Abstract: The invention relates to a method of copy-protection of information stored on an information carrying medium. The method allows a reading device (e.g. a DVD drive) and an application device (e.g. an MPEG decoder) to exchange copy-protection information regarding the information carrying medium (e.g. an optical record carrier like a CD or DVD) and the content on that medium. The method is cryptographically secure, taking into account the situation where reading device and application device are connected to an open bus in a personal computer. In view of the high-volume nature of the drive, the method can be implemented cheaply. The inventive method is robust against a so-called man-in-the-middle attack. The invention relates also to a method of exchanging copy-protection information, to a copy-protection system and to devices for carrying out these methods, in particular a reading device, an application device and a device for playback and/or recording of information.

Abstract: Transmitters (116) for transmitting information and receivers (126) for receiving the information are defined by the information comprising a primary message and a secondary message combined in a same transmission or a same reception, which primary and secondary messages comprise communication protocol signaling messages, to avoid that a protocol conversion arrangement needs to be added to and to be placed between the transmitter (116) and the receiver (126). This increases the efficiency of the transmitter (116) and the receiver (126). The primary and secondary communication protocol messages are in accordance with first and second standards such as 802.11 a and later standards such as 802.11 n. The receiver (126) is able to detect the primary or secondary communication protocol message in case of the receiver (126) being in accordance with the first or second standard.

Abstract: The invention is directed to the reception of high rate radio signals (for example DVB-T signals) while the receiver is moving at a high speed (for example in or with a car). Two or more antennas (12, 16) are closely spaced and arranged behind each other in the direction of motion (v) for receiving the radio signals. A signal is obtained which represents a virtual antenna (26) that is at least temporarily stationary with respect to the environment, despite the movement of the receiver. The receiving signal of the virtual antenna (26) suffers at least less distortions than a signal received by one of the first and second antennas (12, 16). In accordance with the invention the signal which represents the virtual antenna (26) is obtained under the control of a feedback signal (SYNC) of the receiver.

Abstract: The invention is directed to the reception of high rate radio signals (for example DVB-T signals) while the receiver is moving at a high speed (for example in or with a car). Two or more antennas (12, 16) are closely spaced and arranged behind each other in the direction of motion (v) for receiving the radio signals. A difference (S2(t)?S1(t)) of a signal (S1(t)) obtained via the first antenna (12) and a signal (S2(t)) obtained via the second antenna (16) serves as an estimation of the spatial derivative of the receiving channel transfer function. This spatial derivative is interpreted as a temporal derivative and exploited to cancel or at least reduce distortions (for example ICI) due to rapid receiving channel variations.

Abstract: An MPEG-encoded video signal includes groups of pictures (GOPs), each GOP having an intraframe coded (I) picture and a series of predictively encoded (P) pictures and bi-directionally predictively (B) pictures. Usually, the GOP structure IBBPBBP . . . is used. However, in order to embed a watermark in the MPEG-encoded video signal, the MPEG encoder is forced to produce a GOP structure which does not normally occur, e.g., a GOP including a BPP sequence. Different symbol values can be assigned to different positions of the BPP sequence in the GOP.