An Enhanced Lightweight Dynamic Pseudonym Identity Based Authentication and Key Agreement Scheme Using Wireless Sensor Networks for Agriculture Monitoring

. 2019 Mar 6;19(5):1146. doi: 10.3390/s19051146

Step 1:	The $U_{i}$ selects his/her own identity $I D_{i}$ , password $P W_{i}$ and imprints biometric $F_{i}$ on the sensor device and then computes $G e n (F_{i}) = (X_{F}, P_{F})$ , $R P W_{i} = h (P W_{i} ‖ X_{F})$ , where $G e n (.)$ is a generate function of fuzzy extractor and $(X_{F}, P_{F})$ are, respectively, secret and public keys. Now, $U_{i}$ sends ${I D_{i}, R P W_{i}}$ to $B S$ via trustworthy channel.
Step 2:	When obtained the registration request from $U_{i}$ , $B S$ firstly calculates $A_{i} = h (I D_{i} ‖ X)$ , $B_{i} = A_{i} \oplus h (R P W_{i} ‖ I D_{i})$ , $C_{i} = A_{i} \oplus h (B_{i} ‖ X)$ and $D_{i} = h (A_{i} ‖ R P W_{i} ‖ I D_{i}) .$ Afterwards, $B S$ issues a smartcard having parameters, i.e., ${B_{i}, C_{i}, D_{i}, h (.)}$ and sends it to $U_{i}$ via the same channel.
Step 3:	After obtaining the smartcard from $B S$ , $U_{i}$ embeds $P_{F}$ and $G e n (.)$ in the memory of smartcard, i.e., ${B_{i}, C_{i}, D_{i}, h (.), P_{F}, G e n (.)}$ .