-to:references
 :mime-version:from:to:cc:subject:date:message-id:reply-to;
 bh=osjOuJvBwnoh6sQDc1NAmGHY8WiYdXfSehaojPVyTMc=;
 b=PJ/RLW3msYm7C21ZHKCCaD/JiT/I0BsONafmWih68bOYaNTYoE9B0slCkEdxzIe+s8
 rX63pstTeid79vjPRSIAhejlocQKZrD4FAzzsZmrP7c9xovJH/WuwjtYT19enjvZFrwV
 u95Gc5N01zsT4OBteXAlsGRe+JBQmQugVrixQmSvf25FsZnL2y2avL30sDEAlR1yAMk1
 QfxhBYOiP57trqGsrbrU2uCpODNvrDwaGsbQRW684IsRNRlkGOoL5M80M9SE00M2SB5+
 cs5uyL933DLh0LdvTLj4/aO5tWJhzmcO9H9PbINoAOl3QF9lBA8/Th8nuxOpdFxL1cVf
 nHHA==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
 d=1e100.net; s=20210112;
 h=cc:to:subject:message-id:date:from:in-reply-to:references
 :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id
 :reply-to;
 bh=osjOuJvBwnoh6sQDc1NAmGHY8WiYdXfSehaojPVyTMc=;
 b=Dk2GZD9sf2pvoZldO7HxRCITYFfKHWu+ev/nkT7Qk8czWIxpt9F+IVOuO58PP7ItqG
 M/abkCtSoMZ8knykgiljC9CEX9rfP1K2LSRW+UqCX+vgisR1WSZO4jrNyXojdLiKxQa0
 6h1jMcJq0WjULgRlcqoA0PLqgcTJ/K4/aewiidAztQCXi9ZMWqI/1th3fVTwDiRGMcxu
 6bPbRZv8NClubDbX9A0EIcmo6uA6troaxsaQj+6icmTNSfdCJuoAu8+gn/AVrt1lgiwB
 SSRVOw4MGC2+3wH8O/XaN8QABQ63pxpMSX7XinXg4Um8PAs0n4lgv+KKBOl7AYmRTUkq
 linw==
X-Gm-Message-State: ACrzQf0wsOK7N4zdy6LPudJ/qHstR440gkWe7nWaF/w2JjeC/ZKlZqHu
 jl8aLCmCElfMkxZIZEdd+1XgD7I/XfEdfPmjkd72tg==
X-Google-Smtp-Source: AMsMyM5rFaE9bkyNGpUlPAJ/rb+fFstuJP3Xnf9NajjChAYEVF5yPTSwMRoTuSn2gnuUysNjEGAfKBW8GfWUKMp5Tu8=
X-Received: by 2002:a2e:3510:0:b0:26f:aecf:e0c6 with SMTP id
 z16-20020a2e3510000000b0026faecfe0c6mr7148991ljz.483.1666361983723; Fri, 21
 Oct 2022 07:19:43 -0700 (PDT)
MIME-Version: 1.0
References: <CABZBVTC5kh7ca3KhVkFPdQjnsPhP4Kun1k3K6cPkarrjUiTJpA@mail.gmail.com>
 <CABZBVTCgiQFtxEyeOU=-SGDQUDthyy7sOgPwiT+OVi35LVivyA@mail.gmail.com>
 <Y1D3OkdsCq2pLduG@erisian.com.au>
 <CABZBVTBupMcBbOUtLbMaEmAiWGsMwisNW+k+bTUJGsUad2=ZZg@mail.gmail.com>
 <Y1Gocf216O+yKqqS@erisian.com.au>
 <CAB3F3DtbxXiHW0GxtaVMMtAo5X7ZcsCPR7odVnwz50qw_3oCLg@mail.gmail.com>
 <CABZBVTBpZOdENv0tg0CZ4yV9J95ZGu0ME9f6gnQQ8WNyt2yePg@mail.gmail.com>
 <CAB3F3DutXajW4E0zZb82LdfRFBoKFd21Up2mxA-nYtCWooys-g@mail.gmail.com>
In-Reply-To: <CAB3F3DutXajW4E0zZb82LdfRFBoKFd21Up2mxA-nYtCWooys-g@mail.gmail.com>
From: Sergej Kotliar <sergej@bitrefill.com>
Date: Fri, 21 Oct 2022 16:19:32 +0200
Message-ID: <CABZBVTCe3ibbWfDnC5kxi5Fn2g++SDFwToNch7OYpom1576wcQ@mail.gmail.com>
To: Greg Sanders <gsanders87@gmail.com>
Content-Type: multipart/alternative; boundary="0000000000001b88f305eb8c2237"
X-Mailman-Approved-At: Fri, 21 Oct 2022 18:47:17 +0000
Cc: Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>,
 Anthony Towns <aj@erisian.com.au>
Subject: Re: [bitcoin-dev] [Opt-in full-RBF] Zero-conf apps in immediate
	danger
X-BeenThere: bitcoin-dev@lists.linuxfoundation.org
X-Mailman-Version: 2.1.15
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: Fri, 21 Oct 2022 14:19:49 -0000

--0000000000001b88f305eb8c2237
Content-Type: text/plain; charset="UTF-8"

On Fri, 21 Oct 2022 at 16:01, Greg Sanders <gsanders87@gmail.com> wrote:

> Full-rbf is an odd duck, because while it is not a consensus issue, it
> does affect a large % of transactions made by wallets already, contrary to
> most policy changes.
>

Yeah, there are several policy features that are not consensus related but
end up de facto setting rules for how bitcoin behaves. Minrelayfee being
another, and probably other examples out there that I don't know of.


