Random number generators discussion

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thread Is the self-test valid? - Reece Pollack - 2004-03-07
last reply Yes, it is - A Fog - 2004-03-09
Is the self-test valid?
Author:  Date: 2004-03-07 10:40
I haven't had time to look at the theory behind your PRNG in depth, but at first blush it appears to me that the self-test is invalid.

For the self-test to be meaningful, the assertion that "only the initial state can close the circle" (page 3, just after equation 7) must be true. It is well-known that many PRNGs develop cycles that do not return to the initial state, but instead cycle through a sequence that only develops afterwards. In this case, the self-test will never detect the cycle.

It appears that the paragraph on page 4, just after equation 15, may cover this situation, but I'm not sure.


Yes, it is
Author: A Fog Date: 2004-03-09 09:09
The self test is applied only to RNGs with a reversible state transition function. The RANROT generators are constructed so that it is always possible to find state (n-1) from state (n).