Identity Management in IoT Networks Using Blockchain and Smart Contracts

Internet of Things (IoT) devices proliferation is on the rise, where the number of connected devices has surpassed 7 billion devices in 2017, whereas insights foresee a number of 20-50 billion connections by year 2020. Most of those devices are deployed in heterogeneous and complex networks which imposes many challenges on the devices management functionality. Among those challenges is the identity management which pertains to how devices' identities are authenticated and verified in addition to how devices establish the means for authorizing and controlling access to data and services. Blockchain as a distributed ledger technology positions itself as a suitable candidate to address this challenge. That is mainly attributed to Blockchain's use of cryptographic identifiers, records immutability, and provenance. These features, together, provide a platform to implement the functions of IoT devices identity management that can ensure a global and unique identity for the devices, and also provide the mechanism to maintain it throughout the device life cycle. This paper presents a semi-decentralized Blockchain-based IoT identity management framework that provides features of identity creation and transfer of ownership, along with the capability of identity portability among networks visited by the devices. For validation, we describe a set of smart contracts that provide the functions of the registrar and management contracts.