## 3 Proposed Approach
### Physical Layer Attacks and Countermeasures  
The physical layer encompasses critical physical infrastructure such as power grids, power plants, and substations, with the hardware in this layer being a primary target for malware attacks. Attacks on the physical layer target equipment essential to system operations, posing direct operational threats. For instance, Industroyer's infiltration of SCADA systems through unsecured physical ports resulted in widespread power outages, demonstrating the risks to physical security protocols.  
Comprehensive countermeasures are critical, involving strict access control, regular audits, and employee awareness programs. For example, deploying USB port blockers, continuous CCTV monitoring, and biometric access protocols for key infrastructure components, paired with periodic audits, ensure security protocols' consistent efficacy [39; 40].  
As shown in Figure 2, external hackers and insider threats are key risks to the physical layer (Layer 1) of energy infrastructure. The diagram illustrates potential threats such as external attackers targeting power grid hardware and insiders compromising the system through unauthorized physical access.  
Figure 1: Responsibilities of each layered security structure.  
An often overlooked but critical aspect of physical layer security is the human element--particularly insider threats or 'cyber personas'. These include authorized personnel who may unintentionally or deliberately compromise security, often manipulated by external attackers using social engineering tactics. Attackers may deceive or coerce insiders to bypass physical security protocols, allowing them to install malware or grant unauthorized access to critical infrastructure. Such human elements can amplify a system's vulnerabilities, making them a significant risk factor.  
To address these risks, organizations must defend against both external and internal threats by implementing comprehensive physical security measures and detection systems that monitor abnormal insider behaviors. Security frameworks should also include regular audits to assess vulnerabilities to social engineering attacks and insider threats. To address physical vulnerabilities effectively, the following measures should be implemented.  
* CCTV and alarm systems: Continuous monitoring through CCTV and alarm systems is vital for real-time surveillance of critical infrastructure. These systems can quickly detect unauthorized access or breaches, allowing for immediate intervention.
* Insider threat detection system: Organizations need to monitor internal risks by deploying insider threat detection systems. These systems help identify unusual activities or unauthorized actions by employees or contractors with access to sensitive areas.
* Security audits: Regular security audits ensure that vulnerabilities in physical infrastructure are identified and mitigated. Alongside audits, ongoing training programs help employees stay aware of physical security protocols.
* Access control protocols: Implementing strict access control using technologies such as biometrics and secure key cards ensures that only authorized personnel can access critical infrastructure. This minimizes the risk of unauthorized access or sabotage.