Certified Ethical Hacker (CEH v11) — Question 152

Todd has been asked by the security officer to purchase a counter-based authentication system. Which of the following best describes this type of system?

Answer options

• A. A biometric system that bases authentication decisions on behavioral attributes.
• B. A biometric system that bases authentication decisions on physical attributes.
• C. An authentication system that creates one-time passwords that are encrypted with secret keys.
• D. An authentication system that uses passphrases that are converted into virtual passwords.

Correct answer: C

Explanation

The correct answer is C because a counter-based authentication system generates one-time passwords that are secured with secret keys, ensuring that each password is unique and time-sensitive. Options A and B refer to biometric systems that rely on physical or behavioral attributes, which are not relevant to counter-based authentication. Option D describes a different type of authentication that uses passphrases, which does not fit the definition of counter-based systems.