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 1YJVRu-0002sk-O7 for bitcoin-development@lists.sourceforge.net; Thu, 05 Feb 2015 23:03:02 +0000 Received-SPF: pass (sog-mx-3.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.213.45 as permitted sender) client-ip=209.85.213.45; envelope-from=swansontec@gmail.com; helo=mail-yh0-f45.google.com; Received: from mail-yh0-f45.google.com ([209.85.213.45]) by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1YJVRt-0001cm-Vi for bitcoin-development@lists.sourceforge.net; Thu, 05 Feb 2015 23:03:02 +0000 Received: by mail-yh0-f45.google.com with SMTP id a41so297281yho.4 for ; Thu, 05 Feb 2015 15:02:56 -0800 (PST) MIME-Version: 1.0 X-Received: by 10.236.7.70 with SMTP id 46mr128981yho.138.1423177376581; Thu, 05 Feb 2015 15:02:56 -0800 (PST) Received: by 10.170.168.5 with HTTP; Thu, 5 Feb 2015 15:02:56 -0800 (PST) In-Reply-To: References: <54D3D636.1030308@voskuil.org> <279489A5-1E46-48A2-8F58-1A25821D4D96@gmail.com> <6AEDF3C4-DEE0-4E31-83D0-4FD92B125452@voskuil.org> Date: Thu, 5 Feb 2015 15:02:56 -0800 Message-ID: From: William Swanson To: Eric Voskuil Content-Type: text/plain; charset=UTF-8 X-Spam-Score: -1.6 (-) 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 (swansontec[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record -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: 1YJVRt-0001cm-Vi Cc: Bitcoin Dev , Paul Puey Subject: Re: [Bitcoin-development] Proposal for P2P Wireless (Bluetooth LE) transfer of Payment URI 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, 05 Feb 2015 23:03:02 -0000 On Thu, Feb 5, 2015 at 2:10 PM, Eric Voskuil wrote: > A MITM can receive the initial broadcast and then spoof it by jamming the > original. You then only see one. You are right, of course. There is no way to make Bluetooth 100% secure, since it is an over-the-air technology. You could try securing it using a CA or other identity server, but now you've excluded ad-hoc person-to-person payments. Plus, you need an active internet connection to reach the CA. You can try using proximity as a substitute for identity, like requiring NFC to kick-start the connection, but at that point you might as well use QR codes. This BIP is not trying to provide absolute bullet-proof security, since that's impossible given the physical limitations of the Bluetooth technology. Instead, it's trying to provide the best-possible security given those constraints. In exchange for this, we get greatly enhanced usability in common scenarios. There are plenty of usable, real-world technologies with big security holes. Anybody with lock-picking experience will tell you this, but nobody is welding their front door shut. The ability to go in and out is worth the security risk. Bluetooth payments add a whole new dimension to real-world Bitcoin usability. Do we shut that down because it can't be made perfect, or do we do the best we can and move forward? -William