Abstract: Parts of a composite video signal, such as segments of each horizontal scan line, are stored in analog storage devices and retrieved therefrom in a cyclic manner to rearrange them and thereby encode the signal. The cyclic retrieval of the information from the storage devices is carried out on a selective basis in accordance with the binary state of a pseudo-random signal that is generated independently at each of the encoding and decoding stations. Synchronization of the two independently generated signals is provided by a control word and an initialization word that are transmitted with the encoded video signal, one of which is encrypted. Decryption of the word is carried out with a master key at each of the encoding and decoding stations.

Abstract: A subscription television system and method in which billing information regarding programs actually viewed by a subscriber of the system is accumulated over non-dedicated telephone lines. A scrambled television program signal containing a block of television program material, a program identification code unique to the block of program material, and a program category code, is broadcast. The codes are preferably included in the vertical retrace interval of the video portion of the program signal and the transmitted program signal is selectively received at a subscriber station and selectively unscrambled to permit viewing of the block of program material being transmitted in response to subscriber action indicating acceptance for viewing of the block of program material. The received program category code is compared with a locally generated category code to determine whether the program is acceptable for viewing.

Abstract: A method and system for providing subscription services, particularly subscription television services, involving transmissions from a remote location to a subscriber location for which payment is required for access. A cost signal containing a cost or charge associated with the transmissions is transmitted from the remote location, and a credit preferably is stored at the subscriber location. The magnitude of the charge contained in the cost signal is compared with the magnitude of the stored credit, although it need not be if cost is accumulated as in one disclosed embodiment, and access by the subscriber to the transmissions associated with the cost signal is enabled in response to the relative magnitudes of the charge and the stored credit. The magnitude of stored credit is modified by the magnitude of the charge if the subscriber chooses to access to the transmissions by the subscriber.

Abstract: A method and system for scrambling a plurality of input signals for secure transmission thereof, as well as various methods and systems for television transmission, are disclosed. The disclosed scrambling technique, in one form, includes modulating an in-phase component of at least one carrier signal in response to one and then another of a plurality of input signals in a sequence of time intervals such that parts but not all of the one and another of the input signals are carried by the in-phase component. A quadrature component of the at least one carrier signal is modulated in response to the one and another of the plurality of input signals in the sequence of time intervals such that parts but not all of the one and another of the input signals are carried by the quadrature component and such that the in-phase and quadrature components together carry the one and another of the input signals in their entireties. The modulated in-phase and quadrature components are combined for transmission.

Abstract: A method and a system for secure transmission and reception of a video signal wherein parts of the video signal arranged in a first predetermined sequence are delayed in relation to each other to form an encoded video signal having its parts rearranged in sequence relative to their positions in the first predetermined sequence. Rearrangement of the video signal parts is accomplished by storing successive parts of the video signal and retrieving the stored parts so that the transmitted video signal has in parts arranged in a sequence other than their normal sequence. A decoder at a remote location is provided for receiving and restoring the transmitted sequence of video signal parts to its original sequence. In a television scrambling system, the parts of the video signal are fields, lines or segments of lines and, rearrangement of the sequence of video signal parts is accomplished on a line segment, line or field basis.

Abstract: A method and system for scrambling a plurality of input signals for secure transmission thereof, as well as various methods and systems for television transmission, are disclosed. The disclosed scrambling technique, in one form, includes modulating an in-phase component of at least one carrier signal in response to one and then another of a plurality of input signals in a sequence of time intervals such that parts but not all of the one and another of the input signals are carried by the in-phase component. A quadrature component of the at least one carrier signal is modulated in response to the one and another of the plurality of input signals in the sequence of time intervals such that parts but not all of the one and another of the input signals are carried by the quadrature component and such that the in-phase and quadrature components together carry the one and another of the input signals in their entireties. The modulated in-phase and quadrature components are combined for transmission.

Abstract: A subscription television system and method in which billing information regarding programs actually viewed by a subscriber of the system is accumulated over non-dedicated telephone lines. A scrambled television program signal containing a block of television program material, a program identification code unique to the block of program material, and a program category code, is broadcast. The codes are preferably included in the vertical retrace interval of the video portion of the program signal and the transmitted program signal is selectively received at a subscriber station and selectively unscrambled to permit viewing of the block of program material being transmitted in response to subscriber action indicating acceptance for viewing of the block of program material. The received program category code is compared with a locally generated category code to determine whether the program is acceptable for viewing.