> It's also a UX issue, not a safety issue for retail wallet users(except
> Muun, who have given a clear timeline). Clearly considerations would be
> very different otherwise, but retail wallets by and large do not consider
> 0-conf as a valid deposit, or at least put up some warning symbols to that
> effect.
>
> Can only speak for myself, but I am looking for a concrete timeframe from
> 0-conf stakeholders. I have no preference for any particular time frame, as
> long as it can be agreed upon in the near-ish future. This keeps the
> transition technically speaking very simple, and removes uncertainty from
> decision making going forward.
>

It's hard to give a timeframe because it's not clear what the path forward
for these stakeholders is. Most of what I've heard in this channel is
things like "just use Lightning" but that's contradicted by user data. So
the action becomes "stop accepting payments onchain" which isn't really a
timeframe type issue, it will hurt whenever it happens. Maybe a thorough
discussion for a way forward would be useful here. Jeremy Rubin suggested
an interesting idea for using CPFP to force a transaction to complete.
We'll evaluate it and see if it works in the wild for zero-conf of RBF
today and report findings, need to evaluate from several angles first
incentives-wise. There might also be other solutions.

I'd also ask if there might also be other solutions for solving the pinning
issue as well if we dig deep into it? Perhaps there are those with
tradeoffs, but those tradeoffs being less significant than the tradeoffs of
rbf policy?


