The Internet of Things (IoT) is the next evolutionary paradigm of networking technologies that interconnects almost all the smart objects and intelligent sensors related to human activities, machineries, and environment. IoT technologies and Internet Protocol connectivity enable wide ranges of network devices to communicate irrespective of their resource capabilities and local networks. In order to provide seamless connectivity and interoperability, it is notable to maintain secure end-to-end (E2E) communication links in Part of this work has been published in IEEE Globecom, 2015 as 'Efficient Key Establishment for Constrained IoT Devices with Collaborative HIP-based Approach'. The proxy based key establishment component is taken from the paper which is entitled 'Proxy-based End-to-End Key Establishment Protocol for the Internet of Things' and presented at IEEE ICC Workshop on Security and Privacy for Internet of Things and CyberPhysical Systems, 2015. The extensions of these works include the derivation of entire CHIP protocol, implementation it on Waspmote sensors, the measurement of energy costs, and the discussion of performance and security features in detail.