## 3 Security and Privacy-Preserving Solutions for IoE
### Blockchain-Based Security Solutions
#### 3.1.6 Performance of Blockchain Systems  
Blockchain platforms used in IoE systems must be evaluated not only in terms of security but also regarding performance and energy efficiency [92; 93]. This is because massive simultaneous data transmission, latency sensitivity, and limited resources (CPU, battery, bandwidth) are critical in IoE networks. Therefore, different blockchain infrastructures should be compared using key metrics such as transaction speed (TPS), latency, energy consumption, data privacy, scalability, and access control, and the most appropriate system should be selected according to specific IoE requirements [92; 93]. In this context, Table 7 presents a comparative analysis to clearly demonstrate how different blockchain platforms are positioned in terms of performance and security for IoE integration. IoE systems consist of billions of interconnected devices, generating massive amounts of data where low-latency communication plays a critical role. Therefore, blockchain platforms used in IoE must be evaluated not only for their security features but also for their performance criteria such as transaction speed, energy efficiency, data privacy, and flexibility [93; 95]. Table 7 provides a comparative presentation of the technical capabilities of various blockchain infrastructures against these multidimensional requirements. \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Blockchain Feature** & **Use Case in IoE** & **Security Enhancement** \\ \hline Decentralized Identity [74; 84; 85] & User authentication and IoT device identity verification & Prevents unauthorized access and identity spoofing \\ \hline Smart Contracts [86; 87] & Automated access control for IoE services & Reduces human errors and enhances trust \\ \hline Data Integrity and Provenance [88; 89] & Secure healthcare records and industrial IoT logs & Prevents data tampering and enhances regulatory compliance \\ \hline Consensus Mechanisms (PoS, PBFT, DAG-based) [90; 91] & Scalable blockchain for real-time IoE transactions & Lowers energy consumption and improves efficiency \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Blockchain security applications in IoE/IoT. Permissionless blockchains such as Ethereum offer high levels of decentralization and cryptographic security. However, during the Proof-of-Work (PoW) phase, they demonstrated high energy consumption and latency, making them less suitable for real-time and resource-constrained IoE scenarios. Although improvements in transaction capacity and energy efficiency have been achieved with the transition to Proof-of-Stake (PoS), challenges still remain in critical areas such as data privacy and access control due to the open-access nature of permissionless systems [95]. On the other hand, Hyperledger Fabric, with its permissioned structure, offers a controlled participant network and modular architecture, providing high transaction throughput, low latency, and advanced access control mechanisms. These features make it an extremely suitable alternative for enterprise-level IoE applications. The platform's channel-based data isolation, flexible smart contract development, and low energy consumption support operational sustainability, making Hyperledger Fabric a prominent choice in IoE contexts [92; 96; 97]. DAG-based platforms such as IOTA differ from traditional blockchain architectures by offering micro-transaction capability, zero transaction fees, and low latency, directly addressing the hardware limitations of IoT/IoE devices. However, in terms of access control, governance models, and enterprise-grade privacy requirements, current implementations of DAG systems are still limited. Additionally, the maturity level of decentralized security mechanisms in these systems lags behind permissioned platforms [94; 95; 98].