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
|
Return-Path: <gmaxwell@gmail.com>
Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org
[172.17.192.35])
by mail.linuxfoundation.org (Postfix) with ESMTPS id 55D59483
for <bitcoin-dev@lists.linuxfoundation.org>;
Thu, 17 May 2018 18:34:48 +0000 (UTC)
X-Greylist: whitelisted by SQLgrey-1.7.6
Received: from mail-ua0-f174.google.com (mail-ua0-f174.google.com
[209.85.217.174])
by smtp1.linuxfoundation.org (Postfix) with ESMTPS id C23716D0
for <bitcoin-dev@lists.linuxfoundation.org>;
Thu, 17 May 2018 18:34:47 +0000 (UTC)
Received: by mail-ua0-f174.google.com with SMTP id g9-v6so3648105uak.7
for <bitcoin-dev@lists.linuxfoundation.org>;
Thu, 17 May 2018 11:34:47 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025;
h=mime-version:sender:in-reply-to:references:from:date:message-id
:subject:to:cc;
bh=WkRERrfrM+p9UFIeLWhfLH5bRHn/aoxSsjfaAgXBslA=;
b=VCLrob63HY4dXjoQoh5/0P8zJkuBcFuDIvGB73Hxt5Z41iG3k736BowF+C34Z62vfh
R1xJN2zv3m80GHJ7rkqx+8Vmx9M7XjLVbF8my6JcpOsQX0KO42sWGFtbQJdgaY13fZos
4UDfVQkhEdBeEq9g6BhsBSzNwDxoS/jKNi0tYL+w5ifWODMw7ce6+I/pMw5fyRvcjzqg
nJEnqo/mDgDERozePcskNxtUdqxLYvtJY/IefJunwOPK/5HAMpPCbguXamK2EXjKFEk3
R4aodhgKVmjcVkU+AiUQPKCihOonOMtWudUPZXc3rdpsg/D0svzGayJlsBU/BbFfJ3Fd
3lqQ==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=1e100.net; s=20161025;
h=x-gm-message-state:mime-version:sender:in-reply-to:references:from
:date:message-id:subject:to:cc;
bh=WkRERrfrM+p9UFIeLWhfLH5bRHn/aoxSsjfaAgXBslA=;
b=a1atulJ/V0Hov073hR00LLBPzV5wiHrXHl4Sy3UQ5znaWk6NWabZkaOboZ8BdW12bb
Nk5lxo/2zIsBgh8B/PjaHbPU3/+pxk8tuVm5sDAPfxxqsZtB8V4HRltCEo0yB5i9hH8b
swLHNFajBKaNK22GSZ7gkzfzGjw7E/Ok2W8+YDS6HpJakYDktBQiqqMwZAOTSLMn+PfX
jX2vsX23qoCmSljGGVjqADHbMAclLopiycjwQ5IHTMLNL1bSwg07T5ZPMnuYNx6ufyGw
Rmg1IXjmSSdNHBeSkonnxKR2T2haArl6yo1tLCyU8OVC2oqBkxfMCUtfPXzQteJ0ChC6
uTJA==
X-Gm-Message-State: ALKqPwcq9FIwARUPAVIIjySEshtKjECssdcOZsix12RUtTsKxjmkuLj7
UwcmpXaoNgTUcFkhSMZa6EIihGiLr6qqMVtBSAM=
X-Google-Smtp-Source: AB8JxZojI0+OaYAbCkW6XpydL9JL/8g1NfrKZ0rKx/ftic1zTrXxBKWY9iUEAvXKlbpf6d2vpcIyVrv92rZvMO3QRuk=
X-Received: by 2002:ab0:1092:: with SMTP id
d18-v6mr5150705uab.87.1526582086905;
Thu, 17 May 2018 11:34:46 -0700 (PDT)
MIME-Version: 1.0
Sender: gmaxwell@gmail.com
Received: by 10.103.81.132 with HTTP; Thu, 17 May 2018 11:34:45 -0700 (PDT)
In-Reply-To: <22d375c7-a032-8691-98dc-0e6ee87a4b08@mattcorallo.com>
References: <d43c6082-1b2c-c95b-5144-99ad0021ea6c@mattcorallo.com>
<CAAS2fgRF-MhOvpFY6c_qAPzNMo3GQ28RExdSbOV6Q6Oy2iWn1A@mail.gmail.com>
<22d375c7-a032-8691-98dc-0e6ee87a4b08@mattcorallo.com>
From: Gregory Maxwell <greg@xiph.org>
Date: Thu, 17 May 2018 18:34:45 +0000
X-Google-Sender-Auth: pKkCF3uwd3M8SrYeFYhbooAem-0
Message-ID: <CAAS2fgR3QRHeHEjjOS1ckEkL-h7=Na56G12hYW9Bmy9WEMduvg@mail.gmail.com>
To: Matt Corallo <lf-lists@mattcorallo.com>
Content-Type: text/plain; charset="UTF-8"
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,DKIM_SIGNED,
DKIM_VALID, FREEMAIL_FROM,
RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1
X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on
smtp1.linux-foundation.org
Cc: Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] BIP 158 Flexibility and Filter Size
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: Thu, 17 May 2018 18:34:48 -0000
On Thu, May 17, 2018 at 4:59 PM, Matt Corallo <lf-lists@mattcorallo.com> wrote:
> Yea I generally would really prefer something like that but it
> significantly complicates the download logic - currently clients can
> easily cross-check [...] Maybe
> there is some other reasonable download logic to replace it with, however.
I think lite clients cross checking is something which very likely
will never be implemented by anyone, and probably not stay working
(due to under-usage) if it is implemented. This thought is driven by
three things (1) the bandwidth overhead of performing the check, (2)
thinking about the network-interacting-state-machine complexity of it,
and by the multitude of sanity checks that lite clients already don't
implement (e.g. when a lite client noticed a split tip it could ask
peers for the respective blocks and check at least the stateless
checks, but none has ever done that), and...
(3) that kind of checking would be moot if the filters were committed
and validated... and the commitment would be both much simpler to
check for lite clients and provide much stronger protection against
malicious peers.
My expectation is that eventually one of these filter-map designs
would become committed-- not after we already had it deployed and had
worked out the design to the n-th generation (just as your proposed
revisions are doing to the initial proposal), but eventually.
Also, even without this change clients can still do that "are multiple
peers telling me the same thing or different things" kind of checking,
which I expect is the strongest testing we'd actually see them
implement absent a commitment.
|
