Received: from sog-mx-4.v43.ch3.sourceforge.com ([172.29.43.194] helo=mx.sourceforge.net) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1WQgzq-0006Op-LM for bitcoin-development@lists.sourceforge.net; Thu, 20 Mar 2014 17:43:14 +0000 Received-SPF: pass (sog-mx-4.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.128.170 as permitted sender) client-ip=209.85.128.170; envelope-from=alexy.kot.all@gmail.com; helo=mail-ve0-f170.google.com; Received: from mail-ve0-f170.google.com ([209.85.128.170]) by sog-mx-4.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1WQgzo-0000hg-D5 for bitcoin-development@lists.sourceforge.net; Thu, 20 Mar 2014 17:43:14 +0000 Received: by mail-ve0-f170.google.com with SMTP id pa12so1345006veb.1 for ; Thu, 20 Mar 2014 10:43:07 -0700 (PDT) X-Received: by 10.221.29.196 with SMTP id rz4mr34734712vcb.8.1395337386931; Thu, 20 Mar 2014 10:43:06 -0700 (PDT) MIME-Version: 1.0 Sender: alexy.kot.all@gmail.com Received: by 10.59.0.38 with HTTP; Thu, 20 Mar 2014 10:42:26 -0700 (PDT) In-Reply-To: References: <20140320121221.GA25052@netbook.cypherspace.org> From: Alex Kotenko Date: Thu, 20 Mar 2014 17:42:26 +0000 X-Google-Sender-Auth: dCNi55jPCnLaS-az1Lu6CngrgX8 Message-ID: To: Jeff Garzik Content-Type: multipart/alternative; boundary=001a1133a1c04a3db304f50d4de3 X-Spam-Score: -0.6 (/) 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 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (alexy.kot.all[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 1.0 HTML_MESSAGE BODY: HTML included in message -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature X-Headers-End: 1WQgzo-0000hg-D5 Cc: Bitcoin Dev , Andreas Schildbach 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: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 20 Mar 2014 17:43:14 -0000 --001a1133a1c04a3db304f50d4de3 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable 2014-03-20 17:31 GMT+00:00 Jeff Garzik : > On Thu, Mar 20, 2014 at 8:12 AM, Adam Back 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 > 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 > --001a1133a1c04a3db304f50d4de3 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
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> wr= ote:
> Whats a sensible limit on practical/convenient QR code size?

Extremely limited. =C2=A0Preferably under 100 bytes. =C2=A0You will s= ee
increasingly poor operating in varying light conditions, such as
paying via QR code on a printed receipt in a pub at night. =C2=A0That was one of the motivations for BIP 73.
=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're inventing.=C2=A0

=C2=A0


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. =C2=A0Internet connectivity is not a rarity these days. =C2=A0Ne= ar-field
web servers also work fine.

--
Jeff Garzik
Bitcoin core developer and open source evangelist
BitPay, Inc. =C2=A0 =C2=A0 =C2=A0https://bitpay.com/

-----------------------------= -------------------------------------------------
Learn Graph Databases - Download FREE O'Reilly Book
"Graph Databases" is the definitive new guide to graph databases = and their
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-develo= pment@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/bitcoin-de= velopment

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