From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1VZv9M-0002Yk-OZ for bitcoin-development@lists.sourceforge.net; Sat, 26 Oct 2013 04:06:56 +0000 Received-SPF: pass (sog-mx-1.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.217.171 as permitted sender) client-ip=209.85.217.171; envelope-from=gmaxwell@gmail.com; helo=mail-lb0-f171.google.com; Received: from mail-lb0-f171.google.com ([209.85.217.171]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1VZv9L-0003bI-O8 for bitcoin-development@lists.sourceforge.net; Sat, 26 Oct 2013 04:06:56 +0000 Received: by mail-lb0-f171.google.com with SMTP id x18so1384963lbi.30 for ; Fri, 25 Oct 2013 21:06:49 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.152.3.42 with SMTP id 10mr7525160laz.22.1382760408950; Fri, 25 Oct 2013 21:06:48 -0700 (PDT) Received: by 10.112.89.72 with HTTP; Fri, 25 Oct 2013 21:06:48 -0700 (PDT) In-Reply-To: <201310260341.41613.luke@dashjr.org> References: <201310260341.41613.luke@dashjr.org> Date: Fri, 25 Oct 2013 21:06:48 -0700 Message-ID: From: Gregory Maxwell To: Luke-Jr Content-Type: text/plain; charset=UTF-8 X-Spam-Score: -1.6 (-) 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 (gmaxwell[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 0.0 URIBL_BLOCKED ADMINISTRATOR NOTICE: The query to URIBL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [URIs: dashjr.org] -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 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: 1VZv9L-0003bI-O8 Cc: Bitcoin Development Subject: Re: [Bitcoin-development] Payment protocol for onion URLs. 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: Sat, 26 Oct 2013 04:06:57 -0000 On Fri, Oct 25, 2013 at 8:41 PM, Luke-Jr wrote: > Is there any point to additional encryption over tor (which afaik is already > encrypted end-to-end)? Is there a safe way to make this work through tor entry > nodes/gateways? The x.509 in the payment protocol itself is for authentication and non-repudiation, not confidentiality. It's used to sign the payment request so that later there is cryptographic evidence in the event of a dispute: "He didn't send me my alpaca socks!" "Thats not the address I told you to pay!" "He told me he'd send my 99 red-balloons, not just one!" "No way, that was the price for 1 red-balloon!" Just using SSL or .onion (or whatever else) gets you confidentiality and authentication. Neither of these things get you non-repudiation. > It'd be nice to have a way to support namecoin-provided keys too... The payment protocol is extensible, so I hope that someday someone will support namecoin authenticated messages (but note: this requires namecoin to support trust-free SPV resolvers, otherwise there is no way to extract a compact proof that can be stuck into a payment request) and GPG authenticated messages. But those things will require a fair amount of code (even fixing the namecoin protocol in the nmc case), and GPG could be done just by externally signing the actual payment request like you'd sign any file... and considering the sorry state of their _practical_ usability, I don't think they're worth doing at this time. By contrast, I _think_ the tor onion support would require only a relatively few lines of code since it could just be the existing x.509 mechanism with just a simple special validation rule for .onion, plus a little tool to repack the keys. I think it would easily be more widely used than namecoin (though probably both would not really be used, as gavin notes). w/ Gavin's comments I'll go check in with the tor folks and see if anyone has ever though of doing this before and if there is already a canonical structure for the x.509 certs used in this way.