Key Management Schemes for Multilayer and Multiple Simultaneous Secure Group Communication

Table 2

Performance of multilayer SGC.

Number of users in different layers				Number of keys at server		Number of keys at each user
𝑁1	𝑁2	𝑁3	𝑁4	Dexter et al. scheme	Our scheme; (% saving)	Dexter et al. scheme				Our scheme (% saving)
						𝑙1	𝑙2	𝑙3	𝑙4	𝑙1	𝑙2	𝑙3	𝑙4
128	64	64	32	2860	592 (79)	40	40	45	45	12 (70)	12 (70)	13 (71)	13 (71)
4096	1024	512	64	56940	11408 (80)	65	60	60	50	17 (73)	16 (73)	16 (73)	14 (72)
2^15	2^12	64	16	369420	73904 (80)	80	70	45	40	20 (75)	18 (74)	13 (71)	12 (70)
2^20	2^15	2^10	2^7	10824940	2165008 (80)	105	85	65	55	25 (76)	21 (75)	17 (73)	15 (72)