Lightweight Blockchain of Things (BCoT) Architecture for Enhanced Security: A Literature Review

Both the internet of things (IoT) and distributed ledger technology (DLT), more commonly known as the blockchain, are two popular emerging technologies of this era. While blockchain offers strengthened security, along with other benefits, it requires peer-to-peer (P2P) nodes for its consensus process. On the contrary, IoT ecosystems inherently consist of many P2P nodes but it is highly critiqued for its lack of security measures. Therefore, the fusion of these complementary duos, known as the blockchain of things (BCoT), has become a recent research trend. While the fit is good and the benefits such consolidation can offer are obvious, a lot of challenges are yet to be addressed. Therefore, we have conducted a comprehensive literature review, covering 33 research articles, spanning over the last six years (2016–2021), to report the state-of-the-art research in this domain. We have synthesised the existing literature by comparing, contrasting, resembling as well as critically evaluating them and thus, deduced the current challenges and future research directions, particularly with regards to lightweightness.