Two-factor authentication (2FA) is a form of multi-factor authentication (MFA), and is also known as two-step authentication or two-step verification. 2FA is a security measure that requires end-users to verify their identities through two types of identifiers to gain access to an application, system, or network. Think of your most recent login experiences. When you sign in to Netflix, for example, you’re probably asked to simply provide a username and password—a single factor. When you log in to your online banking account, however, you often need to provide a username and password as well as the answer to a security question or an SMS one-time password (OTP). The website asks for two factors in order to verify your identity. 2FA provides an additional layer of protection, securing user identities and preventing organisations’ online resources from being accessed by bad actors. With two-factor authentication, attackers face an.