From mboxrd@z Thu Jan 1 00:00:00 1970 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 1Te9F9-000834-PS for bitcoin-development@lists.sourceforge.net; Thu, 29 Nov 2012 18:53:51 +0000 Received-SPF: pass (sog-mx-3.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; Received: from darla.gnomon.org.uk ([93.93.131.22]) by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.76) id 1Te9F3-0000C7-DX for bitcoin-development@lists.sourceforge.net; Thu, 29 Nov 2012 18:53:51 +0000 Received: from darla.gnomon.org.uk (localhost.gnomon.org.uk [127.0.0.1]) by darla.gnomon.org.uk (8.14.3/8.14.3) with ESMTP id qATIrVWf023962 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT); Thu, 29 Nov 2012 18:53:36 GMT (envelope-from roy@darla.gnomon.org.uk) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.95.3 at darla.gnomon.org.uk Received: (from roy@localhost) by darla.gnomon.org.uk (8.14.3/8.14.1/Submit) id qATIrUGd023960; Thu, 29 Nov 2012 13:53:30 -0500 (EST) (envelope-from roy) Date: Thu, 29 Nov 2012 13:53:30 -0500 From: Roy Badami To: Mike Hearn , g@gnomon.org.uk Message-ID: <20121129185330.GE6368@giles.gnomon.org.uk> References: <20121128233619.GA6368@giles.gnomon.org.uk> <20121129170713.GD6368@giles.gnomon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) X-Spam-Score: -1.5 (-) 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 SPF_PASS SPF: sender matches SPF record -0.4 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.4 AWL AWL: From: address is in the auto white-list X-Headers-End: 1Te9F3-0000C7-DX Cc: Bitcoin Dev Subject: Re: [Bitcoin-development] Payment Protocol Proposal: Invoices/Payments/Receipts 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, 29 Nov 2012 18:53:52 -0000 On Thu, Nov 29, 2012 at 06:31:24PM +0100, Mike Hearn wrote: > > I'd still like to understand the rationale for having the merchant > > broadcast the transaction > > There are several reasons for this: [snip] All good reasons, thanks for the explanation. Though I still like my idea of a ValidatePurchase message that allows a buyer to ask a merchant "would you accept this payment?" without actually supplying a signed transaction. Make it optional if you care about minimising the number of round trips, e.g. for fast NFC payments. Having such a message reduces the extent to which you need to trust the merchant not to spend a transaction that they've rejected. (And in the non-Internet connected case this is particularly useful since the client won't have the ability to broadcast a pay-to-self transaction.) roy