Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1SXpFv-0002lj-OQ for bitcoin-development@lists.sourceforge.net; Fri, 25 May 2012 07:48:15 +0000 Received-SPF: pass (sog-mx-1.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.214.47 as permitted sender) client-ip=209.85.214.47; envelope-from=decker.christian@gmail.com; helo=mail-bk0-f47.google.com; Received: from mail-bk0-f47.google.com ([209.85.214.47]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1SXpFq-0002dF-4c for bitcoin-development@lists.sourceforge.net; Fri, 25 May 2012 07:48:15 +0000 Received: by bkcjm2 with SMTP id jm2so730430bkc.34 for ; Fri, 25 May 2012 00:48:03 -0700 (PDT) Received: by 10.204.128.200 with SMTP id l8mr1012931bks.94.1337932083631; Fri, 25 May 2012 00:48:03 -0700 (PDT) MIME-Version: 1.0 Received: by 10.204.148.76 with HTTP; Fri, 25 May 2012 00:47:23 -0700 (PDT) In-Reply-To: References: <201205250045.24540.luke@dashjr.org> <201205250057.39749.luke@dashjr.org> From: Christian Decker Date: Fri, 25 May 2012 09:47:23 +0200 Message-ID: To: Jeff Garzik Content-Type: multipart/alternative; boundary=00151747be5894162f04c0d79675 X-Spam-Score: -0.6 (/) 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 (decker.christian[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 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 X-Headers-End: 1SXpFq-0002dF-4c Cc: bitcoin-development@lists.sourceforge.net Subject: Re: [Bitcoin-development] Punishing empty blocks? 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: Fri, 25 May 2012 07:48:15 -0000 --00151747be5894162f04c0d79675 Content-Type: text/plain; charset=ISO-8859-1 How about a simple proof of work test? This one though does not ask for CPU work but asks the miner for a random old transaction. If the miner really stores the entire blockchain he will not have any problem answering to that getdata request, whereas a botnet would have to ask someone else for it, which could be detected if the response time deviates too much from what has been previously measured (compare it against getdata for the block they advertise). It's not perfect but it allows an estimate of whether it is a chainless miner. Regards, Chris -- Christian Decker On Fri, May 25, 2012 at 3:17 AM, Jeff Garzik wrote: > On Thu, May 24, 2012 at 8:57 PM, Luke-Jr wrote: > > Block times are not accurate enough for that. > > The times in your log are very accurate, assuming your system clock is > remotely accurate. > > -- > Jeff Garzik > exMULTI, Inc. > jgarzik@exmulti.com > > > ------------------------------------------------------------------------------ > Live Security Virtual Conference > Exclusive live event will cover all the ways today's security and > threat landscape has changed and how IT managers can respond. Discussions > will include endpoint security, mobile security and the latest in malware > threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ > _______________________________________________ > Bitcoin-development mailing list > Bitcoin-development@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/bitcoin-development > --00151747be5894162f04c0d79675 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable How about a simple proof of work test? This one though does not ask for CPU= work but asks the miner for a random old transaction. If the miner really = stores the entire blockchain he will not have any problem answering to that= getdata request, whereas a botnet would have to ask someone else for it, w= hich could be detected if the response time deviates too much from what has= been previously measured (compare it against getdata for the block they ad= vertise). It's not perfect but it allows an estimate of whether it is a= chainless miner.

Regards,
Chris
--
Christian Decker


On Fri, May 25, 2012 at 3:17 AM, Jeff Ga= rzik <jgarzik@exmulti.com> wrote:
On Thu, May 24, 2012 at 8:57 PM, Luke-Jr <luke@dashjr.org> wrote:
> Block times are not accurate enough for that.

The times in your log are very accurate, assuming your system clock i= s
remotely accurate.

--
Jeff Garzik
exMULTI, Inc.
jgarzik@exmulti.com

-----------------------------= -------------------------------------------------
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and
threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122= 263/
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Bitcoin-development mailing list
Bitcoin-develo= pment@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/bitcoin-de= velopment

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