A method for calibrating user behavior based models, in order to enable user validation across different devices (i.e. known and unknown devices), comprising: receiving device usage data generated by monitoring user-device interactions on one or more user devices; employing a user behavior model based on the device usage data and a plurality of values of technical parameters of the one or more devices; receiving a plurality of values of technical parameters of an additional device; receiving device usage data by monitoring user-device interactions on the additional device; and analyzing the device usage data of the additional device by employing the user behavior model to validate an action held using the additional device.