Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1YtaEC-0005dj-FQ for bitcoin-development@lists.sourceforge.net; Sat, 16 May 2015 11:26:00 +0000 Received-SPF: pass (sog-mx-1.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.220.173 as permitted sender) client-ip=209.85.220.173; envelope-from=tier.nolan@gmail.com; helo=mail-qk0-f173.google.com; Received: from mail-qk0-f173.google.com ([209.85.220.173]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1YtaEA-0002bq-Fs for bitcoin-development@lists.sourceforge.net; Sat, 16 May 2015 11:26:00 +0000 Received: by qkai132 with SMTP id i132so19058967qka.2 for ; Sat, 16 May 2015 04:25:53 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.140.33.227 with SMTP id j90mr17752917qgj.6.1431775553118; Sat, 16 May 2015 04:25:53 -0700 (PDT) Received: by 10.140.85.241 with HTTP; Sat, 16 May 2015 04:25:53 -0700 (PDT) In-Reply-To: <20150509030833.GA28871@savin.petertodd.org> References: <554BE0E1.5030001@bluematt.me> <20150508163701.GA27417@savin.petertodd.org> <20150509030833.GA28871@savin.petertodd.org> Date: Sat, 16 May 2015 12:25:53 +0100 Message-ID: From: Tier Nolan Cc: Bitcoin Dev Content-Type: multipart/alternative; boundary=001a113a7d023de54105163139c1 X-Spam-Score: 2.4 (++) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -1.5 SPF_CHECK_PASS SPF reports sender host as permitted sender for sender-domain 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (tier.nolan[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 1.2 MISSING_HEADERS Missing To: header 1.0 HTML_MESSAGE BODY: HTML included in message -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 1.9 MALFORMED_FREEMAIL Bad headers on message from free email service -0.1 AWL AWL: Adjusted score from AWL reputation of From: address X-Headers-End: 1YtaEA-0002bq-Fs Subject: Re: [Bitcoin-development] Block Size Increase Requirements X-BeenThere: bitcoin-development@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 16 May 2015 11:26:00 -0000 --001a113a7d023de54105163139c1 Content-Type: text/plain; charset=UTF-8 On Sat, May 9, 2015 at 4:08 AM, Peter Todd wrote: > > I wonder if having a "miner" flag would be good for the network. > > Makes it trivial to find miners and DoS attack them - a huge risk to the > network as a whole, as well as the miners. > To mitigate against this, two chaintips could be tracked. The miner tip and the client tip. Miners would build on the miner tip. When performing client services, like wallets, they would use the client tip. The client would act exactly the same as any node, the only change would be that it gives miner work based on the mining tip. If the two tips end up significantly forking, there would be a warning to the miner and perhaps eventually refuse to give out new work. That would happen when there was a miner level hard-fork. > That'd be an excellent way to double-spend merchants, significantly > increasing the chance that the double-spend would succeed as you only > have to get sufficient hashing power to get the lucky blocks; you don't > need enough hashing power to *also* ensure those blocks don't become the > longest chain, removing the need to sybil attack your target. > To launch that attack, you need to produce fake blocks. That is expensive. Stephen Cale's suggestion to wait more than one block before counting a transaction as confirmed would also help mitigate. --001a113a7d023de54105163139c1 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
On S= at, May 9, 2015 at 4:08 AM, Peter Todd <pete@petertodd.org>= wrote:
> I wonder if having a "miner" flag would be good for the netw= ork.

Makes it trivial to find miners and DoS attack them - a huge risk to= the
network as a whole, as well as the miners.

To= mitigate against this, two chaintips could be tracked.=C2=A0 The miner tip= and the client tip.

Miners would build on the miner tip.=C2= =A0 When performing client services, like wallets, they would use the clien= t tip.

The client would act exactly the same as any node, the o= nly change would be that it gives miner work based on the mining tip.

If the two tips end up significantly forking, there woul= d be a warning to the miner and perhaps eventually refuse to give out new w= ork.

That would happen when there was a miner level hard-= fork.
=C2=A0
That'd be an excellent way to double-spend merchants, significan= tly
increasing the chance that the double-spend would succeed as you only
have to get sufficient hashing power to get the lucky blocks; you don't=
need enough hashing power to *also* ensure those blocks don't become th= e
longest chain, removing the need to sybil attack your target.

To launch that attack, you need to produce fake bloc= ks.=C2=A0 That is expensive.=C2=A0

Stephen Cale's suggestion to= wait more than one block before counting a transaction as confirmed would = also help mitigate.
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