Table 4.

A performance comparison of RUASN with the existing schemes.

Schemes	Registration		Login and Authentication
	User	Gateway	User	Gateway	Sensor node
Das [18]	-	3H	4H	4H	1H
Daojing et al. [21]	1H	5H	5H	5H	1H
Wong et al. [10]	-	3H	-	1H	3H
Vaidya et al. [14]	2H	2H	3H	3H	3H
Proposed RUASN	1H	3H + 1S	4H + 2S	4H + 2S + 1MAC	1H + 2S + 1MAC