Systems and methods as provided herein may create a biometric model associated with a user. The created biometric model may be used to generate challenges that are presented to the user for authentication purposes. A user response to the challenge may be compared to an expected response, and if the user response matches within a predetermined error of the expected response, the user may be authenticated. The systems and methods may further generate challenges that are adaptively designed to address weaknesses or errors in the created model such that the model is more closely associated with a user and the user is more likely to be the only person capable of successfully responding to the generated challenges.