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| author | Peter Todd <pete@petertodd.org> | 2015-07-13 12:04:53 -0400 |
|---|---|---|
| committer | bitcoindev <bitcoindev@gnusha.org> | 2015-07-13 16:05:06 +0000 |
| commit | 3decb87e8f938de1da5b312270d22295ed69c7ab (patch) | |
| tree | d7d73036e0ef0e66498b8e105ebbb6eb29b06878 | |
| parent | d4043d7d635f8d595ce9fb4e66cbe84885ebec0f (diff) | |
| download | pi-bitcoindev-3decb87e8f938de1da5b312270d22295ed69c7ab.tar.gz pi-bitcoindev-3decb87e8f938de1da5b312270d22295ed69c7ab.zip | |
Re: [bitcoin-dev] SPV Mining reveals a problematic incentive issue.
| -rw-r--r-- | fd/89d092ad4b84132ce84980168ca4b983a9a24d | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/fd/89d092ad4b84132ce84980168ca4b983a9a24d b/fd/89d092ad4b84132ce84980168ca4b983a9a24d new file mode 100644 index 000000000..3b6155499 --- /dev/null +++ b/fd/89d092ad4b84132ce84980168ca4b983a9a24d @@ -0,0 +1,137 @@ +Return-Path: <pete@petertodd.org> +Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org + [172.17.192.35]) + by mail.linuxfoundation.org (Postfix) with ESMTPS id CA817BC4 + for <bitcoin-dev@lists.linuxfoundation.org>; + Mon, 13 Jul 2015 16:05:06 +0000 (UTC) +X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 +Received: from outmail148096.authsmtp.net (outmail148096.authsmtp.net + [62.13.148.96]) + by smtp1.linuxfoundation.org (Postfix) with ESMTP id 1FF3F14F + for <bitcoin-dev@lists.linuxfoundation.org>; + Mon, 13 Jul 2015 16:05:05 +0000 (UTC) +Received: from mail-c237.authsmtp.com (mail-c237.authsmtp.com [62.13.128.237]) + by punt17.authsmtp.com (8.14.2/8.14.2/) with ESMTP id t6DG4xII072582; + Mon, 13 Jul 2015 17:04:59 +0100 (BST) +Received: from savin.petertodd.org (75-119-251-161.dsl.teksavvy.com + [75.119.251.161]) (authenticated bits=128) + by mail.authsmtp.com (8.14.2/8.14.2/) with ESMTP id t6DG4raj000369 + (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); + Mon, 13 Jul 2015 17:04:56 +0100 (BST) +Date: Mon, 13 Jul 2015 12:04:53 -0400 +From: Peter Todd <pete@petertodd.org> +To: Jorge =?iso-8859-1?Q?Tim=F3n?= <jtimon@jtimon.cc> +Message-ID: <20150713160453.GB19337@savin.petertodd.org> +References: <CAFdHNGg2dezj4V-i-E6dRLp99nZMQ_ErKdBo0OgQJ=9WPm90jQ@mail.gmail.com> + <CABm2gDoAa5F5crO4enKO-Qqb+Zd3=9b8ohBDYmrygsPSWdevoQ@mail.gmail.com> +MIME-Version: 1.0 +Content-Type: multipart/signed; micalg=pgp-sha256; + protocol="application/pgp-signature"; boundary="MW5yreqqjyrRcusr" +Content-Disposition: inline +In-Reply-To: <CABm2gDoAa5F5crO4enKO-Qqb+Zd3=9b8ohBDYmrygsPSWdevoQ@mail.gmail.com> +User-Agent: Mutt/1.5.21 (2010-09-15) +X-Server-Quench: e7d47449-2978-11e5-9f75-002590a135d3 +X-AuthReport-Spam: If SPAM / abuse - report it at: + http://www.authsmtp.com/abuse +X-AuthRoute: OCd2Yg0TA1ZNQRgX IjsJECJaVQIpKltL GxAVKBZePFsRUQkR + aQdMdwEUEkAYAgsB AmMbWlNeUFl7XGU7 bA9PbARUfEhLXhtr + VklWR1pVCwQmRRp1 cRpcA0NydwVFfnc+ ZEBqXXYVCUMucUF5 + RkdJF2QBbXphaTUa TUkOcAZJcANIexZF O1F8UScOLwdSbGoL + FQ4vNDcwO3BTJTpg Cjo1Exo3QEAKGDF0 XR0cEDwrBgUMDz0p + KBYiJ1sVAEcaekQ0 OlYnRVMGPlcTERZD Egcl +X-Authentic-SMTP: 61633532353630.1024:706 +X-AuthFastPath: 0 (Was 255) +X-AuthSMTP-Origin: 75.119.251.161/587 +X-AuthVirus-Status: No virus detected - but ensure you scan with your own + anti-virus system. +X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,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] SPV Mining reveals a problematic incentive issue. +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: Mon, 13 Jul 2015 16:05:06 -0000 + + +--MW5yreqqjyrRcusr +Content-Type: text/plain; charset=iso-8859-1 +Content-Disposition: inline +Content-Transfer-Encoding: quoted-printable + +On Sat, Jul 11, 2015 at 11:24:48AM +0200, Jorge Tim=F3n wrote: +> All miners should validate transactions precisely because of the latest +> attack you've described. Full miners can gain a lot from this attack to +> leverage their full validation against spv miners who blindly spend energy +> hashing on top of something that may be worthless crap. SPV mining makes = +no +> sense, but some miners claim they're doind it for very short periods of +> time, which shouldn't be as bad as doing it all the time. +> +> I think it would be more rational for them to keep mining on top of the o= +ld +> block until they've fully validated the new block (which shouldn't take so +> long anyway), even if this slightly increases the orphan rate. + +You're missing something really critical about what F2Pool/AntPool were +(are?) doing: They're finding out about new blocks not by getting block +headers from just anywhere, but by connecting to other pools' via +stratum anonymously and determining what block hash they're telling the +hashers at the pool to work on. (e.g. what prevblockhash is in the block +header of shares being generated) + +If other pools try to fake this information they're immediately and +directly losing money, because they're telling their own hashers to make +invalid blocks. This of course has a high chance of being detected, and +can easily be FUDed into "STOP MINING AT FOO POOL!" reardless of what +the ivory tower game theory might say. The only hope the pools have is +to somehow identify which connections correspond to other pools with +high reliability and target just those connections - good luck on that. + + +Anyway, all this concern about SPV mining is misguided: relying purely +on SPV w/ low #'s of confirmations just isn't very smart. What SPV can +do - at least while the inflation subsidy is still high - is give +reasonable protection against your third-party-run trusted full nodes +=66rom lying to you, simply because doing so has well-defined costs in +terms of energy to create fake blocks. Targetting enough people at once +to make a fake block a worthwhile investment is difficult, particularly +when you take into account how timing works in the defenders favor - the +attacker probably only has a small % of hashing power, so they're going +to wait a long time to find their fake block. Between that and a trusted +third party-run full node you're probably reasonably safe, for now. + +--=20 +'peter'[:-1]@petertodd.org +0000000000000000086007e31decd6eb80e07f77271ef50c69e1e6342161f4e5 + +--MW5yreqqjyrRcusr +Content-Type: application/pgp-signature; name="signature.asc" +Content-Description: Digital signature + +-----BEGIN PGP SIGNATURE----- + +iQGrBAEBCACVBQJVo+GgXhSAAAAAABUAQGJsb2NraGFzaEBiaXRjb2luLm9yZzAw +MDAwMDAwMDAwMDAwMDAwZjk2ODM1ODVhMzA1MDk1ZDBhYmRjNDNiMGMxN2NlMDVk +OGNlYjYxYWU4YjZkZDgvFIAAAAAAFQARcGthLWFkZHJlc3NAZ251cGcub3JncGV0 +ZUBwZXRlcnRvZC5vcmcACgkQJIFAPaXwkftP0AgAgIrHTnaJBQPGksj+KY8BtQzj +xGmpQP4zb7AKWqXIzQFBvxf4YT3wGbxexxG1CUjrACqJG2jND+0P8Ad6A9DFk7oV +D9XB/LylX86Gd4rCCFyz9gB22uUkvLHzxcH2D64CoAQOL4NLUyzizlvD+y4WowhG +a8meum0ikN7hid8yxPXBdSZZrfgjBTDNN/AuvTqwEu5nx/V8FTI5EePCcZUR1sKD +DM760+dFSSqbZtQvSsE+2ra6xkOrBydAgemT8Ow5UNCwtTE3DCEXeP3WhH45QGVW +1YNc+0Pkwug59UAPTua9xKV1W7emhETM18WLIJvDeQ9/I4p6ksZn4mNa8wyKpw== +=ArfO +-----END PGP SIGNATURE----- + +--MW5yreqqjyrRcusr-- + |