An Efficient Approach for Merging Multidimensional Blockchains in Mobile IoT

Graph-based or multidimensional blockchains have been proposed to improve the scalability and efficiency of existing blockchain applications. However, when implemented in mobile Internet of Things (mIoT) networks, these blockchain systems can frequently split and merge and cause the merging algorithm to process a large number of similar blocks (a block is similar or identical when it exists once in multiple blockchains). The presence of similar blocks hinders the merging process, as it consumes time and computational resources to scan, validate, and potentially merge similar blocks. This paper presents an efficient approach for merging graph-based or multidimensional blockchains in mIoT networks by avoiding similar blocks and effectively detecting and merging new blocks that were created after the split. Our proposed merging algorithm employs depth-first search and Merkle tree techniques to minimize the time and computational resources spent on identical blocks. Finally, we evaluate the performance of our method in highly mobile networks and demonstrate that it can execute the merge with a more than 72% reduction in time in comparison to merging algorithms without block similarity handling.

I. Introduction

In recent years, blockchain technology has generated much interest due to its ability to provide secure and private ground-breaking solutions for various problems in many domains, such as finance, healthcare, distributed systems, voting, industry, and real estate. Another essential field that benefits from blockchain and is related to this paper is the mobile Internet of Things (mIoT). These mIoT systems can adopt blockchain technology and benefit, for example, from decentralization, security, privacy, and quality of service (QoS) [1]–[3]. But the benefits of blockchain in mIoT can also come at a cost. For instance, traditional blockchain systems are designed in a chain-based structure similar to the blockchain structure in Nakamoto [4]. This type of structure can result in undesirable performance in terms of scalability, throughput, and confirmation time which make the design unsuitable for mIoT systems Wang et al. [5].