Best,
Sergej

>
> On Fri, Oct 21, 2022 at 8:02 AM Sergej Kotliar <sergej@bitrefill.com>
> wrote:
>
>> On Thu, 20 Oct 2022 at 23:07, Greg Sanders <gsanders87@gmail.com> wrote:
>>
>>> A large number of coins/users sit on custodial rails and this would
>>> essentially encumber protocol developers to those KYC/AML institutions. If
>>> Binance decides to never support Lightning in favor of BNC-wrapped BTC,
>>> should this be an issue at all for reasoning about a path forward?
>>>
>>
>> This is a big question here, with the caveat that it's not just binance
>> but in fact the majority of wallets and services that people use with
>> bitcoin today.
>> But the question remains as you phrased: At which point do we break
>> backwards compatibility? Another analogy would be to have sunset the old
>> P2PKH addresses during rollout of Segwit - it would certainly have led to
>> Segwit getting rolled out faster. The rbf change actually breaks more
>> things than that, takes more effort to address than just implementing a new
>> address format. Previously in the Bitcoin Core process we've chosen to keep
>> backwards compatibility and only roll out opt-in changes with broad
>> consensus over them, with the default behavior being to not roll out
>> changes that are controversial. At which point it's time to back away from
>> that - I honestly don't know. There is probably such a point, and we should
>> maybe have some kind of discussion around that topic on a higher level,
>> just as you phrased it, and I'll paraphrase:
>> If a majority of bitcoin wallets and services continue using legacy
>> patterns and features, preventing progress, at which point do we want to
>> break compatibility with them?
>>
>> Best,
>> Sergej
>>
>>
>> On Thu, Oct 20, 2022 at 3:59 PM Anthony Towns via bitcoin-dev <
>>> bitcoin-dev@lists.linuxfoundation.org> wrote:
>>>
>>>> On Thu, Oct 20, 2022 at 02:37:53PM +0200, Sergej Kotliar via
>>>> bitcoin-dev wrote:
>>>> > > If someone's going to systematically exploit your store via this
>>>> > > mechanism, it seems like they'd just find a single wallet with a
>>>> good
>>>> > > UX for opt-in RBF and lowballing fees, and go to town -- not
>>>> something
>>>> > > where opt-in rbf vs fullrbf policies make any difference at all?
>>>> > Sort of. But yes once this starts being abused systemically we will
>>>> have to
>>>> > do something else w RBF payments, such as crediting the amount in BTC
>>>> to a
>>>> > custodial account. But this option isn't available to your normal
>>>> payment
>>>> > processor type business.
>>>>
>>>> So, what I'm hearing is:
>>>>
>>>>  * lightning works great, but is still pretty small
>>>>  * zeroconf works great for txs that opt-out of RBF
>>>>  * opt-in RBF is a pain for two reasons:
>>>>     - people don't like that it's not treated as zeroconf
>>>>     - the risk of fiat/BTC exchange rate changes between
>>>>       now and when the tx actually confirms is worrying
>>>>       even if it hasn't caused real problems yet
>>>>
>>>> (Please correct me if that's too far wrong)
>>>>
>>>> Maybe it would be productive to explore this opt-in RBF part a bit
>>>> more? ie, see if "we" can come up with better answers to some question
>>>> along the lines of:
>>>>
>>>>  "how can we make on-chain payments for goods priced in fiat work well
>>>>   for payees that opt-in to RBF?"
>>>>
>>>> That seems like the sort of thing that's better solved by a
>>>> collaboration
>>>> between wallet devs and merchant devs (and protocol devs?), rather than
>>>> just one or the other?
>>>>
>>>> Is that something that we could talk about here? Or maybe it's better
>>>> done via an optech workgroup or something?
>>>>
>>>> If "we'll credit your account in BTC, then work out the USD coversion
>>>> and deduct that for your purchase, then you can do whatever you like
>>>> with any remaining BTC from your on-chain payment" is the idea, maybe we
>>>> should just roll with that design, but make it more decentralised: have
>>>> the initial payment setup a lightning channel between the customer and
>>>> the merchant with the BTC (so it's not custodial), but do some magic to
>>>> allow USD amounts to be transferred over it (Taro? something oracle
>>>> based
>>>> so that both parties are confident a fair exchange rate will be used?).
>>>>
>>>> Maybe that particular idea is naive, but having an actual problem to
>>>> solve seems more constructive than just saying "we want rbf" "but we
>>>> want zeroconf" all the time?
>>>>
>>>> (Ideally the lightning channels above would be dual funded so they could
>>>> be used for routing more generally; but then dual funded channels are
>>>> one of the things that get broken by lack of full rbf)
>>>>
>>>> > > I thought the "normal" avenue for fooling non-RBF zeroconf was to
>>>> create
>>>> > > two conflicting txs in advance, one paying the merchant, one paying
>>>> > > yourself, connect to many peers, relay the one paying the merchant
>>>> to
>>>> > > the merchant, and the other to everyone else.
>>>> > > I'm just basing this off Peter Todd's stuff from years ago:
>>>> > >
>>>> https://np.reddit.com/r/Bitcoin/comments/40ejy8/peter_todd_with_my_doublespendpy_tool_with/cytlhh0/
>>>> > >
>>>> https://github.com/petertodd/replace-by-fee-tools/blob/master/doublespend.py
>>>> > Yeah, I know the list still rehashes a single incident from 10 years
>>>> ago to
>>>> > declare the entire practice as unsafe, and ignores real-world data
>>>> that of
>>>> > the last million transactions we had zero cases of this successfully
>>>> > abusing us.
>>>>
>>>> I mean, the avenue above isn't easy to exploit -- you have to identify
>>>> the merchant's node so that they get the bad tx, and you have to connect
>>>> to many peers so that your preferred tx propogates to miners first --
>>>> and probably more importantly, it's relatively easy to detect -- if the
>>>> merchant has a few passive nodes that the attacker doesn't know about
>>>> it, and uses those to watch for attempted doublespends while it tries
>>>> to ensure the real tx has propogated widely. So it doesn't surprise me
>>>> at all that it's not often attempted, and even less often successful.
>>>>
>>>> > > > Currently Lightning is somewhere around 15% of our total bitcoin
>>>> > > > payments.
>>>> > > So, based on last year's numbers, presumably that makes your bitcoin
>>>> > > payments break down as something like:
>>>> > >    5% txs are on-chain and seem shady and are excluded from zeroconf
>>>> > >   15% txs are lightning
>>>> > >   20% txs are on-chain but signal rbf and are excluded from zeroconf
>>>> > >   60% txs are on-chain and seem fine for zeroconf
>>>> > Numbers are right. Shady is too strong a word,
>>>>
>>>> Heh, fair enough.
>>>>
>>>> So the above suggests 25% of payments already get a sub-par experience,
>>>> compared to what you'd like them to have (which sucks, but if you're
>>>> trying to reinvent both money and payments, maybe isn't surprising). And
>>>> going full rbf would bump that from 25% to 85%, which would be pretty
>>>> terrible.
>>>>
>>>> > RBF is a strictly worse UX as proven by anyone
>>>> > accepting bitcoin payments at scale.
>>>>
>>>> So let's make it better? Building bitcoin businesses on the lie that
>>>> unconfirmed txs are safe and won't be replaced is going to bite us
>>>> eventually; focussing on trying to push that back indefinitely is just
>>>> going to make everyone less prepared when it eventually happens.
>>>>
>>>> > > > For me
>>>> > > > personally it would be an easier discussion to have when
>>>> Lightning is at
>>>> > > > 80%+ of all bitcoin transactions.
>>>> > > Can you extrapolate from the numbers you've seen to estimate when
>>>> that
>>>> > > might be, given current trends?
>>>> > Not sure, it might be exponential growth, and the next 60% of
>>>> Lightning
>>>> > growth happen faster than the first 15%. Hard to tell. But we're
>>>> likely
>>>> > talking years here..
>>>>
>>>> Okay? Two years is very different from 50 years, and at the moment
>>>> there's
>>>> not really any data, so people are just going to go with their gut...
>>>>
>>>> If it were growing in line with lightning capacity in BTC, per
>>>> bitcoinvisuals.com/ln-capacity; then 15% now would have grown from
>>>> perhaps 4% in May 2021, so perhaps 8% per year. With linear growth,
>>>> getting from 15% to 80% would then be about 8 years.
>>>>
>>>> Presumably that's a laughably terrible model, of course. But if we had
>>>> some actual numbers where we can watch the progress, it might be a lot
>>>> easier to be patient about waiting for lightning adoption to hit 80%
>>>> or whatever, and focus on productive things in the meantime?
>>>>
>>>> Cheers,
>>>> aj
>>>> _______________________________________________
>>>> bitcoin-dev mailing list
>>>> bitcoin-dev@lists.linuxfoundation.org
>>>> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>>>>
>>>
>>
>> --
>>
>> Sergej Kotliar
>>
>> CEO
>>
>>
>> Twitter: @ziggamon <https://twitter.com/ziggamon>
>>
>>
>> www.bitrefill.com
>>
>> Twitter <https://www.twitter.com/bitrefill> | Blog
>> <https://www.bitrefill.com/blog/> | Angellist
>> <https://angel.co/bitrefill>
>>
>

