Received: from sog-mx-4.v43.ch3.sourceforge.com ([172.29.43.194] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1VvH9x-0007KW-0Y for bitcoin-development@lists.sourceforge.net; Tue, 24 Dec 2013 01:51:49 +0000 Received-SPF: pass (sog-mx-4.v43.ch3.sourceforge.com: domain of gmail.com designates 74.125.82.182 as permitted sender) client-ip=74.125.82.182; envelope-from=ryacko@gmail.com; helo=mail-we0-f182.google.com; Received: from mail-we0-f182.google.com ([74.125.82.182]) by sog-mx-4.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1VvH9v-0004fL-JZ for bitcoin-development@lists.sourceforge.net; Tue, 24 Dec 2013 01:51:48 +0000 Received: by mail-we0-f182.google.com with SMTP id q59so5581158wes.27 for ; Mon, 23 Dec 2013 17:51:41 -0800 (PST) MIME-Version: 1.0 X-Received: by 10.180.106.200 with SMTP id gw8mr20784212wib.50.1387849901388; Mon, 23 Dec 2013 17:51:41 -0800 (PST) Sender: ryacko@gmail.com Received: by 10.194.188.6 with HTTP; Mon, 23 Dec 2013 17:51:41 -0800 (PST) In-Reply-To: <52B7AC86.9010808@monetize.io> References: <52B7AC86.9010808@monetize.io> Date: Mon, 23 Dec 2013 17:51:41 -0800 X-Google-Sender-Auth: AwFAj7YbiRRtBTEGoCOasWfcB0Y Message-ID: From: Ryan Carboni To: Mark Friedenbach , bitcoin-development@lists.sourceforge.net Content-Type: multipart/alternative; boundary=e89a8f234b555fbcf304ee3dfcd1 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 (ryacko[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 0.0 URIBL_BLOCKED ADMINISTRATOR NOTICE: The query to URIBL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [URIs: enigmail.net] 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: 1VvH9v-0004fL-JZ Subject: Re: [Bitcoin-development] Bitcoin difficulty sanity check suggestion 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: Tue, 24 Dec 2013 01:51:49 -0000 --e89a8f234b555fbcf304ee3dfcd1 Content-Type: text/plain; charset=ISO-8859-1 I think you misunderstood my statement. If time > 3 days, and after 4 blocks have been mined, then difficulty would be reset. In theory, one would have to isolate roughly one percent of the Bitcoin network's hashing power to do so. Which would indicate an attack by a state actor as opposed to anything else. Arguably, the safest way to run Bitcoin is through a proprietary dial-up network. On Sun, Dec 22, 2013 at 7:22 PM, Mark Friedenbach wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Ryan, these sort of adjustments introduce security risks. If you were > isolated from the main chain by a low-hashpower attacker, how would > you know? They'd need just three days without you noticing that > network block generation has stalled - maybe they wait for a long > weekend - then after that the block rate is normal but completely > controlled by the attacker (and isolated from mainnet). > > There are fast acting alternative difficulty adjustment algorithms > being explored by some alts, such as the 9-block interval, 144-block > window, Parks-McClellan FIR filter used by Freicoin to recover from > just such a mining bubble. If it were to happen to bitcoin, there > would be sophisticated alternative to turn to, and enough time to make > the change. > > On 12/22/2013 07:10 PM, Ryan Carboni wrote: > > I think Bitcoin should have a sanity check: after three days if > > only four blocks have been mined, difficulty should be adjusted > > downwards. > > > > This might become important in the near future. I project a > > Bitcoin mining bubble. > > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.14 (GNU/Linux) > Comment: GPGTools - http://gpgtools.org > Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ > > iQIcBAEBAgAGBQJSt6yGAAoJEAdzVfsmodw4SegQAIJAWW0OgSjediSWq+EpkReS > qMvC2Y9dmVHtowYLdJVcgwFWbpU8RhA6ApQ1Ks2XF4t0hFCObYDecG6Nl3OIaLfb > snz24v8ymdxYXKNtzHHUP0VBgsaoRghIpkbf7JMUXC22sxPoPOXFt5RevLgJHrvc > oGFZSIcEcGgwhwZ745CgFZLwaKuSmg5+wFFcrjIihlHKJOl47Z7rzeqnD6mf2Oi3 > hDpRuVbuhlGMliYcmhk1E6oV0in2R4Purw1WtoY8C9DxrSP2za7W1oeCkmlFfJZS > to6SzRj7nEIl0LFaPGsIdBrRdDHfvu6eP2OecI+GNLEwLY6qE5v5fkh47mcDkrN0 > 02PmepoX5PRzBqp4sx8WaFKuRbmTRRr3E4i9PGoyzTckkZzq+zFmb1y5fwOy17hE > C+nP+DyuaPzjypjdo6V+/oGzUKtuKPtqcB1vurbm+WBl5C1jWosAXv5pR87mdCUJ > +0e14wPra5blV6yBVqX7yx+2heDGymPKfHJ8i76Dtix7XVOJWKVY4OpIxO7YrYv8 > IKcIswoKhZdSDOJLcjm4Qp4hrzgCHAHWx6vN71r5r2T6zaJTOvp98GS04Yy7VGAr > j38hojcwvJC1ahER3LV/vC0cqO+fxrvY8Q9rW2cUxCnzxzjjG0+Z/gjW8uh73lXN > DOTF7jpt0ZmCm7uhG9z7 > =5Q2H > -----END PGP SIGNATURE----- > --e89a8f234b555fbcf304ee3dfcd1 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
I think you misunderstood my statement. If time > 3 day= s, and after 4 blocks have been mined, then difficulty would be reset.
=
In theory, one would have to isolate roughly one percent of = the Bitcoin network's hashing power to do so. Which would indicate an a= ttack by a state actor as opposed to anything else. Arguably, the safest wa= y to run Bitcoin is through a proprietary dial-up network.


