Blockchain-Based Access Control Model to Preserve Privacy for Personal Health Record Systems

Table 3

The time requirements of the key generation operations and encryption/decryption operations for various number of users.

Number of users	Re-encryption key gen; time of PRES (milliseconds)	Encryption time of PRES (milliseconds)	Decryption time of PRES (milliseconds)	Master key gen; time of ABES (milliseconds)	User key gen; time of ABES (milliseconds)	Encryption time of ABES (milliseconds)	Decryption time of ABES (milliseconds)
1	16.62	142.29	59.19	377.42	375.46	423.11	226.02
2	33.01	142.29	59.19	737.31	375.46	784.47	226.02
4	67.66	142.29	59.19	1471.49	375.46	1501.89	226.02
8	134.52	142.29	59.19	2802.81	375.46	2844.20	226.02
16	272.89	142.29	59.19	5602.93	375.46	5639.91	226.02