summaryrefslogtreecommitdiff
path: root/db/55bf021749ba2a1b20e7fa9086b3900a62de91
blob: 912b275cf8e6669b367f845cba192e1314a2e026 (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
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 8AA69B62
	for <bitcoin-dev@lists.linuxfoundation.org>;
	Thu, 28 Sep 2017 00:58:32 +0000 (UTC)
X-Greylist: whitelisted by SQLgrey-1.7.6
Received: from mail-ua0-f175.google.com (mail-ua0-f175.google.com
	[209.85.217.175])
	by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 1C93B3D5
	for <bitcoin-dev@lists.linuxfoundation.org>;
	Thu, 28 Sep 2017 00:58:32 +0000 (UTC)
Received: by mail-ua0-f175.google.com with SMTP id v12so5812uaf.5
	for <bitcoin-dev@lists.linuxfoundation.org>;
	Wed, 27 Sep 2017 17:58:31 -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; bh=SmlEGfbkgO6YG1z93EkMWcMRdz25KC+jKnn/4pQxly8=;
	b=WnrM7AWDW+f3IyIfwgyq2e/lofjg8ifLIqRKDed7BeIb7arvGiW16d2l+WJq+1pSZO
	M2QJ4MhDJ3UpTXiQ/LVwGJix0Q4XaxT9eO/EXyI6Fdp6OXwO442NHWHZXYw7CKVyCjy/
	vqj++be9LRix1t+WdEU6fLsli8Uazp0bJO3Zd4Yw9AF5BA3xt6v8UOTHzMxp2YhxAaWo
	Xd1O/nbHViudfvP9Ow1E6L0OI2pP2Ab3c9qUHyPx95TmF4lhq3oy21YsmpGCLIC9NU+P
	3Ji4A03ascYkbqFXQnBVk0haoCp3UAriz38j8Qg0/YBk9FmBMH2U2peXQK5NpsqlfhMs
	BjCA==
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;
	bh=SmlEGfbkgO6YG1z93EkMWcMRdz25KC+jKnn/4pQxly8=;
	b=AH3d+0V5tL5Dzz+vR+64nNn60BY+C4eRDgzt5BUOA+r6QdZ9tzU51bRlyU7HKSVO94
	VB8y/Q9Heb3S30bQQY0OvXK46p8iL9TESJfLzddzTkCZD35w4nVhsir5MA2CZvkiZ9Mu
	MsXK9LNIlnmLfzB3UI6NRqq5IXqBjslyKBTTpKy1dGN0HojIrvqqCJSfOKiqA+6XZf6w
	rVMceOMF9EL6H30/CNsnBhV0/vcexkQeXK1mKoci0YrGCxxWZRRNvbbAZPRlOVm2yfBz
	wiXTHs9Nz2DeX6km/RWqCsHpBGPsTOFRfyJZrLFpqFelQNNx+/XawzCClMdF22vSoCol
	tqOg==
X-Gm-Message-State: AMCzsaULDNs3Y7gnf1MvYt+Az7Txo2iFFZ3cropwLp36iQYpgdYKG2eZ
	92n3sXJiF3ezqP/FcaiaejQ4l4ubsu1DuKI/HFo=
X-Google-Smtp-Source: AOwi7QC7X6p0g1xxUpdD6FpNIlOGiKgmQ6Ir/z2kedSiUNx0SEDydprpFQclll9ljGIzJKf8+sCmFKX9JIDJ0sjY6pY=
X-Received: by 10.176.21.109 with SMTP id p42mr2179606uae.127.1506560311280;
	Wed, 27 Sep 2017 17:58:31 -0700 (PDT)
MIME-Version: 1.0
Sender: gmaxwell@gmail.com
Received: by 10.103.146.78 with HTTP; Wed, 27 Sep 2017 17:58:30 -0700 (PDT)
In-Reply-To: <20170927160654.GA12492@savin.petertodd.org>
References: <20170927160654.GA12492@savin.petertodd.org>
From: Gregory Maxwell <greg@xiph.org>
Date: Thu, 28 Sep 2017 00:58:30 +0000
X-Google-Sender-Auth: krNz3z54X8tE8f1A8q5Q6psu608
Message-ID: <CAAS2fgRpMXdqKXeYSOtVBQQ9fmu=nQ9anEO6Wrc_5rms1Y2B2w@mail.gmail.com>
To: Peter Todd <pete@petertodd.org>, 
	Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Content-Type: text/plain; charset="UTF-8"
X-Spam-Status: No, score=0.5 required=5.0 tests=DKIM_SIGNED,DKIM_VALID,
	FREEMAIL_FROM, RCVD_IN_DNSWL_NONE, RCVD_IN_SORBS_SPAM autolearn=disabled
	version=3.3.1
X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on
	smtp1.linux-foundation.org
Subject: Re: [bitcoin-dev] Address expiration times should be added to
	BIP-173
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, 28 Sep 2017 00:58:32 -0000

On Wed, Sep 27, 2017 at 4:06 PM, Peter Todd via bitcoin-dev
<bitcoin-dev@lists.linuxfoundation.org> wrote:
> Re-use of old addresses is a major problem, not only for privacy, but also
> operationally: services like exchanges frequently have problems with users
> sending funds to addresses whose private keys have been lost or stolen; there

When Pieter and I were working on Bech32 we specifically designed for
error correcting codes that had good performance for longer lengths
than we technically needed specifically to incorporate things like
dates and explicit amounts.

(explicit amounts so that typos and bit flips in amounts displayed or
in memory couldn't result in sending the wrong amount)

But we also thought that also adding those features at the same time
would retard adoption-- both due to debating over the encodings and
because handling would result in different software requirements and
layering, so you couldn't just drop them in.

Doubly unfortunately, people have even deployed BIP173 already (prior
to it even having much peer review or being adopted by its own
authors), so I think a rethink now wouldn't be timely (I mean as a
replacement to BIP173 rather than an additional format). :(

But I do support the idea.

One thing to keep in mind is that address format linked fields are
most efficient if they're multiples of 5 bits.  Perhaps use 1 bit to
indicate an embedded amount and 19 bits of 1 day precision, resulting
in a 1435 year span.

Keep in mind that high precision of the expiration times is asking the
sender to have a higher precision of idea of the time, date only is
kinda nice.  I think shorter expiration times are unlikely to be
useful due to clock skew-- you can't assume a signer has any access to
the Bitcoin network at all.