In the handbook of applied cryptography, we can find the following formula for testing PRNG. My question is what does mean 2 in the upper index of the n_00 and others? It is not power because then the formula does not make sense.


  • 2
    $\begingroup$ $n_{ab}$ should be the number of the sequence ab appearing, so squaring over the integer should make sense here? $\endgroup$ – SEJPM Mar 6 '18 at 19:40
  • $\begingroup$ As you can see it follow chi square so result shall be bellow 1.0 $\endgroup$ – whd Mar 6 '18 at 21:20
  • $\begingroup$ Did you mean this "answer" to be a response to my comment or to kodlu's (community wiki) answer? $\endgroup$ – SEJPM Mar 6 '18 at 21:22
  • $\begingroup$ This does not provide an answer to the question. Once you have sufficient reputation you will be able to comment on any post; instead, provide answers that don't require clarification from the asker. - From Review $\endgroup$ – Maeher Mar 7 '18 at 4:21
  • $\begingroup$ whd, you may want to merge your two accounts. $\endgroup$ – SEJPM Mar 7 '18 at 12:45

The comment by @SEJPM is correct, all those subscripted $n_0,n_{01}$ etc are nonnegative integers counting the occurrences of subsequences such as $0,01$ respectively.

So no problem with exponentiation.

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.