Image scanning and encoding technologies can be utilized to authenticate devices to virtual desktops and to transfer virtual desktop sessions between devices. One device (e.g., PC or laptop) may encode certain information into an image that is displayed on a display screen, while another mobile device equipped with a digital camera (e.g., mobile phone or tablet) can be used to scan the image on the display screen. Once the image is scanned, it can be decoded by the mobile device to get the information encoded in the image (e.g., device ID, session ID, etc.). The information obtained from the image can be used to authenticate a device or to transfer a virtual desktop session between the devices.