Which of the following types of locks are primarily used within the Department of Defense?

The primary reason combination locks and key-operated locks are widely utilized within the Department of Defense (DoD) is their reliability and effectiveness in securing sensitive areas. Combination locks provide a straightforward security measure that does not require physical keys, reducing the chance of unauthorized access. Key-operated locks, on the other hand, offer traditional security with the ability to restrict access based on key distribution, making them controllable and manageable within military environments.

These types of locks also align with standard security protocols and policies within the DoD, which often emphasize the need for robust access controls to protect classified information and secure facilities. The adherence to traditional locking mechanisms like these reflects the DoD's practices in ensuring that only authorized personnel have access to sensitive locations.

In contrast, while deadbolts and sliding bolts provide additional security, they may not be as commonly used in contexts where quick access or specific clearance protocols are necessary. Cylindrical locks and biometric locks can offer modern security features, but their implementation might vary and depend on specific facility requirements or upgrades. Smart locks and keyless entry systems, despite being advanced and convenient, may not meet the stringent security standards or operational needs of the DoD in some cases, as they may introduce potential cybersecurity vulnerabilities.