On Sun,= Dec 22, 2013 at 7:22 PM, Mark Friedenbach <mark@monetize.io>= wrote:
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Ryan, these sort of adjustments introduce security risks. If you were
isolated from the main chain by a low-hashpower attacker, how would
you know? They'd need just three days without you noticing that
network block generation has stalled - maybe they wait for a long
weekend - then after that the block rate is normal but completely
controlled by the attacker (and isolated from mainnet).

There are fast acting alternative difficulty adjustment algorithms
being explored by some alts, such as the 9-block interval, 144-block
window, Parks-McClellan FIR filter used by Freicoin to recover from
just such a mining bubble. If it were to happen to bitcoin, there
would be sophisticated alternative to turn to, and enough time to make
the change.

On 12/22/2013 07:10 PM, Ryan Carboni wrote:
> I think Bitcoin should have a sanity check: after three days if
> only four blocks have been mined, difficulty should be adjusted
> downwards.
>
> This might become important in the near future. I project a
> Bitcoin mining bubble.
>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.14 (GNU/Linux)
Comment: GPGTools - http:= //gpgtools.org
Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/

iQIcBAEBAgAGBQJSt6yGAAoJEAdzVfsmodw4SegQAIJAWW0OgSjediSWq+EpkReS
qMvC2Y9dmVHtowYLdJVcgwFWbpU8RhA6ApQ1Ks2XF4t0hFCObYDecG6Nl3OIaLfb
snz24v8ymdxYXKNtzHHUP0VBgsaoRghIpkbf7JMUXC22sxPoPOXFt5RevLgJHrvc
oGFZSIcEcGgwhwZ745CgFZLwaKuSmg5+wFFcrjIihlHKJOl47Z7rzeqnD6mf2Oi3
hDpRuVbuhlGMliYcmhk1E6oV0in2R4Purw1WtoY8C9DxrSP2za7W1oeCkmlFfJZS
to6SzRj7nEIl0LFaPGsIdBrRdDHfvu6eP2OecI+GNLEwLY6qE5v5fkh47mcDkrN0
02PmepoX5PRzBqp4sx8WaFKuRbmTRRr3E4i9PGoyzTckkZzq+zFmb1y5fwOy17hE
C+nP+DyuaPzjypjdo6V+/oGzUKtuKPtqcB1vurbm+WBl5C1jWosAXv5pR87mdCUJ
+0e14wPra5blV6yBVqX7yx+2heDGymPKfHJ8i76Dtix7XVOJWKVY4OpIxO7YrYv8
IKcIswoKhZdSDOJLcjm4Qp4hrzgCHAHWx6vN71r5r2T6zaJTOvp98GS04Yy7VGAr
j38hojcwvJC1ahER3LV/vC0cqO+fxrvY8Q9rW2cUxCnzxzjjG0+Z/gjW8uh73lXN
DOTF7jpt0ZmCm7uhG9z7
=3D5Q2H
-----END PGP SIGNATURE-----

--e89a8f234b555fbcf304ee3dfcd1--