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 BCFF8258 for ; Sun, 26 Feb 2017 16:53:40 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-it0-f66.google.com (mail-it0-f66.google.com [209.85.214.66]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id BDAB6180 for ; Sun, 26 Feb 2017 16:53:39 +0000 (UTC) Received: by mail-it0-f66.google.com with SMTP id e137so9255188itc.0 for ; Sun, 26 Feb 2017 08:53:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=mK4wO+7JfDrRAE5s68G21eHeNWLhxQQfrkWXBM1StCY=; b=A3AnTtPQa4Rhc5drobwgLtC60eiXxsqWUCfjfjWsGGE5aG1nE2fOxmRy9nVG8/Ncfa rr7hX8sX2EpwTde6IudOlB4SrwA1rKja+xHzvnX87ygqda+aci2wD57Mm+LnQQ4NMTYk IunHtNL41xqlFabmz1ts0N0Lhu4HjOIaJHG9rcl/tFq5FLrMy/MUSK2rRPo7d68L7jcC 8Tal6OWZjiX7c6gX/ib3ZHmGEO4JjdjzKcmhEPrJWKJmRpJK+4m0mJHP8SOzbgxZx3xK 0flNLn4wLfxJ/Hvnnq2QiJRZIdYgK9k3I7QEk/MbrUd+aaPuYjmIsyETX0YEVKf524Js /Ttg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=mK4wO+7JfDrRAE5s68G21eHeNWLhxQQfrkWXBM1StCY=; b=t1BvWooB9Iv3udumyk2Bvbrpe99Nmcw2IY71tsLThNzl0mpubR9ZtxfYUNIZv5Ydju jsp4kns0MUt6EMOefIENUQugM2dlf6WZpJig7ZvfZAdmEQ/sTh9TGZXoIEBnRvpTHcA0 06ozrnfp0FgznKKhnZ9MpUJPWn3j8D5YKHTIwtMpLSX+lR3LwdwOr8CdAYLAQaZEphEb FicPY5tlsPo69SOMqcwm5oeeJVEp/UZc/reoiHiULsuuP1qdXRwk5qdaDDM78OZYpNpG Iz9JU/2k8KEMira8GUhPKsJIW0upDSWrdauR24A+VRmt/UtuC5GWXRqI80yaQKH/V6DU j1Gw== X-Gm-Message-State: AMke39nxj+B5gGm32H+Oqu0nycQZaxixM31iRH/Xrlhl/KyRPI8KV/ND1nbEmoox8S2KBQ== X-Received: by 10.36.44.4 with SMTP id i4mr10427908iti.105.1488128019166; Sun, 26 Feb 2017 08:53:39 -0800 (PST) Received: from [10.0.1.42] (71-81-80-204.dhcp.stls.mo.charter.com. [71.81.80.204]) by smtp.gmail.com with ESMTPSA id h91sm3493424ioi.24.2017.02.26.08.53.37 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 26 Feb 2017 08:53:37 -0800 (PST) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 10.2 \(3259\)) From: Steve Davis In-Reply-To: Date: Sun, 26 Feb 2017 10:53:29 -0600 Content-Transfer-Encoding: quoted-printable Message-Id: References: <8F096BE1-D305-43D4-AF10-2CC48837B14F@gmail.com> <20170225010122.GA10233@savin.petertodd.org> <208F93FE-B7C8-46BE-8E00-52DBD0F43415@gmail.com> <20170225191201.GA15472@savin.petertodd.org> <20170225210406.GA16196@savin.petertodd.org> <4FE38F6A-0560-4989-9C53-7F8C94EA4C76@gmail.com> <20170225214018.GA16524@savin.petertodd.org> <4F6C2972-A320-429A-BD13-623B01F390A3@gmail.com> To: Pieter Wuille X-Mailer: Apple Mail (2.3259) X-Spam-Status: No, score=-1.5 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, RCVD_IN_DNSWL_NONE, RCVD_IN_SORBS_SPAM autolearn=no version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org X-Mailman-Approved-At: Sun, 26 Feb 2017 17:02:21 +0000 Cc: Bitcoin Dev Subject: Re: [bitcoin-dev] SHA1 collisions make Git vulnerable to attakcs by third-parties, not just repo maintainers 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: Sun, 26 Feb 2017 16:53:40 -0000 > On Feb 26, 2017, at 1:36 AM, Pieter Wuille = wrote: >=20 > Typical hash function breaks produce collision attacks, while a = preimage attack is needed to reduce single-key address security. Thank you Pieter - that was really helpful. I realize now that I was = thinking of a preimage attack but had mistakenly assumed that the = birthday bound applied... So the unit operation: [genkeypair; = ripemd160(sha256(pubkey));check_utxoset] would need to be performed = 2.9*10^42 and not (as I had first calculated) 2.4*10^18.=20 Oops. My bad.=