A Lightweight Blockchain for the Internet of Medical Things Using Hash-based Message Authentication Codes

Blockchains allow to create and maintain distributed immutable registries of data. The internet of things (IoT) is one of possible applications, where blockchain technologies are demanded. Due to their properties and possibilities, blockchains can essentially improve characteristics of IoT systems in many applications, therefore at the moment a lot of attempts are made to adopt blockchains to use them in the IoT (including the internet of medical things (IoMT) that is a particular case of the IoT). One of the main approaches of such adoption is creating lightweight blockchains optimized for specific cases of use. In this paper, we propose a scheme of a lightweight blockchain for processing the data in the IoMT with low-resourced sensor devices. Our scheme is built upon the use of hash-based message authentication codes (HMAC) to provide the integrity and authenticity of circulated data and on a simplistic consensus algorithm that is adequate to the use scenario.