Abstract: System and method for performing multi-factor authentication of a mobile computing device. Information identifying a mobile computing device may be received over a network, where the mobile computing device has requested access to a resource, and where the mobile computing device has a registered user. The mobile computing device may be identified based on the information identifying the mobile computing device. Information regarding a current physical interaction style with respect to the mobile computing device may be received over the network. A confidence level may be determined based on the current physical interaction style, where the confidence level indicates a degree of confidence that mobile computing device is currently being operated by the registered user of the mobile computing device. The mobile computing device may be granted access to the resource in response to the confidence level meeting or exceeding a specified threshold value.