From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1YJfss-0002ia-UC for bitcoin-development@lists.sourceforge.net; Fri, 06 Feb 2015 10:11:34 +0000 Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.223.176 as permitted sender) client-ip=209.85.223.176; envelope-from=laanwj@gmail.com; helo=mail-ie0-f176.google.com; Received: from mail-ie0-f176.google.com ([209.85.223.176]) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1YJfsr-0007hX-QX for bitcoin-development@lists.sourceforge.net; Fri, 06 Feb 2015 10:11:34 +0000 Received: by iecat20 with SMTP id at20so157262iec.3 for ; Fri, 06 Feb 2015 02:11:28 -0800 (PST) MIME-Version: 1.0 X-Received: by 10.107.137.8 with SMTP id l8mr1483818iod.9.1423217488424; Fri, 06 Feb 2015 02:11:28 -0800 (PST) Received: by 10.64.147.196 with HTTP; Fri, 6 Feb 2015 02:11:28 -0800 (PST) In-Reply-To: <20150204142323.DEC4BE2DCDE@quidecco.de> References: <20150204142323.DEC4BE2DCDE@quidecco.de> Date: Fri, 6 Feb 2015 10:11:28 +0000 Message-ID: From: Wladimir To: Isidor Zeuner 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 (laanwj[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record -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 0.0 AWL AWL: Adjusted score from AWL reputation of From: address X-Headers-End: 1YJfsr-0007hX-QX Cc: Bitcoin Development Subject: Re: [Bitcoin-development] determining change addresses using the least significant digits 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: Fri, 06 Feb 2015 10:11:35 -0000 On Wed, Feb 4, 2015 at 2:23 PM, Isidor Zeuner wrote: > A possible approach to handle this issue would be to add a randomized > offset amount to the payment amount. This offset amount can be small > in comparison to the payment amount. > > Any thoughts? Adding/subtracting a randomized offset amount is one way, but there have also been more sophisticated ideas to obfuscate the amount, e.g. by adding multiple change outputs or even distributing over multiple transactions (potentially coinjoined for further privacy). Mike Hearn had some ideas regarding obfuscation of payment amounts, which still make sense, and he wrote about them here: https://medium.com/@octskyward/merge-avoidance-7f95a386692f Wladimir