Two-Factor Authentication

Two-factor authentication, often abbreviated 2FA, is a security method that requires a person to prove their identity with two different kinds of evidence before gaining access to an account or system, typically something the person knows, such as a password, combined with something the person physically holds, such as a hardware token or a code sent to their phone. The American company Security Dynamics Technologies, later renamed RSA Security, introduced one of the first widely deployed computer implementations in 1986 with its SecurID token, a small device that generated a new numeric code every sixty seconds which a user had to enter alongside their password. Two-factor authentication remained mostly a corporate and government security tool for two decades before becoming a mainstream consumer feature during the 2010s, as banks, email providers and social media platforms adopted it, usually sending a one-time code by text message or a dedicated authenticator app, to counter the rising toll of stolen passwords.