2FA (Two-Factor Authentication)
Two-factor authentication (also known as 2FA) is a method of confirming a user's claimed identity by using a combination of two different factors: 1) something they know, 2) something they have, or 3) something they are. Withdrawing money from a cash maching is a good example, where the user has a bank card (something they have) and a PIN code (something they know). An alternative is using a One-Time Password (OTP) to provide a single-use PIN or password that is generated by a device in the user's possession or sent to the user's mobile phone via SMS, email or push.
See Melrose Labs Identity and Location, Melrose Labs One-Time Password
Melrose Labs: We deliver innovative services in cloud communications across mobile, fixed-line, satellite and internet. Through these services, we enable businesses to communicate better with their staff and customers, and by doing so, increase their success.