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| author | Jonathan Toomim <j@toom.im> | 2015-12-25 04:00:11 -0800 |
|---|---|---|
| committer | bitcoindev <bitcoindev@gnusha.org> | 2015-12-25 12:00:06 +0000 |
| commit | 4cd4c6b953d6e634944729c91d34d595a795c34c (patch) | |
| tree | 60abd595f4f47fd37280fbf7aa32dc9b1bc97c5c | |
| parent | df56e6f017d7dca1a2a8a91dba345bcb3d282086 (diff) | |
| download | pi-bitcoindev-4cd4c6b953d6e634944729c91d34d595a795c34c.tar.gz pi-bitcoindev-4cd4c6b953d6e634944729c91d34d595a795c34c.zip | |
Re: [bitcoin-dev] We need to fix the block withholding attack
| -rw-r--r-- | 47/6a1808c2db52566e2be46b04210bcf12a9c4b5 | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/47/6a1808c2db52566e2be46b04210bcf12a9c4b5 b/47/6a1808c2db52566e2be46b04210bcf12a9c4b5 new file mode 100644 index 000000000..9e9d6fb8d --- /dev/null +++ b/47/6a1808c2db52566e2be46b04210bcf12a9c4b5 @@ -0,0 +1,185 @@ +Return-Path: <j@toom.im> +Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org + [172.17.192.35]) + by mail.linuxfoundation.org (Postfix) with ESMTPS id 721C6FBF + for <bitcoin-dev@lists.linuxfoundation.org>; + Fri, 25 Dec 2015 12:00:06 +0000 (UTC) +X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 +Received: from c.mail.sonic.net (c.mail.sonic.net [64.142.111.80]) + by smtp1.linuxfoundation.org (Postfix) with ESMTPS id C6500A5 + for <bitcoin-dev@lists.linuxfoundation.org>; + Fri, 25 Dec 2015 12:00:05 +0000 (UTC) +Received: from [192.168.1.190] (63.135.62.197.nwinternet.com [63.135.62.197] + (may be forged)) (authenticated bits=0) + by c.mail.sonic.net (8.15.1/8.15.1) with ESMTPSA id tBPBxu3I030688 + (version=TLSv1 cipher=DHE-RSA-AES128-SHA bits=128 verify=NOT); + Fri, 25 Dec 2015 03:59:57 -0800 +Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.6\)) +Content-Type: multipart/signed; + boundary="Apple-Mail=_EAA8C5C6-89A8-462E-9728-F8DFF91CB830"; + protocol="application/pgp-signature"; micalg=pgp-sha512 +X-Pgp-Agent: GPGMail 2.5.2 +From: Jonathan Toomim <j@toom.im> +In-Reply-To: <CABT1wW=r5DPG1e6XFe7NMHrquo1FzygPCdjEJ2QQnmGbqVMH2Q@mail.gmail.com> +Date: Fri, 25 Dec 2015 04:00:11 -0800 +Message-Id: <8BA2CF44-4237-460E-8339-F22A29504AE5@toom.im> +References: <20151219184240.GB12893@muck> + <CAAcC9yvh2ma2dFhNDEKs7vfXyQF9L+T0YtRvOsJ15AbfVti=cw@mail.gmail.com> + <219f125cee6ca68fd27016642e38fdf1@xbt.hk> + <CAAcC9ys_t7X0WpQ8W3577M8GLiA5sPV2F1BJ9qZbnMkE-1j3+Q@mail.gmail.com> + <aff8da46a69bdd7ef92ca87725866a5c@xbt.hk> + <CAPkFh0vNECi1OmBwki+8NNAQbe6EG2FEE4RR5z=kYVLLDFHUXg@mail.gmail.com> + <20151220132842.GA25481@muck> + <CAPkFh0t-+WhZYVLyT_auLa87zAATNOH=CpU4S5H=n6S1wmZ-oQ@mail.gmail.com> + <CABeL=0jgv3G8qx6wM+ZfwN154qhQY-GJdXnABc-iWL=YDNmhag@mail.gmail.com> + <CABT1wW=r5DPG1e6XFe7NMHrquo1FzygPCdjEJ2QQnmGbqVMH2Q@mail.gmail.com> +To: Ittay <ittay.eyal@cornell.edu> +X-Mailer: Apple Mail (2.1878.6) +X-Sonic-CAuth: UmFuZG9tSVYG27lgQAiCeVwg8cDp0ipp5Xhhfr6yg2VjUumfzt7T6PQs7h9NDDLZ2Jg5nMVpzDhzgTgZuKxXv17fsHJUXJ6q +X-Sonic-ID: C;VozEA/+q5RGWE/8vZz0oYQ== M;vBZ+BP+q5RGWE/8vZz0oYQ== +X-Sonic-Spam-Details: 3.8/5.0 by cerberusd +X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,HTML_MESSAGE, + 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 <bitcoin-dev@lists.linuxfoundation.org> +Subject: Re: [bitcoin-dev] We need to fix the block withholding attack +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: