Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1XEj3I-0008LQ-RQ for bitcoin-development@lists.sourceforge.net; Tue, 05 Aug 2014 18:01:36 +0000 Received-SPF: pass (sog-mx-1.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.214.174 as permitted sender) client-ip=209.85.214.174; envelope-from=alex.mizrahi@gmail.com; helo=mail-ob0-f174.google.com; Received: from mail-ob0-f174.google.com ([209.85.214.174]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1XEj3H-00058x-44 for bitcoin-development@lists.sourceforge.net; Tue, 05 Aug 2014 18:01:36 +0000 Received: by mail-ob0-f174.google.com with SMTP id vb8so965401obc.19 for ; Tue, 05 Aug 2014 11:01:29 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.60.60.167 with SMTP id i7mr8109075oer.41.1407261689611; Tue, 05 Aug 2014 11:01:29 -0700 (PDT) Received: by 10.202.175.136 with HTTP; Tue, 5 Aug 2014 11:01:29 -0700 (PDT) In-Reply-To: References: <3826251.5rGb1MfKOu@crushinator> <1515086.GQImTWpAiA@crushinator> Date: Tue, 5 Aug 2014 21:01:29 +0300 Message-ID: From: Alex Mizrahi To: Gregory Maxwell , Bitcoin Dev Content-Type: multipart/alternative; boundary=089e0158bab41d8ca504ffe5a559 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 (alex.mizrahi[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: 1XEj3H-00058x-44 Subject: Re: [Bitcoin-development] deterministic transaction expiration 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: Tue, 05 Aug 2014 18:01:37 -0000 --089e0158bab41d8ca504ffe5a559 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable > > A distinction there is that they can only become invalid via a > conflict=E2=80=94 replaced by another transaction authored by the prior > signers. If no other transaction could be created (e.g. you're a > multisigner and won't sign it again) then there is no such risk. You need to check transaction's dependencies up to a certain depth to know whether it is safe: If one of inputs depends on transaction which is signed by parties with unknown trustworthiness, then it isn't safe. > It now introduces chance events ("act of god") into the mix where they > they didn't exist before. You need to check transaction's dependencies up to a certain depth to know whether it is safe: If one of inputs depends on transaction time-locked script (or other unrecognized script), then it isn't safe. Situation is identical, you might need several extra lines of code. I think it would matter only if we had deterministic, reliable mempool and reorganization behavior. But it's not something we can depend on. --089e0158bab41d8ca504ffe5a559 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
A distinction there is that they can only become= invalid via a
conflict=E2=80=94 replaced by another transaction authored by the prior
signers. If no other transaction could be created (e.g. you're a
multisigner and won't sign it again) then there is no such risk.

You need to check transaction's dependencies = up to a certain depth to know whether it is safe:
=C2=A0If one of= inputs depends on transaction which is signed by parties with unknown trus= tworthiness, then it isn't safe.
=C2=A0
=C2=A0It=C2=A0now intr= oduces chance events ("act of god") into the mix where they
they didn't exist before.

You need to c= heck transaction's dependencies up to a certain depth to know whether i= t is safe:
=C2=A0 If one of inputs depends on transaction time-lo= cked script (or other unrecognized script), then it isn't safe.

Situation is identical, you might need several extra li= nes of code.

I think it would matter only if we ha= d deterministic, reliable mempool and reorganization behavior. But it's= not something we can depend on.

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