From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 4 Mar 2008 21:09:15 -0800 From: Roman Shaposhnik Subject: Re: [9fans] thoughs about venti+fossil In-reply-to: <3220ce5ba20c40077bcde180368a471b@quanstro.net> To: Fans of the OS Plan 9 from Bell Labs <9fans@cse.psu.edu> Message-id: MIME-version: 1.0 Content-type: text/plain; format=flowed; charset=US-ASCII Content-transfer-encoding: 7BIT References: <3220ce5ba20c40077bcde180368a471b@quanstro.net> Topicbox-Message-UUID: 6f105716-ead3-11e9-9d60-3106f5b1d025 On Mar 4, 2008, at 8:43 PM, erik quanstrom wrote: >> On Mar 4, 2008, at 8:00 PM, Enrico Weigelt wrote: >>> some thoughts about venti that go around in my mind: >>> >>> 1. how stable is the keying ? sha-1 has only 160 bits, while >>> data blocks may be up to 56k long. so, the mapping is only >>> unique into one direction (not one-to-one). how can we be >>> *really sure*, that - even on very large storages (TB or >>> even PB) - data to each key is alway (one-to-one) unique ? >> >> http://www.nmt.edu/~val/review/hash/index.html >> >> Not that this analysis is without flaws, though. > > have you invented the 9fans.net effect? Meaning? I guess the reference went over my head. > this link may or may not be similar. but it is on point: > http://www.valhenson.org/review/hash.pdf I believe it to be exactly the same paper. > do you care to elaborate on the flaws of this analysis? I tend to agree with counter arguments published here: http://monotone.ca/docs/Hash-Integrity.html I'm not an expert in this field (although I dabbled in cryptograhy somewhat given my math background) and thus I would love if somebody can show that the counter arguments don't stand. Thanks, Roman.