Scramble/descramble method and apparatus for data broadcasting

A data transmission system comprising:

• a transmitter for transmitting news data via satellite wherein the transmitter comprises:
• an information storage unit for storing news data;
• an information scramble processing unit for scrambling the news data using a predetermined first key to produce and 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;
• and
• a receiver for receiving the twice scrambled news data transmitted via the satellite, wherein the receiver comprises:
• 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 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.

A method of transmitting news data which includes either or both of text data or graphical data via a broadcast satellite comprising the steps of:

• storing the news data in a storage medium;
• retrieving the news data from the storage medium;
• encoding the news data once, using a feat key, to produce once encoded data;
• encoding the once encoded data, using a second key, to produce a twice encoded data signal;
• and
• broadcasting the twice encoded data signal via the broadcast satellite.

A method of receiving news data via a broadcast satellite comprising the steps of:

• receiving twice encoded data via the broadcast satellite;
• decoding the twice encoded data using a second key to produce once encoded data;
• decoding the once encoded data using a first key to produce news data which includes either or both of text data or graphic data;
• and
• storing the news data in a storage medium.

A news data broadcast system comprising:

• a transmitter for encoding and transmitting news data via a broadcast satellite and including:
• a storage medium for storing news data,
• a first encoder for encoding the news data using primary key data to produce primary encoded news data,
• a second encoder for encoding the primary encoded news data using secondary key data to produce secondary encoded news data;
• and
• a receiver for receiving the secondary encoded news data via the broadcast satellite and including:
• a first decoder for decoding the secondary encoded news data using the secondary key data to produce the primary decoded news data,
• a second decoder for decoding the primary decoded news data using the primary key data to produce the news data;
• and
• a storage medium for storing the news data.

A transmitter for transmitting news data via satellite comprising:

• an information scramble processing unit for scrambling the news data once using a predetermined first key to produce and output first scrambled news data;
• a data scrambler for scrambling the once scrambled news data again using a predetermined second key to produce and output twice scrambled news data;
• and
• transmitting circuitry for broadcasting the twice scrambled news data via a transmitter antenna.

A receiver for receiving news data broadcast via satellite comprising:

• circuitry for receiving twice scrambled news data broadcast via satellite;
• a data descrambler for decoding the twice scrambled news data using a predetermined first key and outputting first descrambled data;
• a storage medium for storing the first descrambled news data;
• an information descramble processing unit for reading the first descrambled news data from the storage medium and descrambling the first descrambled news data using a second key to produce a fully descrambled news data signal;
• and
• a user terminal for viewing the fully descrambled news data.

A data transmitting apparatus for transmitting data, comprising:

• a first encryptor for encrypting the data and outputting a first encrypted data;
• a second encryptor for encrypting said first encrypted data and outputting a second encrypted data;
• and
• a transmitter for transmitting to a receiver said second encrypted data together with a first key which is used to decrypt the second encrypted data;
• wherein said transmitter transmits to said receiver a second key in response to a request from the receiver, the second key being used to decrypt said first encrypted data.

A data transmitting method for transmitting data, comprising the steps of:

• encrypting the data to produce a first encrypted data;
• encrypting said first encrypted data to produce a second encrypted data;
• transmitting to a receiver said second encrypted data together with a first key which is used to decrypt the second encrypted data;
• and
• transmitting in response to a request from said receiver a second key which is used to decrypt said first encrypted data.

A data receiving apparatus for receiving encrypted data which is transmitted from a transmitter apparatus, the encrypted data is generated by encrypting original data twice by using two different-keys, comprising:

• a receiver for receiving said encrypted data and a first key;
• a first decryptor for decrypting said received encrypted data by using said first key;
• a requestor for requesting a second key;
• and
• a second decryptor decrypting said decrypted data by using said second key.

A method for receiving encrypted data which is transmitted from a transmitter apparatus, the encrypted data being generated by encrypting original data twice by using two different keys, comprising the steps of:

• receiving said encrypted data and a first key;
• decrypting said received encrypted data by using said first key;
• requesting a second key;
• and
• decrypting said decrypted data by using said second key.

A data transmitting and receiving method, comprising the steps of:

• encrypting data to produce a first encrypted data;
• encrypting said first encrypted data to produce a second encrypted data;
• transmitting to said second encrypted data together with a first key which is used to decrypt the second encrypted data;
• receiving said second encrypted data and said first key;
• decrypting said received second encrypted data by using said first key;
• requesting a second key;
• and
• decrypting said first encrypted data by using said second key.