From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <42a1ec9c5fef102e9c9ec920db53bccf@plan9.bell-labs.com> From: "Russ Cox" To: 9fans@cse.psu.edu Subject: Re: [9fans] compare-by-hash In-Reply-To: <20030531234803.1028.qmail@infidel.telus.net> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Sat, 31 May 2003 19:54:05 -0400 Topicbox-Message-UUID: bfaadad2-eacb-11e9-9e20-41e7f4b1d025 The paper seems correct on most things, but is unfair to Venti. Venti is closer to hashing than compare-by-hash. Venti does look for SHA1 hash collisions -- once a block with a particular SHA1 hash has been written, you can't write any others. Therefore you can't possibly end up thinking there are two different blocks stored on the same server and represented by the same SHA1 hash -- the store of the second will fail! Russ