-- 

Sergej Kotliar

CEO


Twitter: @ziggamon <https://twitter.com/ziggamon>


www.bitrefill.com

Twitter <https://www.twitter.com/bitrefill> | Blog
<https://www.bitrefill.com/blog/> | Angellist <https://angel.co/bitrefill>

--0000000000001b88f305eb8c2237
Content-Type: text/html; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr"><div dir=3D"ltr"><br></div><br><div class=3D"gmail_quote">=
<div dir=3D"ltr" class=3D"gmail_attr">On Fri, 21 Oct 2022 at 16:01, Greg Sa=
nders &lt;<a href=3D"mailto:gsanders87@gmail.com">gsanders87@gmail.com</a>&=
gt; wrote:<br></div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0=
px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div =
dir=3D"ltr">Full-rbf is an odd duck, because while it is not a consensus is=
sue, it does affect a large % of transactions made by wallets already, cont=
rary to most policy changes.=C2=A0</div></blockquote><div><br></div><div>Ye=
ah, there are several policy features that are not consensus related but en=
d up de facto setting rules for how bitcoin behaves. Minrelayfee being anot=
her, and probably other examples out there that I don&#39;t know of.=C2=A0<=
/div><div>=C2=A0</div><blockquote class=3D"gmail_quote" style=3D"margin:0px=
 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><di=
v dir=3D"ltr"><div>It&#39;s also a UX issue, not a safety issue for retail =
wallet users(except Muun, who have given a clear timeline). Clearly conside=
rations would be very different otherwise, but retail wallets by and large =
do not consider 0-conf as a valid deposit,=C2=A0or at least put up some war=
ning symbols to that effect.<br><div><br></div><div>Can only speak for myse=
lf, but I am looking for a concrete timeframe from 0-conf stakeholders. I h=
ave no preference for any particular time frame, as long as it can be agree=
d upon in the near-ish future. This keeps the transition technically speaki=
ng very simple, and removes uncertainty from decision making going forward.=
</div></div></div></blockquote><div><br></div><div>It&#39;s hard to give a =
timeframe because it&#39;s not clear what the path forward for these stakeh=
olders is. Most of what I&#39;ve heard in this channel is things like &quot=
;just use Lightning&quot; but that&#39;s contradicted by user data. So the =
action becomes &quot;stop accepting payments onchain&quot; which isn&#39;t =
really a timeframe type issue, it will hurt whenever it happens. Maybe a th=
orough discussion for a way forward would be useful here. Jeremy Rubin sugg=
ested an interesting idea for using CPFP to force a transaction to complete=
. We&#39;ll evaluate it and see if it works in the wild for zero-conf of RB=
F today and report findings, need to evaluate from several angles first inc=
entives-wise. There might also be other solutions.=C2=A0</div><div><br></di=
v><div>I&#39;d also ask if there might also be other solutions for solving =
the pinning issue as well if we dig deep into it? Perhaps there are those w=
ith tradeoffs, but those tradeoffs being less significant than the tradeoff=
s of rbf policy?</div><div>=C2=A0</div><div><br></div><div>Best,=C2=A0</div=
><div>Sergej</div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px=
 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div di=
r=3D"ltr"><div><br></div></div><div class=3D"gmail_quote"><div dir=3D"ltr" =
class=3D"gmail_attr">On Fri, Oct 21, 2022 at 8:02 AM Sergej Kotliar &lt;<a =
href=3D"mailto:sergej@bitrefill.com" target=3D"_blank">sergej@bitrefill.com=
</a>&gt; wrote:<br></div><blockquote class=3D"gmail_quote" style=3D"margin:=
0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">=
<div dir=3D"ltr"><div dir=3D"ltr">On Thu, 20 Oct 2022 at 23:07, Greg Sander=
s &lt;<a href=3D"mailto:gsanders87@gmail.com" target=3D"_blank">gsanders87@=
gmail.com</a>&gt; wrote:<br></div><div class=3D"gmail_quote"><blockquote cl=
ass=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid=
 rgb(204,204,204);padding-left:1ex"><div dir=3D"ltr"><div>A large number of=
 coins/users sit on custodial rails and this would essentially encumber pro=
tocol developers to those KYC/AML institutions. If Binance decides to never=
 support Lightning in favor of BNC-wrapped BTC, should this be an issue at =
all for reasoning about a path forward?</div></div></blockquote><div><br></=
div><div>This is a big question here, with the caveat that it&#39;s not jus=
t binance but in fact the majority of wallets and services that people use =
with bitcoin today.</div><div>But the question remains as you phrased: At w=
