summaryrefslogtreecommitdiff
path: root/8f/55f470dc7e1ffed1a77aed44ece54e8f42a3f2
blob: fa9da2fd4048149a2ed97ef61442297121287ae1 (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
Return-Path: <micaroni3@gmail.com>
Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138])
 by lists.linuxfoundation.org (Postfix) with ESMTP id 02CD9C002D
 for <bitcoin-dev@lists.linuxfoundation.org>;
 Mon, 11 Jul 2022 18:39:19 +0000 (UTC)
Received: from localhost (localhost [127.0.0.1])
 by smtp1.osuosl.org (Postfix) with ESMTP id C24C4826AA
 for <bitcoin-dev@lists.linuxfoundation.org>;
 Mon, 11 Jul 2022 18:39:18 +0000 (UTC)
DKIM-Filter: OpenDKIM Filter v2.11.0 smtp1.osuosl.org C24C4826AA
Authentication-Results: smtp1.osuosl.org;
 dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com
 header.a=rsa-sha256 header.s=20210112 header.b=JorIdWoA
X-Virus-Scanned: amavisd-new at osuosl.org
X-Spam-Flag: NO
X-Spam-Score: 0.852
X-Spam-Level: 
X-Spam-Status: No, score=0.852 tagged_above=-999 required=5
 tests=[BAYES_50=0.8, DKIM_SIGNED=0.1, DKIM_VALID=-0.1,
 DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1,
 FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001,
 HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001,
 SPF_PASS=-0.001] 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 65WBLOns7MNw
 for <bitcoin-dev@lists.linuxfoundation.org>;
 Mon, 11 Jul 2022 18:39:14 +0000 (UTC)
X-Greylist: whitelisted by SQLgrey-1.8.0
DKIM-Filter: OpenDKIM Filter v2.11.0 smtp1.osuosl.org 6E7EA82640
Received: from mail-lj1-x22e.google.com (mail-lj1-x22e.google.com
 [IPv6:2a00:1450:4864:20::22e])
 by smtp1.osuosl.org (Postfix) with ESMTPS id 6E7EA82640
 for <bitcoin-dev@lists.linuxfoundation.org>;
 Mon, 11 Jul 2022 18:39:14 +0000 (UTC)
Received: by mail-lj1-x22e.google.com with SMTP id o12so4646781ljc.3
 for <bitcoin-dev@lists.linuxfoundation.org>;
 Mon, 11 Jul 2022 11:39:14 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112;
 h=mime-version:references:in-reply-to:from:date:message-id:subject:to;
 bh=6CA0tH1ajRBIXnhF/lo5BaszZiUowby4BC79IVH3VOs=;
 b=JorIdWoAwdMopSUrTj3IwtDwWsyiEm2N87fiVGmOaqCPvT67cWgaOc/gAC14DSwhEI
 ro6e/VgvC96S2bcQUJnQXBOPFdLhLtSCs5kxxfqh4pBY3tARR01owLktmJgJ2KiloQ3E
 pDV29VQL1ArKJQkyvHIv/dDABD9MMCBPF4Z2QaaZa9OqKaSL7p7DjZs5egLzzdPPWIKo
 V5yJP/9E0TXydF/xS/Zzq4T1IpUPr2A/Vm1tyEmnFz/8JkRaf7mx8gYqh8fhasf+hahH
 fWsWF+ZCQ0DLclm+R2dZb7Lq/WTEUAUpS6xpUuQD60E0nXj4o2o/8Pg1p+DeuVVQ0G+X
 YVvw==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
 d=1e100.net; s=20210112;
 h=x-gm-message-state:mime-version:references:in-reply-to:from:date
 :message-id:subject:to;
 bh=6CA0tH1ajRBIXnhF/lo5BaszZiUowby4BC79IVH3VOs=;
 b=AEEBxwJdcZ4WYfw1gRJ0BQl4qbpN/6TvLZZ3D1b7d3QGLbAvOsQAH9pIuTPvsByHp5
 hu1tlwVe87n3ZIqxecZEG/9D8oIPFSHcSVZObBOfd9loqew4vucUxRbVdXLyKy4vzR7Q
 nJ2aeJC3GwoZM5AwUXHW0VpI+u9IZIQy3mANauso+z5VWqfp2rVSatgMR0tROkMcwYSn
 sfiWBS5ETQ8xj8CSkb+GFKm2k92XYaFW0pDDnAS3lU5aXwnbDAlr6bYjJzwoJAs8rcIU
 25qKSV/sQbtMJZFFUngNKuBtMvsKeQJmPnbrFozVLDAkLKFpT3bu68au75YxT41OTJCU
 oj5w==
X-Gm-Message-State: AJIora8ZfrQE9kYop57Hi1SNBf4kg45ubXVUernzAILqx6NF44MQ7Xhp
 fSccFz07GeyOeMMHgBq1hoJcT9ZBd3ZUT6NQLAs=
X-Google-Smtp-Source: AGRyM1tsx7CkpW9lfFC72wD42/2b3QeBGQQKN16y6Tcia+cblCjvfwgZBC31MjPBrNgk1pWLjDCPO/zuL9m64ZG7SMo=
X-Received: by 2002:a05:651c:211f:b0:25a:86c4:bfe4 with SMTP id
 a31-20020a05651c211f00b0025a86c4bfe4mr11042100ljq.531.1657564752193; Mon, 11
 Jul 2022 11:39:12 -0700 (PDT)
MIME-Version: 1.0
References: <CAHUJnBDYDbgr3C158o7c6_XXdG+kqJruFo=od_RmPFk_GS0udw@mail.gmail.com>
In-Reply-To: <CAHUJnBDYDbgr3C158o7c6_XXdG+kqJruFo=od_RmPFk_GS0udw@mail.gmail.com>
From: micaroni@gmail.com
Date: Mon, 11 Jul 2022 15:38:34 -0300
Message-ID: <CAHvMVPTi5wLzNvW6z2F7aEcKd=Sqwqr39_W7rCQMbSN_hWApYQ@mail.gmail.com>
To: Bram Cohen <bram@chia.net>, 
 Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Content-Type: multipart/alternative; boundary="0000000000003f30ec05e38bde5f"
X-Mailman-Approved-At: Mon, 11 Jul 2022 23:06:55 +0000
Subject: Re: [bitcoin-dev] Security problems with relying on transaction
 fees for security
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: Mon, 11 Jul 2022 18:39:19 -0000

