What is two-factor authentication?

Two-factor authentication is a critical security measure that enhances the protection of systems and data by requiring two distinct forms of identification from a user before granting access to a resource. Typically, this process combines something the user knows (like a password) with something the user has (such as a mobile device to receive a one-time code) or something the user is (like a fingerprint). This layered approach significantly reduces the risk of unauthorized access, as it is not enough for an attacker to possess just one form of identification to gain entry.

The other options do not accurately describe the concept of two-factor authentication. The second choice refers to a training method involving instructors, which is unrelated to authentication. The third choice suggests a type of malware requiring dual protection, which does not fit within the realm of authentication processes. Lastly, the fourth option discusses creating two versions of sensitive data, which again, bears no relevance to the authentication process. Thus, the first choice accurately captures the essence and purpose of two-factor authentication, making it the correct selection.