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 secret and public key respectively. Now, $U_{i}$ computes $R E G_{i} = r_{0} \oplus (I D_{i} \| \| R P W_{i} \| \| A_{i})$ and sends ${I D_{i}^{p r e}, R E G_{i}}$ to $B S$ .
Step 2:	When the registration request is received from $U_{i}$ , if $B S$ successfully verifies that ( $I D_{i}^{p r e}, r_{0}$ ) is in $B S$ ’s storage and has not been registered, then $B S$ computes $(I D_{i} \| \| R P W_{i} \| \| A_{i}) = R E G_{i} \oplus r_{0}$ , $B_{i} = h (A_{i} ‖ X) \oplus h (I D_{i} ‖ R P W_{i})$ and $D_{i} = h (A_{i} ‖ R P W_{i} ‖ I D_{i})$ . Afterwards, $B S$ computes $R S P_{i} = h ((I D_{i} \| \| r_{0}) \oplus (B_{i} \| \| D_{i})$ and sends { $R S P_{i}$ } to $U_{i}$ .
Step 3:	After receiving the response from $B S$ , $U_{i}$ computes $(B_{i} \| \| D_{i}) = R S P_{i} \oplus h ((I D_{i} \| \| r_{0})$ , and embeds $A_{i}, B_{i}, D_{i}, h (.), P_{F}$ and $G e n (.)$ in the memory of $S C$ .