Secure Hybrid Publish-Subscribe Messaging Architecture.

In many applications of the Internet of Things (IoT) and Machine to machine (M2M) communications, maintaining low latency is an important performance indicator. Encryption protocols are known to be CPU intensive, affecting the dissipated power and increasing the latency. Therefore, the security is often neglected in order to speed up, in particular, the realtime applications that require prompt response. However, in advanced communication networks the security should not be compromised. When data is sent over the Internet, encryption and authentication are required, whereas in the case of a trusted LAN network, encryption and authentication are not necessary in order to sustain lower latency. In this paper, we propose a hybrid approach which secures the WAN and minimizes the delay on the LAN. We evaluate our solution by measuring the Round Trip Time (RTT) with and without security enabled to determine the actual security overhead introduced for different computing platforms.