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-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1Y2rJE-00086d-Ri for bitcoin-development@lists.sourceforge.net; Mon, 22 Dec 2014 00:57:16 +0000 Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.217.172 as permitted sender) client-ip=209.85.217.172; envelope-from=snow.paul@gmail.com; helo=mail-lb0-f172.google.com; Received: from mail-lb0-f172.google.com ([209.85.217.172]) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1Y2rJC-0006pP-G4 for bitcoin-development@lists.sourceforge.net; Mon, 22 Dec 2014 00:57:16 +0000 Received: by mail-lb0-f172.google.com with SMTP id u10so3209625lbd.3 for ; Sun, 21 Dec 2014 16:57:08 -0800 (PST) X-Received: by 10.112.150.102 with SMTP id uh6mr7818458lbb.66.1419209828152; Sun, 21 Dec 2014 16:57:08 -0800 (PST) MIME-Version: 1.0 Received: by 10.112.50.107 with HTTP; Sun, 21 Dec 2014 16:56:28 -0800 (PST) In-Reply-To: <20141221185126.GC18711@savin.petertodd.org> References: <20141221185126.GC18711@savin.petertodd.org> From: paul snow Date: Sun, 21 Dec 2014 18:56:28 -0600 Message-ID: To: Peter Todd Content-Type: multipart/alternative; boundary=047d7b34318aab3e0d050ac38988 X-Spam-Score: -0.6 (/) 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 (snow.paul[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 1.0 HTML_MESSAGE BODY: HTML included in message -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: 1Y2rJC-0006pP-G4 Cc: Bitcoin Dev Subject: Re: [Bitcoin-development] one-show signatures (Re: The relationship between Proof-of-Publication and Anti-Replay Oracles) 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: Mon, 22 Dec 2014 00:57:17 -0000 --047d7b34318aab3e0d050ac38988 Content-Type: text/plain; charset=UTF-8 On Sun, Dec 21, 2014 at 12:51 PM, Peter Todd wrote: > On Sun, Dec 21, 2014 at 06:10:47PM +0000, Adam Back wrote: > > Yes you could for example define a new rule that two signatures > > (double-spend) authorises something - eg miners to take funds. (And > > this would work with existing ECDSA addresses & unrestricted R-value > > choices). > > > > I wasnt really making a point other than an aside that it maybe is > > sort-of possible to do with math what you said was not possible where > > you said "This [preventing signing more than one message] is > > impossible to implement with math alone". > > Introducing a bunch of clever ECDSA math doesn't change the fact that > the clever math isn't what is preventing double-spending, clever > economics is. Just like Bitcoin itself. > > No sense getting people potentially confused by a bunch of complex > equations that aren't relevant to the more fundemental and much more > important principle that math alone can't prevent double-spending. Math alone describes all of Bitcoin's structure; as math is a way to model reality, it has no limits. Saying Math can't prevent double-spending is near equivalent to saying it cannot be done. --047d7b34318aab3e0d050ac38988 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
On S= un, Dec 21, 2014 at 12:51 PM, Peter Todd <pete@petertodd.org> wrote:
On Sun, Dec 21, 2014 at 0= 6:10:47PM +0000, Adam Back wrote:
> Yes you could for example define a new rule that two signatures
> (double-spend) authorises something - eg miners to take funds. (And > this would work with existing ECDSA addresses & unrestricted R-val= ue
> choices).
>
> I wasnt really making a point other than an aside that it maybe is
> sort-of possible to do with math what you said was not possible where<= br> > you said "This [preventing signing more than one message] is
> impossible to implement with math alone".

Introducing a bunch of clever ECDSA math doesn't change the fact= that
the clever math isn't what is preventing double-spending, clever
economics is. Just like Bitcoin itself.

No sense getting people potentially confused by a bunch of complex
equations that aren't relevant to the more fundemental and much more important principle that math alone can't prevent double-spending.

Math alone describes all of Bitcoin's struc= ture; as math is a way to model reality, it has no limits. Saying Math can&= #39;t prevent double-spending is near equivalent to saying it cannot be don= e. =C2=A0
--047d7b34318aab3e0d050ac38988--