Table 2: Performance of multilayer SGC.

Number of users in different layersNumber of keys at serverNumber of keys at each user
𝑁 1 𝑁 2 𝑁 3 𝑁 4 Dexter et al. schemeOur scheme
(% saving)
Dexter et al. schemeOur scheme (% saving)
𝑙 1 𝑙 2 𝑙 3 𝑙 4 𝑙 1 𝑙 2 𝑙 3 𝑙 4

1 2 8 6 4 6 4 3 2 2 8 6 0 5 9 2 (79) 4 0 4 0 4 5 4 5 1 2 (70) 1 2 (70) 1 3 (71 ) 1 3 (71)
4 0 9 6 1 0 2 4 5 1 2 6 4 5 6 9 4 0 1 1 4 0 8 (80) 6 5 6 0 6 0 5 0 1 7 (73) 1 6 (73) 1 6 (73) 1 4 (72)
2 1 5 2 1 2 6 4 1 6 3 6 9 4 2 0 7 3 9 0 4 (80) 8 0 7 0 4 5 4 0 2 0 (75) 1 8 (74) 1 3 (71) 1 2 (70)
2 2 0 2 1 5 2 1 0 2 7 1 0 8 2 4 9 4 0 2 1 6 5 0 0 8 (80) 1 0 5 8 5 6 5 5 5 2 5 (76) 2 1 (75) 1 7 (73) 1 5 (72)