Kertakäyttötunniste

A kertakäyttötunniste, often translated as a one-time password (OTP) or single-use token, is a security code that is valid for a single login session or transaction. It is a crucial component in multi-factor authentication (MFA) systems, adding an extra layer of security beyond just a username and password. The primary purpose of a kertakäyttötunniste is to prevent unauthorized access even if an attacker obtains the user's primary credentials.

These codes are generated dynamically and are typically time-based or event-based. Time-based one-time passwords (TOTP) change at regular intervals, usually every 30 or 60 seconds, relying on synchronized clocks between the authentication server and the user's device. Event-based one-time passwords (HOTP) are generated sequentially and increment with each use. Kertakäyttötunniste can be delivered through various methods, including SMS messages to a registered mobile phone, authentication apps like Google Authenticator or Authy, or through hardware tokens. The short lifespan and unique nature of each code make them significantly more secure than static passwords, as they cannot be reused by an attacker who might have intercepted them.