On Sun, Aug 24, 2003 at 11:09:09AM -0700, Brian Hatch wrote: > Is there a way to sort on the reverse of @STRENGTH? I'd like > to support ALL:eNULL in preferential order of weekest to > strongest, without explicitly listing them if I can. > > Is there a converse of @STRENGTH? > > Right now I have eNULL:EXPORT40:EXPORT56:LOW:MEDIUM:HIGH:ALL > which is the best I can do, but it preferss 256 bit AES over > 168 bit 3DES in the HIGH suit, for example. I want the worst > crypto (fastest speed, since security is not a design goal at > all) possible.
I have never expected a request like this... thus I have not implemented
@WEAKEST :-)
Nevertheless, I would recommend you to reconsider your goal. The "strength"
given by the number of "secret" bits is not proportional to the speed.
RC4 by design is a 128bit alogrithm. When using 40bit RC4, the 128bit
algorithm is used but 88bit are fixed and known. AES was designed with
software implementations in mind while DES is known to favor hardware
implementations. It may therefore well be possible that AES128 might
even be faster than DES168, depending on the implementation and machine.
HP-UX 10.20, HP's ANSI C compiler with +O4:
The 'numbers' are in 1000s of bytes per second processed.
type 16 bytes 64 bytes 256 bytes 1024 bytes 8192 bytes
des cbc 3606.59k 3815.63k 3879.86k 3892.93k 3891.20k
des ede3 1480.06k 1537.94k 1558.34k 1556.96k 1558.68k
aes-128 cbc 6142.92k 6611.84k 6724.15k 6782.11k 6773.52k
aes-192 cbc 5749.39k 6117.82k 6215.65k 6282.48k 6241.26k
aes-256 cbc 5340.24k 5687.77k 5792.13k 5793.85k 5830.78k
As you can easily see, AES on HP-UX is much faster than DES. Even AES256 beats
the hell out of DES (56bit)... :-)
On other platforms the results may differ.
Thus, if you have control over both sides of the channel, you might consider
to optimize your cipher suite against the result of "openssl speed". If you
don't know your peer's platform, well, ...
Best regards,
Lutz
--
Lutz Jaenicke [EMAIL PROTECTED]
http://www.aet.TU-Cottbus.DE/personen/jaenicke/
BTU Cottbus, Allgemeine Elektrotechnik
Universitaetsplatz 3-4, D-03044 Cottbus
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