Fri, 25 Dec 2015 12:00:06 -0000 + + +--Apple-Mail=_EAA8C5C6-89A8-462E-9728-F8DFF91CB830 +Content-Type: multipart/alternative; + boundary="Apple-Mail=_7EFA8C1F-F68C-47DB-B550-2A2711E0E268" + + +--Apple-Mail=_7EFA8C1F-F68C-47DB-B550-2A2711E0E268 +Content-Transfer-Encoding: quoted-printable +Content-Type: text/plain; + charset=us-ascii + +On Dec 25, 2015, at 3:15 AM, Ittay via bitcoin-dev = +<bitcoin-dev@lists.linuxfoundation.org> wrote: + +> Treating the pool block withholding attack as a weapon has bad = +connotations, and I don't think anyone directly condones such an attack. + +I directly condone the use of block withholding attacks whenever pools = +get large enough to perform selfish mining attacks. Selfish mining and = +large, centralized pools also have bad connotations. + +It's an attack against pools, not just large pools. Solo miners are = +immune. As such, the presence or use of block withholding attacks makes = +Bitcoin more similar to Satoshi's original vision. One of the issues = +with mining centralization via pools is that miners have a direct = +financial incentive to stay relatively small, but pools do not. = +Investing in mining is a zero-sum game, where each miner gains revenue = +by making investments at the expense of existing miners. This also means = +that miners take revenue from themselves when they upgrade their = +hashrate. If a miner already has 1/5 of the network hashrate, then the = +marginal revenue for that miner of adding 1 TH/s is only 4/5 of the = +marginal revenue for a miner with 0% of the network and who adds 1 TH/s. = +The bigger you get, the smaller your incentive to get bigger. + +This incentive applies to miners, but it does not apply to pools. Pools = +have an incentive to get as big as possible (except for social backlash = +and altruistic punishment issues). Pools are the problem. I think we = +should be looking for ways of making pooled mining less profitable than = +solo mining or p2pool-style mining. Block withholding attacks are one = +such tool, and maybe the only usable tool we'll get. If we have to = +choose between making bitcoin viable long-term and avoiding things with = +bad connotations, it might be better to let our hands get a little bit = +dirty. + +I don't intend to perform any such attacks myself. I like to keep my hat = +a nice shiny white. However, if anyone else were to perform such an = +attack, I would condone it. + +P.S.: Sorry, pool operators. I have nothing against you personally. I = +just think pools are dangerous, and I wish they didn't exist. + +--Apple-Mail=_7EFA8C1F-F68C-47DB-B550-2A2711E0E268 +Content-Transfer-Encoding: quoted-printable +Content-Type: text/html; + charset=us-ascii + +<html><head><meta http-equiv=3D"Content-Type" content=3D"text/html = +charset=3Dus-ascii"></head><body style=3D"word-wrap: break-word; = +-webkit-nbsp-mode: space; -webkit-line-break: = +after-white-space;"><div>On Dec 25, 2015, at 3:15 AM, Ittay via = +bitcoin-dev <<a = +href=3D"mailto:bitcoin-dev@lists.linuxfoundation.org">bitcoin-dev@lists.li= +nuxfoundation.org</a>> wrote:</div><div><br = +class=3D"Apple-interchange-newline"><blockquote type=3D"cite"><span = +style=3D"font-family: Helvetica; font-size: 12px; font-style: normal; = +font-variant: normal; font-weight: normal; letter-spacing: normal; = +line-height: normal; orphans: auto; text-align: