Re: Intel announcements at RSA '99

[Michael Motyka]

Eric Murray wrote:
> 
> Since PRNGs cycle, with enough output you could tell if a given
> chip is using a PRNG[1].
> 
> 1. assuming that the RNG produces output fast enough since good PRNGs
> have long cycles.  You wouldn't have to store all the output, just
> the beginning X bytes to detect the start of the next cycle.
> 
A 64 bit LFSR using a primitive polynomial and producing bits at 400 MHz
would still take >1400 years to make one lap...registers are cheap and
small, forget about storing and testing against "just the beginning X
bytes". Unless of course the designer >intends< it to turn laps quickly.