> It appears that this lil guy has hardware AES-128 support [1] that > reportedly more than doubles AES performance [2]
Oh, good find! In addition to reducing the time taken to compute AES-128 by a factor of 2.5 (according to [2]), it also presumably reduces the load on the CPU during that time since the AES-specific circuits are doing most of the work, right? So it could free up more than just 2.5 times as many CPU cycles for other purposes. So I wonder if a Davies-Meyer based on AES-128 would have both (a) a very good chance that it has 2nd-preimage-resistance, and (b) dramatically better performance on SheevaPlugs than a dedicated hash function which would have to run in software. > but unfortunately it > appears like the crypto processor is only accessible from kernel mode ... > so the distro, or the user, would > have to patch them in - and the number of people who are going to roll > their own custom patched kernel is pretty small compared to the number > of people who might theoretically want to run Tahoe on a plug). Well, if people aren't willing and able to do that, then they could run Davies-Meyer-AES-128 in software. I wonder how efficient that would be. > Perhaps some of the DSP instructions could be used to speed up the FEC > encoding/decoding? I haven't investigated this area at all yet. My assumption is that FEC will be a minimal cost that it won't be worth optimizing. :-) But I would like to find out real numbers! Regards, Zooko _______________________________________________ tahoe-dev mailing list [email protected] http://tahoe-lafs.org/cgi-bin/mailman/listinfo/tahoe-dev
