ABSTRACT
The internet of things (IoT) provides a novel vision to the internet user. It also provides computational and economical convenience by connecting each object with the internet. The IoT bolsters the variety of applications in an efficient way. To satisfy such diverse applications’ computational and communication requirements, the protocol stack of IoT provides the layered architecture, which includes a variety of protocols to meet the needs of all applications. The protocols in the protocol stacks are designed for constrained devices to provide the required reliability, connectivity, and efficiency for IoT applications. As security is the key facet for any application, this chapter puts forth comprehensive surveys for analyzing the existing protocol in each layer of the IoT protocol stack. The chapter further discusses the existing secure communication methods, open challenges, and future researc
