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
|
Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192]
helo=mx.sourceforge.net)
by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76)
(envelope-from <gcbd-bitcoin-development@m.gmane.org>)
id 1WQweZ-00016i-67 for bitcoin-development@lists.sourceforge.net;
Fri, 21 Mar 2014 10:26:19 +0000
Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of m.gmane.org
designates 80.91.229.3 as permitted sender)
client-ip=80.91.229.3;
envelope-from=gcbd-bitcoin-development@m.gmane.org;
helo=plane.gmane.org;
Received: from plane.gmane.org ([80.91.229.3])
by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256)
(Exim 4.76) id 1WQweX-0007UO-Ax
for bitcoin-development@lists.sourceforge.net;
Fri, 21 Mar 2014 10:26:19 +0000
Received: from list by plane.gmane.org with local (Exim 4.69)
(envelope-from <gcbd-bitcoin-development@m.gmane.org>)
id 1WQweQ-0004e7-H8 for bitcoin-development@lists.sourceforge.net;
Fri, 21 Mar 2014 11:26:10 +0100
Received: from e179064016.adsl.alicedsl.de ([85.179.64.16])
by main.gmane.org with esmtp (Gmexim 0.1 (Debian))
id 1AlnuQ-0007hv-00 for <bitcoin-development@lists.sourceforge.net>;
Fri, 21 Mar 2014 11:26:10 +0100
Received: from andreas by e179064016.adsl.alicedsl.de with local (Gmexim 0.1
(Debian)) id 1AlnuQ-0007hv-00
for <bitcoin-development@lists.sourceforge.net>;
Fri, 21 Mar 2014 11:26:10 +0100
X-Injected-Via-Gmane: http://gmane.org/
To: bitcoin-development@lists.sourceforge.net
From: Andreas Schildbach <andreas@schildbach.de>
Date: Fri, 21 Mar 2014 11:25:59 +0100
Message-ID: <lgh438$tnn$1@ger.gmane.org>
References: <lc5hmg$1jh$1@ger.gmane.org>
<leuunm$tjk$1@ger.gmane.org> <CANEZrP3nQfvDArKTRgje0Cus4G2JD_zpxSjA3fXfxM2TNAP80Q@mail.gmail.com> <CALDj+BafD+6KTNcYDBEu5gNPzYozSkiC-JCxrY-PzXL2DYBRsw@mail.gmail.com> <CAJHLa0N4J_Z907+D0ENSNKfNAW2N=7Jf4JzSCO=SU558GtGTzA@mail.gmail.com> <lge7nk$3mf$2@ger.gmane.org> <CANEZrP0J849oDvMWjf8LWi0xj44Q8DaUwDip5_smVBMNgeQ3mw@mail.gmail.com>
<20140320121221.GA25052@netbook.cypherspace.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
X-Complaints-To: usenet@ger.gmane.org
X-Gmane-NNTP-Posting-Host: e179064016.adsl.alicedsl.de
User-Agent: Mozilla/5.0 (X11; Linux x86_64;
rv:24.0) Gecko/20100101 Thunderbird/24.3.0
In-Reply-To: <20140320121221.GA25052@netbook.cypherspace.org>
X-Enigmail-Version: 1.5.2
X-Spam-Score: -0.4 (/)
X-Spam-Report: Spam Filtering performed by mx.sourceforge.net.
See http://spamassassin.org/tag/ for more details.
-1.5 SPF_CHECK_PASS SPF reports sender host as permitted sender for
sender-domain
-0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/,
no trust [80.91.229.3 listed in list.dnswl.org]
-0.0 SPF_HELO_PASS SPF: HELO matches SPF record
1.1 DKIM_ADSP_ALL No valid author signature,
domain signs all mail
-0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay
domain
-0.0 SPF_PASS SPF: sender matches SPF record
X-Headers-End: 1WQweX-0007UO-Ax
Subject: Re: [Bitcoin-development] Payment Protocol for Face-to-face Payments
X-BeenThere: bitcoin-development@lists.sourceforge.net
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: <bitcoin-development.lists.sourceforge.net>
List-Unsubscribe: <https://lists.sourceforge.net/lists/listinfo/bitcoin-development>,
<mailto:bitcoin-development-request@lists.sourceforge.net?subject=unsubscribe>
List-Archive: <http://sourceforge.net/mailarchive/forum.php?forum_name=bitcoin-development>
List-Post: <mailto:bitcoin-development@lists.sourceforge.net>
List-Help: <mailto:bitcoin-development-request@lists.sourceforge.net?subject=help>
List-Subscribe: <https://lists.sourceforge.net/lists/listinfo/bitcoin-development>,
<mailto:bitcoin-development-request@lists.sourceforge.net?subject=subscribe>
X-List-Received-Date: Fri, 21 Mar 2014 10:26:19 -0000
On 03/20/2014 01:12 PM, Adam Back wrote:
> Whats a sensible limit on practical/convenient QR code size?
Technically 3 KB. In my experience codes above 1.5 KB become impossible
to scan (ZXing scanner, 3 years ago). You will want to stay below 500
bytes for convenient scanning. That said, I'm convinced there is a lot
of room for scanning improvements.
> How much of the payment protocol message size comes from use of x509?
As said in the OP, a minimal PR uses 50 bytes. X.509 seems to put about
4000 bytes on top of that.
As you can see, we have quite some room for improvements to PR payload
(PaymentDetails). X.509 certification will probably not be possible via
QR, at least not until specialized CA's will issue space-efficient certs
(using ECDSA?).
|
