Received: from sog-mx-4.v43.ch3.sourceforge.com ([172.29.43.194] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1YxKFD-0004KU-Ub for bitcoin-development@lists.sourceforge.net; Tue, 26 May 2015 19:10:31 +0000 Received-SPF: pass (sog-mx-4.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.213.174 as permitted sender) client-ip=209.85.213.174; envelope-from=gmaxwell@gmail.com; helo=mail-ig0-f174.google.com; Received: from mail-ig0-f174.google.com ([209.85.213.174]) by sog-mx-4.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1YxKFD-0006Md-8C for bitcoin-development@lists.sourceforge.net; Tue, 26 May 2015 19:10:31 +0000 Received: by igbpi8 with SMTP id pi8so67992512igb.0 for ; Tue, 26 May 2015 12:10:26 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.107.17.17 with SMTP id z17mr37277666ioi.76.1432667425992; Tue, 26 May 2015 12:10:25 -0700 (PDT) Received: by 10.107.147.213 with HTTP; Tue, 26 May 2015 12:10:25 -0700 (PDT) In-Reply-To: <5564B33D.3070107@thinlink.com> References: <20150526051305.GA23502@savin.petertodd.org> <5564B33D.3070107@thinlink.com> Date: Tue, 26 May 2015 19:10:25 +0000 Message-ID: From: Gregory Maxwell To: Tom Harding Content-Type: text/plain; charset=UTF-8 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: 1YxKFD-0006Md-8C Cc: Bitcoin Dev Subject: Re: [Bitcoin-development] First-Seen-Safe Replace-by-Fee 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, 26 May 2015 19:10:32 -0000 On Tue, May 26, 2015 at 5:54 PM, Tom Harding wrote: > It's not difficult to > imagine real-world consequences to not having contributed to the > transaction. I'm having a hard time. Can you help me understand a specific case where this makes a difference. It appears to be a gratuitous requirement; if I have another unused input that happens to be larger by the required fee-- why not just use it? The inherent malleability of signatures makes it unreliable to depend on the signature content of a transaction until its good and buried, regardless. And an inability to replace an input means you could not RBF for additional fees without taking change in more cases; there ought to be a benefit to that.