Abstract: Embodiments of techniques or systems for usage modeling or gesture based authentication are provided herein. Actions of a user may be captured, classified, and utilized to generate an authentication scheme for a device based on gesture recognition, gesture analysis, or action analysis. Training data may be determined based on actions deemed to be training actions and one or more action models may be generated based on the training data. An action model may be indicative of how a user performs a particular or predetermined action. When a security mode is enabled, usage actions may be recorded and usage data may be extracted or determined based on the usage actions. A usage action may be identified and corresponding usage data may be compared with training data from an appropriate action model. An identity of a user associated with the usage action may be determined based on this comparison.