Received: from sog-mx-4.v43.ch3.sourceforge.com ([172.29.43.194] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1Rh2jx-0000gF-4Q for bitcoin-development@lists.sourceforge.net; Sat, 31 Dec 2011 17:29:05 +0000 X-ACL-Warn: Received: from nm7.bullet.mail.ne1.yahoo.com ([98.138.90.70]) by sog-mx-4.v43.ch3.sourceforge.com with smtp (Exim 4.76) id 1Rh2jw-0001Pt-7O for bitcoin-development@lists.sourceforge.net; Sat, 31 Dec 2011 17:29:05 +0000 Received: from [98.138.90.52] by nm7.bullet.mail.ne1.yahoo.com with NNFMP; 31 Dec 2011 17:28:59 -0000 Received: from [98.138.87.2] by tm5.bullet.mail.ne1.yahoo.com with NNFMP; 31 Dec 2011 17:28:59 -0000 Received: from [127.0.0.1] by omp1002.mail.ne1.yahoo.com with NNFMP; 31 Dec 2011 17:28:59 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 17098.40527.bm@omp1002.mail.ne1.yahoo.com Received: (qmail 14546 invoked by uid 60001); 31 Dec 2011 17:28:58 -0000 X-YMail-OSG: EYjaedgVM1kT0PDBfje_W2Gyz3aE.gWJxeYIG_qSqXkJuMT 6R4CPDOix__edkuSxvEnEs2VQDopJgQmkqERj5yQ93CEV78GYJYwejPEEepR F9ZS_XuqEXIHRbVsOyPvlFSLN0qaVKDzCUKw7d8SrtfXUOwXqVYTZMgmyafD qMplzBPqlBobE2PkX5XJ2_sWNdKIvqjkj.4qwy304iOplkLBKqtd9snacLLh 2irBiwPGgrWgWwDLHShw5tyh1xxUuV7O.ZEXIEO9.m5F5nT2xG6OvjwUodtE 0eixFG4ehPBK6pVYcculMAPeQNseB_a5tuOHLLNezmElfeW6kAud9lHj0yWo fIZJGbP4HptcTnrF3TN0poOlXaYTZDKyoJeX4zT2IVSlLd_guDgktF2iEoPF ziTPmKHfHQY40UZxLZWtQRJT89CM6pIPoY6A9ec7XQ3bUZeciQL3lTTAzG8V x1iv_EIkvhtGwuKPUQe0vSlJJDS3LNyQav4j517OvHwfXiNKnKbtYO5Cn3Af xeb7CEWP_vrN3UeDtzlxSbOBi3OFBnHZvtCywFEs8MNokUVfBU.shF7TFriA 8acb_rYy5RUgMiQGfNL7H6s4jIuXaJ7eJ8SvEdq45c7N.wOt84g-- Received: from [108.8.0.178] by web120904.mail.ne1.yahoo.com via HTTP; Sat, 31 Dec 2011 09:28:58 PST X-Mailer: YahooMailClassic/15.0.4 YahooMailWebService/0.8.115.331698 Message-ID: <1325352538.2068.YahooMailClassic@web120904.mail.ne1.yahoo.com> Date: Sat, 31 Dec 2011 09:28:58 -0800 (PST) From: Zell Faze To: roconnor@theorem.ca, Joel Joonatan Kaartinen In-Reply-To: <1325325253.2800.3.camel@mei> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Spam-Score: -1.4 (-) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [98.138.90.70 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (zellfaze[at]yahoo.com) -1.3 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -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: From: address is in the auto white-list X-Headers-End: 1Rh2jw-0001Pt-7O Cc: bitcoin-development@lists.sourceforge.net Subject: Re: [Bitcoin-development] Alternative to OP_EVAL 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: Sat, 31 Dec 2011 17:29:05 -0000 I agree with Joel. I think someone brought this up earlier as well. Most= OP_EVAL transactions won't be complex enough to require more than a few lo= ops.=0A=0A--Zell=0A=0A------------------------=0A"It stopped being just a w= ebsite a long time ago. For many of us, most of us, Wikipedia has become an= indispensable part of our daily lives."=0A=E2=80=94 Jimmy Wales, Founder o= f Wikipedia =0AHelp protect it now. Please make a donation today: http://ww= w.wikimediafoundation.org/wiki/Donate=0A=0A=0A=0A--- On Sat, 12/31/11, Joel= Joonatan Kaartinen wrote:=0A=0A> From: Joel Joo= natan Kaartinen =0A> Subject: Re: [Bitcoin-develo= pment] Alternative to OP_EVAL=0A> To: roconnor@theorem.ca=0A> Cc: bitcoin-d= evelopment@lists.sourceforge.net=0A> Date: Saturday, December 31, 2011, 4:5= 4 AM=0A> Wouldn't it work to restrict the=0A> number of executions of OP_EV= AL allowed=0A> per transaction? That way it wouldn't allow for unlimited=0A= > looping. If=0A> there's too many OP_EVAL executions during the transactio= n=0A> evaluation,=0A> just consider the transaction illegal. 3 would be eno= ugh=0A> for the=0A> purposes people have been planning for here I think.=0A= > =0A> - Joel=0A> =0A> On Thu, 2011-12-29 at 11:42 -0500, roconnor@theorem.= ca=0A> wrote:=0A> > On Thu, 29 Dec 2011, theymos wrote:=0A> > =0A> > > On T= hu, Dec 29, 2011, at 01:55 AM, roconnor@theorem.ca=0A> wrote:=0A> > >> The = number of operations executed is still=0A> bounded by the number of=0A> > >= > operations occurring in the script.=C2=A0=0A> With the OP_EVAL proposal t= he=0A> > >> script language becomes essentially Turing=0A> complete, with o= nly an=0A> > >> artificial limit on recursion depth=0A> preventing arbitrar= y computation=0A> > >> and there is no way to know what code will=0A> run w= ithout executing it.=0A> > >=0A> > > Even if OP_EVAL allowed infinite depth= , you'd=0A> still need to explicitly=0A> > > specify all operations perform= ed, since there is=0A> no way of looping.=0A> > =0A> > That's not true.=C2= =A0 Gavin himself showed how to use=0A> OP_EVAL to loop:=0A> > OP_PUSHDATA = {OP_DUP OP_EVAL} OP_DUP OP_EVAL.=0A> > =0A> > Basically OP_DUP lets you dup= licate the code on the=0A> stack and that is the =0A> > key to looping.=C2= =A0 I'm pretty sure from here we get=0A> get Turing completeness. =0A> > Us= ing the stack operations I expect you can implement=0A> the SK-calculus =0A= > > given an OP_EVAL that allows arbitrary depth.=0A> > =0A> > OP_EVAL adds= dangerously expressive power to the=0A> scripting language.=0A> > =0A> =0A= > =0A> =0A> ---------------------------------------------------------------= ---------------=0A> Ridiculously easy VDI. With Citrix VDI-in-a-Box, you do= n't=0A> need a complex=0A> infrastructure or vast IT resources to deliver s= eamless,=0A> secure access to=0A> virtual desktops. With this all-in-one so= lution, easily=0A> deploy virtual =0A> desktops for less than the cost of P= Cs and save 60% on VDI=0A> infrastructure =0A> costs. Try it free! http://p= .sf.net/sfu/Citrix-VDIinabox=0A> __________________________________________= _____=0A> Bitcoin-development mailing list=0A> Bitcoin-development@lists.so= urceforge.net=0A> https://lists.sourceforge.net/lists/listinfo/bitcoin-deve= lopment=0A>