How does two-factor authentication improve security?

Two-factor authentication (2FA) enhances security by requiring two distinct forms of verification before granting access to an account or system. This process generally involves something the user knows (like a password) and something the user possesses (such as a smartphone or hardware token that generates a time-sensitive code). By necessitating both factors, 2FA significantly reduces the likelihood of unauthorized access, even if one factor, such as the password, is compromised.

The additional layer of security means that an attacker would need more than just the password to gain access to the account, making it much harder for them to breach security measures. This dual requirement is a critical component in safeguarding sensitive information and systems against unauthorized access and potential breaches.

In contrast, the other options do not contribute to enhancing security in the same way. Providing a single password for access offers minimal protection, as it can be easily stolen or guessed. Encrypting data alone does not prevent unauthorized access without a robust authentication mechanism in place. Allowing access from multiple devices simultaneously without stringent verification can also lead to security vulnerabilities, as it may facilitate unauthorized access points.