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-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1YrSRY-0007Mp-Vh for bitcoin-development@lists.sourceforge.net; Sun, 10 May 2015 14:43:00 +0000 Received-SPF: pass (sog-mx-3.v43.ch3.sourceforge.com: domain of mcelrath.org designates 50.31.3.130 as permitted sender) client-ip=50.31.3.130; envelope-from=bob_bitcoin@mcelrath.org; helo=mcelrath.org; Received: from moya.mcelrath.org ([50.31.3.130] helo=mcelrath.org) by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.76) id 1YrSRY-0006k3-63 for bitcoin-development@lists.sourceforge.net; Sun, 10 May 2015 14:43:00 +0000 Received: from mcelrath.org (localhost [127.0.0.1]) by mcelrath.org (8.14.3/8.14.3/Debian-9.4) with ESMTP id t4AEgsBP020144 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT) for ; Sun, 10 May 2015 14:42:55 GMT Received: (from mcelrath@localhost) by mcelrath.org (8.14.3/8.14.3/Submit) id t4AEgsol020143 for bitcoin-development@lists.sourceforge.net; Sun, 10 May 2015 14:42:54 GMT X-Authentication-Warning: mcelrath.org: mcelrath set sender to bob_bitcoin@mcelrath.org using -f Date: Sun, 10 May 2015 14:42:54 +0000 From: Bob McElrath To: Bitcoin Dev Message-ID: <20150510144254.GE6182@mcelrath.org> References: <20150510133525.GD6182@mcelrath.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Content-Transfer-Encoding: quoted-printable X-MIME-Autoconverted: from 8bit to quoted-printable by mcelrath.org id t4AEgsBP020144 X-Spam-Score: -1.0 (-) 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 -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -0.0 SPF_PASS SPF: sender matches SPF record 0.5 AWL AWL: Adjusted score from AWL reputation of From: address X-Headers-End: 1YrSRY-0006k3-63 Subject: Re: [Bitcoin-development] A suggestion for reducing the size of the UTXO database 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: Sun, 10 May 2015 14:43:01 -0000 That's a lot of work, a lot of extra utxo's, and a lot of blockchain spam= , just so I can do a convoluted form of arithmetic on my balance. If a tx contained an explicit miner fee and a change address, but did not compute the change, letting the network compute it (and therefore merge transactions spending the same utxo), could one add some form of ring sig= nature a la Dash to alleviate the worsened privacy implications? Jeff Garzik [jgarzik@bitpay.com] wrote: > This has been frequently explored on IRC. >=20 > My general conclusion is "dollar bills" - pick highly common denominati= ons of > bitcoins.=A0 Aggregate to obtain these denominations, but do not aggreg= ate > further. >=20 > This permits merge avoidance (privacy++), easy coinjoin where many hide= in the > noise (privacy++), wallet dust de-fragmentation, while avoiding the > over-aggregation problem where you have consolidated down to one output. >=20 > Thus a wallet would have several consolidation targets. >=20 > Another strategy is simply doubling outputs.=A0 Say you pay 0.1 BTC to > Starbucks.=A0 Add another 0.1 BTC output to yourself, and a final chang= e output.=A0 > Who can say which output goes to Starbucks? >=20 > There are many iterations and trade-offs between fragmentation and priv= acy. -- Cheers, Bob McElrath "The individual has always had to struggle to keep from being overwhelmed= by the tribe. If you try it, you will be lonely often, and sometimes fright= ened. But no price is too high to pay for the privilege of owning yourself."=20 -- Friedrich Nietzsche