Breaking Chains, Empowering IoT: A Comparative Study of Holochain and Blockchain

The Internet of Things (IoT) is rapidly spreading across a wide range of applications because it is a critical technology for overcoming interoperability and heterogeneity barriers in many applications. IoT is increasingly being deployed in a distributed setting because of the vast number of devices and the physical dispersal of many use cases. Because IoT devices are often resource-restricted, this scattered implementation style exposes devices to unprecedented privacy and security risks. Distributed Ledger Technologies (DLT), such as blockchain, appear to be a perfect solution to integrate with IoT systems to overcome these challenges thanks to its key pillars: decentralisation, transparency and immutability. The use of blockchain in IoT has been widely examined, and the findings demonstrate how blockchain can be a crucial enabler for IoT. However, blockchain consensus mechanisms are often very energy-intensive, whereas IoT devices are resource-constrained with limited computational power, storage and energy. Therefore, as the literature emphasises, new consensus algorithms could solve most of these issues associated with blockchain technology. Holochain is an emerging DLT that promises to provide blockchain's key benefits and eliminate problems that come with it, such as consensus algorithms and the requirement to maintain a globally synchronised ledger. It has already attained the research community's awareness due to its potential to replace blockchain as a distributed computing solution. This paper compares blockchain and holochain in the context of IoT, considering scalability, availability, security and resource requirements.

I. Introduction

The Internet of Things (IoT) is a rapidly expanding network of lightweight devices that use embedded sensing, processing, and communication technologies to collect and communicate data over the Internet [1]. IoT is spreading in all aspects of our lives as it is a vital technology to overcome interoperability and heterogeneity resistances in applications [2]. Due to the large number of devices and its physical spread of many use cases, IoT is increasingly implemented in a distributed setting. This nature of implementation is exposed to unprecedented privacy and security threats as IoT devices are generally resource-constrained. Distributed Ledger Technologies (DLT), such as blockchain, offer several advantages, such as decentralization, transparency, and im-mutability, which are helpful in many applications. Because blockchain is designed to support distributed networks, it is an ideal candidate for solving these issues in the IoT network. In the literature, several works discuss the critical role blockchain can play in future IoT networks [3]. However, IoT devices are resource-constrained, with limited memory, low computational power and energy supply. The main issue with current blockchain implementations is that they use very computationally intensive consensus algorithms, which are optional for certain non-critical applications, such as resource-constrained IoT devices willing to trade some level of data integrity for computation and energy savings [2]. Holochain [4] is an emerging technology that promises to provide an open-source distributed network infrastructure to facilitate a secure network without excessive resource requirements [5]. A holochain network is powered by Distributed Hash Table (DHT) for data propagation and a hash chain for preserving data integrity [1] [5].