[Retracted] A Novel Hierarchical Key Assignment Scheme for Data Access Control in IoT

Table 1

Security comparison among some existing HKASs.

Scheme	Security assumption	Secure against collusive attack	Secure against sibling attack	Secure against collaborative attack	Forward security	Backward security
Hwang-Yang scheme [19]	Integers factorization
Lo et al.’s scheme [21]	PKE with CPA-secure and hash function
Jeng and Wang scheme [24]	ECC
Chung et al.’s scheme [25]	ECC and hash function
Our scheme	CMDH and DMDH