System, method, and medium for broadcasting service contents

• US 6,594,758 B1
• Filed: 06/02/1999
• Issued: 07/15/2003
• Est. Priority Date: 06/02/1998
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Okui, Tamio
• Primary Examiner(s): Peeso, Thomas R.
• Application Number:
  US09/323,856
• Time in Patent Office: 1,504 Days
• Field of Search: 713/150, 713/153, 713/162, 713/163, 713/168, 713/171
• US Class Current: 713/163
• CPC Class Codes: H04H 60/15 on receiving information
• CPC Class Codes: H04H 60/23 using cryptography, e.g. encryption, authentication, key distribution
• CPC Class Codes: H04L 12/1859 adapted to provide push services, e.g. data channels
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload

Abstract

A Ca server 13 generates and encrypts a work key (Kw) and delivers the key to receiving terminals. The CA server further updates scramble key (Ks) at a predetermined interval and delivers the key to the terminals. A contents server 14 encrypts service contents using the Kw and the Ks to deliver the contents toward an IP address for the group. A delivering router 15 receives the contents and delivers the content to the receiving terminals based on the IP address. The receiving terminals, when receives the encrypted contents, decode the contents using the Kw and the Ks and replace the IP address with its own IP address.

Claims

1. A broadcasting system which includes a source sending unit and a plurality of receiving terminals each of which is connected to the source sending unit via a network, said broadcasting system being operable to broadcast service contents from the source sending unit to the plurality of receiving terminals, the source sending unit comprising:

a data packet generator which generates a data packet including a part of the service contents and a group address assigned to a predetermined group of the receiving terminals as a destination address; and

a service contents delivering unit which delivers the data packet to the predetermined group of the receiving terminals based on the group address;

wherein each of the receiving terminals of the predetermined group processes the part of the service contents sent directly to the receiving terminal by replacing the group address portion of the destination address with its own address after the receiving terminal receives the data packet.

2. The system claimed in claim 1 further comprising:

a router which passes through the only data packet which includes the group address destined to the predetermined group of the receiving terminals.

3. A broadcasting system which includes a source sending unit and a plurality of terminals each of which is connected to the source sending unit via a network, the broadcasting system broadcasting service contents from the source sending unit to the plurality of receiving terminals, the source sending unit comprising:

key supplying means which generates a work key for each service of the service contents and sends the work to the receiving terminals;

contents encrypting means which encrypts the service contents by using the work key; and

contents delivering means which delivers the encrypted service contents to the receiving terminals,

each of the receiving terminals comprising;

key receiving means which receives the work key from the source sending unit;

contents receiving means which receives the encrypted service contents from the source sending unit; and

contents decoding means which decodes the received and encrypted service contents into decoded service contents;

wherein each of the receiving terminals of the predetermined group processes the part of the service contents sent directly to the receiving terminal by replacing the group address portion of the destination address with its own address after the receiving terminal receives the data packet.

4. The system claimed in claim 3, wherein the key supplying means further encrypts the work key for each receiving terminal by using master keys each of which is uniquely assigned to each of the receiving terminals and

each of the key receiving means further decodes the work key by using the master key of the receiving terminal terminal.

5. The system claimed in claim 3, wherein the key supplying means further sends a scramble key to the receiving terminals;

the contents encrypting means further encrypting the service contents by using the scramble key;

each of the key receiving means further receiving the scramble key, and each of the contents decoding means further decoding the service contents by using the scramble key.

6. The system claimed in claim 5, wherein the scramble key is updated periodically and sent to the receiving.

7. A method of broadcasting service contents from a source sending unit to a plurality of receiving terminals each of which is connected to the source sending unit via a network, the method comprising the steps of:

preparing the source sending unit,

generating a data packet including a part of the service contents and a group address assigned to a predetermined group of the receiving terminals as a destination address; and

broadcasting the data packet to the predetermined group of the receiving terminals on the basis of the group address;

wherein each of the receiving terminals of the predetermined group processes the part of the service contents sent directly to the receiving terminal by replacing the group address portion of the destination address with its own address after the receiving terminal receives the data packet.

8. A method of broadcasting service contents from a source sending unit to a plurality of receiving terminals each of which is connected to the source sending unit via a network, the method comprising the steps of:

preparing the source sending unit,

generating a work key for each service of the service contents and sending the work key to the receiving terminals;

encrypting the service contents by using the working key; and

delivering the encrypted service contents to the receiving terminals;

at each of the receiving terminals,

receiving the work key from the source sending unit;

receiving the encrypted service contents from the source sending unit; and

decoding the received and encrypted service contents;

wherein each of the receiving terminals of the predetermined group processes the part of the service contents sent directly to the receiving terminal by replacing the group address portion of the destination address with its own address after the receiving terminal receives the data packet.

9. The method as claimed in claim 8 further comprising the steps of:

encrypting the work key for each receiving terminal by using master keys each of which is uniquely assigned to each of the receiving terminals before the work key is sent to the receiving terminals from the source sending unit; and

decoding the work key by using the master key of the receiving terminal at each of the receiving terminals.

10. The method claimed in claim 8 further comprising the steps of:

sending a scramble key from the source sending unit to the receiving terminals before each of the receiving terminal uses the scramble key;

encrypting the service contents by using the scramble key before the service contents are sent to the receiving terminal from the source sending unit;

receiving the scramble key after the scramble key is sent from the source sending unit at each of the receiving terminals; and

decoding the service contents by using the scramble key at each of the receiving terminals.

11. The method as claimed in claim 10, wherein the scramble key is updated periodically and sent to the receiving terminals.

12. A computer readable medium which stores a program operable for broadcasting service contents from a source sending unit to a plurality of receiving terminals each of which is connected to the source sending unit via a network, the program comprising, at the source sending unit, the steps of:

generating a data packet including a part of the service contents and a group address which represents a predetermined group of the receiving terminals as a destination address; and

broadcasting the data packet to the predetermined group of the receiving terminals based on the group address;

wherein each of the receiving terminals of the predetermined group processes the part of the service contents sent directly to the receiving terminal by replacing the group address portion of the destination address with its own address after the receiving terminal receives the data packet.

13. A computer readable medium which stores a program operable for broadcasting service contents from a source sending unit to a plurality of receiving terminals each of which is connected to the source sending unit via network, the program being used in the sources sending unit and comprising the steps of:

generating a work key for each service of the service contents and sending the work key to the receiving terminals;

encrypting the service contents using the work key; and

delivering the encrypted service contents to the receiving terminals;

the program being used in each of the receiving terminals and comprising the steps of;

receiving the work key from the source sending unit;

receiving the encrypted service contents from the source sending unit; and

decoding the received and encrypted service contents

wherein each of the receiving terminals of the predetermined group processes the part of the service contents sent directly to the receiving terminals by replacing the group address portion of the destination address with its own address after the receiving terminal receives the data packet.