--0000000000003f30ec05e38bde5f
Content-Type: text/plain; charset="UTF-8"

The expectation is that in a few years a space in the block will be very
competitive / expensive and be used only as a bridge for second layers or
big transactions. Who would have thought in 2017 that one day we would be
worried about cheap rates!

Anyway, it seems like a good point and I suggest giving this issue some
name for easy and later reference.


On Mon, Jul 11, 2022 at 3:20 PM Bram Cohen via bitcoin-dev <
bitcoin-dev@lists.linuxfoundation.org> wrote:

> If transaction fees came in at an even rate over time all at the exact
> same level then they work fine for security, acting similarly to fixed
> block rewards. Unfortunately that isn't how it works in the real world.
> There's a very well established day/night cycle with fees going to zero
> overnight and even longer gaps on weekends and holidays. If in the future
> Bitcoin is entirely dependent on fees for security (scheduled very
> strongly) and this pattern keeps up (overwhelmingly likely) then this is
> going to become a serious problem.
>
> What's likely to happen is that at first there will simply be no or very
> few blocks mined overnight. There are likely to be some, as miners at first
> turn off their mining rigs completely overnight then adopt the more
> sophisticated strategy of waiting until there are enough fees in the
> mempool to warrant attempting to make a block and only then doing it.
> Unfortunately the gaming doesn't end there. Eventually the miners with
> lower costs of operation will figure out that they can collectively reorg
> the last hour (or some time period) of the day overnight and this will be
> profitable. That's likely to cause the miners with more expensive
> operations to stop attempting mining the last hour of the day preemptively.
>
> What happens after that I'm not sure. There are a small enough number of
> miners with a quirky enough distribution of costs of operation and
> profitability that the dynamic is heavily dependent on those specifics, but
> the beginnings of a slippery slope to a mining cabal which reorgs everyone
> else out of existence and eventually 51% attacks the whole thing have
> begun. It even gets worse than that because once there's a cabal
> aggressively reorging anyone else out when they make a block other miners
> will shut down and rapidly lose the ability to quickly spin up again, so
> the threshold needed for that 51% attack will keep going down.
>
> In short, relying completely on transaction fees for security is likely to
> be a disaster. What we can say from existing experience is that having
> transaction fees be about 10% of rewards on average works well. It's enough
> to incentivize collecting fees but not so much that it makes incentives get
> all weird. 90% transaction fees is probably very bad. 50% works but runs
> the risk of spikes getting too high.
>
> There are a few possible approaches to fixes. One would be to drag most of
> east asia eastward to a later time zone thus smoothing out the day/night
> cycle but that's probably unrealistic. Another would be to hard fork in
> fixed rewards in perpetuity, which is slightly less unrealistic but still
> extremely problematic.
>
> Much more actionable are measures which smooth out fees over time. Having
> wallets opportunistically collect their dust during times of low
> transaction fees would help and would save users on fees. Also making UX
> which clarifies when things are likely to take a day or week but that it's
> reliable would be a reasonable thing to do, but users unfortunately are
> very averse to transactions taking a while.
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev@lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>

