Privacy-Preserving Two-Factor Key Agreement Protocol Based on Chebyshev Polynomials

Table 7

Storage cost and communication cost comparison.

	SC1 (in bits)	SC2	SC2 (in bits)	SC3	SC3 (in bits)	SC4	SC4 (in bits)
Fan et al. [22]	2048	3	512	3	1856	#	#
Juang et al. [23]	896	3	578	3	1536	5	2560
Sun et al. [24]	512	2	192	3	1548	0	0
Li et al. [25]	640	1	576	3	3200	5	5248
Maitra [27]	1600	1	1792	2	4416	0	0
Chaudhry et al. [28]	512	1	512	3	2624	#	#
Guo et al. [19]	896	1	320	2	1792	2	1408
Lin [20]	896	1	320	2	1408	2	1280
Lee [21]	512	1	320	2	1088	2	1440
Irshad et al. [29]	768	1	1344	2	1088	0	0
Irshad et al. [30]	1024	1	1344	5	5184	0	0
Our protocols	1280	1	320	3	2294	0	0

SC₁ denotes the storage cost of the smart card in the registration phase. SC₂^∗ denotes the round number of message transmission in the registration phase. SC₂ denotes the total size of the transmitted message in the registration phase. SC₃^∗ denotes the number of message transmissions in the authenticated key exchange phase. SC₃ denotes the total size of the transmitted message in the authenticated key exchange phase. SC₄^∗ denotes the number of the message transmission in the password change phase. SC₄ denotes the total size of transmitted message in the password change phase. # denotes that the scheme does not provide the functionality of password updating.