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Altera_Forum's avatar
Altera_Forum
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21 years ago

Noise sources

Hi folks,

i need to create some strong random numbers but for this i should have some noise sources on nios2.

i could take the timer as the first source but that's not enough i think.

Possibly someone of you got any idea what sources of noise i could take!

thanks in advance

Steffen

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    21 years ago

    Hi Steffen,

    > i need to create some strong random numbers

    This is always a considerable challenge, no?

    > Possibly someone of you got any idea what sources of noise i could take.

    For the time being, the most reasonable source (for me) has been interrupts that

    are asynchronous/aperiodic in nature (e.g. uart, ethernet, etc). But that's just

    half (or less) of the problem: how you use them can be a headache as well ;-)

    Combining an async driven LFSR with a clock-based LFSR as a salt source for

    a crypto algorithm (the output of which is the random data) appears good -- but

    I never did the math 8-P

    Please don't be shy about posting your ideas -- this is very, very challenging stuff!

    Regards,

    --Scott
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    21 years ago

    If you are able to use custom electronics, there are proven physical methods. For instance, measure the voltage on a diode with a very accurate A2D and take the LSB as a source of random noise. It should be very simple to write a NIOS driver for the A2D.