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The following archive was created by hippie-mail 7.98617-22 on Sat Apr 10 1999 - 01:18:27
andreas@andreas.org
17 Feb 1999 21:59:24 +0100
"Perry E. Metzger" <perry@piermont.com> writes:
> > Hmm...the trouble with quoting rates is the context. Basically my
> > understanding from a colleague of mine who is working on LAN video
> > transmission (between win95 boxes) is that decent frame rates requires
> > crypto that can encipher at 20 MB/s or better.
> 20MB/s is 160Mbps. That is above fast ethernet speeds. What sort of
> "LAN" would this be?
Well, there's Fibrechannel, Gigabit Ethernet and ATM to choose
from. And you only need those data rates if you deal with uncompressed
video (PAL resolution is 704x576x24, at three bytes per pixel, that's
about 240Mbps), MPEG2 video has a reasonable quality at about 4-6Mbps,
as already stated on this list.
I could think of a few scenarios where you'd need encryption for
uncompressed video streams. But the equipment to transmit these is so
expensive that the couple of ASICs you need for encryption are not a
major budget item anymore.
For MPEG2 applications, there are two algorithms in common use: one is
CSS (content scrambling system), which is used for DVD; the other is
SimulCrypt, which is in use for DVB, the European digital television
standard. Both are undisclosed.
And whoever rates encryption speed higher than security might be
interested to buy my new FastSecure[TM] product, based on the
patent-pending Identity Transformation, formerly known as ROT26.
Andreas
-- "It is by caffeine alone I set my mind in motion. It is by the Beans of Java that thoughts acquire speed, the hands acquire shaking, the shaking becomes a warning. It is by caffeine alone I set my mind in motion." -- seen on slashdot
The following archive was created by hippie-mail 7.98617-22 on Sat Apr 10 1999 - 01:18:27