For peer-to-peer payments, how common do we think that the payment is
of an ad hoc nature rather than to a known contact?

If I want to pay my friends/colleagues/etc over a restaurant table
there's no reason why I couldn't already have their public keys in my
contact list - then it would be pretty straightforward to have a
watertight mechanism where I would know who I was paying. You could
probably even relatively securely bootstrap a key exchange over SMS,
relying only on the contacts already having each other in their
phonebooks.

As for comsumer-to-merchant transactions where the merchant is a
bricks and mortar merchant, IMHO it absolutely has to be "pay that
terminal over there". It's the trust model we all currently use -
whether paying cash or card - and it's the only trust model that works
IMHO (and customers and businesses alike are well aware of the risks
of a fraudster standing behind the counter pretending to be an
employee accepting payment - and by and large are pretty good at
mitigating it). OTOH as we've discussed here before there are many
use cases where the custoemr doesn't actually know or care about the
name of the shop or bar they walked into but is pretty damn sure that
they need to make payment to the person over there behind the counter.

Granted, there are cases taht dont' fall into either of the above -
but they're the cases that are (a) harder to figure out how to
authenticate and consequently (b) the use cases that are going to be
most subject to attempted fraud.

roy

On Thu, Feb 05, 2015 at 03:02:56PM -0800, William Swanson wrote:

On Thu, Feb 5, 2015 at 2:10 PM, Eric Voskuil <eric@voskuil.org> 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

------------------------------------------------------------------------------

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