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 178EDC11 for ; Fri, 8 Nov 2019 03:16:02 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-pl1-f173.google.com (mail-pl1-f173.google.com [209.85.214.173]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 816A2710 for ; Fri, 8 Nov 2019 03:16:01 +0000 (UTC) Received: by mail-pl1-f173.google.com with SMTP id y24so3052378plr.12 for ; Thu, 07 Nov 2019 19:16:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=voskuil-org.20150623.gappssmtp.com; s=20150623; h=content-transfer-encoding:from:mime-version:date:subject:message-id :references:in-reply-to:to; bh=n/abpFNkzJc9niAtao+R9gyNFdigQC0AjcyZHGci+Q0=; b=B6UgcCDroMuzMkuf0pyadSf3qUK+kOQT6ntAa1uQ2HNDztVZ9l8ByzhQy3e68n89Wt 1n0Gr1PBHpKCeInph9gTvyJL1873DCBowPnwxEQsZoLH1EFlNf9ogEDOZNJw2LarpdTR GG5KakURTW74kqjzYFH3IBpY8TorT2iUwyuV9Yl9m9g3QuRuFhRlBU6QFMgFalpVIqzO SafGJ7m0aykAs2748AjQhZZllF/QCK4cM8RTI/7jv/gAzfjeauliCFpVoLAJ8+mEJ8xw VaLaA9Xxb/0rjdVS8K+E8eOE6VDwMYEUljMcM5YEgYh2hBMMgZsqbBdPIEKsfjsxtQYx 2YMQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:content-transfer-encoding:from:mime-version:date :subject:message-id:references:in-reply-to:to; bh=n/abpFNkzJc9niAtao+R9gyNFdigQC0AjcyZHGci+Q0=; b=NwUMsfRm/5CUy8E8GUzKh901eJukAGo9qJvAGVRUSkx2on1FHEedL6s+Aq7B75VC4m GNsoxZC2z+dXIuOmLXMJaG0QJD5ONZa8fxwafD8tlkbqXk/6T4IWvPFn9EsR82bnsMle LDuqRxoaI2cAKOLOSypNN11AGXnbHpycRBAS/bfVX+sr3VkXLuCvhyswMLU5W2rWK/XU LxoXrnHP8c9somv3B/emEzvuJ7YQxTnnj0p9bs1FIcmqh4jPmGxxBUxKs8oxNzJXvlXc 8ZGw4XWr2eb7Nl/WgzPRI1zqK7sw2VasDwnwp/lxNLTeEaX38KE9BxI7hlyp5M4zkOrW isoA== X-Gm-Message-State: APjAAAU69YoWsWHnzpTfrOj6d1x6sLWY8MlnuNxeFa451sJ+E0XByZII woz/X+KCZyUKFJQZkfEpfGpvrvvXhOs= X-Google-Smtp-Source: APXvYqzq/++quG/30ncFlv/RnI/MT16ZN8uDtSK5P8oUfXkuK8PzfxlVlWyaCn3yMId9TVIB27DraQ== X-Received: by 2002:a17:90a:3522:: with SMTP id q31mr10175621pjb.18.1573182960591; Thu, 07 Nov 2019 19:16:00 -0800 (PST) Received: from [172.19.248.34] ([38.98.37.142]) by smtp.gmail.com with ESMTPSA id y24sm5059304pfr.116.2019.11.07.19.15.58 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 07 Nov 2019 19:15:59 -0800 (PST) Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable From: Eric Voskuil Mime-Version: 1.0 (1.0) Date: Fri, 8 Nov 2019 12:15:53 +0900 Message-Id: References: <20191108021541.n3jk54vucplryrbl@ganymede> In-Reply-To: <20191108021541.n3jk54vucplryrbl@ganymede> To: "David A. Harding" , Bitcoin Protocol Discussion X-Mailer: iPhone Mail (17A878) X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, MIME_QP_LONG_LINE, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org X-Mailman-Approved-At: Fri, 08 Nov 2019 03:40:55 +0000 Subject: Re: [bitcoin-dev] Bech32 weakness and impact on bip-taproot addresses 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, 08 Nov 2019 03:16:02 -0000 > On Nov 8, 2019, at 11:16, David A. Harding via bitcoin-dev wrote: >=20 > =EF=BB=BFOn Thu, Nov 07, 2019 at 02:35:42PM -0800, Pieter Wuille via bitco= in-dev wrote: >> In the current draft, witness v1 outputs of length other >> than 32 remain unencumbered, which means that for now such an >> insertion or erasure would result in an output that can be spent by >> anyone. If that is considered unacceptable, it could be prevented by >> for example outlawing v1 witness outputs of length 31 and 33. >=20 > Either a consensus rule or a standardness rule[1] would require anyone > using a bech32 library supporting v1+ segwit to upgrade their library. > Otherwise, users of old libraries will still attempt to pay v1 witness > outputs of length 31 or 33, causing their transactions to get rejected > by newer nodes or get stuck on older nodes. This is basically the > problem #15846[2] was meant to prevent. >=20 > If we're going to need everyone to upgrade their bech32 libraries > anyway, I think it's probably best that the problem is fixed in the > bech32 algorithm rather than at the consensus/standardness layer. As an implementer of both the address encoding and script validation, I agre= e. e > -Dave >=20 > [1] https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2019-November/= 017444.html > [2] https://github.com/bitcoin/bitcoin/pull/15846 >=20 > P.S. My thanks as well to the people who asked the question during > review that lead to this discussion: >=20 > http://www.erisian.com.au/meetbot/taproot-bip-review/2019/taproot-bip-= review.2019-11-05-19.00.log.html#l-88 > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev