(ISC)2 Certified in Cybersecurity Practice Exam

What is the barrier that allows only one person at a time to enter a restricted area?

1. Gate

2. Turnstile

3. Barrier

4. Portal

The correct answer is: Turnstile

A turnstile is specifically designed to allow only one individual to enter at a time, which makes it an effective physical security measure for controlling access to restricted areas. It typically consists of rotating horizontal arms that allow entry after proper validation, such as swiping a badge or entering a code. This mechanism ensures that patrons cannot push through in groups, thereby maintaining a controlled flow of individuals entering a secure location. Other options, while related to controlling access, do not provide the same level of restriction. A gate can be opened to allow multiple people through simultaneously, depending on its design. A barrier may refer to any obstruction that stops or limits access but does not specify the one-at-a-time entry feature. A portal generally refers to an entry point or doorway and does not inherently control the number of individuals passing through at once. Thus, turnstiles are uniquely suited for scenarios where single-access control is required.