This research explores the applications of blockchain in the Internet of Things.

The blockchain technology has revolutionised the digital currency space with the pioneering cryptocurrency platform named Bitcoin. From an abstract perspective, a blockchain is a distributed ledger capable of maintaining an immutable log of transactions happening in a network.

In recent years, this technology has attracted significant scientific interest in research areas beyond the financial sector, one of them being the Internet of Things (IoT). Applications of blockchain in this space are seen as the missing link toward building a truly decentralised, trustless, and secure environment for the IoT.

In this survey, the authors aim to shape a coherent and comprehensive picture of the current state-of-the-art efforts in this direction. They start with fundamental working principles of blockchains and how blockchain-based systems achieve the characteristics of decentralisation, security, and auditability.

From there, the authors build their narrative on the challenges posed by the current centralised IoT models, followed by recent advances made both in industry and research to solve these challenges and effectively use blockchains to provide a decentralised, secure medium for the IoT.

Discover how the application of blockchain makes the world of IoT possible and the use cases that it provides.