## 2 Edge Computing
### Security and Privacy Challenges
#### 2.1.2 Data Security Measures
* Access control and authentication: Edge devices frequently join and leave IoT networks dynamically, necessitating a connectivity framework that ensures security by authenticating the various devices within the network. Additionally, an access control mechanism should govern and monitor authorization to regulate access to network resources [49]. * Trusted execution environments (TEEs): TEEs provide a hardware-based secure sandbox to shield sensitive programs. A TEE establishes a secure and isolated region within edge devices through the application of both hardware and software techniques [50; 51]. It typically includes key components such as secure bootstrapping, which ensures the system initializes in a trusted state; isolated execution, which safeguards data and computations; and secure input/output mechanisms, such as sealed storage for protecting data at rest. TEEs also support remote attestation, enabling a remote party to verify the integrity and trustworthiness of a communication peer within the TEE [52]. * Blockchains for decentralized security: Blockchain is a shared, decentralized, and distributed state machine in which a chain of blocks is linked through address pointers based on hash values [53]. A peer-to-peer model facilitates the storage and management of ledger data across multiple computers within the network. Integrating blockchain enables the distribution of computing and storage resources within the EC environment while also reducing the blockchain's storage and computational load on performance-sensitive devices [54]. * Secure software and firmware updates: The use of software or firmware updates can help reduce potential threats posed by the malicious actions of cybercriminals [55]. IoT devices rely on Over-the-Air (OTA) updates throughout their lifecycle to address bugs and apply patches to their firmware. However, a device's security can be compromised if the server-side firmware database is breached [56]. * Data minimization: This technique reduces the collection, processing, and storage of redundant data, thereby mitigating the risks of data breaches, unauthorized access, and misuse. This can be achieved through deduplication, which eliminates redundancy by retaining only a single copy of the data [57]. * Policy-based governance: Cultural beliefs, legal frameworks, and ethical practices collectively shape the concept of privacy. The General Data Protection Regulation (GDPR) in Europe and the California Consumer Privacy Act (CCPA) aim to protect privacy rights through effective data management [58]. * Edge-aware intrusion detection systems (IDSs): An IDS is a software- or hardware-based solution designed to detect malicious activities on data networks. IDSs can be categorized into two classes based on their detection approach: signature-based and anomaly-based techniques. A signature-based system compares monitored events against a database of known intrusion techniques, while an anomaly-based system learns the system's normal behavior and flags any deviations [59]. * Secure multi-party computation (SMPC): It is a cryptographic method that enables collaborative computations among multiple participants [60]. The protocol ensures that no participant gains access to information beyond the final computational results, provided that at least some participants follow the protocol. It restricts access to inputs, intermediate computations, and metadata such as value frequency distributions [61]. Consequently, SMPC eliminates the need for a trusted third party, as all computations are carried out exclusively by the participants [62]. * Privacy-preserving AI models: AI-based applications enable real-time anomaly detection, allowing systems to identify and mitigate potential threats. Machine learning (ML) algorithms analyze network data patterns to predict vulnerabilities and implement countermeasures [63]. Edge AI deploys ML algorithms on end devices, enabling data processing at the network edge [64].