Lucky Green writes :

In article <199508152206.SAA23244@acmex.gatech.edu>, gt7508b@prism.gatech.edu (PHrEaK!) wrote:

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Does anyone know of sources for des chips??? Are there any public key chips out there??? Has anyone ever tried putting PGP on a chip??? RSA??? (Are these too slow for realistic real time hardware voice/data encryption??) I know a little about digital electronics (I am a computer engineering student) and I would love to get some data books and see if I could come up with a secure "encryption box" that people could build.

I don't know off the top of my head who makes DES and RSA chips. I am sure there are many manufactors of DES chips. Try TI, National, and Motorola. I belive that Schneier has a list of RSA chip makers.

I'm quite convinced that with a fast microcontroller and especially a really fast DSP engine you can do both 3-DES and idea in the same hardware that does the rest. You need only to encrypt somewhere between 9.6 kbits and 16 kbits per second or between 1 and 2 kbytes/sec or 125 to 250 block encryptions per second which is lots less than 100+ kbytes/second people have been getting for DES file encryption on high end PC class processors. And a good DSP core carefully programmed is probably quite comparable to the performance of a DX-4 or mid range Pentium on algorithms such as DES, idea or even RC4. I should think realistically there should be a lot of bandwidth left over for the voice compression - for the encryption you might possibly be talking 5% of the dsp cpu if you use a 50 mhz part. And while RSA is nice, it has usually been confined to key exchange because it so slow. There are hardware versions of RSA that will work at modem speeds or better with reasonable moduluses but this is specialized VLSI hardware and as far as I have ever noticed is not available cheaply as is the kind of DSP used for V.34 modems. And certainly doing key exchange RSA on a dsp or 32 bit microcontroller is reasonable if it only adds a second or two of call setup.

For the DSP part of a "bump in the cord" encrytion box, you want to get the "TI TMS320 Family Development Support" booklet by calling (800) 477-8924. You also want to look at Motorola's 68000 CPU, DSP, and controller on one chip. I can't recall the exact product number. Just call Motorola and ask for it.

I reiterate my suggestion of a few months ago that one could quite easily adapt the firmware on one of the new simultanious data and digital voice on the same phone line modems to incorperate encryption, and quite possibly encryption/key exhange interoperable with some mode of PGPphone. Doing this would relieve one of the need to develop or manufacture any hardware at all - all that would be required to have a portable "bump in the cord" encrypter widely available for a low price would be creating a new version of the downloadable flash ROM image that did encryption and PGPphone key exchange. Dave Emery die@die.com