[47605] in Cypherpunks
Re: HAVAL (was Re: crypto benchmarks)
daemon@ATHENA.MIT.EDU (Deranged Mutant)
Sat Jan 20 17:04:59 1996
From: "Deranged Mutant" <WlkngOwl@UNiX.asb.com>
To: Wei Dai <weidai@eskimo.com>
Date: Sat, 20 Jan 1996 16:57:07 +0000
Cc: Cyperphunks <cypherpunks@toad.com>
> Thanks. It looks like F4 and F5 are improved. Do you know how these
> optimizations can be done in general? I tried playing with F2
> as a multivariate polynomial with coefficients in GF(2) in Mathematica.
> This seems to work and I found several equivalent expressions that take
> 13 operations (the original also takes 13 operations). Is there a tool
> that can do this automaticly?
I did the optimizations by hand. Simple rules of boolean arithmetic
and logic (you know, things like Demorgan's Law applied to binary
operations). Other processor-related optimizations can be done by
hand, such as add x,x instead of shl x,1.
I think I had the same proglems with F2 as well. Couldn't find a way
to optimize it reasonably.
> The biggest problem I have with HAVAL now is that with 4 or 5 passes the
> transform functions are larger than 10k even with compiler optimzation for
> size. Since the Pentium L1 instruction cache is only 8k, this makes HAVAL
> with 4 or 5 passes extremely slow. Do you have ideas how I can fit the
> transform functions into L1 cache?
You might do some creative optimization to use more registers than it
does. I haven't looked at it in a while. The code was so huge and
slow compared to optimized MD5 and SHS that I have up using it for an
unfinished encrypted file system.
Rob.
--- "Mutant" Rob <wlkngowl@unix.asb.com>
Send a blank message with the subject "send pgp-key"
(not in quotes) for a copy of my PGP key.
