An efficient multilevel security architecture for blockchain-based IoT networks using principles of cellular automata.

The tremendous increase in the use of Internet of Things (IoT) has made an impact worldwide by changing the mode of day-to-day life. Like any other application, IoT based networks also have to be protected since the data produced consist of sensitive information. Existing algorithms for providing security in such networks do not consider all the security objectives. Starting from the sensing of data from IoT environment, the data have to be protected from several types of attacks. Also, the authentication of involved entities, integrity of data, access control and confidentiality are to be achieved. This work proposes a novel security architecture for IoT based distributed applications. The architecture uses the best known lightweight cipher ChaCha20. Principles of cellular automata are applied for random number generation to attain more security and randomness. Double encryption ensures multilevel protection of data during the data uploading and storing phases. Providing encryption based on dynamic session keys guarantees the security of the method. It also ensures secure data sharing, mutual authentication between communicating entities, fast execution, user authentication and message integrity. The IoT device connected to a gateway node has to complete registration phase successfully. Subsequently, each time a data transfer between the device and gateway node takes place, mutual authentication phase is executed. Blockchain network used at the edge level ensures authentication of participating nodes and hence, unintended modification of data is prevented. The proposed architecture proves to be efficient in terms of throughput, execution time and resistance to various security attacks.