Because you trust a cloud provider with your personal and/or corporate information, it is important that they verify your identity each time you log in. The best kind of identity verification tool is some sort of two-factor authentication device. Two-factor authentication is “something you know,” like your username, and “something you have.”
An example of “something you have” is one-time password (OTP) token, a small device or a mobile application that generates a different password you must enter for every login. Some cloud service providers are now offering two-factor authentication. Facebook, for example, introduced OTPs last year.Google, too, started rolling out OTP-based authentication last February. Both of these include mobile OTP applications.