Multi-factor authentication (MFA) is a method of authentication that requires the use of more than one verification method and adds a second layer of security to user sign-ins and transactions. It works by requiring any two or more of the following verification methods:
- A randomly generated pass code
- A phone call
- A smart card (virtual or physical)
- A biometric device
Multi-factor authentication in Office 365
Office 365 uses multi-factor authentication to help provide the extra security and is managed from the Microsoft 365 admin center. Office 365 offers the following subset of Azure multi-factor authentication capabilities as a part of the subscription:
- The ability to enable and enforce multi-factor authentication for end users
- The use of a mobile app (online and one-time password [OTP]) as a second authentication factor
- The use of a phone call as a second authentication factor
- The use of a Short Message Service (SMS) message as a second authentication factor
- Application passwords for non browser clients (for example, the Microsoft Lync 2013 communications software)
- Default Microsoft greetings during authentication phone calls
