Need information about embedded systems

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I have heard that public key encryption and related cryptologies need
32bit processors to execute at a reasonable rate.  If this is not true,
please correct me.

Could someone recommend a cheap 32bit development board, preferably
with an ethernet MAC (I should be able to get transceiver, magnetics,
and connector if need be).

Also what are the pros/cons of using a MCU with and without a MMU?
Is programming significantly more difficult without one?

--David


Re: Need information about embedded systems

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That all depends on what you mean by reasonable.  An 8-bit uP with a
hardware multiply will do quite well.  For RSA you need to multiply
and take remainders for numbers with more that 1000 bits.  That can be
done 8 bits at a time.


-Robert Scott
 Ypsilanti, Michigan
(Reply through this forum, not by direct e-mail to me, as automatic reply
address is fake.)

Re: Need information about embedded systems
Well I need to be able to encrypt 256 bits in less than 5 sec. or
generate a 256 bit key with DH key exchange in the same time.
Also any suggestions on cheap development kits

--David


Re: Need information about embedded systems

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The 32 byte memory requirement shouldn't be much of a strain.
A 32-bit processor with an MMU may not be needed.

As for speed, I don't think anyone makes a processor
this slow anymore.

Pick anything you want.  If this is a 'one-of' then a
"Basic Stamp" would work fine.  Otherwise, use whatever
you have at hand and are familiar with.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer:  Electronics; Informatics; Photonics.
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Re: Need information about embedded systems
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I implemented a *very* non-optimal "big number"
library and DH key exchange, and was amazed at how
long it took to execute on an MPC860.

I also implemented DES, which didn't seem too
heavy weight. The key exchange was by far the most
processor intensive part of the process.

I did this for "fun", and I really don't have any
encryption experience other than that. Just thought
it might be an "interesting" data point.


--
Michael N. Moran           (h) 770 516 7918
5009 Old Field Ct.         (c) 678 521 5460
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Re: Need information about embedded systems
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As most smart cards used to be 8 bit (8051 a lot of them) and had RSA
you clearly don't need a 32 bit processor.  Though to be fair a lot of
them also tended to have a crypto engine on them.

BTW define "reasonable" :-)


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Re: Need information about embedded systems
Well the problem is: the ones I've seen range from more than my car now
($2000) to more than my car when I bought it a few years ago ($5000).

Is it possible to build yourself a development kit (with a good chance
of success) cheaply from an available MCU?
Or buy a reasonable priced kit?

As I said, correct me if an 8 or 16 bit MCU will do.  Suggestions of
suitable kits would be appreciated.

Also I would prefer not having to write my own TCP/IP stack or buying
one for $1000+.  So if it is a product with a freely available TCP/IP
stack, the happier I be.
Also what are your thoughts on the MMU?

--David


Re: Need information about embedded systems

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You might have a look at http://www.theARMPatch.com Both 32-bit,
~60MHz ARM eval boards there sell for about $300 USD, have 10BaseT
ethernet, a CompactFlash connector,  RTC. and come with a minimal port
of lwIP (an open-source TCP/IP stack).  There are several gcc (as well
as reasonably low-cost commercial) distributuons available on the
internet that are suitable for development tools

Regards
-Bill Knight



Re: Need information about embedded systems

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Define 'reasonable'.  PKE was common on 4.77MHz 8088 XT's.

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The obverse.  For a stand-alone application it is easier without one.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer:  Electronics; Informatics; Photonics.
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Re: Need information about embedded systems
The device will need to do the following things:

NTP client to update RTC
Custom server protocol for configuring device with encryption of
communication
Main program that will output particular data to certain peripherals
(IR/RF encoders -> IR/RF blasters) at particular times as configured by
client over TCP/IP through integrated ethernet.

If all this can be smushed into one program then I guess I don't need a
MMU or OS.
But I don't if it will work well.

--David


Re: Need information about embedded systems
A better aproach which I took when implementing a design which used AES
as the crypto system was to design an fpga which did the bulk of the
encryption/decryption and a smal cheapo processor to get the results on
and off the board and handle the key scheduling.
This saved a lot of processor time as its very easy to pipeline
the aes algo within the fpga.


Re: Need information about embedded systems

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again, what is reasonable ?
Some implementations use FPGAs to do as much in parallel
as possible. AFAIK, the Rhyndael/AES is available as core.

Rene
--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
& commercial newsgroups - http://www.talkto.net

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