From mboxrd@z Thu Jan 1 00:00:00 1970 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 1VuwE6-0002YO-23 for bitcoin-development@lists.sourceforge.net; Mon, 23 Dec 2013 03:30:42 +0000 Received: from mail-pb0-f54.google.com ([209.85.160.54]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1VuwE4-0002vU-HC for bitcoin-development@lists.sourceforge.net; Mon, 23 Dec 2013 03:30:42 +0000 Received: by mail-pb0-f54.google.com with SMTP id un15so4842547pbc.27 for ; Sun, 22 Dec 2013 19:30:34 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:message-id:date:from:organization:user-agent :mime-version:to:subject:references:in-reply-to:content-type :content-transfer-encoding; bh=tsk45KLVFqDQaCvTtft1qLY+xOR5Py4+o8NmT+hXDsM=; b=NwMP6VQAZKiIRdk7QR4o87frs70l48DDEWYS3xD8BfGYQi25aJZjMhWE/kAjV2TN8z USqQkn3b1dkz3YCzFLWBSH8Q/Z0Jgr4DxKIOSeyaSXwYKR0SBv/6cxyLnolvBAbAg+Lf 0dDQTM8W6JN4c1AkbI1cq8cMuhp6YsOUNrRfc3PHmiU5k+0JMAgbnlc6ytecZVlsXQtx 48q6Kx7pTrSGdwRB9boqlldCteYOuWyDyhFdkwuvDktEzFSkaRMM/Ij1++3K3kzeRVoq 1E4ArvP80asoNHewQJxsKzkmiY+Xk7CfWuPtzynpr3zOR3lffR7BbcL8GQdyngK2dIf6 Uotg== X-Gm-Message-State: ALoCoQlkscoQUzQnsnDXQgMWPgCKNfE27J5orrZ6ABvFu962xZWFxDwSJOtqtMz2g9p0MB4VQGMD X-Received: by 10.66.189.229 with SMTP id gl5mr23369551pac.47.1387768982909; Sun, 22 Dec 2013 19:23:02 -0800 (PST) Received: from [192.168.127.188] (50-0-36-217.dsl.dynamic.sonic.net. [50.0.36.217]) by mx.google.com with ESMTPSA id ka3sm30446987pbc.32.2013.12.22.19.22.54 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sun, 22 Dec 2013 19:23:01 -0800 (PST) Message-ID: <52B7AC86.9010808@monetize.io> Date: Sun, 22 Dec 2013 19:22:46 -0800 From: Mark Friedenbach Organization: Monetize.io Inc. User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: Ryan Carboni , Bitcoin Dev References: In-Reply-To: X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Spam-Score: 0.0 (/) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. 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] X-Headers-End: 1VuwE4-0002vU-HC 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: Mon, 23 Dec 2013 03:30:42 -0000 -----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-----