From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id E165BD75; Fri, 13 Jul 2018 00:05:06 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from ozlabs.org (ozlabs.org [203.11.71.1]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 5B06177D; Fri, 13 Jul 2018 00:05:06 +0000 (UTC) Received: by ozlabs.org (Postfix, from userid 1011) id 41RY341bYLz9s0n; Fri, 13 Jul 2018 10:05:04 +1000 (AEST) From: Rusty Russell To: DING FENG , Luke Dashjr In-Reply-To: References: <871sewirni.fsf@gmail.com> <201807031213.51127.luke@dashjr.org> Date: Fri, 13 Jul 2018 09:34:14 +0930 Message-ID: <878t6gxapt.fsf@rustcorp.com.au> MIME-Version: 1.0 Content-Type: text/plain X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Cc: Bitcoin Protocol Discussion , lightning-dev@lists.linuxfoundation.org Subject: Re: [bitcoin-dev] [Lightning-dev] BIP sighash_noinput X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Protocol Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 13 Jul 2018 00:05:07 -0000 DING FENG writes: > Hi, > > I'm a junior developer and a bitcoin user. > And I have read this thread carefully. > > I'm very worried about "SIGHASH_NOINPUT". > > Because "SIGHASH_NOINPUT" looks will be widely used, and it makes reuse > address more dangerous. No. A wallet should *never* create a SIGHASH_NOINPUT to spend its own UTXOs. SIGHASH_NOINPUT is useful for smart contracts which have unique conditions, such as a pair of peers rotating keys according to an agreed schedule (eg. lightning). Cheers, Rusty.