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
|
Return-Path: <voisine@gmail.com>
Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org
[172.17.192.35])
by mail.linuxfoundation.org (Postfix) with ESMTPS id 7A7D487A
for <bitcoin-dev@lists.linuxfoundation.org>;
Wed, 4 Jan 2017 08:56:33 +0000 (UTC)
X-Greylist: whitelisted by SQLgrey-1.7.6
Received: from mail-qk0-f172.google.com (mail-qk0-f172.google.com
[209.85.220.172])
by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 9484CCD
for <bitcoin-dev@lists.linuxfoundation.org>;
Wed, 4 Jan 2017 08:56:32 +0000 (UTC)
Received: by mail-qk0-f172.google.com with SMTP id a20so5039761qkc.1
for <bitcoin-dev@lists.linuxfoundation.org>;
Wed, 04 Jan 2017 00:56:32 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025;
h=mime-version:references:in-reply-to:from:date:message-id:subject:to;
bh=L/xVMFJb+ljppAupkmweCOkFrerEBnmyqAyZU+CYdSY=;
b=NYoCx5MBJg6OAmLIW9hBVgN3jP/voRynECKt5zYo0Q9tD/Qfcs1CCFie/eymOiT/3Q
4xHQTzmRPGYwMzBGBFJIOaZvG//p/Qsyaf0Db5a0tmqU9EuX/hTDeayeobV2XVnxHinh
5LFB+vYX+E9JuaCIDvRY9KntjBln7d2rRK0ck/f8jd1EIk1OWF4Sa0rfXLbkPt6paxL3
NAuBqjktrdUHhMKgkztGl3n58gdQgBJzDm3Mryp7r+zMsV2+0HmMs1kM3i3mPj8znLEb
EvKT6uzC09xXcyMxVtXcs/qWwNpSxqyT1VMuA2O49y7YW0WwjgBNf/mbz3N7fOB+7sPC
mLtA==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=1e100.net; s=20161025;
h=x-gm-message-state:mime-version:references:in-reply-to:from:date
:message-id:subject:to;
bh=L/xVMFJb+ljppAupkmweCOkFrerEBnmyqAyZU+CYdSY=;
b=uW6O4Ynp71SAAR+b9KZogDJ19SIraD4rv3jFiuHBX/sSVZiS8tXZIsNtCX4Zx47BMl
x4RJFyMI6JiCgNmELP9hZVDmmNo/RZPPgZxLy1RR+nwD155DAuW/ZxL4OeH3EWQaX2Td
CE1Z9yOlUHJ0p5fSBl7+0mQrOQhp3hAV+1D+VgRh42F8zg6nzOvJ5Kb0hDYDLJf1jeim
zQw0vvkJ8IJFNF0fq9XOF6M2kGLEk7n34i+9F+4C7enb3lkDZPTR4uRpmQ5A1mOCQKp6
c5j39StdGf5SFqb5vhhfmWf3FUPCgkEe9GQu7e357l+UONz1mC+/S/ojOUOtIoX4A+di
d5hw==
X-Gm-Message-State: AIkVDXIpJ2uuFYv8Y5Ps7oIfYTGnVfx0s+o+hzfnF7Tvwmclve5NwDJ00H+kvHqvB0FgCSmHOO+5kU76o7CRUQ==
X-Received: by 10.55.93.131 with SMTP id r125mr64744760qkb.258.1483520191740;
Wed, 04 Jan 2017 00:56:31 -0800 (PST)
MIME-Version: 1.0
References: <71d822e413ac457a530e1c367811cc24@cock.lu>
<77b6dd25-0603-a0bd-6a9e-38098e5cb19d@jonasschnelli.ch>
<74aeb4760316b59a3db56c0d16d11f28@cock.lu>
<CACq0ZD7XT_h8ADptKA0uBT7617fvvgh3uGndkc08RZUSQM2yQg@mail.gmail.com>
<f335731c-3928-6694-5ed8-aa1999b401f1@jonasschnelli.ch>
In-Reply-To: <f335731c-3928-6694-5ed8-aa1999b401f1@jonasschnelli.ch>
From: Aaron Voisine <voisine@gmail.com>
Date: Wed, 04 Jan 2017 08:56:21 +0000
Message-ID: <CACq0ZD7xdYVaBGs-xCjN2RFKcF5q_RNA1nRmjgU-k2x9VotY_Q@mail.gmail.com>
To: Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>,
Jonas Schnelli <dev@jonasschnelli.ch>, bfd@cock.lu
Content-Type: multipart/alternative; boundary=001a114e6ace0bcbd3054540f636
X-Spam-Status: No, score=-2.2 required=5.0 tests=BAYES_00,DKIM_SIGNED,
DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, HTML_MESSAGE,
RCVD_IN_DNSWL_LOW,
RCVD_IN_SORBS_SPAM autolearn=ham version=3.3.1
X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on
smtp1.linux-foundation.org
Subject: Re: [bitcoin-dev] Committed bloom filters for improved wallet
performance and SPV security
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, 04 Jan 2017 08:56:33 -0000
--001a114e6ace0bcbd3054540f636
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
It's easy enough to mark a transaction as "pending". People with bank
accounts are familiar with the concept.
