A Lightweight Three-Factor Authentication and Key Agreement Scheme for Multigateway WSNs in IoT

Table 1

Notations.

Notation	Description
	The identity , password , and biological factor of the user
	The identity of the sensor node
	The identity and the private key of home gateway node
	The identity and the private key of home gateway node
SA	The system administrator
SC	The smart card
	The maximum permitted transmission delay
	The negotiated session key
	The hash function
	The biometric feature extraction function and verification function
	The XOR operator
	The concatenation operator
	sends messages to over a public channel
	sends messages to over a private channel