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-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1UPmBR-0003Zi-M1 for bitcoin-development@lists.sourceforge.net; Wed, 10 Apr 2013 03:58:53 +0000 Received-SPF: pass (sog-mx-1.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.217.174 as permitted sender) client-ip=209.85.217.174; envelope-from=gmaxwell@gmail.com; helo=mail-lb0-f174.google.com; Received: from mail-lb0-f174.google.com ([209.85.217.174]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1UPmBL-00027D-VU for bitcoin-development@lists.sourceforge.net; Wed, 10 Apr 2013 03:58:53 +0000 Received: by mail-lb0-f174.google.com with SMTP id s10so100510lbi.19 for ; Tue, 09 Apr 2013 20:58:41 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.112.42.37 with SMTP id k5mr355567lbl.49.1365566320554; Tue, 09 Apr 2013 20:58:40 -0700 (PDT) Received: by 10.112.134.164 with HTTP; Tue, 9 Apr 2013 20:58:40 -0700 (PDT) In-Reply-To: References: Date: Tue, 9 Apr 2013 20:58:40 -0700 Message-ID: From: Gregory Maxwell To: Robert Backhaus Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable 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 -0.1 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: 1UPmBL-00027D-VU Cc: Bitcoin Development Subject: Re: [Bitcoin-development] =?utf-8?q?To_prevent_arbitrary_data_storage?= =?utf-8?q?_in_txouts_=E2=80=94_The_Ultimate_Solution?= 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: Wed, 10 Apr 2013 03:58:53 -0000 On Tue, Apr 9, 2013 at 8:52 PM, Robert Backhaus wrote: > That sounds workable. I take it that the P2SH address is not stored? I li= ke > it that this denies the possibility of storing data in the block chain, b= ut > does not block interesting uses like creating date stamps - You can still > store the 'fake P2SH' value whose checksum is secured by the blockchain. Correct. It doesn't prevent value commitment (which is actually what we need for our currency use), just data storage. And as Peter points out=E2=80=94 you could try to store a little data, but that has a computational cost which is exponential in the amount of data stored per output. ... like storing data in values, thats awkward enough to not be especially problematic, I expect.