ABSTRACT
In this technology era, the Internet of Things (IoT) plays predominant role in several aspects of real-life problem. The thrust area of IoT applications include smart city, smart transport, smart healthcare, smart environment, smart agriculture, etc. The IoT system involves heterogeneous sensors and devices at the edge layer of the protocol stack. These IoT devices are characterized in term of hardware specification, different communication protocols, services offered by these devices and trustable users of the IoT devices. Hence, the IoT requires efficient security and privacy mechanism for heterogeneous IoT devices and as well as voluminous amount of data generated by these IoT devices. Conventionally, the security for homogenous devices is provided by the centralized mechanism through authentication, encryption/decryption of data, digital signatures and cryptographic algorithms. However, IoT has characteristics of heterogeneous, autonomous and resource constraint IoT devices, in which case, the conventional centralized security solutions fail tremendously. Hence, the decentralized approach of Block chain is well suited for this scenario. This chapter targets to provide the comprehensive review of various security, privacy and access issues, solution approaches and challenges towards IoT. The role block chains in five different IoT applications are discussed in this chapter. These IoT applications include Intelligence Transport system, Smart Healthcare system, supply chain management, IoT ecosystem, Smart City. This chapter discusses how block chain provides security, smart contracts, access control and proof-of-work and proof-of-state are carried out at decentralized manner. The chapter presents the use case of block chain beyond crypto currency and bit coin, the data are to be preserved through block chain technique and different mining techniques used in block chain for these IoT applications.
