Height and Punishment: Toward Accountable IoT Blockchain With Network Sanitization

A Blockchain network consists of a distributed ledger and a set of nodes participating in the network. The consistency in the ledger’s state is maintained by a Blockchain consensus mechanism. This property is essential since it is assumed that the participants in the network do not trust each other. Most Blockchain consensus algorithms are unsuitable for resource-constrained nodes due to their power consumption, storage, network overhead, and computation requirements. Furthermore, many consensus methods do not address the issue of data accountability, which guarantees that an entity will be judged on its performance or conduct concerning a duty they have taken. This study proposes a novel consensus mechanism termed Proof of Block Height (PoBH) that prioritizes accountability for reporting IoT data transactions and considers factors such as low computation cost and energy consumption. The approach relies on a pre-existing comparable deterministic value based on the height of the committed blocks. The model identifies a malicious intent using a set of predicates and consequently incurs a computation penalty to keep such nodes away from the network. As a preventive measure, the model also seeks to increment this penalty appropriately by making the network free from dishonest nodes for as long as possible, thus sanitizing the network. Importantly, the developed method does not augment the basic hierarchy of an IoT network. A formal analysis of the mechanism’s operation shows that the resource and time required to cheat the system grows exponentially with the number of faulty blocks a node tries to append to the shared ledger. The factors affecting the mechanism’s performance, scalability, and effort required (by malicious nodes) to stay within the network are also quantitatively evaluated.

I. Introduction

In simple terms, Blockchain is a distributed ledger that stores transactions while providing immutability due to the nature of the cryptographic chains it employs. This notion was first adopted with the birth of Bitcoin [1]. The idea behind Bitcoin was to attain complete decentralization and eliminate any third party participating in digital payments. In the original work, the Bitcoin Blockchain organized data by employing block hash values in the form of a chain; thus the name was adopted as Blockchain. The Blockchain structure can be perceived as a linked-list type data structure that grows in a single direction. Shortly, another Blockchain called Ethereum [2] was introduced. In addition to facilitating digital transactions, Ethereum provides a decentralized computing platform. It supports the concept of smart contracts [3], which is equivalent to a legal document with specific terms and conditions. In recent years, there has been a significant technological advancement due to the advent of Blockchain technology. Many diverse fields have benefited from the integration of Blockchain technology, including supply chain management, agriculture, e-commerce and distributed storage [4], [5], [6].