Abstract: An information signal (INF) which is transmitted in coded form (CINF) from a signal source (RC) to a signal receiver (4, 5) is decoded at the receiver and at the same time marked (MINF) by the introduction of an identification information (ID) which is characteristic of the receiver or its possessor. The signal from a video disc (RC) carrying a coded programme is decoded and marked before it is supplied to a television set (6). Via said identification information of so-called pirate copy is directly traceable to its originator. Thereby a protection against such copying is obtained. A device for the playback of a video disc of this type comprises a decoding and modification unit to which the necessary decoding information and identification information may be supplied from a personal data carrier (ID).

Abstract: A data carrier (preferably shaped as a credit card or the like) holds information about the owner, card issuing organization, account number, etc., and comprises an internal processor for processing supplied identification information of the owner during a card verification process, and for generating an acceptance signal as a result of a positive verification. The internal processor includes a verification device which comprises a sensor (2) for sensing a fingertip of the owner and obtaining corresponding finger print line information. The sensor has sensing elements, each having a sensing surface (9') for contacting the fingertip and a registration device (23,24) which is controllable by the sensing surface.

Abstract: An information signal (INF) which is transmitted in coded form (CINF) from a signal source (RC) to a signal receiver (4,5) is decoded at the receiver and at the same time marked (MINF) by the introduction of an identification information (ID) which is characteristic of the receiver or its possessor. The signal from a video disc (RC) carrying a coded programme is decoded and marked before it is supplied to a television set (6). Via said identification information a so-called pirate copy is directly traceable to its originator. Thereby a protection against such copying is obtained. A device for the playback of a video disc of this type comprises a decoding and modification unit to which the necessary decoding information and identification information may be supplied from a personal data carrier (ID).