hich point do we break backwards compatibility? Another analogy would be to=
 have sunset the old P2PKH addresses during rollout of Segwit - it would ce=
rtainly have led to Segwit getting rolled out faster. The rbf change actual=
ly breaks more things than that, takes more effort to address than just imp=
lementing a new address format. Previously in the Bitcoin Core process we&#=
39;ve chosen to keep backwards compatibility and only roll out opt-in chang=
es with broad consensus over them, with the default behavior being to not r=
oll out changes that are controversial. At which point it&#39;s time to bac=
k away from that - I honestly don&#39;t know. There is probably such a poin=
t, and we should maybe have some kind of discussion around that topic on a =
higher level, just as you phrased it, and I&#39;ll paraphrase:=C2=A0</div><=
div>If a majority of bitcoin wallets and services continue using legacy pat=
terns and features, preventing progress, at which point do we want to break=
 compatibility with them?</div><div><br></div><div>Best,</div><div>Sergej</=
div><div><br></div><div><br></div><blockquote class=3D"gmail_quote" style=
=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding=
-left:1ex"><div class=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr"=
>On Thu, Oct 20, 2022 at 3:59 PM Anthony Towns via bitcoin-dev &lt;<a href=
=3D"mailto:bitcoin-dev@lists.linuxfoundation.org" target=3D"_blank">bitcoin=
-dev@lists.linuxfoundation.org</a>&gt; wrote:<br></div><blockquote class=3D=
"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(2=
04,204,204);padding-left:1ex">On Thu, Oct 20, 2022 at 02:37:53PM +0200, Ser=
gej Kotliar via bitcoin-dev wrote:<br>
&gt; &gt; If someone&#39;s going to systematically exploit your store via t=
his<br>
&gt; &gt; mechanism, it seems like they&#39;d just find a single wallet wit=
h a good<br>
&gt; &gt; UX for opt-in RBF and lowballing fees, and go to town -- not some=
thing<br>
&gt; &gt; where opt-in rbf vs fullrbf policies make any difference at all?<=
br>
&gt; Sort of. But yes once this starts being abused systemically we will ha=
ve to<br>
&gt; do something else w RBF payments, such as crediting the amount in BTC =
to a<br>
&gt; custodial account. But this option isn&#39;t available to your normal =
payment<br>
&gt; processor type business.<br>
<br>
So, what I&#39;m hearing is:<br>
<br>
=C2=A0* lightning works great, but is still pretty small<br>
=C2=A0* zeroconf works great for txs that opt-out of RBF<br>
=C2=A0* opt-in RBF is a pain for two reasons:<br>
=C2=A0 =C2=A0 - people don&#39;t like that it&#39;s not treated as zeroconf=
<br>
=C2=A0 =C2=A0 - the risk of fiat/BTC exchange rate changes between<br>
=C2=A0 =C2=A0 =C2=A0 now and when the tx actually confirms is worrying<br>
=C2=A0 =C2=A0 =C2=A0 even if it hasn&#39;t caused real problems yet<br>
<br>
(Please correct me if that&#39;s too far wrong)<br>
<br>
Maybe it would be productive to explore this opt-in RBF part a bit<br>
more? ie, see if &quot;we&quot; can come up with better answers to some que=
stion<br>
along the lines of:<br>
<br>
=C2=A0&quot;how can we make on-chain payments for goods priced in fiat work=
 well<br>
=C2=A0 for payees that opt-in to RBF?&quot;<br>
<br>
That seems like the sort of thing that&#39;s better solved by a collaborati=
on<br>
between wallet devs and merchant devs (and protocol devs?), rather than<br>
just one or the other?<br>
<br>
Is that something that we could talk about here? Or maybe it&#39;s better<b=
r>
done via an optech workgroup or something?<br>
<br>
If &quot;we&#39;ll credit your account in BTC, then work out the USD covers=
ion<br>
and deduct that for your purchase, then you can do whatever you like<br>
with any remaining BTC from your on-chain payment&quot; is the idea, maybe =
we<br>
should just roll with that design, but make it more decentralised: have<br>
the initial payment setup a lightning channel between the customer and<br>
the merchant with the BTC (so it&#39;s not custodial), but do some magic to=
<br>
allow USD amounts to be transferred over it (Taro? something oracle based<b=
r>
so that both parties are confident a fair exchange rate will be used?).<br>
<br>
Maybe that particular idea is naive, but having an actual problem to<br>
solve seems more constructive than just saying &quot;we want rbf&quot; &quo=
t;but we<br>
want zeroconf&quot; all the time?<br>
<br>
(Ideally the lightning channels above would be dual funded so they could<br=
>
be used for routing more generally; but then dual funded channels are<br>
one of the things that get broken by lack of full rbf)<br>
