Access Control and Data Security of IoT Applications Using Blockchain Technology

Abstract

Almost all data collected today is in digital form and is stored in various places ranging from local databases to the cloud-based storage. However, all this data is useful only when collected and aggregated for further processing and analysis. As such, data sharing among various sources has now become very important. Openly sharing data tends to violate confidentiality and privacy of users. Due to this, sharing of data employs a number of access control methods to ensure that only the authorized and authenticated users are getting access. Most access control methods however, are controlled by a single centralized entity, responsible for writing and enforcing the access policies. Such a system faces the issues as any centralized system includes single point of failure and malicious behavior. With the rising presence of a lot of sensitive and personal-related data such as in healthcare and the Internet of Things (IoT), it has become important to enable fine-grained access control that is in the hands of the owners of the data rather than centralized personnel. It has also become important to ensure that the system is fault-tolerant and secure from attacks as a single breach of data could cause a great loss of sensitive data. Along with this, it is necessary for systems to be able to record access trails for higher security purposes. Blockchain is a public distributed ledger technology that has proven to be tamper-proof and does not require any trusted third party for its usage. With the development of smart contracts on the blockchain, enabling the automatic execution of turing-complete code on the the blockchain network, it has grown to a wide number of applications with one of them being to provide secure and privacy-preserving access control methods. This paper provides a survey of the various access control methods that have been developed in the recent years using blockchain. A study considering the usage of blockchain, smart contracts, methods proposed, and improvised as well as limitations if any of the various papers has been performed and depicted in tabular and descriptive manner. This paper aims to guide readers to gain an in-depth understanding of current research in this field as well as gain insights on future prospects.