Which security control prevents unauthorized individuals from following an authorized person through a door?

Which security control prevents unauthorized individuals from following an authorized person through a door?

• A. Man trap
• B. Pick-resistant locks
• C. Electronic key systems
• D. Electronic combination locks

Answer: (A)

Tailgating—the risk of an unauthorized person slipping in behind an authorized user—requires a control that enforces single-person passage. A man trap does this by using two interlocking doors in sequence. When someone authenticates at the entry, the first door must close and lock before the second door will open. This design ensures only one person can be inside the vestibule at a time, giving the system a chance to verify each individual before access is granted to the secure area. It can also integrate with badge readers or biometrics for added assurance. Locks that are pick-resistant help resist forceful entry but don’t stop someone from following closely behind. Electronic key systems manage who is allowed entry but don’t inherently prevent tailgating unless paired with additional anti‑tailgating measures. Electronic combination locks depend on a code, which can be shared or observed, so they don’t by themselves stop someone from piggybacking through. Therefore, the man trap is the most effective control for preventing unauthorized individuals from following an authorized person through a door.

Tailgating—the risk of an unauthorized person slipping in behind an authorized user—requires a control that enforces single-person passage. A man trap does this by using two interlocking doors in sequence. When someone authenticates at the entry, the first door must close and lock before the second door will open. This design ensures only one person can be inside the vestibule at a time, giving the system a chance to verify each individual before access is granted to the secure area. It can also integrate with badge readers or biometrics for added assurance.

Locks that are pick-resistant help resist forceful entry but don’t stop someone from following closely behind. Electronic key systems manage who is allowed entry but don’t inherently prevent tailgating unless paired with additional anti‑tailgating measures. Electronic combination locks depend on a code, which can be shared or observed, so they don’t by themselves stop someone from piggybacking through. Therefore, the man trap is the most effective control for preventing unauthorized individuals from following an authorized person through a door.