Internet is no longer a mere source of information as the concept of interconnectivity has expanded to connect real things or objects like every kind of machines, cars, homes, hospitals, even our bodies through wearable devices. The concept of interconnectivity of billions of objects (mobile or stationary) providing and exchanging real time data is called Internet of Things (IoT). Myriad IoT applications are touching every aspect of our lives and have the latent to develop the basic quality of life for masses. However, prerequisite for successful implementation of any IoT application is uninterrupted and high-quality network connectivity and handling of huge amounts of personal and sensitive user data which gives rise to the questions of security. A handoff authentication protocol with high security and efficiency is required for enabling secure and seamless handoff of mobile nodes between different access points (AP). However, there are number of challenges in designing a secure handoff protocol for IoT systems like limited power of mobile nodes, computational capability, security and vulnerability of open IoT networks. In this paper, we propose a secure and reliable handoff authentication protocol for such IoT devices. Compared with other well-known similar handoff protocols, the protocol proposed here satisfies all relevant security requirements of handoff such as batch verification, mobile node un-traceability, and anonymity and is unaffected by other attacks like replay attacks and also provides mutual authentication. To demonstrate the security strength (against replay attacks) of our protocol, simulation has been done using AVISPA. Thus, protocol proposed by us is more appropriate for IoT environment compared to the alike protocols.