With Duo's Two Factor Authentication, you get the simplest, most effective way to make sure users are really who they say they are. Duo Mobile secures every application while verifying the identities of your users to ensure Trusted Users. Duo’s contextual user access policies let you gain greater control over who can access your applications. Duo’s 2FA solution only requires your users to carry one device - their smartphone, with the Duo Mobile app installed on it. Logging in via push notification is fast and easy with Duo Mobile.