## 3 Analysis of TEE Usage in Edge Intelligence and IoT
### Analysis of SGX in Edge Intelligence and IoT  
SGX is widely used in IoT scenarios based on its security guarantees and remote attestation features. Table 1 summarizes some applications of SGX in IoT. The application scenarios can be broadly categorized into four types, with the first focusing on the use of SGX for IoT architecture. The work in [41] describes the entire process from data acquisition at the edge devices, to encrypted transmission, and finally, decryption and processing at the gateway, with SGX responsible for key management tasks. Based on device virtual cloning, SGX-Cloud [42] was constructed to allow users to choose which data to place into the cloud. The methods outlined in [43] utilized SGX's privacy-preserving mechanisms to achieve secure multi-party data sharing. Second, the remote attestation mechanism of SGX can be better utilized to achieve a security-enhanced identity authentication [44]. Third, blockchain is a key component in IoT scenarios, and its integration with SGX can achieve better privacy protection. The work in [45] sets up oracle nodes running in an SGX environment, enabling blockchain to securely obtain external data. [PERSON] et al. [46] leveraged SGX in industrial IoT to track data flow and prevent data abuse. According to the study in [4], SGX edge servers were set up to implement attribute-based fine-grained access control. Furthermore, SGX can also be applied in fields such as federated learning [47], smart grids [48] and health data protection [49]. However, SGX usage in edge intelligence still has limitations. In edge intelligence scenarios, where device resources are limited and data mobility are complex, SGX, though capable of providing hardware-level data security, still faces significant challenges. Security and performance analyses are crucial in understanding the effectiveness and practicality \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Category** & **Reference** & **IoT Application** & **SGX Use Case** \\ \hline \multirow{4}{*}{Architecture} & [PERSON] et al., 2019 [41] & An end-to-end, SGX-based, IoT data & Key management, \\  & & protection framework & Remote attestation \\ \cline{2-4}  & [PERSON] et al., 2022 [42] & Building SGX-Cloud based on device & Data encryption, \\  & & virtual cloning & Data integrity \\ \cline{2-4}  & [PERSON] et al., 2021 [43] & Secure multi-party data interaction & Privacy-preserving, \\  & & architecture & Identity authentication \\ \hline \multirow{2}{*}{Attestation} & [PERSON] et al., 2018 [44] & Policy-based security-enhanced & \\  & & authentication mechanism between remote & Remote attestation \\  & & terminal and IoT devices & \\ \hline \multirow{4}{*}{Blockchain-based} & [PERSON] et al., 2020 [45] & Methods for securely obtaining external & \\  & & data on the blockchain & Trusted intermediary \\ \cline{2-4}  & [PERSON] et al., 2022 [46] & Establishing a secure data trading & Identity authentication, \\  & & environment to prevent data abuse & Behavior monitoring \\ \cline{2-4}  & [PERSON] et al., 2022 [4] & Attribute-based fine-grained access control & Edge intelligence, \\ \hline \multirow{4}{*}{Other Scenarios} & \multirow{4}{*}{[PERSON] et al., 2023 [47]} & Comprehensive federated learning & \\  & & framework from data collection to local & \\ \cline{1-1}  & & model generation and secure & Secure model aggregation \\ \cline{1-1}  & & model aggregation & \\ \cline{1-1} \cline{2-4}  & [PERSON] et al., 2020 [48] & Efficient privacy-preserving architecture in & \\ \cline{1-1}  & & smart grids & Confidential database \\ \cline{1-1} \cline{2-4}  & [PERSON] et al., 2021 [49] & Protection of sensitive medical data to & \\ \cline{1-1}  & & build a secure Internet of Medical Things & Device registration \\ \hline \hline \end{tabular}
\end{table} 
Table 1: SGX application in IoT scenarios. of SGX in these scenarios. On the one hand, data security is a significant concern in edge devices, as data exchanged with peripherals or the cloud are vulnerable to leakage.