From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <jimmyjack@gmail.com> Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id E8259BE1 for <bitcoin-dev@lists.linuxfoundation.org>; Wed, 15 Jul 2015 15:49:19 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-wi0-f180.google.com (mail-wi0-f180.google.com [209.85.212.180]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 364791EF for <bitcoin-dev@lists.linuxfoundation.org>; Wed, 15 Jul 2015 15:49:18 +0000 (UTC) Received: by wiga1 with SMTP id a1so3789225wig.0 for <bitcoin-dev@lists.linuxfoundation.org>; Wed, 15 Jul 2015 08:49:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=content-type:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=lEXxEVF1j/CWp4TP/rNuQrbIqIplLYogT3gPIcIu+Vg=; b=bZ35a0ZtXFNsZL/VRQ23sW3EeSQnontCWOW80fSv3OR0lTxtzcMntLumamGjOOPOBn qBdtr1gAD4pxO3l9NBrKge0hyudny4E7/QAHtIRk2h76zJ2PMJ+rrw7k3hCm2J2rR+1U mNUQiZ2/e8Q2nYDME+ahh5d9MIAg5EK7jkr4iELyNCrrX6CSVaVTQVntjxSlTWN8Dr7P U96dfhxaabq/wrXKvPna1R2xotgoGyukDMbtWesYnPNrfnOysm5Bmqf14qYbdlVu5gPY c3ULJw561jqX5brfNtxRbpv3+jiXBvMiOAZByYhThRlMnDhwFUF+gF8Nrk5s6Wd/JS9o VdOw== X-Received: by 10.180.79.133 with SMTP id j5mr1547036wix.38.1436975356983; Wed, 15 Jul 2015 08:49:16 -0700 (PDT) Received: from [10.0.0.210] ([194.46.128.92]) by smtp.gmail.com with ESMTPSA id jz4sm8523376wjb.16.2015.07.15.08.49.14 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 15 Jul 2015 08:49:16 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 9.0 \(3067\)) From: Me <jimmyjack@gmail.com> In-Reply-To: <20150715151825.GB20029@savin.petertodd.org> Date: Wed, 15 Jul 2015 08:49:13 -0700 Content-Transfer-Encoding: quoted-printable Message-Id: <CDB5FC27-F3F0-44F7-BBC6-670ACAE740D2@gmail.com> References: <24662b038abc45da7f3990e12a649b8a@airmail.cc> <55A66FA9.4010506@thinlink.com> <20150715151825.GB20029@savin.petertodd.org> To: Peter Todd <pete@petertodd.org> X-Mailer: Apple Mail (2.3067) X-Spam-Status: No, score=-2.7 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Cc: bitcoin-dev@lists.linuxfoundation.org Subject: Re: [bitcoin-dev] Significant losses by double-spending unconfirmed transactions X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Development Discussion <bitcoin-dev.lists.linuxfoundation.org> List-Unsubscribe: <https://lists.linuxfoundation.org/mailman/options/bitcoin-dev>, <mailto:bitcoin-dev-request@lists.linuxfoundation.org?subject=unsubscribe> List-Archive: <http://lists.linuxfoundation.org/pipermail/bitcoin-dev/> List-Post: <mailto:bitcoin-dev@lists.linuxfoundation.org> List-Help: <mailto:bitcoin-dev-request@lists.linuxfoundation.org?subject=help> List-Subscribe: <https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev>, <mailto:bitcoin-dev-request@lists.linuxfoundation.org?subject=subscribe> X-List-Received-Date: Wed, 15 Jul 2015 15:49:20 -0000 Thank you Simon for sharing your tests, if possible can you share TX = hashes please. I would recommend to send them money post-mortem. What = you did is really valuable information, however it can be classified as = fraud. I really don=E2=80=99t want open this topic here, just suggesting = to keep your record clean :-)=20 > the double-spent txs > had near 100% propagation on blockchain.info (who has unfortunately > purged the relevant data already) Can you please share the TX Hash > Blockcypher's "confidence factor" model(1) > under the hood - yet another one of those sybil attacking network > monitoring things Peter, I noticed on your twitter you have a lot of bad things to say = about Blockcypher and their business model (which I might not full = agree, but totally respect), can you share any evidence they perform any = form of Sybil attack on the network, please.=20 > On Jul 15, 2015, at 8:18 AM, Peter Todd via bitcoin-dev = <bitcoin-dev@lists.linuxfoundation.org> wrote: >=20 > On Wed, Jul 15, 2015 at 07:35:21AM -0700, Tom Harding via bitcoin-dev = wrote: >>=20 >> You perform a valuable service with your demonstration, but you >> neglected to include the txid's to show that you actually did it. >=20 >> Your advice is must-follow for anyone relying on an unconfirmed tx: = it >> must pay a good fee and be highly relayable/minable. >=20 > Actually, I was looking at what I believe was (part of?) this attack > yesterday in the logs on my full-RBF nodes and the txs involved *did* > have good fees and were highly relayable/minable - the double-spent = txs > had near 100% propagation on blockchain.info (who has unfortunately > purged the relevant data already) >=20 > Shapeshift.io depends on Blockcypher's "confidence factor" model(1) > under the hood - yet another one of those sybil attacking network > monitoring things - to estimate tx confirmation probability by looking > at the % of nodes a tx has propagated too. But miners frequently use > customized Bitcoin Core codebases that don't follow normal policies, = so > those measurements don't actually tell you what you need to know. >=20 > hapeshift confirmed(2) the attack - confirming that they disabled > unconfirmed tx acceptance - said they're going to "improve" their > system... It'll be interesting to see what that actually entails. >=20 > 1) = https://medium.com/blockcypher-blog/from-zero-to-hero-bitcoin-transactions= -in-8-seconds-7c9edcb3b734 > 2) = https://www.reddit.com/r/Bitcoin/comments/3ddkhy/bitcoindev_significant_lo= sses_by_doublespending/ct468p7 >=20 > --=20 > 'peter'[:-1]@petertodd.org > 000000000000000010bf087ed645cba129e2523930d5cde636ddbae9e03aef9c > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev