Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1XTQSk-0007WV-3z for bitcoin-development@lists.sourceforge.net; Mon, 15 Sep 2014 07:12:38 +0000 Received-SPF: pass (sog-mx-1.v43.ch3.sourceforge.com: domain of m.gmane.org designates 80.91.229.3 as permitted sender) client-ip=80.91.229.3; envelope-from=gcbd-bitcoin-development@m.gmane.org; helo=plane.gmane.org; Received: from plane.gmane.org ([80.91.229.3]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.76) id 1XTQSh-0006IH-Of for bitcoin-development@lists.sourceforge.net; Mon, 15 Sep 2014 07:12:38 +0000 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1XTQSV-0002Iu-It for bitcoin-development@lists.sourceforge.net; Mon, 15 Sep 2014 09:12:23 +0200 Received: from f052144115.adsl.alicedsl.de ([78.52.144.115]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 15 Sep 2014 09:12:23 +0200 Received: from andreas by f052144115.adsl.alicedsl.de with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 15 Sep 2014 09:12:23 +0200 X-Injected-Via-Gmane: http://gmane.org/ To: bitcoin-development@lists.sourceforge.net From: Andreas Schildbach Date: Mon, 15 Sep 2014 09:12:03 +0200 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: f052144115.adsl.alicedsl.de User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.1 In-Reply-To: X-Spam-Score: -1.1 (-) 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_HELO_PASS SPF: HELO matches SPF record 1.1 DKIM_ADSP_ALL No valid author signature, domain signs all mail -0.0 SPF_PASS SPF: sender matches SPF record -0.7 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain X-Headers-End: 1XTQSh-0006IH-Of Subject: Re: [Bitcoin-development] BIP72 amendment proposal 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: Mon, 15 Sep 2014 07:12:38 -0000 I agree that this would be another way of achieving the same goal. I'd be fine with that if there is a majority. However, I also see downsides of this approach: 1. It's more complicated. It touches more BIPs, and although signing is terribly difficult its still more difficult than just hashing. E.g. signing the payment request twice (ECC + X.509) poses the question in which order you sign, and which signature fields to null for signing. 2. Isn't it discouraged to disclose the public key you're going to receive coins on? (not sure about that) 3. Unlike an hash we can just re-assign to different objects (see my proposal) I think we cannot easily do the same with a signature. It's probably not very important to have this option, but still it should be considered. 4. I'm afraid of the idea of re-purposing the BIP21 address. Someone might send money to it although it isn't meant to receive money any more (service is already using an advanced BIP70 usecase). A clear separation into two parameters would prevent such mistakes, and as soon as the address can go away the URL needn't be longer than it used to be. 5. A hash can be checked without knowing a secret. Are we excluding stateless devices (e.g. proxies, smartwatches)? Generally about the URL length discussion: Currently we have address, amount and r, and it works well. In future we would have h and r. So all we need to do is make sure h not longer than address+amount. I think this is already the case with untruncated SHA256 hashes. But I'd be fine with truncating to maybe 192 bits to save a few characters. On 09/12/2014 06:31 PM, Mike Hearn wrote: > Putting aside the question of necessity for a moment, a more efficient > approach to this would be; > > 1. Add another marker param like &s to the end of the URL > 2. Add another field to PaymentRequest that contains an ECC signature > calculated using the public key that hashes to the address in the URI > 3. Upgraded wallets look for the additional param and if it's there, > expect to find the PaymentDetails signed with the address key. PKI > signing of course is still useful to provide an actual identity for > receipts, display on hardware wallets, dispute mediation etc. > > This adds only a few characters to a normal backwards-compatible QR > code, and is not hard to implement. > > > On Fri, Sep 12, 2014 at 5:37 PM, Mike Hearn > wrote: > > That way we leave up to implementers to experiment with different > lengths and figure out what the optimum is > > > Ah, that's a good suggestion if we do go this way. > > > > > ------------------------------------------------------------------------------ > Want excitement? > Manually upgrade your production database. > When you want reliability, choose Perforce > Perforce version control. Predictably reliable. > http://pubads.g.doubleclick.net/gampad/clk?id=157508191&iu=/4140/ostg.clktrk > > > > _______________________________________________ > Bitcoin-development mailing list > Bitcoin-development@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/bitcoin-development >