Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1X1ugV-0004H5-1s for bitcoin-development@lists.sourceforge.net; Tue, 01 Jul 2014 09:49:07 +0000 Received-SPF: pass (sog-mx-3.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-3.v43.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.76) id 1X1ugT-0004Wm-4y for bitcoin-development@lists.sourceforge.net; Tue, 01 Jul 2014 09:49:07 +0000 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1X1ugL-00050J-Ky for bitcoin-development@lists.sourceforge.net; Tue, 01 Jul 2014 11:48:57 +0200 Received: from f052195207.adsl.alicedsl.de ([78.52.195.207]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Tue, 01 Jul 2014 11:48:57 +0200 Received: from andreas by f052195207.adsl.alicedsl.de with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Tue, 01 Jul 2014 11:48:57 +0200 X-Injected-Via-Gmane: http://gmane.org/ To: bitcoin-development@lists.sourceforge.net From: Andreas Schildbach Date: Tue, 01 Jul 2014 11:48:44 +0200 Message-ID: References: <20140320215208.GC88006@giles.gnomon.org.uk> <20140326224826.GE62995@giles.gnomon.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: f052195207.adsl.alicedsl.de User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 In-Reply-To: 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: 1X1ugT-0004Wm-4y 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: Tue, 01 Jul 2014 09:49:07 -0000 On 07/01/2014 10:18 AM, Mike Hearn wrote: > ​However it's not ideal at the moment. Basically the main problem is > that in the BIP72 there is no way to provide a fallback alternative > URI for payment request fetch if client wallet supports BIP70 but > doesn't not support fetching over bluetooth or bluetooth connection > fails for any reason. I think the way to go here is using multiple r= parameters. > So the idea here is that the recipient wallet both uploads to the > internet and exposes the payment request over Bluetooth simultaneously, > then let's the sending wallet pick whatever radio layer works best in > its current conditions? Either that, or just use the other ones as a fallback. Currently, Bitcoin Wallet just falls back to BIP21 if fetching the PR via the r= URL fails. > I think having multiple r= params is reasonable, but the Bluetooth > support is not specced in any BIP anyway. And if it were to be, people > would point out the lack of link-layer encryption. Its "specced" in code and implemented by several parties. I think its clear that link-layer encryption has to be an add-on to the current unencrypted connection, just like HTTPS is on top of HTTP. Anyway, that's unrelated to the question of how to provide fallback URLs. One more thought: We have a similar problem with the BIP70 payment URL. It doesn't allow for fallbacks either. I brought this issue up in the discussion phase of BIP70, but it was dismissed I think because of "let's not get too complex for the first version". The fallback here is to send the transaction via the P2P network. (I think BIP70 via P2P radio will get used more often in future. I plan to look into Bluetooth 4 LE as soon as I have devices and wanted to try WIFI Direct again also. I hope we can skip BIP72 for both of those, but lets see.)