What is one common method used in two-factor authentication?

A security token device is a widely recognized method used in two-factor authentication. Two-factor authentication (2FA) enhances security by requiring two forms of verification before access is granted. The first factor typically involves something the user knows, such as a password. The second factor usually involves something the user has, which is where the security token comes into play.

A security token device generates a unique code at fixed intervals that users must input alongside their password. This means that even if a potential attacker obtains the user's password, they would still need access to the token to gain entry, significantly reducing the likelihood of unauthorized access.

In contrast, relying only on a username or a simple password lacks the additional layer of security that a second factor provides, making it vulnerable to common attacks like phishing or password cracking. An internet connection, while necessary for many online services, does not contribute to the authentication process itself and doesn't provide an added layer of security. Thus, the use of a security token device is a practical and effective approach within two-factor authentication.