<br>
&gt; &gt; I thought the &quot;normal&quot; avenue for fooling non-RBF zeroc=
onf was to create<br>
&gt; &gt; two conflicting txs in advance, one paying the merchant, one payi=
ng<br>
&gt; &gt; yourself, connect to many peers, relay the one paying the merchan=
t to<br>
&gt; &gt; the merchant, and the other to everyone else.<br>
&gt; &gt; I&#39;m just basing this off Peter Todd&#39;s stuff from years ag=
o:<br>
&gt; &gt; <a href=3D"https://np.reddit.com/r/Bitcoin/comments/40ejy8/peter_=
todd_with_my_doublespendpy_tool_with/cytlhh0/" rel=3D"noreferrer" target=3D=
"_blank">https://np.reddit.com/r/Bitcoin/comments/40ejy8/peter_todd_with_my=
_doublespendpy_tool_with/cytlhh0/</a><br>
&gt; &gt; <a href=3D"https://github.com/petertodd/replace-by-fee-tools/blob=
/master/doublespend.py" rel=3D"noreferrer" target=3D"_blank">https://github=
.com/petertodd/replace-by-fee-tools/blob/master/doublespend.py</a><br>
&gt; Yeah, I know the list still rehashes a single incident from 10 years a=
go to<br>
&gt; declare the entire practice as unsafe, and ignores real-world data tha=
t of<br>
&gt; the last million transactions we had zero cases of this successfully<b=
r>
&gt; abusing us.<br>
<br>
I mean, the avenue above isn&#39;t easy to exploit -- you have to identify<=
br>
the merchant&#39;s node so that they get the bad tx, and you have to connec=
t<br>
to many peers so that your preferred tx propogates to miners first --<br>
and probably more importantly, it&#39;s relatively easy to detect -- if the=
<br>
merchant has a few passive nodes that the attacker doesn&#39;t know about<b=
r>
it, and uses those to watch for attempted doublespends while it tries<br>
to ensure the real tx has propogated widely. So it doesn&#39;t surprise me<=
br>
at all that it&#39;s not often attempted, and even less often successful.<b=
r>
<br>
&gt; &gt; &gt; Currently Lightning is somewhere around 15% of our total bit=
coin<br>
&gt; &gt; &gt; payments.<br>
&gt; &gt; So, based on last year&#39;s numbers, presumably that makes your =
bitcoin<br>
&gt; &gt; payments break down as something like:<br>
&gt; &gt;=C2=A0 =C2=A0 5% txs are on-chain and seem shady and are excluded =
from zeroconf<br>
&gt; &gt;=C2=A0 =C2=A015% txs are lightning<br>
&gt; &gt;=C2=A0 =C2=A020% txs are on-chain but signal rbf and are excluded =
from zeroconf<br>
&gt; &gt;=C2=A0 =C2=A060% txs are on-chain and seem fine for zeroconf<br>
&gt; Numbers are right. Shady is too strong a word,<br>
<br>
Heh, fair enough.<br>
<br>
So the above suggests 25% of payments already get a sub-par experience,<br>
compared to what you&#39;d like them to have (which sucks, but if you&#39;r=
e<br>
trying to reinvent both money and payments, maybe isn&#39;t surprising). An=
d<br>
going full rbf would bump that from 25% to 85%, which would be pretty<br>
terrible.<br>
<br>
&gt; RBF is a strictly worse UX as proven by anyone<br>
&gt; accepting bitcoin payments at scale.<br>
<br>
So let&#39;s make it better? Building bitcoin businesses on the lie that<br=
>
unconfirmed txs are safe and won&#39;t be replaced is going to bite us<br>
eventually; focussing on trying to push that back indefinitely is just<br>
going to make everyone less prepared when it eventually happens.<br>
<br>
&gt; &gt; &gt; For me<br>
&gt; &gt; &gt; personally it would be an easier discussion to have when Lig=
htning is at<br>
&gt; &gt; &gt; 80%+ of all bitcoin transactions.<br>
&gt; &gt; Can you extrapolate from the numbers you&#39;ve seen to estimate =
when that<br>
&gt; &gt; might be, given current trends?<br>
&gt; Not sure, it might be exponential growth, and the next 60% of Lightnin=
g<br>
&gt; growth happen faster than the first 15%. Hard to tell. But we&#39;re l=
ikely<br>
&gt; talking years here..<br>
<br>
Okay? Two years is very different from 50 years, and at the moment there&#3=
9;s<br>
not really any data, so people are just going to go with their gut...<br>
<br>
If it were growing in line with lightning capacity in BTC, per<br>
<a href=3D"http://bitcoinvisuals.com/ln-capacity" rel=3D"noreferrer" target=
=3D"_blank">bitcoinvisuals.com/ln-capacity</a>; then 15% now would have gro=
wn from<br>
perhaps 4% in May 2021, so perhaps 8% per year. With linear growth,<br>
getting from 15% to 80% would then be about 8 years. <br>
<br>
Presumably that&#39;s a laughably terrible model, of course. But if we had<=
br>
some actual numbers where we can watch the progress, it might be a lot<br>
easier to be patient about waiting for lightning adoption to hit 80%<br>
or whatever, and focus on productive things in the meantime?<br>
