Just a thought about your XOR encryption:

Are you trying the render the encrypted channel unintelligable?

My gut feeling is that by using a simple byte-by-byte XOR method, the
encrypted sound will still be very easy to undertand.  XOR does not alter
the overall cadence, or frequency content of the sound very much.

To do it properly it is best to distribute the sound energy in both time
and frequency.

You might want to test a quick implementation of your scheme on a PC
first... to see how it works.... I would like to hear the results!

Cheers,
Don

At 05:26 PM 1/6/00 +1100, you wrote:
>Hello all,
>I am interested in making a PIC based project in which I need to encrypt
>voice. The voice is encrypted for transmission using a UHF radio.
>Basically the person speaks into the microphone normally, the PIC samples
>the analog data from the microphone at a minimum rate of 8kHz, XOR's it
>with a preset 'key' and converts it back to analog for transmission. At
>the other end the opposite is done. My question is does you run of the
>mill ADC0831 8-bit ADC have what it takes to sample a voice signal?
>
>Wesley
>
>___________________________________________
>Wesley Moore
>RMIT - BEng/BApp.Sc. 2nd Year
>
>wmoore@cs.rmit.edu.au
>http://wmoore.tsx.org/
>