I. Introduction
Heterogeneous Wireless Sensor Nodes (WSNs) or digital devices/machines are increasingly becoming integral part of Internet of Things (IoT) Machine to Machine (M2M) Communication and Cyber Physical Systems (CPS) paradigms [1]. In future, it is estimated that huge number of WSNs are to be deployed across the digital globe to realize these paradigms [2]. They are often utilized to sense, compute, store and communicate for various IoT applications. IoT paradigm has several challenges such as Interoperability, integrity, security and privacy [2]. To enable the trustworthiness among the user community of IoT security and privacy are the key challenges need to be addressed. Very often the Things (WSNs) of IoT are vulnerable to various security threats such as eavesdropping, Denial of Service (DoS), Distributed DoS, Side channel and replay attacks [2] due to their limited computing, storage, power and broadcast nature of wireless communication. To confront these attacks and enable integrity of stored data and secure data communication between the WSNs, cryptographic techniques are used quite often [3]–[5]. In general traditional crypto graphic techniques (symmetric and asymmetric) require Public Key Infrastructure(to facilitate crypto parameters, public and private keys) for performing encryption, decryption and authentication operations between peer WSNs and these operations are power hungry and drains the battery of WSNs and thus reduces their lifetime. Thus Identity Based Elliptic Curve Cryptography (IBE-ECC) schemes with Tate Paring which requires no Public Key Infrastructure and key exchanges (Public key of the user can be generated from the publicly known identity of the users: IP address, email id, SSN, etc.) and with smaller key size (when compared to Traditional PKI schemes such as RSA) reduces the consumption of battery power of the nodes are emerging as a fore runner among them [5]. However these techniques suffer from complex computations which consequently drain the energy of the nodes and thereby reduce their lifetime.