What is a one-time code in relation to two-factor authentication?

A one-time code in relation to two-factor authentication is a unique code sent to a user for single-use during authentication. This type of code enhances security by ensuring that even if someone intercepts it, they cannot use it again after its initial use.

In two-factor authentication, the one-time code typically pairs with something the user knows (like a password) and is often generated by an authenticator app, sent via SMS, or emailed to the user. This method helps to verify the identity of the user effectively, as it requires possession of a dynamic, time-sensitive credential in addition to the static password.

Having a code that can be used multiple times would diminish the security aspect because it could be reused by unauthorized individuals who might gain access to it. Similarly, a permanent code saved on the user’s device would not provide the additional layer of security intended. Codes generated after every login do not accurately reflect the one-time nature that enhances the security of two-factor authentication as they may lead to redundancy between logins. It is specifically the single-use characteristic of the unique one-time code that makes it a robust element of secure authentication processes.