AES and MQTT based security system in the internet of things

Internet of Things grew rapidly over the last few years, the focus on security has not been kept up. In today’s world, smart city has developed as a contemporary paradigm to dynamically optimize the resources in cities and serve better facilities and excellence of life for the citizens. In this paper, a model is proposed using Advanced Encryption Standard-256 and Secure Hashing Algorithm-256 to attain the security in the IoT system. The data collected from devices is first encrypted using AES-256 with a symmetric key that has been created by using SHA-256 and finally the ciphertext is created. Now, this ciphertext is added to a new layer of security called Message Queuing Telemetry Transport protocol, which is an ISO standard (ISO/IEC PRF 20922) publish-subscribe based model used for the secure transmission of data. On the receiver side, the original data is extracted. In this way, three- layer security has been added to data collected by smart objects before transmission.