. 2016 Feb 1;16(2):179. doi: 10.3390/s16020179

Table 1.

Definition of notations in the proposed secure and privacy-preserving body sensor data collection and query (SPCQ) scheme.

Notation	Definition
μ	the system security parameter
$p_{1}, p_{2}$	two big prime numbers
$N = p_{1} \cdot p_{2}$	the product of $p_{1}$ and $p_{2}$
$G, G_{t}$	the bilinear groups with order N
e, g ,h	the parameters of bilinear groups
$B_{1}$	$B_{1} = g^{p_{1}}$
$B_{2}$	$B_{2} = e {(g, g)}^{p_{1}}$
$E ()$	the asymmetric encryption algorithm, i.e., ECC
H()	the secure cryptographic hash function
HPS	the evaluation dataset
$(x_{i 1}, x_{i 2}, \dots, x_{i n})$	the feature parameters of a data item
$W = (w_{1}, w_{2}, \dots, w_{n})$	the weighted number of different dimensions
d	the weighted Euclidean search range of DU’s query
$F_{i} = (f_{i 1}, f_{i 1}^{'}, f_{i 2}, f_{i 2}^{'}, \dots, f_{i n}, f_{i n}^{'})$	the encrypted search index of a data item
$〈q_{1}, q_{1}^{'}, \dots, q_{n}, q_{n}^{'}〉$	DU’s encrypted query parameters