Although the risk of accepting gossip information from multiple random
peers, in the case where the sender does not control the receivers network
is still minimal. Random node operators have no incentive to send fake
transactions, and would need to control all the nodes a client connects to,
and find a non-false-positive address belonging to the victims wallet.
It's not impossible, but it's non trivial, would only temporarily show a
pending transaction, and provide no benefit to the node operator. There are
much juicier targets for an attacker with the ability to sybil attack the
entire bitcoin p2p network.
Aaron
On Tue, Jan 3, 2017 at 11:47 PM Jonas Schnelli <dev@jonasschnelli.ch> wrote=
:
> Hi
>
>
>
> > Unconfirmed transactions are incredibly important for real world use.
>
> > Merchants for instance are willing to accept credit card payments of
>
> > thousands of dollars and ship the goods despite the fact that the
>
> > transaction can be reversed up to 60 days later. There is a very large
>
> > cost to losing the ability to have instant transactions in many or
>
> > even most situations. This cost is typically well above the fraud risk.
>
> >
>
> > It's important to recognize that bitcoin serves a wide variety of use
>
> > cases with different profiles for time sensitivity and fraud risk.
>
> >
>
> I agree that unconfirmed transactions are incredibly important, but not
>
> over SPV against random peers.
>
>
>
> If you offer users/merchants a feature (SPV 0-conf against random
>
> peers), that is fundamentally insecure, it will =E2=80=93 sooner or later=
=E2=80=93 lead
>
> to some large scale fiasco, hurting Bitcoins reputation and trust from
>
> merchants.
>
>
>
> Merchants using and trusting 0-conf SPV transactions (retrieved from
>
> random peers) is something we should **really eliminate** through
>
> education and by offering different solution.
>
>
>
> There are plenty, more sane options. If you can't run your own full-node
>
> as a merchant (trivial), maybe co-use a wallet-service with centralized
>
> verification (maybe use two of them), I guess Copay would be one of
>
> those wallets (as an example). Use them in watch-only mode.
>
>
>
> For end-users SPV software, I think it would be recommended to...
>
> ... disable unconfirmed transactions during SPV against random peers
>
> ... enable unconfirmed transactions when using SPV against a trusted
>
> peer with preshared keys after BIP150
>
> ... if unconfirmed transactions are disabled, show how it can be enabled
>
> (how to run a full-node [in a box, etc.])
>
> ... educate, inform users that a transaction with no confirmation can be
>
> "stopped" or "redirected" any time, also inform about the risks during
>
> low-conf phase (1-5).
>
>
>
> I though see the point that it's nice to make use of the "incoming
>
> funds..." feature in SPV wallets. But =E2=80=93 for the sake of stability=
and
>
> (risk-)scaling =E2=80=93 we may want to recommend to scarify this feature=
and =E2=80=93
>
> in the same turn =E2=80=93 to use privacy-preserving BFD's.
