Table 1:
Comparison of storage and encryption cost.
Dexter et al. scheme
Our scheme
Storage at KDC
(
𝑡
−
1
)
(
2
𝑁
−
1
)
2
𝑁
+
𝑡
−
2
Storage at each user of layer
𝑖
(
𝑡
−
1
)
(
⌈
l
o
g
2
𝑆
𝑖
⌉
+
𝑖
)
𝑡
+
⌈
l
o
g
2
𝑆
𝑖
⌉
+
𝑖
−
1
Number of elements encrypted during leave from layer
𝑖
(
𝑡
−
1
)
(
⌈
l
o
g
2
𝑆
𝑖
⌉
+
𝑖
)
⌈
l
o
g
2
𝑆
𝑖
⌉
+
𝑖
𝑡