Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of gnomon.org.uk
	designates 93.93.131.22 as permitted sender)
	client-ip=93.93.131.22; envelope-from=roy@gnomon.org.uk;
	helo=darla.gnomon.org.uk; 
Date: Thu, 5 Feb 2015 22:49:09 +0000
From: Roy Badami <roy@gnomon.org.uk>
To: Eric Voskuil <eric@voskuil.org>
Message-ID: <20150205224909.GO39876@giles.gnomon.org.uk>
References: <CABdy8DKS4arkkCLGC=66SUJm5Ugib1EWP7B6MkQRX1k-yd3WBw@mail.gmail.com>
	<CANEZrP3v=ySS4gragaWuBMWi_swocRRRq_kw2edo6+9kifgrFQ@mail.gmail.com>
	<54D3D636.1030308@voskuil.org>
	<CANEZrP3ekWQWeV=Yw_E=n0grORBLHaXLUh3w0EFQdz=HsjWvZw@mail.gmail.com>
	<279489A5-1E46-48A2-8F58-1A25821D4D96@gmail.com>
	<CANEZrP3VAWajxE=mNxb6sLSQbhaQHD=2TgRKvYrEax2PAzCi2A@mail.gmail.com>
	<6AEDF3C4-DEE0-4E31-83D0-4FD92B125452@voskuil.org>
	<CABdy8DLRGyy5dvmVb_B3vao7Qwz-zdAC3-+2nJkg9rSsU6FLbw@mail.gmail.com>
	<C28CD881-DAB8-4EDB-B239-7D45A825EAF0@voskuil.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <C28CD881-DAB8-4EDB-B239-7D45A825EAF0@voskuil.org>
User-Agent: Mutt/1.5.20 (2009-06-14)
Cc: Bitcoin Dev <bitcoin-development@lists.sourceforge.net>,
	Paul Puey <paul@airbitz.co>
Subject: Re: [Bitcoin-development] Proposal for P2P Wireless (Bluetooth LE)
 transfer of Payment URI
Precedence: list

Personally I like the simplicity of tapping two phones together to
make payment - it should be quicker and easier than scanning QR codes
and it's a trust model that's hard to misunderstand.

Is NFC good enough for that?  I fear even with NFC it is possible to
produce a device with longer range than one would expect.  What
happened to the idea of tapping two devices together and then
comparing the timing of the tap (as detected by the phones'
accelerometers) to make spoofing a transaction harder?  I remember
hearing about that years ago - is that still a thing?

roy

On Thu, Feb 05, 2015 at 02:10:51PM -0800, Eric Voskuil wrote:
> A MITM can receive the initial broadcast and then spoof it by jamming the original. You then only see one.
> 
> e
> 
> > On Feb 5, 2015, at 2:07 PM, Paul Puey <paul@airbitz.co> wrote:
> > 
> > So if you picked up the BLE broadcast request. All you know is that *someone* within 100m is requesting bitcoin at a certain address. Not necessarily who. The *name* is both optional, and possibly just a *handle* of the user. If I'm sitting 5 ft away from someone at dinner and wanted to pay them via BLE, I might see "Monkey Dude" on my list and simply ask him "is that you?" If so, I send it. If there are two "Monkey Dude's" Then I have to bother with the address prefix, but not otherwise.
> > 
> >> On Thu, Feb 5, 2015 at 1:46 PM, Eric Voskuil <eric@voskuil.org> wrote:
> >> BLE has an advertised range of over 100m. 
> >> 
> >> http://www.bluetooth.com/Pages/low-energy-tech-info.aspx
> >> 
> >> In the case of mass surveillance that range could most likely be extended dramatically by the reviewer. I've seen  WiFi ranges of over a mile with a strong (not FCC approved) receiver.
> >> 
> >> WiFi hotspots don't have strong identity or a guaranteed position, so they can't be trusted for location.
> >> 
> >> e
> >> 
> >> On Feb 5, 2015, at 1:36 PM, Mike Hearn <mike@plan99.net> wrote:
> >> 
> >>>> This sounds horrible. You could basically monitor anyone with a wallet in a highly populated area and track them super easily by doing facial recognition.
> >>> 
> >>> We're talking about BLE, still? The radio tech that runs in the so called "junk bands" because propagation is so poor?
> >>> 
> >>> My watch loses its connection to my phone if I just put it down and walk around my apartment. I'm all for reasonable paranoia, but Bluetooth isn't going to be enabling mass surveillance any time soon. It barely goes through air, let alone walls.
> >>> 
> >>> Anyway, whatever. I'm just bouncing around ideas for faster user interfaces. You could always switch it off or set it to be triggered by the presence of particular wifi hotspots, if you don't mind an initial bit of setup.
> >>> 
> >>> Back on topic - the debate is interesting, but I think to get this to the stage of being a BIP we'd need at least another wallet to implement it? Then I guess a BIP would be useful regardless of the design issues. The prefix matching still feels flaky to me but it's hard to know if you could really swipe payments out of the air in practice, without actually trying it.
> > 

> ------------------------------------------------------------------------------
> Dive into the World of Parallel Programming. The Go Parallel Website,
> sponsored by Intel and developed in partnership with Slashdot Media, is your
> hub for all things parallel software development, from weekly thought
> leadership blogs to news, videos, case studies, tutorials and more. Take a
> look and join the conversation now. http://goparallel.sourceforge.net/

> _______________________________________________
> Bitcoin-development mailing list
> Bitcoin-development@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/bitcoin-development