start; text-indent: 0px; = +text-transform: none; white-space: normal; widows: auto; word-spacing: = +0px; -webkit-text-stroke-width: 0px; float: none; display: inline = +!important;">Treating the pool block withholding attack as a weapon has = +bad connotations, and I don't think anyone directly condones such an = +attack. </span></blockquote><div><br></div><div>I directly condone the = +use of block withholding attacks whenever pools get large enough to = +perform selfish mining attacks. Selfish mining and large, centralized = +pools also have bad connotations.</div><div><br></div><div>It's an = +attack against pools, not just large pools. Solo miners are immune. As = +such, the presence or use of block withholding attacks makes Bitcoin = +more similar to Satoshi's original vision. One of the issues with mining = +centralization via pools is that miners have a direct financial = +incentive to stay relatively small, but pools do not. Investing in = +mining is a zero-sum game, where each miner gains revenue by making = +investments at the expense of existing miners. This also means that = +miners take revenue from themselves when they upgrade their hashrate. If = +a miner already has 1/5 of the network hashrate, then the marginal = +revenue for that miner of adding 1 TH/s is only 4/5 of the marginal = +revenue for a miner with 0% of the network and who adds 1 TH/s. The = +bigger you get, the smaller your incentive to get = +bigger. </div><div><br></div><div>This incentive applies to miners, = +but it does not apply to pools. Pools have an incentive to get as big as = +possible (except for social backlash and altruistic punishment issues). = +Pools are the problem. I think we should be looking for ways of making = +pooled mining less profitable than solo mining or p2pool-style mining. = +Block withholding attacks are one such tool, and maybe the only usable = +tool we'll get. If we have to choose between making bitcoin viable = +long-term and avoiding things with bad connotations, it might be better = +to let our hands get a little bit dirty.</div><div><br></div><div>I = +don't intend to perform any such attacks myself. I like to keep my hat a = +nice shiny white. However, if anyone else were to perform such an = +attack, I would condone it.</div><div><br></div><div>P.S.: Sorry, pool = +operators. I have nothing against you personally. I just think pools are = +dangerous, and I wish they didn't exist.</div></div></body></html>= + +--Apple-Mail=_7EFA8C1F-F68C-47DB-B550-2A2711E0E268-- + +--Apple-Mail=_EAA8C5C6-89A8-462E-9728-F8DFF91CB830 +Content-Transfer-Encoding: 7bit +Content-Disposition: attachment; + filename=signature.asc +Content-Type: application/pgp-signature; + name=signature.asc +Content-Description: Message signed with OpenPGP using GPGMail + +-----BEGIN PGP SIGNATURE----- +Comment: GPGTools - https://gpgtools.org + +iQEcBAEBCgAGBQJWfS/NAAoJEIEuMk4MG0P1cxQH/A+15Yp/NU6bcRVj4lQUtuxk +AqBbp6klno3nMs1KO2ffsqShhQ/9stN6OdrzwKOhDybOxDXQ3TMMud68FG1kKQMu +OqUUgHIXXcb4SnW04sxJ+QMZBSFSQsKlrdDt0adHNoJzCRWozu5MOll2t0OML6/L +Wdjao8pR9DWjbwu3QqeY9OOIuCwSRl+NJ6GSiBCVqDLC+byK2SjOg6MYsW5Mr/Bl +1oEYIypFhhCnU8G7C5YdQuK/GYaTSScAY1qcZpuuthcSiYSs997GOFsm0C/xOnqv +RevfcE1thxh+WvLmjoRYWTfnRRrq0JZmOmdGjWivHIcOUj0jYGlYxlI02ya2jzs= +=xysR +-----END PGP SIGNATURE----- + +--Apple-Mail=_EAA8C5C6-89A8-462E-9728-F8DFF91CB830-- + |