## 3 Security and Privacy Challenges  
The first level of data processing is at the edge of EC, making them vulnerable to security attacks and data theft associated with end users. Security measures adopted in IoTs include advanced security algorithms like attribute-based access control, authentication based on group signatures, homomorphic encryption, and techniques based on public-key cryptography. Such algorithms demand sizable computational capabilities and memory availability on the devices where they are deployed [107]. The cloud can host almost unlimited resources like memory, computing capabilities, power, etc., but lacks real-time user experience due to its physical distance from IoT end devices. Some research efforts have been made in developing and deploying edge-based security architecture designs like firewalls, Packet filters, intrusion detection systems, side-channel signal analysis, authentication and authorization protocols, privacy-preserving mechanisms, real-time traffic monitoring systems (RTMSs), and cryptographic schemes. Adversaries use various hardware- and software-based techniques to falsify, change, steal, or remove data within edge networks and infect and manipulate edge nodes, devices, or servers found at the edge [112]. Numerous security threats that can compromise user privacy and data integrity or disrupt critical services exist in the edge device layer, communication layer, and edge computing layer in the EC paradigm of IoT network [7, 16, 113, 114]. The commonly identified edge/communication network attacks are eavesdropping, replay attacks, denial-of-service, and jamming [9, 115]. The vulnerabilities associated with various edge peripherals within the computing layer are mostly DoS and DDoS attacks [116], whereas ref. [18] has placed DDoS attacks, side-channel attacks, malware injection attacks, and authentication and authorization attacks under the EC infrastructure layer. However, the research outcomes for edge-based IoT security remain in the early stages of development [107, 117]. Initially, EC was assumed to be resilient against cyberattacks since user data no longer needed to travel to cloud servers. Nonetheless, the edge network layer's dynamic nature makes it susceptible to data security threats, as unified security protocols cannot be uniformly applied [118]. Numerous factors contribute to data security and privacy concerns in EC. The vicinity of end users to edge nodes increases the risk of data interception by adversaries. Additionally, the constrained memory and processing capabilities of edge devices, when compared to cloud computing, impede the application of complex encryption techniques and thus aggravate security challenges [119]. It is essential for all stakeholders within an EC ecosystem, like service providers, system and application developers, and end users, to appreciate data security's ethical, legal, and financial implications. Another pressing concern is determining the ownership of sensitive data collected at edge nodes [120]. [PERSON] et al. proposed a layered security framework shown in Figure 5 implemented on cloud EC architecture [121]. Authentication features are implemented at every layer to ensure that only verified end devices can access cloud and edge services. Additionally, location-specific EC is applied at the edge and end-device levels to safeguard user privacy. Moreover, firewalls and intrusion detection systems deployed in both cloud and edge infrastructures help identify and thwart network intrusions. Common security components can exist across multiple layers due to network layer and device requirements, and their purpose and functionality might differ [121]. Robust cryptographic techniques are needed in the cloud edge collaborative architecture, as a huge amount of data flows through unsecured or least secure public channels with a higher probability of privacy leakage and unauthorized data access [122]. Implementing a uniform security strategy across all edge nodes is extremely difficult due to their management by various users.