Layered Security Strategies for Protecting Critical Infrastructure

Critical infrastructure lies at the very foundation of modern civilization, providing power, water, fuel, connectivity and other vital resources to support every aspect of daily life. Even the slightest disruptions to these services can have far-reaching consequences for families, businesses, schools, the government and all other aspects of society. 

As critical infrastructure facilities serve essential functions, they are governed by a host of regulatory compliance laws. These include the requirement to have a “defensible” physical security strategy in place, with only authorized individuals permitted on-site. Regulated sites must implement access control, have supervision to ensure access is controlled and maintain access records to verify compliance. 

A defensible strategy is not only about perimeter access control. The best approach to protecting a facility is through a layered security model. This model starts at the outermost perimeter and becomes increasingly secure as one moves towards the most sensitive areas. The concept is to implement security measures of escalating strength, culminating in the most robust security at the facility’s core.

Importance of regulatory compliance

Security entrances play a vital role in this layered approach. These solutions can be categorized into three levels of security based on their ability to mitigate tailgating: deterrence, detection and prevention. Selecting the right security entrance for each area of the facility is critical.

Deterrence — The first layer of security is deterrence. This is typically applied to the outermost perimeter of the facility, such as a fence line or parking area. Full-height turnstiles are a common choice here. These robust barriers physically prevent unauthorized individuals from entering while allowing access to those with valid credentials. While they are highly effective, it is essential to note that two individuals may attempt to pass through the same turnstile compartment, making this a deterrent rather than a complete solution. 

Full-height turnstiles not only secure the perimeter but also provide a discreet pedestrian entry option, reducing the risk of unauthorized vehicles entering. Their durable construction ensures they can withstand harsh outdoor conditions, making them ideal for critical infrastructure facilities such as power plants, ports, or chemical facilities.

Detection — The second layer of security is detection, typically positioned in facility lobbies or reception areas. At this level, the goal is to detect unauthorized access attempts and respond accordingly. Optical turnstiles are a common security measure, combining sleek design with advanced sensor technology. They not only provide a visual barrier but also detect and alert security personnel to tailgating attempts. 

Reception or guard staff can monitor these entrances, verifying visitor credentials and ensuring compliance. This setup provides an additional layer of accountability, as all entries and exits are monitored and logged. This level of security is crucial for large critical infrastructure facilities where visitor management is necessary.

Prevention — The final and most secure layer is prevention, suitable for the most sensitive areas of a facility. Security mantrap portals or high-security revolving doors are ideal for this level. These systems ensure that only one person can enter at a time, and they often require dual authentication methods, such as a biometric scan (fingerprint, iris, or facial recognition) and a security credential. 

Mantrap portals are highly effective because they are self-contained. Users must pass through two interlocking doors, with the second door only unlocking once the first is securely closed. These portals can be configured to require additional identity verification, providing the highest level of access control. Security revolving doors offer a similar high-security solution, particularly for employee-only areas, where they can operate without continuous supervision.