By double 
When it comes to securing a facility, the external perimeter is the first line of defense. It’s where unauthorized individuals attempt to gain entry, and it’s where access control systems like gates, barriers, and fences come into play.
However, these systems, especially those with wireless components, can be vulnerable to attack. This is particularly true for wirelessly controlled parking barriers and gates, which rely on wireless signals for access control.
In this blog, we’ll explore the critical checks performed during a site survey focused on external access points, with a special emphasis on identifying vulnerabilities such as signal sniffing and replay attacks.
What Is a Site Survey for External Perimeter Security?
A site survey for external perimeter security is a detailed evaluation of all access points that allow entry to a facility’s outer boundaries. The goal of this survey is to assess the effectiveness of the security measures protecting the premises from unauthorized access, theft, or other threats. During the survey, security professionals examine gates, parking barriers, fences, and surveillance systems to identify vulnerabilities and suggest improvements.
The external perimeter serves as the first layer of defense, and any weaknesses here can provide an opening for intruders to access more secure areas inside the facility.
Key Areas of Focus in a Site Survey of the External Perimeter
1. Evaluating Access Control Systems at Gates and Barriers
Access points such as gates, fences, and parking barriers are often controlled wirelessly, using technologies like RFID, Bluetooth, or Wi-Fi. During a site survey, the security team evaluates these systems to ensure they are properly secured and resistant to tampering.
Key aspects checked during this phase include:
- Control Method and Technology: Check what technology is used to control the entry points. Is the system using RFID cards, key fobs, or smartphone apps? Is it Bluetooth or Wi-Fi enabled? Each of these technologies comes with different security risks.
- Signal Strength and Range: The range and strength of the wireless signals are checked to determine how far the signals can be intercepted. A weak or overly strong signal may provide an opportunity for attackers to intercept and replay the communication.
- Barriers and Gates Functionality: Evaluate the operational efficiency of barriers and gates. Are they functioning smoothly? If they malfunction or have vulnerabilities, they can create an easy entry point for unauthorized access.
2. Sniffing and Replay Attacks on Wireless Communication
One of the key concerns during a site survey is the security of wireless communications used to control gates and barriers. Wireless systems rely on signals to transmit information between devices (e.g., access cards or smartphones) and the locking mechanism on gates or barriers. This makes them susceptible to sniffing and replay attacks.
- Sniffing: In a sniffing attack, an attacker uses a device to intercept and listen in on the communication between the access control system and the credentialing device (e.g., RFID card, fob, or smartphone). If the signal is unencrypted or weakly encrypted, the attacker could capture the data and use it to gain unauthorized access.
- Replay Attacks: In a replay attack, the attacker captures a valid access signal (for example, a signal sent from an authorized RFID card or key fob) and replays it to the system at a later time to gain access. This could allow the attacker to bypass the security system without needing to crack the encryption or gain physical possession of the credential.
During the site survey, security experts look for the following:
- Signal Interception: Evaluating if the access control system sends unencrypted or weakly encrypted signals that can be easily intercepted.
- Lack of Rolling Codes: Systems that use static codes are more susceptible to replay attacks. The survey checks if the access system uses dynamic or rolling codes, which change with every access attempt, making it harder for attackers to replay the same signal.
- Encryption: Check if the communication between access control systems and wireless devices (such as RFID tags or mobile apps) is encrypted using strong algorithms, such as AES (Advanced Encryption Standard). Lack of encryption or the use of weak encryption can make the system vulnerable to sniffing and replay attacks.
- Distance and Signal Reach: Wireless systems may have signals that reach too far beyond the intended entry point. This could allow attackers to intercept signals at a distance. The site survey checks the radius of operation for wireless systems and evaluates whether the signal is contained within secure boundaries.
3. Reviewing the Physical Security of Gates and Barriers
While wireless systems are critical, the physical security of gates and barriers themselves also needs attention. No matter how secure the digital systems are, an unlocked or malfunctioning physical gate can be an open invitation for an intruder.
Key considerations during the site survey include:
- Gate Construction and Reinforcement: Evaluate whether the gates and barriers are physically robust. Are they constructed from high-quality, tamper-resistant materials? Are they reinforced to prevent bypass or forced entry?
- Emergency Access: Are gates designed to be accessible during an emergency? If not properly secured, an emergency exit can become a vulnerability. The survey checks whether emergency access procedures are implemented while still maintaining security.
- Automatic Barriers and Fail-Safes: Assess the functionality of automatic barriers (used in parking lots and gated communities). Do they have fail-safe mechanisms in place in case of malfunction? Do they allow unauthorized vehicles to bypass in case of an emergency or technical failure?
4. Surveillance and Monitoring Systems
A well-designed surveillance system is key to monitoring activity around external access points, especially gates and barriers. Cameras can capture suspicious behavior, such as someone trying to tamper with a barrier or attempting to gain unauthorized access.
During the site survey, the security team checks:
- Camera Placement and Coverage: Are there enough cameras to monitor gates and barriers from multiple angles? Are blind spots or areas of poor visibility identified and addressed?
- Real-time Monitoring: Is there real-time monitoring of access points? Are surveillance feeds logged and accessible for future review?
Mitigating Risks: Best Practices for Wireless Controlled Barriers
To reduce the risks associated with wirelessly controlled barriers and gates, it’s important to follow best practices for security:
- Encryption: Ensure that wireless communications are encrypted using strong encryption algorithms, such as AES.
- Rolling Codes: Use rolling code technology to prevent replay attacks, where the access code changes with every use, making it harder for attackers to replay intercepted signals.
- Limit Signal Range: Limit the range of wireless communication to the minimum required for functionality, preventing interception from unauthorized locations.
- Physical Barriers: In addition to electronic systems, reinforce physical barriers, and ensure gates and barriers are difficult to bypass physically.
- Regular Testing and Audits: Regularly test and audit wireless access control systems for vulnerabilities, including testing for signal interception and replay attack susceptibility.
Strengthening the External Perimeter Against Attacks
Securing the external perimeter is critical to preventing unauthorized access and protecting your facility from physical and digital threats. During a site survey, careful attention must be paid to wireless-controlled gates and parking barriers, as they are prime targets for sniffing and replay attacks.
By evaluating the physical and digital security measures in place, you can identify vulnerabilities and take steps to enhance the security of your external perimeter. Implementing the best practices outlined above can significantly reduce the risk of unauthorized access and ensure your facility remains secure.
This blog provides a detailed look into the security checks for external perimeter access points, particularly focusing on the vulnerabilities and risks associated with wireless-controlled barriers and gates.