<br>
Cheers,<br>
aj<br>
_______________________________________________<br>
bitcoin-dev mailing list<br>
<a href=3D"mailto:bitcoin-dev@lists.linuxfoundation.org" target=3D"_blank">=
bitcoin-dev@lists.linuxfoundation.org</a><br>
<a href=3D"https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev" =
rel=3D"noreferrer" target=3D"_blank">https://lists.linuxfoundation.org/mail=
man/listinfo/bitcoin-dev</a><br>
</blockquote></div>
</blockquote></div><br clear=3D"all"><div><br></div>-- <br><div dir=3D"ltr"=
><div dir=3D"ltr"><div dir=3D"ltr"><div dir=3D"ltr"><div dir=3D"ltr"><div d=
ir=3D"ltr"><div dir=3D"ltr"><div dir=3D"ltr"><div dir=3D"ltr"><div dir=3D"l=
tr"><div dir=3D"ltr"><p dir=3D"ltr" style=3D"line-height:1.38;margin-top:0p=
t;margin-bottom:0pt"><span style=3D"font-size:9.5pt;font-family:Arial;color=
:rgb(0,0,0);background-color:transparent;font-weight:700;font-style:normal;=
font-variant:normal;text-decoration:none;vertical-align:baseline;white-spac=
e:pre-wrap">Sergej Kotliar</span></p><p dir=3D"ltr" style=3D"line-height:1.=
38;margin-top:0pt;margin-bottom:0pt"><span style=3D"font-size:9.5pt;font-fa=
mily:Arial;color:rgb(0,0,0);background-color:transparent;font-weight:700;fo=
nt-style:normal;font-variant:normal;text-decoration:none;vertical-align:bas=
eline;white-space:pre-wrap">CEO</span></p><p dir=3D"ltr" style=3D"line-heig=
ht:1.38;margin-top:0pt;margin-bottom:0pt"><b style=3D"font-weight:normal"><=
br></b></p><p dir=3D"ltr" style=3D"line-height:1.38;margin-top:0pt;margin-b=
ottom:0pt"><span style=3D"font-size:11pt;font-family:Arial;color:rgb(102,10=
2,102);background-color:transparent;font-weight:700;font-style:normal;font-=
variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre=
-wrap"><span style=3D"border:none;display:inline-block;overflow:hidden;widt=
h:220px;height:80px"><img src=3D"https://lh4.googleusercontent.com/wU5i7e8b=
oCd7o3P52cUTKrqeTa7jV2dPEXluijGtPBy0f1F0R2_zIg_zOQ2kigkbVbSWqLlVdwuBYgo_txX=
MKkCWdMfBFRNhsDhFpNv1QrRZsD-gPxDui-4l0tZI1QcjtefCDkNG" width=3D"220" height=
=3D"80" style=3D"margin-left: 0px; margin-top: 0px;"></span></span></p><p d=
ir=3D"ltr" style=3D"line-height:1.38;margin-top:0pt;margin-bottom:0pt"><spa=
n style=3D"font-size:9.5pt;font-family:Arial;color:rgb(102,102,102);backgro=
und-color:transparent;font-weight:400;font-style:normal;font-variant:normal=
;text-decoration:none;vertical-align:baseline;white-space:pre-wrap">Twitter=
: @</span><a href=3D"https://twitter.com/ziggamon" style=3D"text-decoration=
:none" target=3D"_blank"><span style=3D"font-size:9.5pt;font-family:Arial;c=
olor:rgb(102,102,102);background-color:transparent;font-weight:400;font-sty=
le:normal;font-variant:normal;text-decoration:underline;vertical-align:base=
line;white-space:pre-wrap">ziggamon</span></a><span style=3D"font-size:9.5p=
t;font-family:Arial;color:rgb(102,102,102);background-color:transparent;fon=
t-weight:400;font-style:normal;font-variant:normal;text-decoration:none;ver=
tical-align:baseline;white-space:pre-wrap">=C2=A0</span></p><p dir=3D"ltr" =
style=3D"line-height:1.38;margin-top:0pt;margin-bottom:0pt"><b style=3D"fon=
t-weight:normal"><br></b></p><p dir=3D"ltr" style=3D"line-height:1.38;margi=
n-top:0pt;margin-bottom:0pt"><a href=3D"http://www.bitrefill.com/" style=3D=
"text-decoration:none" target=3D"_blank"><span style=3D"font-size:9.5pt;fon=
t-family:Arial;color:rgb(102,102,102);background-color:transparent;font-wei=
ght:400;font-style:normal;font-variant:normal;text-decoration:underline;ver=
tical-align:baseline;white-space:pre-wrap">www.bitrefill.com</span></a></p>=
<p dir=3D"ltr" style=3D"line-height:1.38;margin-top:0pt;margin-bottom:0pt">=
<a href=3D"https://www.twitter.com/bitrefill" target=3D"_blank"><span style=
=3D"font-size:9.5pt;font-family:Arial;color:rgb(102,102,102);background-col=
or:transparent;vertical-align:baseline;white-space:pre-wrap">Twitter</span>=
</a><span style=3D"font-size:9.5pt;font-family:Arial;color:rgb(102,102,102)=
;background-color:transparent;vertical-align:baseline;white-space:pre-wrap"=
> | </span><a href=3D"https://www.bitrefill.com/blog/" target=3D"_blank"><s=
pan style=3D"font-size:9.5pt;font-family:Arial;color:rgb(102,102,102);backg=
round-color:transparent;vertical-align:baseline;white-space:pre-wrap">Blog<=
/span></a><span style=3D"font-size:9.5pt;font-family:Arial;color:rgb(102,10=
2,102);background-color:transparent;vertical-align:baseline;white-space:pre=
-wrap"> | </span><a href=3D"https://angel.co/bitrefill" target=3D"_blank"><=
span style=3D"font-size:9.5pt;font-family:Arial;color:rgb(102,102,102);back=
