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Re: MD5 vs. SHA-1, Selection Criteria
> Date: Thu, 23 May 1996 18:00:48 -0400
> From: John Kennedy <jkennedy@cylink.com>
> Subject: MD5 vs. SHA-1, Selection Criteria
>
> HUGO@watson.ibm.com wrote:
> {stuff deleted}
> > Due to this fact and the performance advantages of MD5 over other
> > alternatives (e.g., SHA-1)...
> I'm still not convinced that throughput performance should be a
> criteria for choosing a default hash function. Just for reference,
> could someone repost their best performance times for both algorithms?
> Are we talking about a factor of 2, 10, 100?
2. On A Sun SPARC 20/71 in SunOS 4.1.3, I have measured:
stand-alone MD5 60 Mbps +/- 3 Mbps
stand-alone SHA 30 Mbps +/- 2 Mbps
Note that these are not the performance expected from IP.
Our current measurements of MD5 in IPv4 depend on the
MTU:
34 Mbps for 8 KB packets (upper bound on our system)
16 Mbps for 4 KB packets
0.6 Mbps for 1.5 KB (ethernet MTU) packets
0.5 Mbps for Internet MTU (512 B) packets
> The fact that HMAC-MD5 is a mode for MD5 usage that doesn't
> *currently* seem susceptible to the recent attack described by Hans
> Dobbertin says more for the HMAC technique than the long-term
> viability of MD5.
How is HMAC affected by the properties of the hash function used?
I have another hash which is admittedly weaker than MD5, but
which runs twice as fast as MD5, each in IPv4, for large MTUs.
For small MTUs (1KB or less), this is really moot. Three different
hashes we tested all run down around 0.3-0.5 Mbps.
Joe
PS - this is in preparation for Infocomm.
----------------------------------------------------------------------
Joe Touch - touch@isi.edu http://www.isi.edu/~touch/
ISI / Project Leader, ATOMIC-2, LSAM http://www.isi.edu/atomic2/
USC / Research Assistant Prof. http://www.isi.edu/lsam/
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