## 4 Findings
\begin{table}
\begin{tabular}{p{42.7 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Ref \#** & **Objective** & **TRL** \\ \hline
[104] & This paper presents a privacy-protected blockchain-based system for medical image retrieval using layered architecture, a threat model, and a customized transaction structure & 5 \\ \hline
[105] & This work offers an architecture designed for IoMT and other possible applications. In addition, authentication schemes are introduced based on ECC and PUF to ensure the system’s privacy & 5 \\ \hline
[106] & A system that secures IoT devices in the healthcare domain using IPFS and blockchain technology. This system is designed to allow continuous monitoring for patients with chronic diseases & 5 \\ \hline
[107] & GaliMediChain is a healthcare system based on blockchain technology and garlic routing to enable secure sharing of health data (COVID-19). Furthermore, a new consensus mechanism (PoEol) is proposed for blocks generation and miner selection processes & 5 \\ \hline
[108] & A medical Hyperledger Fabric-enabled blockchain-based architecture called BIoMT is proposed to increase the medical environment’s reliability while reducing the consumption of networking resources. Moreover, a customized consensus algorithm is designed to increase security and privacy & 5 \\ \hline
[109] & An implementation for critical systems to enhance privacy and security through combining Information Hiding Techniques (IHT), IoT, and blockchain technology & 5 \\ \hline
[110] & DSMAC is a decentralized system proposed to preserve the security and privacy of sharing medical records using Verifiable Cerredentials (VC), Decentralized Identifiers (DIDs), Attribute-Based Access Control (ABAC), Role-Based Access Control (RBAC), Self-Sovereign Identity (SSI), and blockchain & 5 \\ \hline
[111] & This approach aims to develop a blockchain-connected gateway for IoT devices that can adapt and securely retain the privacy preferences of users; security and privacy preferences can both be ensured by the proposed digital signature mechanism (PDSS) & 5 \\ \hline
[112] & This article discusses how the security gateway architecture of an IoT device can be provided with a basic interface using blockchain to allow decentralization and authentication. This offers IoT infrastructure with the required anonymity and versatility & 5 \\ \hline
[113] & By leveraging blockchain, bilinear pairing, and a lifted EC-ELGamal cryptosystem, this paper proposes a novel remote data integrity check approach for IoT information management systems that preserves privacy without requiring trusted third parties & 5 \\ \hline
[114] & This study presents a lightweight IoT data-sharing security framework based on a double-chain paradigm that combines data and transaction blockchains. To prevent malicious local dominance behavior, a dynamic game method of node cooperation is presented. This approach aims to improve privacy protection, data registration efficiency, and the PBFT consensus algorithm & 5 \\ \hline
[115] & The primary goal is to improve the privacy of users and their data by implementing user-controlled privacy using the anonymization characteristics of blockchain. This paper proposed an architecture to address privacy and security issues of IoT applications & 5 \\ \hline
[116] & A blockchain-based control access system integrated with IoT to improve smart cities services and performance & 2 \\ \hline
[117] & This research offered a smart city hybrid model that included five core features that the authors consider necessary to provide security and privacy & 2 \\ \hline
[118] & PrivySharing: a framework for secure, private IoT data sharing in smart cities via blockchain technology. By separating the blockchain network over multiple channels, data privacy is ensured & 5 \\ \hline
[119] & Transform the standard IoT architecture by introducing multi-center security and privacy blockchain architecture. Design the architecture’s data interaction and algorithmic processes. The specific solution is discussed using an automated manufacturing platform & 7 \\ \hline
[120] & A smart home-based IoT-Blockchain (SHIB) approach is proposed to address privacy, security, and authentication challenges & 5 \\ \hline
[121] & ELIB is a smart home model that is based on an overlay network that validates dedicated security and privacy by merging resources with high levels of capability into a public BC. This approach consists of three levels: DTM scheme, CC model, and consensus algorithm & 5 \\ \hline
[122] & This paper proposes a lightweight scalable blockchain (LSB) approach that focuses on achieving decentralization and optimizing the performance for IoT requirements through overlay networks. A time-based consensus algorithm is also proposed to reduce the delay and mining processing overhead & 5 \\ \hline
[123] & In order to develop a robust framework for smart home systems, they present an authentication model that integrates attribute-based access control with smart contracts and edge computing. In addition, they designed a Stochastic Gradient Descent (SGD) algorithm & 5 \\ \hline
[124] & In response to the need for data mining and analytic activities in IoT, a privacy-protected and inter-cloud data fusion platform based on JointCloud blockchain is proposed in this paper & 2 \\ \hline  & Blockchain, fog computing, and the alliance chain concept are used in this research to provide a distributed access control solution for IoT data security that relies on LSB (Least Significant Bit) and MLNCML (mixed linear and nonlinear spatiotemporal chaotic systems) techniques & 5 \\ \hline
[126] & This works presents a cross-domain access control scheme that provides reliability and security. The distributed access control is achieved using blockchain and NetwOrked Smart object (NOS) middleware & 5 \\ \hline
[127] & A decentralized trust model is proposed in this research in order to maintain the reputation of publicly available fog nodes. The public fog nodes’ reputation is preserved by the opinions of previous users and their interactions with them & 5 \\ \hline  & & \\ \hline \hline  & & \\ \end{tabular}
\end{table}