Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id D27AB10F5 for ; Sat, 26 Dec 2015 21:22:12 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from d.mail.sonic.net (d.mail.sonic.net [64.142.111.50]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 65FB7ED for ; Sat, 26 Dec 2015 21:22:12 +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 d.mail.sonic.net (8.15.1/8.15.1) with ESMTPSA id tBQLM7W6020422 (version=TLSv1 cipher=DHE-RSA-AES128-SHA bits=128 verify=NOT); Sat, 26 Dec 2015 13:22:08 -0800 Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.6\)) Content-Type: multipart/signed; boundary="Apple-Mail=_B7C15672-F739-4C78-A890-78ED9F44E21A"; protocol="application/pgp-signature"; micalg=pgp-sha512 X-Pgp-Agent: GPGMail 2.5.2 From: Jonathan Toomim In-Reply-To: Date: Sat, 26 Dec 2015 13:22:36 -0800 Message-Id: References: To: Bitcoin Dev X-Mailer: Apple Mail (2.1878.6) X-Sonic-CAuth: UmFuZG9tSVZzIR7J8wNw60B3JpDhPrLiE3Br2D/+WGX3SJIFA1Hxpul7yZAwFWfBo3Imut35quXLUMe1DHTAtjk1XCOioLUZ X-Sonic-ID: C;7j3gtxas5RGArMgxU3XIUw== M;hgBTuBas5RGArMgxU3XIUw== X-Sonic-Spam-Details: 3.8/5.0 by cerberusd X-Spam-Status: No, score=-1.2 required=5.0 tests=BAYES_05,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 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 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 26 Dec 2015 21:22:12 -0000 --Apple-Mail=_B7C15672-F739-4C78-A890-78ED9F44E21A Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii Another option for how to deal with block withholding attacks: Give the = miner who finds the block a bonus. This could even be part of the = coinbase transaction. Block withholding is effective because it costs the attacker 0% and = costs the pool 100%. If the pool's coinbase tx was 95% to the pool, 5% = (1.25 BTC) to the miner, that would make block withholding attacks much = more expensive to the attacker without making a huge impact on reward = variance for small miners. If your pool gets attacked by a block = withholding attack, then you can respond by jacking up the bonus ratio. = At some point, block withholding attacks become unfeasibly expensive to = perform. This can work because the pool sacrifices a small amount of = variance for its customers by increasing the bonus, but the block = attacker sacrifices revenue. This should make the attacker give up = before the pool does. This system already exists in p2pool, although there the reward bonus = for the block's finder is only 0.5%. This must have been proposed before, right? Anyone know of a good = analysis of the game theory math? --Apple-Mail=_B7C15672-F739-4C78-A890-78ED9F44E21A 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 iQEcBAEBCgAGBQJWfwUdAAoJEIEuMk4MG0P1XFUH/1glJZESMdK0tSxDxJCrpyZl eRXXP794Rp09nBb7v5lopgiCfBVQos/jixnmAGmqteHr4ArxUQG49cip3lSE8yuQ n7V4K3sY4JGNYU1hFeDPXvbgtxBSIV9v+LH4HxjNua4p06n1Bdf83BfNx7bFAz9x j1pkKl5nwW98fK2qQuIj+xL35h9+n1HpLfg2LC8NDkV8L4GsP7k1a0+n89t/3YKR JCQ/7UHDA7n+0K24TETSY9busP3hOdHTTe33RReryx90UZzRQXe3BJnJWKBUQ6Ch qVFcKN3HJj3nX68YLcRnTt4D/V4ZG7eVP4RAZSQvLSAFoheiAXtdGAbBrtwonas= =Dvf/ -----END PGP SIGNATURE----- --Apple-Mail=_B7C15672-F739-4C78-A890-78ED9F44E21A--