ground-color:transparent;vertical-align:baseline;white-space:pre-wrap">Ange=
llist </span></a><br></p></div></div></div></div></div></div></div></div></=
div></div></div></div>
</blockquote></div>
</blockquote></div><br clear=3D"all"><div><br></div>-- <br><div dir=3D"ltr"=
 class=3D"gmail_signature"><div dir=3D"ltr"><div dir=3D"ltr"><div dir=3D"lt=
r"><div dir=3D"ltr"><div dir=3D"ltr"><div dir=3D"ltr"><div dir=3D"ltr"><div=
 dir=3D"ltr"><div dir=3D"ltr"><div dir=3D"ltr"><p dir=3D"ltr" style=3D"line=
-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style=3D"font-size:9.5=
pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-wei=
ght:700;font-style:normal;font-variant:normal;text-decoration:none;vertical=
-align:baseline;white-space:pre-wrap">Sergej Kotliar</span></p><p dir=3D"lt=
r" style=3D"line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style=
=3D"font-size:9.5pt;font-family:Arial;color:rgb(0,0,0);background-color:tra=
nsparent;font-weight:700;font-style:normal;font-variant:normal;text-decorat=
ion:none;vertical-align:baseline;white-space:pre-wrap">CEO</span></p><p dir=
=3D"ltr" style=3D"line-height:1.38;margin-top:0pt;margin-bottom:0pt"><b sty=
le=3D"font-weight:normal"><br></b></p><p dir=3D"ltr" style=3D"line-height:1=
.38;margin-top:0pt;margin-bottom:0pt"><span style=3D"font-size:11pt;font-fa=
mily:Arial;color:rgb(102,102,102);background-color:transparent;font-weight:=
700;font-style:normal;font-variant:normal;text-decoration:none;vertical-ali=
gn:baseline;white-space:pre-wrap"><span style=3D"border:none;display:inline=
-block;overflow:hidden;width:220px;height:80px"><img src=3D"https://lh4.goo=
gleusercontent.com/wU5i7e8boCd7o3P52cUTKrqeTa7jV2dPEXluijGtPBy0f1F0R2_zIg_z=
OQ2kigkbVbSWqLlVdwuBYgo_txXMKkCWdMfBFRNhsDhFpNv1QrRZsD-gPxDui-4l0tZI1Qcjtef=
CDkNG" width=3D"220" height=3D"80" style=3D"margin-left: 0px; margin-top: 0=
px;"></span></span></p><p dir=3D"ltr" style=3D"line-height:1.38;margin-top:=
0pt;margin-bottom:0pt"><span style=3D"font-size:9.5pt;font-family:Arial;col=
or:rgb(102,102,102);background-color:transparent;font-weight:400;font-style=
:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;wh=
ite-space:pre-wrap">Twitter: @</span><a href=3D"https://twitter.com/ziggamo=
n" style=3D"text-decoration:none" target=3D"_blank"><span style=3D"font-siz=
e:9.5pt;font-family:Arial;color:rgb(102,102,102);background-color:transpare=
nt;font-weight:400;font-style:normal;font-variant:normal;text-decoration:un=
derline;vertical-align:baseline;white-space:pre-wrap">ziggamon</span></a><s=
pan style=3D"font-size:9.5pt;font-family:Arial;color:rgb(102,102,102);backg=
round-color:transparent;font-weight:400;font-style:normal;font-variant:norm=
al;text-decoration:none;vertical-align:baseline;white-space:pre-wrap">=C2=
=A0</span></p><p dir=3D"ltr" style=3D"line-height:1.38;margin-top:0pt;margi=
n-bottom:0pt"><b style=3D"font-weight:normal"><br></b></p><p dir=3D"ltr" st=
yle=3D"line-height:1.38;margin-top:0pt;margin-bottom:0pt"><a href=3D"http:/=
/www.bitrefill.com/" style=3D"text-decoration:none" target=3D"_blank"><span=
 style=3D"font-size:9.5pt;font-family:Arial;color:rgb(102,102,102);backgrou=
nd-color:transparent;font-weight:400;font-style:normal;font-variant:normal;=
text-decoration:underline;vertical-align:baseline;white-space:pre-wrap">www=
.bitrefill.com</span></a></p><p dir=3D"ltr" style=3D"line-height:1.38;margi=
n-top:0pt;margin-bottom:0pt"><a href=3D"https://www.twitter.com/bitrefill" =
target=3D"_blank"><span style=3D"font-size:9.5pt;font-family:Arial;color:rg=
b(102,102,102);background-color:transparent;vertical-align:baseline;white-s=
pace:pre-wrap">Twitter</span></a><span style=3D"font-size:9.5pt;font-family=
:Arial;color:rgb(102,102,102);background-color:transparent;vertical-align:b=
aseline;white-space:pre-wrap"> | </span><a href=3D"https://www.bitrefill.co=
m/blog/" target=3D"_blank"><span style=3D"font-size:9.5pt;font-family:Arial=
;color:rgb(102,102,102);background-color:transparent;vertical-align:baselin=
e;white-space:pre-wrap">Blog</span></a><span style=3D"font-size:9.5pt;font-=
family:Arial;color:rgb(102,102,102);background-color:transparent;vertical-a=
lign:baseline;white-space:pre-wrap"> | </span><a href=3D"https://angel.co/b=
itrefill" target=3D"_blank"><span style=3D"font-size:9.5pt;font-family:Aria=
l;color:rgb(102,102,102);background-color:transparent;vertical-align:baseli=
ne;white-space:pre-wrap">Angellist </span></a><br></p></div></div></div></d=
iv></div></div></div></div></div></div></div></div>

--0000000000001b88f305eb8c2237--