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From: Alex Kotenko <alexykot@gmail.com>
Date: Thu, 20 Mar 2014 17:42:26 +0000
Message-ID: <CALDj+BbF5=L88n6VvDt=ctnr+_1730L3RN+3nb2N3AW3RLESRg@mail.gmail.com>
To: Jeff Garzik <jgarzik@bitpay.com>
Content-Type: multipart/alternative; boundary=001a1133a1c04a3db304f50d4de3
Cc: Bitcoin Dev <bitcoin-development@lists.sourceforge.net>,
	Andreas Schildbach <andreas@schildbach.de>
Subject: Re: [Bitcoin-development] Payment Protocol for Face-to-face Payments
Precedence: list

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2014-03-20 17:31 GMT+00:00 Jeff Garzik <jgarzik@bitpay.com>:

> On Thu, Mar 20, 2014 at 8:12 AM, Adam Back <adam@cypherspace.org> wrote:
> > Whats a sensible limit on practical/convenient QR code size?
>
> Extremely limited.  Preferably under 100 bytes.  You will see
> increasingly poor operating in varying light conditions, such as
> paying via QR code on a printed receipt in a pub at night.  That was
> one of the motivations for BIP 73.
>
=E2=80=8BHmm, in this case I think base43 discussion is irrelevant. Even wi=
th best
space utilization we can get =E2=80=8Bwe will not be able to fit in anythin=
g bigger
than a smallest unsigned payment certificate. And that is not so useful. So
probably we should stick with BIP73 approach and bluetooth URI scheme we're
inventing.



>
>
> On Thu, Mar 20, 2014 at 4:09 AM, Andreas Schildbach
> <andreas@schildbach.de> wrote:
> > Afaik, BIP73 needs an external server (the web server).
>
> Yes.  Internet connectivity is not a rarity these days.  Near-field
> web servers also work fine.
>
> --
> Jeff Garzik
> Bitcoin core developer and open source evangelist
> BitPay, Inc.      https://bitpay.com/
>
>
> -------------------------------------------------------------------------=
-----
> Learn Graph Databases - Download FREE O'Reilly Book
> "Graph Databases" is the definitive new guide to graph databases and thei=
r
> applications. Written by three acclaimed leaders in the field,
> this first edition is now available. Download your free book today!
> http://p.sf.net/sfu/13534_NeoTech
> _______________________________________________
> Bitcoin-development mailing list
> Bitcoin-development@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/bitcoin-development
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<div dir=3D"ltr"><div class=3D"gmail_default" style=3D"font-family:courier =
new,monospace;color:#003300"><span style=3D"font-family:arial;color:rgb(34,=
34,34)">2014-03-20 17:31 GMT+00:00 Jeff Garzik </span><span dir=3D"ltr" sty=
le=3D"font-family:arial;color:rgb(34,34,34)">&lt;<a href=3D"mailto:jgarzik@=
bitpay.com" target=3D"_blank">jgarzik@bitpay.com</a>&gt;</span><span style=
=3D"font-family:arial;color:rgb(34,34,34)">:</span><br>

</div><div class=3D"gmail_extra"><div class=3D"gmail_quote"><blockquote cla=
ss=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;pa=
dding-left:1ex"><div class=3D"">On Thu, Mar 20, 2014 at 8:12 AM, Adam Back =
&lt;<a href=3D"mailto:adam@cypherspace.org">adam@cypherspace.org</a>&gt; wr=
ote:<br>


&gt; Whats a sensible limit on practical/convenient QR code size?<br>
<br>
</div>Extremely limited. =C2=A0Preferably under 100 bytes. =C2=A0You will s=
ee<br>
increasingly poor operating in varying light conditions, such as<br>
paying via QR code on a printed receipt in a pub at night. =C2=A0That was<b=
r>
one of the motivations for BIP 73.<br></blockquote><div><div class=3D"gmail=
_default" style=3D"font-family:&#39;courier new&#39;,monospace;color:rgb(0,=
51,0)">=E2=80=8BHmm, in this case I think base43 discussion is irrelevant. =
Even with best space utilization we can get =E2=80=8Bwe will not be able to=
 fit in anything bigger than a smallest unsigned payment certificate. And t=
hat is not so useful. So probably we should stick with BIP73 approach and b=
luetooth URI scheme we&#39;re inventing.=C2=A0</div>

<br></div><div>=C2=A0</div><blockquote class=3D"gmail_quote" style=3D"margi=
n:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div class=3D""><br>
<br>
On Thu, Mar 20, 2014 at 4:09 AM, Andreas Schildbach<br>
&lt;<a href=3D"mailto:andreas@schildbach.de">andreas@schildbach.de</a>&gt; =
wrote:<br>
&gt; Afaik, BIP73 needs an external server (the web server).<br>
<br>
</div>Yes. =C2=A0Internet connectivity is not a rarity these days. =C2=A0Ne=
ar-field<br>
web servers also work fine.<br>
<div class=3D"im HOEnZb"><br>
--<br>
Jeff Garzik<br>
Bitcoin core developer and open source evangelist<br>
BitPay, Inc. =C2=A0 =C2=A0 =C2=A0<a href=3D"https://bitpay.com/" target=3D"=
_blank">https://bitpay.com/</a><br>
<br>
</div><div class=3D"HOEnZb"><div class=3D"h5">-----------------------------=
-------------------------------------------------<br>
Learn Graph Databases - Download FREE O&#39;Reilly Book<br>
&quot;Graph Databases&quot; is the definitive new guide to graph databases =
and their<br>
applications. Written by three acclaimed leaders in the field,<br>
this first edition is now available. Download your free book today!<br>
<a href=3D"http://p.sf.net/sfu/13534_NeoTech" target=3D"_blank">http://p.sf=
.net/sfu/13534_NeoTech</a><br>
_______________________________________________<br>
Bitcoin-development mailing list<br>
<a href=3D"mailto:Bitcoin-development@lists.sourceforge.net">Bitcoin-develo=
pment@lists.sourceforge.net</a><br>
<a href=3D"https://lists.sourceforge.net/lists/listinfo/bitcoin-development=
" target=3D"_blank">https://lists.sourceforge.net/lists/listinfo/bitcoin-de=
velopment</a><br>
</div></div></blockquote></div><br></div></div>

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