Well,I disagree about psuedo random number generation, sort of. First, if I have PSR sequence of the known variety (ie, ANSI or ITU), and if it's mapped to some telecom standard (DS-1/3, OC-3/12/48/192), then my test set can and should be able to lock onto that sequence. This is true whether that telecom signal is raw PRBS, or if it has been mapped into the

At 07:40 PM 10/18/02 -0400, Tyler Durden wrote: payload

(you use different test sets).

1. Shift reg sequences are cryptographically weak. 2. Re-synch'ing with a PR stream is useful for some apps, true. 3. In crypto, we consider the adversary who claims to have a true RNG but instead is faking us out with an opaque PRNG. If We are not privvy to the PRNG algorithm (or key) then we can't tell if its truly random or not.

With encrypted info who knows? I would think that testing if there's monkey business might boil down to algorithms--ie, if certain bit patterns happen too often, then something's wrong...

Bit-bias is trivial to correct (see Shannon). Take a look at Prof. Marsaglia's "Diehard" suite of statistical-structural tests for a real obstacle course. But no such "does it look random" test can tell good PRNG from TRNG. You must peek under the hood.