A Comparitive Study of Blockchain Applications for Enhancing Internet of Things Security

IoT devices or smart devices have become a part and parcel of the human existence. Every day, the counts of devices, which are being connected to the internet, are becoming unquantifiable. One among the prominent applications in commercial IoT is medical IoT. Privacy maintenance and ensuring security of user data is a major concern in certain scenarios such as that of the medical IoT. Conventionally the data generated from a sensor should be highly confidential and private. The centralized data management adopted in majority of IoT systems are having high set up cost and are prone to single point of failure and does not provide any guarantee of data authenticity and security. The inherent nature of IoT systems such as limited storage and low processing capabilities make them an unsuitable candidate for the use of complex and highly computational cryptographic algorithms. Even though the use of modern server platforms such as the AWS and Google helped in mitigating the issues of high setup cost and less security, the problems of data authenticity and access control still persists. Blockchain is a decentralized mechanism for secure management and exchange of data in any IoT system, particularly healthcare. Hence blockchain with its inherent properties of immutability, consensus mechanism, provenance and encryption can solve the problems of authenticity and access control in IoT. There exists several research works related to IoT security with the inclusion of blockchain framework. However, a collation of various works related to blockchain IoT is absent in the literature and this paper aims to provide a detailed amalgam of the wide range of works in blockchain IoT. We also aim to highlight the necessity of securing an IoT system and present a comparison of blockchain and other security techniques in terms of robustness, setup cost, risk of failure etc. and also propose an ideal security technique that can be adopted for IoT applications.