An SKP-ABE Scheme for Secure and Efficient Data Sharing in Cloud Environments

Table 3

Comparison between the Proposed SKP-ABE scheme and the existing KP-ABE scheme.

	Yin et al. scheme [7]	Ameri et al. scheme [8]	Li et al. scheme [9]	Longo et al. scheme [13]	Zhang et al. scheme [14]	Proposed scheme
Ciphertext search	Provided			Not provided		Provided
Number of searches	Number of searches increases by the number of attributes					Only one search is required because of attribute aggregation (fast search)
Key escrow problem	Key escrow issues not considered (key escrow problems may occur enough)			Key escrow problem solved (multiauthority)		Key escrow problem solved (user generates decryption key)
Ciphertext size	Proportional to the number of attributes			Constant-size ciphertext	Proportional to the number of attributes	Constant-size ciphertext
Secret key (ciphertext decryption)
Encryption (ciphertext)	—
Encryption (ciphertext index)				Not provided(this is index encryption search)
Search (test)
Decryption (user)	—			+(n-1)

: pairing operation; : multiplication operation; : exponentiation operation;: number of attributes; : hash function; ; ; .