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-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1XAU5f-0005hy-E1 for bitcoin-development@lists.sourceforge.net; Fri, 25 Jul 2014 01:14:31 +0000 Received-SPF: pass (sog-mx-1.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.192.177 as permitted sender) client-ip=209.85.192.177; envelope-from=ron.ohara54@gmail.com; helo=mail-pd0-f177.google.com; Received: from mail-pd0-f177.google.com ([209.85.192.177]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1XAU5e-00022x-Cx for bitcoin-development@lists.sourceforge.net; Fri, 25 Jul 2014 01:14:31 +0000 Received: by mail-pd0-f177.google.com with SMTP id p10so4673755pdj.36 for ; Thu, 24 Jul 2014 18:14:24 -0700 (PDT) X-Received: by 10.66.227.225 with SMTP id sd1mr15115452pac.106.1406250864522; Thu, 24 Jul 2014 18:14:24 -0700 (PDT) Received: from [10.0.0.21] (CPE-137-147-172-228.lnse7.win.bigpond.net.au. [137.147.172.228]) by mx.google.com with ESMTPSA id xk1sm26376387pac.21.2014.07.24.18.14.22 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 24 Jul 2014 18:14:23 -0700 (PDT) Message-ID: <53D1AF6C.7010802@gmail.com> Date: Fri, 25 Jul 2014 02:14:20 +0100 From: Ron OHara User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: bitcoin-development@lists.sourceforge.net X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Spam-Score: -1.4 (-) 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 (ron.ohara54[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 0.2 FREEMAIL_ENVFROM_END_DIGIT Envelope-from freemail username ends in digit (ron.ohara54[at]gmail.com) -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: 1XAU5e-00022x-Cx Subject: [Bitcoin-development] Time 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, 25 Jul 2014 01:14:31 -0000 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 I thought I should shortcut my research by asking a direct question here. As I understand it, the blockchain actually provides an extra piece of reliable data that is not being exploited by applications. Which data? The time. In this case 'the time' as agreed by >50% of the participants, where those participants have a strong financial incentive to keep that 'time' fairly accurate. (+/- about 10 minutes) Is this a reasonable understanding of 'time'? ... aka timestamps on the block Ok... 'time' on the blockchain could be 'gamed' ... but with great difficulty. An application presented with a fake blockchain can use quite a few heuristics to test the 'validity' of the block chain. It can review the usual cryptographic proofs, and check that difficulty is growing/declining only in a realistic manner up to the most recent block. Even use some arbitrary test like difficulty > 10,000,000,000 ... on the presumption that any less means that the Bitcoin system has failed massively from where it currently is and has become an unreliable time source. Reliable 'time' has been impossible up until now - because you need to trust the time source, and that can always be faked. Using the blockchain as an approximate time source gives you a world wide consensus without direct trust of any player. So if this presumption is correct, then we can now build time capsule applications that can not be tricked into exposing their contents too early by running them in a virtual environment with the wrong system time. Is this right? or did miss I something fundamental? Ron - -- public identify: https://www.onename.io/ron_ohara -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.20 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBAgAGBQJT0a9sAAoJEAla1VT1+xc2ONQH/0R09guSNNCxP36KziAjfcBc JEhxMpIlqTTYEvNXaBmuPy4BN+IZQ9izgrW/cvlEJJNMmc5/VIBk83WZltmDwcKl oo4MIdmp6vz984GWToyyLcLSEDT60UE9Hhe+U9RyF5J9kwbN8Uy4ozUHhFVP/0EL q4O1V6ggPbHWgH4q8m8E9qWOlIFXCDgCjxpL8Ptxsk+UlBq2NWMiwTz6Tbc9KOB4 hOffzXCZV+DkwjFZD2Rc4rHaxw1yLuYr7DzmzwZbhRQclv9tZt9hoVaAT+RQpE1k X7pi+zVzeMMng0bzUv8t/G+gq0gaelyV41MJQRparEXhnuYkgU7rAPKIQEG8qpc= =T5fw -----END PGP SIGNATURE-----