The growth of the Internet of Things (IoT)-embedded intelligent systems
with both the industrial perspective and research enables communication and data
transfer among heterogeneous devices in real-time without any physical human
intervention. These devices are resource-constrained devices in terms of power and
storage. This autonomous and constrained behavior of smart IoT devices leads to
privacy and security vulnerabilities. The existing cryptographic techniques for security
and privacy preservation are not suitable enough to deal with the issues of these
systems. Blockchain technology provides a platform for decentralized computation and
secure information sharing in a distributed manner among multiple authoritative
participants. These participants do not trust each other but cooperate, coordinate, and
collaborate in a rational decision-making process. Blockchain uses a cryptographic
environment to secure the data and network. Different characteristics of blockchain
technology, such as decentralization, immutability, transparency, security, and
reliability, make it the ideal and effective candidate for integration with smart IoT
systems. The main objective of this paper is to analyze the use of blockchain
technology and its concept in the context of smart IoT to improve capabilities and
enhance its security. This paper first highlights the introduction of smart IoT with
security and privacy concerns for these systems. This is followed by a detailed
systematic analysis of blockchain architecture, its characteristics, consensus algorithms,
various platforms, and application areas in smart IoT with the aim of analyzing the
concept and workings of blockchain technology. Various benefits and challenges in the
integration of blockchain with IoT are then analyzed and illustrated.
Keywords: Blockchain technology, Consensus, Decentralization, Internet of Things, Intelligence, Security, Smart IoT, Smart contract.
