Revisiting a Multifactor Authentication Scheme in Industrial IoT

Table 1

Notations and abbreviations.

Symbol	Description
	Gateway node
	’s identity
	user and sensing device
	’s and ’s identity, respectively
	A random nonce
	’s password and biometrics
	’s biometrics key and public reproduction parameter
	Generation and reproduction algorithm of fuzzy extractor, respectively
	Current timestamp
	Maximum transmission delay
	Symmetric key between and
	Session key between the user and sensing devices
	Secret value utilized for secret sharing
	’s secret parameters
	Hash function
	Concatenation and bit-wise XOR operation