Abstract: A method for key management for a broadcasting system includes generating a receiver group key (RGK) seed and a plurality of parameters for a receiver group provided by the broadcasting system; and calculating an RGK for the receiver group based on the RGK seed and the plurality of parameters.

Abstract: A key management system is provided. The key management system includes a key server. The key server generates secret keys by constructing a rights hierarchy and a resource hierarchy, associating the rights hierarchy with the resource hierarchy, and converting a rights-resource relationship into a node in a service hierarchy. The rights hierarchy includes a rights node and the resource hierarchy includes a resource node. The rights hierarchy is set above the resource hierarchy. The right hierarchy and the resource hierarchy are in a partial order relationship.

Abstract: A method for assigning a plurality of users of a broadcasting system, wherein each of the plurality of users subscribes to at least one of a plurality of receiver groups provided by the broadcasting system. The method includes dividing the plurality of users into a plurality of temporary groups each including ones of the plurality of users that subscribe to a same one of the plurality of receiver groups; and assigning the ones of the plurality of users to at least one user group.

Abstract: In a system for transmitting analog video signals, the luminance and chrominance components are each subjected to different bandwidth reduction processes. In addition, the high and low frequency portions of the luminance component are subjected to different bandwidth reduction signal processes.

Abstract: A digital TV receiver includes circuitry for performing hue control by rotation of the axes of the I and Q color mixture signals. The I and Q color mixture signals are time division multiplexed and applied to a multiplicand input port of a multiplier circuit. The sines and cosines of the angle by which the I and Q vectors are to be rotated are also applied to the multiplier wherein alternate pairs of the I and Q signals are multiplied by the sine terms and intervening pairs of the I and Q signals are multiplied by cosine terms. The signal from the multiplier is applied to a delay element which delays successive samples by one sample period. Delayed and nondelayed signal samples are applied to an ADDER which produces the algebraic sums Icos .phi.+Qsin .phi. and Qcos .phi.-Isin .phi. corresponding to the desired modified I and Q signals respectively. The sums from the ADDER are demultiplexed by latches to generate separate I and Q signals.

Abstract: Impulse noise detection circuitry for determining the occurrence of short noise pulses in TV video signal includes two 1H delay lines to align successive image lines for signal comparison. The amplitude of signal from one image line is compared with the signal amplitude of a succeeding and a preceding image line along a vertical line. If the amplitude of the one signal concurrently exceeds the signal of both the preceding and the succeeding image lines, then a control signal, indicative of the presence of impulse noise, is produced.