. 2016 Dec 14;16(12):2123. doi: 10.3390/s16122123

Table 1.

Notations.

Notation	Meaning
$p, q$	two large primes
$U_{i}$	user i
$S_{j}$	sensor node j
$G W N$	gateway node
$S C_{i}$	smart card of the user $U_{i}$
$I D_{i} / p w_{i}$	identity/password of $U_{i}$
$B I O_{i}$	biometric template of $U_{i}$
$T I D_{i}$	temporal identity of $U_{i}$
$S I D_{j}$	identity of $S_{j}$
$I D_{S}$	identity of $S C_{i}$
$A$	adversary
K	a master secret of $G W N$
$G_{1}$	cyclic group of order q
P	generator of $G_{1}$
$T_{i}, T_{j}, T_{G}$	timestamps
⨁	XOR operation
$\| \|$	concatenate operation
$h (\cdot)$	a secure one-way hash function