Abstract: A method for authorizing an action via authentication of a user for a device comprising sensors and emitters, a processor, and a memory. The method comprises: requesting the processor perform an action, verifying the level of authentication required by the user for performing the action, adjusting the user's level of authentication when the level of authentication is insufficient, authorizing the action, wherein adjusting the user's level of authentication comprises: emitting at least one random or non-random sequence of stimuli to the user, capturing behavioral biometric data on the user's reactions to the emitted stimuli, by recording the actuated sensor(s) and the type of action performed on the sensor provided by the received signal, validating the user's response by comparing the reaction performed by the user on the basis of the response to the stimuli previously recorded in the memory, with an expected response allowing validation of user authentication.