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
|
Return-Path: <jl2012@xbt.hk>
Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org
[172.17.192.35])
by mail.linuxfoundation.org (Postfix) with ESMTPS id 050BD256
for <bitcoin-dev@lists.linuxfoundation.org>;
Fri, 20 May 2016 11:34:13 +0000 (UTC)
X-Greylist: from auto-whitelisted by SQLgrey-1.7.6
Received: from s47.web-hosting.com (s47.web-hosting.com [199.188.200.16])
by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 942561D1
for <bitcoin-dev@lists.linuxfoundation.org>;
Fri, 20 May 2016 11:34:12 +0000 (UTC)
Received: from neubau-gw.kalkbreite.net ([62.12.170.156]:32061
helo=[172.27.201.177])
by server47.web-hosting.com with esmtpsa (TLSv1:DHE-RSA-AES256-SHA:256)
(Exim 4.86_1) (envelope-from <jl2012@xbt.hk>)
id 1b3igz-000s12-MA; Fri, 20 May 2016 07:34:10 -0400
From: Johnson Lau <jl2012@xbt.hk>
Content-Type: multipart/alternative;
boundary="Apple-Mail=_B8560957-882F-481C-8B0F-9AA06396F04D"
Message-Id: <CBBB62CD-2E30-4C9F-962E-3F340B29EDA7@xbt.hk>
Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\))
Date: Fri, 20 May 2016 13:34:03 +0200
References: <CAAEDBiEB_RXBjrLB8kDb52bJOwZK-arVeHA_9LyoDgAraLKHNg@mail.gmail.com>
To: Matthew Roberts <matthew@roberts.pm>,
bitcoin-dev <bitcoin-dev@lists.linuxfoundation.org>
In-Reply-To: <CAAEDBiEB_RXBjrLB8kDb52bJOwZK-arVeHA_9LyoDgAraLKHNg@mail.gmail.com>
X-Mailer: Apple Mail (2.3124)
X-AntiAbuse: This header was added to track abuse,
please include it with any abuse report
X-AntiAbuse: Primary Hostname - server47.web-hosting.com
X-AntiAbuse: Original Domain - lists.linuxfoundation.org
X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12]
X-AntiAbuse: Sender Address Domain - xbt.hk
X-Get-Message-Sender-Via: server47.web-hosting.com: authenticated_id:
jl2012@xbt.hk
X-Authenticated-Sender: server47.web-hosting.com: jl2012@xbt.hk
X-Source:
X-Source-Args:
X-Source-Dir:
X-From-Rewrite: unmodified, already matched
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,HTML_MESSAGE,
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
Subject: Re: [bitcoin-dev] BIP: OP_PRANDOM
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: Fri, 20 May 2016 11:34:13 -0000
--Apple-Mail=_B8560957-882F-481C-8B0F-9AA06396F04D
Content-Transfer-Encoding: quoted-printable
Content-Type: text/plain;
charset=us-ascii
Using the hash of multiple blocks does not make it any safer. The miner =
of the last block always determines the results, by knowing the hashes =
of all previous blocks.
>=20
> =3D=3D Security
> Pay-to-script-hash can be used to protect the details of contracts =
that use OP_PRANDOM from the prying eyes of miners. However, since there =
is also a non-zero risk that a participant in a contract may attempt to =
bribe a miner the inclusion of multiple block hashes as a source of =
randomness is a must. Every miner would effectively need to be bribed to =
ensure control over the results of the random numbers, which is already =
very unlikely. The risk approaches zero as N goes up.
--Apple-Mail=_B8560957-882F-481C-8B0F-9AA06396F04D
Content-Transfer-Encoding: 7bit
Content-Type: text/html;
charset=us-ascii
<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div>Using the hash of multiple blocks does not make it any safer. The miner of the last block always determines the results, by knowing the hashes of all previous blocks.</div><div><br class=""></div><div><blockquote type="cite" class=""><div dir="ltr" class=""><p style="margin-bottom:0in;line-height:100%" class=""><br class="">
</p><p style="margin-bottom:0in;line-height:100%" class="">== Security</p><p style="margin-bottom:0in;line-height:100%" class="">Pay-to-script-hash
can be used to protect the details of contracts that use OP_PRANDOM
from the prying eyes of miners. However, since there is also a
non-zero risk that a participant in a contract may attempt to bribe a
miner the inclusion of multiple block hashes as a source of
randomness is a must. Every miner would effectively need to be bribed
to ensure control over the results of the random numbers, which is
already very unlikely. The risk approaches zero as N goes up.</p></div></blockquote></div><br class=""></body></html>
--Apple-Mail=_B8560957-882F-481C-8B0F-9AA06396F04D--
|
