# Internet of Things and Blockchain Integration: Security, Privacy, Technical, and Design Challenges
## 2 Background and Related Work
### Related Work
\begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Recent Survey Article** & **Year** & **Domain** & **BIoT Challenges** \\ \hline [PERSON] and [PERSON] [4] & 2018 & BIoT applications & Technical, standardization, BC infrastructure, regulations, and different BC varieties. \\ \hline [PERSON] et al. [63] & 2018 & BIoT integration & Security attacks, adequate security framework, power consumption, trust management, BC infrastructure, skyline query processing, and vehicular cloud advertisement dissemination. \\ \hline [PERSON] et al. [46] & 2018 & BIoT integration & Scalability, security, privacy, smart contracts, legislations, and consensus. \\ \hline [PERSON] et al. [25] & 2018 & BIoT applications & Scalability, security, privacy, resources, public/private implementation, big data and machine learning (ML), SDN network, and cellular network. \\ \hline [PERSON] et al. [64] & 2019 & BC applications in IIoT & Scalability, security, privacy, energy and cost, resources, and regulations. \\ \hline [PERSON] et al. [66] & 2019 & BIoT integration security challenges & Security, data privacy, authentication and identity management, trust establishment, decentralized cooperation, and consensus protocol. \\ \hline [PERSON] et al. [26] & 2019 & BIoT for smart cities & Security, privacy, energy, incentive and punishment mechanisms, cost, and regulations. \\ \hline [PERSON] et al. [36] & 2019 & BC in edge computing & Scalability, security, privacy, artificial intelligence (AI), self-organization, function integration, resource management, and big data. \\ \hline [PERSON] et al. [67] & 2020 & BIoT in smart cities & Security, privacy, data, structure, bandwidth, and latency. \\ \hline [PERSON] et al. [68] & 2020 & BIoT for green agriculture & Scalability, ML and database of intrusion detection, choosing consensus algorithm, cryptographic protocol, security attacks, and slicing threat of 5G. \\ \hline [PERSON] and [PERSON] [69] & 2020 & BIoT integration & Security, privacy, computation and storage, the granularity of transactions, trust, and successful pilots of BIoT, and awareness. \\ \hline [PERSON] et al. [71] & 2020 & BIoT-based database & Bitcoin Backbone Protocol (BBP) database. \\ \hline [PERSON] et al. [70] & 2020 & BC for industrial IoT & Performance, privacy, standardization, and complexity. \\ \hline [PERSON] et al. [11] & 2021 & BIoT integration & Scalability, security, privacy, resources, consensus choice, big data, device mobility, smart contracts, and standardization. \\ \hline [PERSON] et al. [73] & 2021 & BIoT unification & Scalability, IoT resources, BC infrastructure, BIoT and cellular network, privacy, and ML, and big data. \\ \hline [PERSON] et al. [74] & 2021 & BIoT integration & Security, privacy, throughput, latency, resources, usability, and centralization. \\ \hline \hline \end{tabular}
\end{table} 
Table 4: BIoT integration challenges—survey studies. Several articles on BIoT challenges were recently published. [PERSON] et al. [11] outlined the primary challenges that BIoT systems face and suggested a role in addressing them. They presented a two-layer BIoT architecture based on dew and cloudlet computing. [PERSON] et al. [73] provided an overview of how to adapt BC to specific IoT requirements to construct BIoT applications. In [PERSON] et al. [74], the authors provided a comprehensive reference architecture, as well as the basics, current achievements, promises, and challenges of BC and IoT convergence. Focusing on consensus techniques and BC platforms, the important prerequisites for integrating BC with smart cities were discussed in [57]. [PERSON] et al. [75] discussed the BC important elements, and they presented a full examination of potential security challenges, as well as the current solutions that may be used as countermeasures. [PERSON] et al. [58] reviewed the BC for IoT, fog, and cloud in the context of smart cities, eHealth, and intelligent transportation. [PERSON] et al.