Flexible and Lightweight Access Control for Online Healthcare Social Networks in the Context of the Internet of Things

Table 1

Notions for our proposed system.

Notions	Description
	Two cyclic multiplicative groups with the same prime order
	A computable bilinear map
	The integer modulo
	Select a random number from
	A function maps bit strings to a group element in
	A function maps an element in to a random number in
	User’s identity
	Group identity
	System public key/system master secret key
	Group public key/group master secret key
	Reencryption key
	Transformation key/retrieval key
	User’s decryption secret key
	Encapsulated key/session key
TA	The trusted authority
GA	The trusted group administrator
CSS	The cloud storage server
DSP	The decryption cloud service provider
	Probabilistic polynomial time
	Key derivation function