>
>
>
> </jonas>
>
>
>
>
>
>
--001a114e6ace0bcbd3054540f636
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
<div>It's easy enough to mark a transaction as "pending". Peo=
ple with bank accounts are familiar with the concept.</div><div><br></div><=
div>Although the risk of accepting gossip information from multiple random =
peers, in the case where the sender does not control the receivers network =
is still minimal. Random node operators have no incentive to send fake tran=
sactions, and would need to control all the nodes a client connects to, and=
find a non-false-positive address belonging to the victims wallet.=C2=A0</=
div><div><br></div><div>It's not impossible, but it's non trivial, =
would only temporarily show a pending transaction, and provide no benefit t=
o the node operator. There are much juicier targets for an attacker with th=
e ability to sybil attack the entire bitcoin p2p network.</div><div><br></d=
iv><div>Aaron</div><div><br><div class=3D"gmail_quote"><div>On Tue, Jan 3, =
2017 at 11:47 PM Jonas Schnelli <<a href=3D"mailto:dev@jonasschnelli.ch"=
>dev@jonasschnelli.ch</a>> wrote:<br></div><blockquote class=3D"gmail_qu=
ote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex=
">Hi<br class=3D"gmail_msg"><br><br class=3D"gmail_msg"><br>> Unconfirme=
d transactions are incredibly important for real world use.<br class=3D"gma=
il_msg"><br>> Merchants for instance are willing to accept credit card p=
ayments of<br class=3D"gmail_msg"><br>> thousands of dollars and ship th=
e goods despite the fact that the<br class=3D"gmail_msg"><br>> transacti=
on can be reversed up to 60 days later. There is a very large<br class=3D"g=
mail_msg"><br>> cost to losing the ability to have instant transactions =
in many or<br class=3D"gmail_msg"><br>> even most situations. This cost =
is typically well above the fraud risk.<br class=3D"gmail_msg"><br>><br =
class=3D"gmail_msg"><br>> It's important to recognize that bitcoin s=
erves a wide variety of use<br class=3D"gmail_msg"><br>> cases with diff=
erent profiles for time sensitivity and fraud risk.<br class=3D"gmail_msg">=
<br>><br class=3D"gmail_msg"><br>I agree that unconfirmed transactions a=
re incredibly important, but not<br class=3D"gmail_msg"><br>over SPV agains=
t random peers.<br class=3D"gmail_msg"><br><br class=3D"gmail_msg"><br>If y=
ou offer users/merchants a feature (SPV 0-conf against random<br class=3D"g=
mail_msg"><br>peers), that is fundamentally insecure, it will =E2=80=93 soo=
ner or later =E2=80=93 lead<br class=3D"gmail_msg"><br>to some large scale =
fiasco, hurting Bitcoins reputation and trust from<br class=3D"gmail_msg"><=
br>merchants.<br class=3D"gmail_msg"><br><br class=3D"gmail_msg"><br>Mercha=
nts using and trusting 0-conf SPV transactions (retrieved from<br class=3D"=
gmail_msg"><br>random peers) is something we should **really eliminate** th=
rough<br class=3D"gmail_msg"><br>education and by offering different soluti=
on.<br class=3D"gmail_msg"><br><br class=3D"gmail_msg"><br>There are plenty=
, more sane options. If you can't run your own full-node<br class=3D"gm=
ail_msg"><br>as a merchant (trivial), maybe co-use a wallet-service with ce=
ntralized<br class=3D"gmail_msg"><br>verification (maybe use two of them), =
I guess Copay would be one of<br class=3D"gmail_msg"><br>those wallets (as =
an example). Use them in watch-only mode.<br class=3D"gmail_msg"><br><br cl=
ass=3D"gmail_msg"><br>For end-users SPV software, I think it would be recom=
mended to...<br class=3D"gmail_msg"><br>... disable unconfirmed transaction=
s during SPV against random peers<br class=3D"gmail_msg"><br>... enable unc=
onfirmed transactions when using SPV against a trusted<br class=3D"gmail_ms=
g"><br>peer with preshared keys after BIP150<br class=3D"gmail_msg"><br>...=
if unconfirmed transactions are disabled, show how it can be enabled<br cl=
ass=3D"gmail_msg"><br>(how to run a full-node [in a box, etc.])<br class=3D=
"gmail_msg"><br>... educate, inform users that a transaction with no confir=
mation can be<br class=3D"gmail_msg"><br>"stopped" or "redir=
ected" any time, also inform about the risks during<br class=3D"gmail_=
msg"><br>low-conf phase (1-5).<br class=3D"gmail_msg"><br><br class=3D"gmai=
l_msg"><br>I though see the point that it's nice to make use of the &qu=
ot;incoming<br class=3D"gmail_msg"><br>funds..." feature in SPV wallet=
s. But =E2=80=93 for the sake of stability and<br class=3D"gmail_msg"><br>(=
risk-)scaling =E2=80=93 we may want to recommend to scarify this feature an=
d =E2=80=93<br class=3D"gmail_msg"><br>in the same turn =E2=80=93 to use pr=
ivacy-preserving BFD's.<br class=3D"gmail_msg"><br><br class=3D"gmail_m=
sg"><br></jonas><br class=3D"gmail_msg"><br><br class=3D"gmail_msg"><=
br><br class=3D"gmail_msg"><br></blockquote></div></div>
--001a114e6ace0bcbd3054540f636--
|
