From mboxrd@z Thu Jan  1 00:00:00 1970
From: Milan Broz <gmazyland@gmail.com>
Subject: Re: [dm-devel] Some thoughts about providing data block checksumming
 for ext4
Date: Wed, 05 Nov 2014 22:37:09 +0100
Message-ID: <545A9885.8070901@gmail.com>
References: <20141103233308.GA27842@thunk.org> <alpine.LRH.2.02.1411041622490.30941@file01.intranet.prod.int.rdu2.redhat.com> <alpine.LRH.2.02.1411041703590.7145@file01.intranet.prod.int.rdu2.redhat.com> <alpine.LRH.2.02.1411041915430.32105@file01.intranet.prod.int.rdu2.redhat.com>
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To: Mikulas Patocka <mpatocka@redhat.com>, Theodore Ts'o <tytso@mit.edu>
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On 11/05/2014 01:27 AM, Mikulas Patocka wrote:

> So you really need cryptographic hashes instead of checksums to avoid the 
> collisions.

I am not sure if it was mentioned but also see how integrity is implemented in
FreeBSD GELI system by playing with sector sizes
 
http://svnweb.freebsd.org/base/head/sys/geom/eli/g_eli_integrity.c?view=co

Also, for encrypted devices (either on file level or block level) I think 
there are still requests for implementing real crypto authenticated modes (like GCM)
which obviously need similar space for auth tag. (I think ZFS uses it this way.) 

Milan