Scramble/descramble method and apparatus for data broadcasting

Abstract

A transmitter for transmitting news data via satellite and which includes an information storage unit for storing news data, an information scramble processing unit for scrambling the news data using a predetermined first key to output once scrambled news data, a data scrambler for scrambling the once scrambled news data using a predetermined second key and outputting twice scrambled news data, a transmitter for broadcasting the twice scrambled news data via a transmitter antenna to a receiver which includes a data descrambler for descrambling the twice scrambled news data using the second key and outputting once descrambled news data, a storage medium for storing the once descrambled news data, an information descramble processing unit for reading the once descrambled data from the recording medium and descrambling the once descrambled news data using the first key to produce fully descrambled news data, and a user terminal for reading the fully descrambled news data.

Description

FIELD OF THE INVENTIONThe present invention relates to a scramble system for use in satellite broadcasting of text and graphical information, such as that which might be found in a typical newspaper, magazine or book.BACKGROUND OF THE INVENTIONIn, for instance, a pay television broadcasting system(or a music / audio program broadcasting system) by way of a broadcasting satellite, programs are often scrambled, or encoded for broadcast so as to prevent these programs from being illegally intercepted by unauthorized parties. A person who wishes to become an authorized viewer / listener, or contractor(subscriber), of such a pay television program typically must contract with a programming service provider for such service. Upon contracting for service, the subscriber typically receives a scramble key (decrypt key) or code, so that he / she may descramble the scrambled program to legally listen to the pay TV program.Nowadays, so-called "COATEC" system and the "SKYPORT" system have been practic...

AI Technical Summary

Problems solved by technology

In other words, according to the above-described scramble system since the programs are transmitted by only selecting one of the two transmission data processing methods, namely by scrambling the program data or by processing the program data in the non-scramble manner, merely uniform program service may be provided so that all of the contractors can observe the specific newspaper data and is not possible that some contractors cannot observe this specific newspaper data.

Accordingly, in the view of the contractors, they must pay not only the service fees for the necessary newspaper data, but also the service fees for the unnecessary newspaper data, so that they may feel an unfair fee payment system.

This unfair fee payment system could impede promotion of the program contract, and furthermore could lower the profit of the information suppliers.

As a consequence, for instance, if the newspaper data (namely, scrambled newspaper data) have been received prior to the establishment of a contract are recorded on the recording medium, after the establishment of the contract, even if the contractor may have his own scramble key, he cannot decrypt the scrambled newspaper data which have been recorded on this recording medium.

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