Subject: Re: Val Henson's critique of hash-based content storage systems

From: "H. Peter Anvin" <[email-masked]>
Date: Fri, 29 Apr 2005 13:14:09 -0700

Rob Jellinghaus wrote:
> I assume most people here have read this, but just in case:
> 
> http://www.usenix.org/events/hotos03/tech/full_papers/henson/henson.pdf
> 

I have to pull out the big flamethrower, especially against someone I 
consider a friend, but that paper is a classic example on how many 
people don't understand probability.

The *only* valid criticism in it is that we may not know enough about 
the future validity of cryptographic hash function, however, she also 
does not analyze the failure scenarios applicable to those kinds of 
failures barely at all.

In the end, the whole paper centers around "this makes me feel nervous", 
without really justifying it in any reasonable way.

It is just one of many papers on cryptoanalysis written by someone with 
no real background in the field.  It really saddens me to see someone 
like Val fall into that particular trap.

	-hpa