Internet of Things (IoT) technology is one of the contributors to Industry 4.0 revolution. IoT is a system of interconnected devices called as things or nodes. Data is shared between such two physical devices like a sensor and a smart mobile phone using an existing internet and different types of network infrastructures. IoT systems are usually deployed using special protocols called light weight protocols which are different from the traditional internet based communication protocols. There are many constraints on devices used in IoT system such as use of low end micro-controllers with limited computing power, limited power consumption, and use of unreliable networks with low bandwidth. To work with and manage such devices with constraints, different types of light weight protocols have been developed and used in the IoT systems. Message Queue Telemetry and Transport (MQTT) is machine to machine (M2M) light weight data protocol most commonly used in the deployment of IoT systems and for sharing and delivery of data at application layer. When data is shared in the IoT system between the two physical devices with MQTT protocol, the security of data is a very critical requirement for reliability and adaptation of IoT systems. MQTT protocol being a light weight protocol does not provide any built in powerful and robust security techniques and it only supports very basic security mechanism like a password authentication. When used, this password is also shared in a clear text and it may be visible to the intruders. Due to the weak security features in MQTT protocol, many times the data is compromised and it is vulnerable to different types of malicious attacks like sniffing attack. Most common way to provide security to the MQTT based IoT application is at the transport layer by using an existing Transport Layer Security (TLS) protocol. TLS protocol may be suitable for internet applications like web applications and browsing but it is not suitable and designed for use with constrained IoT devices which works with light weight protocols.TLS protocol demands lots of complex computations and it needs more powerful resources like high end microprocessors and large memory which are only available with general computing machines like laptop or desktop computers. TLS approach may not provide end to end security in IoT applications since MQTT is asynchronous protocol. To achieve end to end security independent of TLS, robust security architecture is proposed in the IoT systems for MQTT protocol. These researches aims at developing efficient security architecture for MQTT protocol and improve the security of MQTT protocol.

Internet of Things Protocol MQTT Security Architecture