From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastian Morr Subject: Re: Yo dawg, I heard you like trees... Date: Wed, 7 Dec 2011 16:54:11 +0100 Message-ID: <20111207155411.GB2003@thinkpad> References: <20111205235740.GB27318@thinkpad> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: git@vger.kernel.org To: Phil Hord X-From: git-owner@vger.kernel.org Wed Dec 07 16:54:21 2011 Return-path: Envelope-to: gcvg-git-2@lo.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1RYJp6-0005Qs-6N for gcvg-git-2@lo.gmane.org; Wed, 07 Dec 2011 16:54:20 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756506Ab1LGPyP (ORCPT ); Wed, 7 Dec 2011 10:54:15 -0500 Received: from static.148.34.47.78.clients.your-server.de ([78.47.34.148]:38802 "EHLO morr.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756152Ab1LGPyP (ORCPT ); Wed, 7 Dec 2011 10:54:15 -0500 Received: by morr.cc (Postfix, from userid 1001) id 4423D476231F; Wed, 7 Dec 2011 16:54:13 +0100 (CET) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on morr.cc X-Spam-Level: X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED autolearn=unavailable version=3.3.1 Received: from thinkpad (w0772.wlan.rz.tu-bs.de [134.169.203.10]) by morr.cc (Postfix) with ESMTPSA id D50DE476231C; Wed, 7 Dec 2011 16:54:12 +0100 (CET) Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: > Git uses a DAG. The A stands for "acyclic". Loops are not allowed. I'm aware of that. It's acyclic by design, but is this actually enforced by the code? Or does it simply trust that no loops will ever occur, because it's so improbable? After Andrew's response I investigated a bit, and it seems I overvalued the attempts to "break" SHA-1. Wikipedia quotes a 2008 attack, that can create a collision with 2^51 hash function calls. Which, of course, is still way to much. Good for you! :-)