A mobile apparatus configured to obtain secure printing and scanning services from one or more output devices, the mobile apparatus including a processor and a storage device storing one or more programs of instructions executable by the processor of the mobile apparatus to configure the mobile apparatus to comprise: a wireless communication module to communicate through a wireless network interface and a network, with a server for said printing and scanning services, to register the mobile apparatus and authenticate a user of the mobile apparatus; a short-range communication module configured to communicate by short-range point-to-point communication with an output device amongst the one or more output devices when the output device is within a short-range communication range of the mobile apparatus; a false-positive detection module that monitors a signal strength of the output device in the short-range point-to-point communication by the short-range communication module with the output device, determines based on said signal strength whether the output device is within a short-range operation range of the mobile apparatus, and determines, when the output device is within the short-range operation range of the mobile apparatus, whether the mobile apparatus is substantially stationary, wherein when the false-positive detection module determines that the output device is within the short-range operation range of the mobile apparatus and that the mobile apparatus is substantially stationary, the mobile apparatus communicates with the server to obtain activation of a user interface to operate the output device, characterized in that when the false-positive detection module determines that the output device is within the short-range operation range of the mobile apparatus and that the mobile apparatus is not stationary, the mobile apparatus does not request the server for access to the output device. a wireless communication module to communicate through a wireless network interface and a network, with a server for said printing and scanning services, to register the mobile apparatus and authenticate a user of the mobile apparatus; a short-range communication module configured to communicate by short-range point-to-point communication with an output device amongst the one or more output devices when the output device is within a short-range communication range of the mobile apparatus; a false-positive detection module that monitors a signal strength of the output device in the short-range point-to-point communication by the short-range communication module with the output device, determines based on said signal strength whether the output device is within a short-range operation range of the mobile apparatus, and determines, when the output device is within the short-range operation range of the mobile apparatus, whether the mobile apparatus is substantially stationary, wherein when the false-positive detection module determines that the output device is within the short-range operation range of the mobile apparatus and that the mobile apparatus is substantially stationary, the mobile apparatus communicates with the server to obtain activation of a user interface to operate the output device, characterized in that when the false-positive detection module determines that the output device is within the short-range operation range of the mobile apparatus and that the mobile apparatus is not stationary, the mobile apparatus does not request the server for access to the output device.