On Wed, 19 Jan 2005, Fruhwirth Clemens wrote: > On Wed, 2005-01-19 at 12:03 -0500, Bill Davidsen wrote: > > On Tue, 18 Jan 2005, Dan Hollis wrote: > > > > > On Tue, 18 Jan 2005, Venkat Manakkal wrote: > > > > As for cryptoloop, I'm sorry, I cannot say the same. The password hashing > > > > system being changed in the past year, poor stability and machine lockups are > > > > what I have noticed, besides there is nothing like the readme here: > > > > > > cryptoloop is also unusably slow, even on my x86_64 machines... > > > > I'm obviously doing something wrong, I just copied about 40MB of old > > kernels (vmlinuz*) and some jpg files into a subdir on my cryptoloop > > filesystem, and I measured 4252.2375kB/s realtime and 18819.7879 kB/s CPU > > time. This doesn't seem unusably slow, even on my mighty P-II/350 and > > eight year old 4GB drives. The hdb is so old it has to run in pio mode, to > > give you an idea, and the original data was not in memory. > > I've rewritten some CBC code to fit the facilities I introduce in my LRW > patch[1]. Here are the results for my P4@xxxxxx: > > loop-aes, CBC: ~30.5mb/s > dm-crypt, CBC prior to my rewrite: ~23mb/s > dm-crypt, CBC with my LRW patch: ~27mb/s > dm-crypt, LRW with my LRW patch: ~27mb/s (slightly faster than CBC) > > As you can see my LRW patches (actually it's the generic scatterwalker > which is part of the LRW patch set) halves the gap to loop-aes. Actually I was using the built-in cryptoloop, not aes, I was just noting that on a really slow CPU it's still usefully fast in my estimation. > > I'm sure dm-crypt is never going to achieve the speed of loop-aes. > That's just the price you pay, when you have to do things right and > clean, so they get merged into main. Kernel developers are choosey > customers, you know. Yes, I delighted that cryptoloop is in the kernel. The dm-crypt is an interesting method suitable for technically adept users who do all their own sysadmin and need better crypto to protect something very valuable or illegal. But for a company trying to protect information on laptops from casual laptop theves, the existing cryptoloop is fine, and the greater complexity of dm-crypt isn't cost effective. Speed isn't an issue, ease of use and avoiding training costs is. > > [1] http://clemens.endorphin.org/patches/lrw/ > > -- > Fruhwirth Clemens <clemens@xxxxxxxxxxxxx> http://clemens.endorphin.org > -- bill davidsen <davidsen@xxxxxxx> CTO, TMR Associates, Inc Doing interesting things with little computers since 1979.
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