Abstract: The invention relates to a power supply device for wireless communication with a communication device, in particular a wireless contact based or contactless communication device, of a user and for supplying power to an authenticated device based on a result of the wireless communication, wherein the authenticated device is a user's device or an on-demand service device authenticated by the power supply device. According to the invention, the power supply device comprises a securing element configured for mutual secure authentication with an external communication device, and in that the user is granted permission to use the authenticated device with the power supplied by the power supply device based on a successful mutual secure authentication between the securing element and the user's communication device. The invention further relates to a corresponding method for granting a user access to power supply from a power supply device.

Abstract: The present invention provides for a method of indexing video data (18) by the creation of a plurality of scaled-down reference pictures (24) and including the steps of creating an index file (26) comprising a plurality of compression-encoded reference frames (28), and adding the plurality of reference pictures (24) created during the recording of the video data to a respective plurality of the said compression—encoded reference frames (28), the compression-encoded reference frames (28) being capable containing a plurality of reference pictures (24) each created from a plurality of different video recordings.