A Lightweight and Secure Anonymous User Authentication Protocol for Wireless Body Area Networks

Table 6

The comparison of communication cost in different schemes.

Scheme	Number of messages	Communication cost (bits)
Wu et al.’s scheme	3	2112
Shen et al.’s scheme	4	3040
Das et al.’s scheme	2	1536
Liu et al.’s scheme	4	3840
Proposed scheme	2	2816