10.30684/ etj.29.7.2


The Randomness is one of the basic criterions to measure Key Generator
Efficiency. The key generator depends basically on Linear FeedBack Shift
Register which is considered as one of the basic units of Stream Cipher Systems.
In this paper, the frequency postulate of Randomness criteria is calculated
theoretically for non-linear key generator before it be implemented or constructed
(software or hardware), this procedure save time and costs. Two non-linear key
generators are chosen to apply the theoretical studies; these key generators are the
Product and Brüer.