Re: Transparent compression in the FS

[Chris Meadors]

On Thu, 2003-10-16 at 17:02, Jeff Garzik wrote:

> I'm curious if anyone has done any work on using multiple different 
> checksums?  For example, the cost of checksumming a single block with 
> multiple algorithms (sha1+md5+crc32 for a crazy example), and storing 
> each checksum (instead of just one sha1 sum), may be faster than reading 
> the block off of disk to compare it with the incoming block.  OTOH, 
> there is still a mathematical possibility (however-more-remote) of a 
> collission...

I don't think multiple hashes will gain any more uniqueness over just a
larger hash value.  But as long as the hash is smaller than the block
being hashed there is the possibility of two dissimilar blocks producing
the same hash.

-- 
Chris

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