Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192] helo=mx.sourceforge.net) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1WT7Ef-0006oh-62 for bitcoin-development@lists.sourceforge.net; Thu, 27 Mar 2014 10:08:33 +0000 Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.214.182 as permitted sender) client-ip=209.85.214.182; envelope-from=mh.in.england@gmail.com; helo=mail-ob0-f182.google.com; Received: from mail-ob0-f182.google.com ([209.85.214.182]) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1WT7EZ-0006VZ-Mq for bitcoin-development@lists.sourceforge.net; Thu, 27 Mar 2014 10:08:33 +0000 Received: by mail-ob0-f182.google.com with SMTP id uz6so4018393obc.27 for ; Thu, 27 Mar 2014 03:08:22 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.60.44.8 with SMTP id a8mr688633oem.19.1395914902356; Thu, 27 Mar 2014 03:08:22 -0700 (PDT) Sender: mh.in.england@gmail.com Received: by 10.76.71.231 with HTTP; Thu, 27 Mar 2014 03:08:22 -0700 (PDT) In-Reply-To: References: <20140320215208.GC88006@giles.gnomon.org.uk> <20140326224826.GE62995@giles.gnomon.org.uk> Date: Thu, 27 Mar 2014 11:08:22 +0100 X-Google-Sender-Auth: _KsqF5pWmv-gxA5wmz-Z8usP2rY Message-ID: From: Mike Hearn To: Andreas Schildbach Content-Type: multipart/alternative; boundary=001a11c2e458e4487904f593c350 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: 1WT7EZ-0006VZ-Mq Cc: Bitcoin Dev 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: Thu, 27 Mar 2014 10:08:33 -0000 --001a11c2e458e4487904f593c350 Content-Type: text/plain; charset=UTF-8 > > But these cases are the norm, rather than the exception. > Well, you're lucky, you live in Berlin. Most of the payments I make with Bitcoin are online, to websites. So this will differ between people. I wonder how critical it is. Let's say you are paying for a meal. In your head the place you're at is just "the little Indian restaurant on the corner". In the companies register and therefore certificate it's something like "Singh Food GmbH". That's probably good enough to prevent shenanigans. Even if there's a virus on your phone, it can't really replace the cert with a random stolen one, otherwise your meal could show up like "IronCore Steel Inc" or something that's obviously bogus. It'd have to be an incredibly smart virus that knew how to substitute one name for a different one, from a large library of stolen identities, such that the swap seemed plausible. That sounds very hard, certainly too hard to bother with for stealing restaurant fees. And if a waiter at the restaurant is corrupt and they replace the cert with one that's for their own 1-man business "BP-Gupta" or something, OK, you might pay the wrong person by mistake. But eventually the corrupt waiter will be discovered and then someone will have proof of what they did. It's FAR more likely they'd just strip the signature entirely and try to convince you the restaurant doesn't use BIP70 at all. Still, if we want to fix this, one approach I was thinking about is to have a super-cheesy CA just for us that issues certs with addresses in them, for any name you ask for. That is, if you say you want a cert for "Shamrock Irish Pub, Wollishofen, Zurich, CH" then it either sends a postcard to that address with a code to check ownership of the address, or it checks ownership of the place on Google Maps (which does the same postcard trick but for free!). That doesn't work for vending machines, but perhaps we just don't care about those. If a MITM steals your lunch money, boo hoo. --001a11c2e458e4487904f593c350 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
But these cases are the norm, rather than the exception.

Well, you're lucky, you live in Berlin. Most of the p= ayments I make with Bitcoin are online, to websites. So this will differ be= tween people.

I wonder how critical it is. Let's say you are paying for a= meal. In your head the place you're at is just "the little Indian= restaurant on the corner". In the companies register and therefore ce= rtificate it's something like "Singh Food GmbH". That's p= robably good enough to prevent shenanigans. Even if there's a virus on = your phone, it can't really replace the cert with a random stolen one, = otherwise your meal could show up like "IronCore Steel Inc" or so= mething that's obviously bogus. It'd have to be an incredibly smart= virus that knew how to substitute one name for a different one, from a lar= ge library of stolen identities, such that the swap seemed plausible. That = sounds very hard, certainly too hard to bother with for stealing restaurant= fees.

And if a wa= iter at the restaurant is corrupt and they replace the cert with one that&#= 39;s for their own 1-man business "BP-Gupta" or something, OK, yo= u might pay the wrong person by mistake. But eventually the corrupt waiter = will be discovered and then someone will have proof of what they did. It= 9;s FAR more likely they'd just strip the signature entirely and try to= convince you the restaurant doesn't use BIP70 at all.

Still, if w= e want to fix this, one approach I was thinking about is to have a super-ch= eesy CA just for us that issues certs with addresses in them, for any name = you ask for. That is, if you say you want a cert for "Shamrock Irish P= ub, Wollishofen, Zurich, CH" then it either sends a postcard to that a= ddress with a code to check ownership of the address, or it checks ownershi= p of the place on Google Maps (which does the same postcard trick but for f= ree!).

That doesn&= #39;t work for vending machines, but perhaps we just don't care about t= hose. If a MITM steals your lunch money, boo hoo.

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