Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1WLYbB-00010y-5q for bitcoin-development@lists.sourceforge.net; Thu, 06 Mar 2014 13:44:33 +0000 Received-SPF: pass (sog-mx-1.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.214.175 as permitted sender) client-ip=209.85.214.175; envelope-from=mh.in.england@gmail.com; helo=mail-ob0-f175.google.com; Received: from mail-ob0-f175.google.com ([209.85.214.175]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1WLYbA-0004gH-8l for bitcoin-development@lists.sourceforge.net; Thu, 06 Mar 2014 13:44:33 +0000 Received: by mail-ob0-f175.google.com with SMTP id uy5so2544121obc.20 for ; Thu, 06 Mar 2014 05:44:27 -0800 (PST) MIME-Version: 1.0 X-Received: by 10.60.98.73 with SMTP id eg9mr450725oeb.81.1394113466896; Thu, 06 Mar 2014 05:44:26 -0800 (PST) Sender: mh.in.england@gmail.com Received: by 10.76.71.231 with HTTP; Thu, 6 Mar 2014 05:44:26 -0800 (PST) In-Reply-To: References: Date: Thu, 6 Mar 2014 14:44:26 +0100 X-Google-Sender-Auth: Zzf-yEn8_RshRScTXqmjd7jELJU Message-ID: From: Mike Hearn To: Andreas Schildbach Content-Type: multipart/alternative; boundary=089e0139fc60f9a02d04f3f0553e X-Spam-Score: -0.5 (/) 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 (mh.in.england[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 1.0 HTML_MESSAGE BODY: HTML included in message 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: 1WLYbA-0004gH-8l Cc: Bitcoin Dev Subject: Re: [Bitcoin-development] Instant / contactless 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, 06 Mar 2014 13:44:33 -0000 --089e0139fc60f9a02d04f3f0553e Content-Type: text/plain; charset=UTF-8 On Thu, Mar 6, 2014 at 12:26 PM, Andreas Schildbach wrote: > I'm not sure if iso-dep is the way to go here. Afaik as soon as you pick > up the phone the connection breaks. If the phone isn't willing to immediately authorise then it'd have to fall back to HTTPS or Bluetooth as normal. > Besides, how do you plan to risk-analyse the memo field? > I guess only the amount and destination are relevant for risk analysis. > It's already very short if you can do without Android Beam, e.g. on > Android 2.3. I think IsoDep based protocols must bypass Beam - when I scan my e-passport there's no beam animation. > The most obvious optimization to speed up signature checking is to make > it lazy. The user can already inspect the payment while signatures are > being checked. Well, for <400msec there can't be any user interaction. But checking signatures on the payment request and constructing and signing the inputs can all be done in parallel - you should be able to max out every core, at least for a brief moment. > Even the current ~10 second roundtrip is a huge improvement to the > status quo. I recently tried to buy a subway ticket and it took me 7 > full minutes (just for the payment process)! Then that subway kind of sucks ;) Have you been to London and used Oyster? I think the capital wouldn't work at all without the low latency Oyster cards. The tube would have stopped scaling some time ago. --089e0139fc60f9a02d04f3f0553e Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
On T= hu, Mar 6, 2014 at 12:26 PM, Andreas Schildbach <andreas@schildbach.de= > wrote:
I'm not sure if iso-dep is the way to go= here. Afaik as soon as you pick
up the phone the connection breaks.

If the = phone isn't willing to immediately authorise then it'd have to fall= back to HTTPS or Bluetooth as normal.
=C2=A0
Besides, how do you plan to risk-analyse the memo field?

I guess only the amount and destination are relevant for = risk analysis.
=C2=A0
It's already very short if you can do without Android B= eam, e.g. on
Android 2.3.

I think IsoDep based protocols= must bypass Beam - when I scan my e-passport there's no beam animation= .
=C2=A0
The most obvious optimization to speed up signature checking is to make
it lazy. The user can already inspect the payment while signatures are
being checked.

Well, for <400msec there = can't be any user interaction. But checking signatures on the payment r= equest and constructing and signing the inputs can all be done in parallel = - you should be able to max out every core, at least for a brief moment.
=C2=A0
Even the current ~10 second= roundtrip is a huge improvement to the
status quo. I recently tried to buy a subway ticket and it took me 7
full minutes (just for the payment process)!

Then that subway kind of sucks ;) Have you been to London and used Oyster= ? I think the capital wouldn't work at all without the low latency Oyst= er cards. The tube would have stopped scaling some time ago.=C2=A0
--089e0139fc60f9a02d04f3f0553e--