DBoT: Enhancing Scalability and Privacy in Intelligent Building Spaces through a Direct Acyclic Graph Blockchain

Intelligent Building spaces are critical in creating smarter living spaces, which are composed of interconnected Internet of Things (IoT) devices. The growing dependence on these advanced, connected environments has led to several operational challenges related to privacy, security, and scalability due to their distributed architectures and the complex interplay among numerous IoT systems. Recently, Blockchain Technology has emerged as a critical solution for addressing privacy and security challenges in intelligent buildings. However, the IoT devices within Intelligent Building spaces (IBDs) are resource-constrained and face notable challenges in performance and scalability. This indicates a need for a more scalable, energy-efficient blockchain solution without compromising security or privacy. To overcome these challenges within IBDs, we propose a novel approach using the Direct Acyclic Graph Blockchain of Things (DBoT), which utilizes IOTA Tangle Blockchains. We develop a lightweight bundle message model that enhances scalability with an advanced algorithm for energy-efficient proof-of-work computation across network nodes. The DBoT architecture significantly boosts scalability and performance in IBD IoT nodes, simultaneously improving user privacy and access control with varied granularity. Our findings show that the Blockchain-based DBoT method effectively ensures secure connectivity and information flow with growing IoT systems without sacrificing performance.