Patent ID: 8396711

Claim:
A method comprising: storing, by an authentication server, a plurality of prerecorded voice samples for authenticating a user, the prerecorded voice samples comprising predetermined phrases spoken by the user, each predetermined phrase being recorded at a plurality of cadences different from a speaking cadence of the user; associating, by the authentication server, the user with an electronic identifier of a device provided to the user in a restricted operating mode; receiving, by the authentication server, a request for authentication transmitted by the device; receiving, by the authentication server, the electronic identifier of the device; randomly selecting, by the authentication server, one of the prerecorded voice samples as a challenge phrase; prompting, by the authentication server, the user to speak the challenge phrase into a microphone of the device; recording, by the authentication server, a voice response spoken by the user into the microphone; and authenticating, by the authentication server, the user for enabling use of the device in an unrestricted operating mode based on a comparison of the voice response and the prerecorded voice sample that was selected as the challenge phrase.