What does "two-factor authentication" provide?

• A. Automatic password recovery
• B. Single sign-on capabilities
• C. An additional layer of security
• D. Real-time email verification

Answer: (C)

Two-factor authentication (2FA) provides an additional layer of security by requiring two different forms of verification before granting access to an account. This typically involves something the user knows, like a password, in combination with something the user has, like a smartphone or a security token that generates a code. This dual requirement helps ensure that even if a password is compromised, unauthorized access is still prevented unless the second factor is also provided. The increased difficulty in gaining access without meeting both criteria significantly enhances security for sensitive information and accounts.

In contrast, other options do not represent the primary function of two-factor authentication. Automatic password recovery pertains to recovery methods for lost or forgotten passwords and does not inherently add any security layers. Single sign-on capabilities allow access to multiple services with one set of credentials, simplifying user experience rather than increasing security. Real-time email verification involves confirming a user's email address but does not specifically refer to the dual verification process that 2FA employs.