--0000000000003f30ec05e38bde5f
Content-Type: text/html; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr"><div><span class=3D"gmail_default" style=3D"font-family:ar=
ial,helvetica,sans-serif;font-size:small;color:rgb(0,0,0)"></span>The expec=
tation is that in a few years a space in the block will be very competitive=
 <span class=3D"gmail_default" style=3D"font-family:arial,helvetica,sans-se=
rif;font-size:small;color:rgb(0,0,0)">/</span> expensive<span class=3D"gmai=
l_default" style=3D"font-family:arial,helvetica,sans-serif;font-size:small;=
color:rgb(0,0,0)"> </span>and be used only as a bridge for second layers or=
 big transactions.<span class=3D"gmail_default" style=3D"font-family:arial,=
helvetica,sans-serif;font-size:small;color:rgb(0,0,0)"> Who would have thou=
ght in 2017 that one day we would be worried about cheap rates!</span></div=
><div><span class=3D"gmail_default" style=3D"font-family:arial,helvetica,sa=
ns-serif;font-size:small;color:rgb(0,0,0)"><br></span></div><div><span clas=
s=3D"gmail_default" style=3D"font-family:arial,helvetica,sans-serif;font-si=
ze:small;color:rgb(0,0,0)">Anyway, it seems like a good point and I suggest=
 giving this issue some name for easy and later reference.</span></div><div=
><span class=3D"gmail_default" style=3D"font-family:arial,helvetica,sans-se=
rif;font-size:small;color:rgb(0,0,0)"><br></span></div><div><br></div><div =
class=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On Mon, Jul 11,=
 2022 at 3:20 PM Bram Cohen via bitcoin-dev &lt;<a href=3D"mailto:bitcoin-d=
ev@lists.linuxfoundation.org">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(204,204,204);padding-left:1ex"><div dir=
=3D"ltr">If transaction fees came in at an even rate over time all at the e=
xact same level then they work fine for security, acting similarly to fixed=
 block rewards. Unfortunately that isn&#39;t how it works in the real world=
. There&#39;s a very well established day/night cycle with fees going to ze=
ro overnight and even longer gaps on weekends and holidays. If in the futur=
e Bitcoin is entirely dependent on fees for security (scheduled very strong=
ly) and this pattern keeps up (overwhelmingly likely) then this is going to=
 become a serious problem.<div><br></div><div>What&#39;s likely to happen i=
s that at first there will simply be no or very few blocks mined overnight.=
 There are likely to be some, as miners at first turn off their mining rigs=
 completely overnight then adopt the more sophisticated strategy of waiting=
 until there are enough fees in the mempool to warrant attempting to make a=
 block and only then doing it. Unfortunately the gaming doesn&#39;t end the=
re. Eventually the miners with lower costs of operation will figure out tha=
t they can collectively reorg the last hour (or some time period) of the da=
y overnight and this will be profitable. That&#39;s likely to cause the min=
ers with more expensive operations to stop attempting mining the last hour =
of the day preemptively.=C2=A0</div><div><br></div><div>What happens after =
that I&#39;m not sure. There are a small enough number of miners with a qui=
rky enough distribution of costs of operation and profitability that the dy=
namic is heavily dependent on those specifics, but the beginnings of a slip=
pery slope to a mining cabal which reorgs everyone else out of existence an=
d eventually 51% attacks the whole thing have begun. It even gets worse tha=
n that because once there&#39;s a cabal aggressively reorging anyone else o=
ut when they make a block other miners will shut down and rapidly lose the =
ability to quickly spin up again, so the threshold needed for that 51% atta=
ck will keep going down.</div><div><br></div><div>In short, relying complet=
ely on transaction fees for security is likely to be a disaster. What we ca=
n say from existing experience is that having transaction fees be about 10%=
 of rewards on average works well. It&#39;s enough to incentivize collectin=
g fees but not so much that it makes incentives get all weird. 90% transact=
ion fees is probably very bad. 50% works but runs the risk of spikes gettin=
g too high.</div><div><br></div><div>There are a few possible approaches to=
 fixes. One would be to drag most of east asia eastward to a later time zon=
e thus smoothing out the day/night cycle but that&#39;s probably unrealisti=
c. Another would be to hard fork in fixed rewards in perpetuity, which is s=
lightly less unrealistic but still extremely problematic.=C2=A0</div><div><=
br></div><div>Much more actionable are measures which smooth out fees over =
time. Having wallets opportunistically collect their dust during times of l=
ow transaction fees would help and would save users on fees. Also making UX=
 which clarifies when things are likely to take a day or week but that it&#=
39;s reliable would be a reasonable thing to do, but users unfortunately ar=
e very averse to transactions taking a while.</div></div>
_______________________________________________<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></div>

--0000000000003f30ec05e38bde5f--