Measuring the Sum-of-Squares Indicator of Boolean Functions in Encryption Algorithm for Internet of Things

Table 4

The cross-correlation value distributions of any two 4-variable bent functions.

1		6720	15 (448)	256	16
2		7168	16 (448)	256	16
3		107520	560 (192)	256	8
4		107520	560 (192)	256	8
5		86016	448 (192)	256	4

(1) is the times of cross-correlation value; for example, in line 1, implies that the cross-correlation value 16 occurs one time and the cross-correlation value 0 occurs 15 times; for example, the cross-correlation distributions and all belong to .
(2) is the number of pairs with the same .
(3) express the number of each class. For example, in line 1, 15(448) denotes that 6720 can be classified into 15 classes (each class has the same cross-correlation distribution) and each class has 448 pairs (the number of any two different bent functions which have the same cross-correlation is 448).