Data delivery method and data delivery system using sets of passkeys generated by dividing an encryption key

• US 7,421,082 B2
• Filed: 10/27/2001
• Issued: 09/02/2008
• Est. Priority Date: 12/28/2000
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Yamashita, Masami, Kamiya, Shigeki
• Primary Examiner(s): Sheikh; Ayaz
• Assistant Examiner(s): Henning; Matthew T
• Application Number:
  US10/032,722
• Publication Number:
  US 20020106086A1
• Time in Patent Office: 2,502 Days
• Field of Search: 380/277, 380281-282, 380/283, 713/162, 725/31
• US Class Current: 380/278
• CPC Class Codes: G11B 20/00086 Circuits for prevention of unauthorised reproduction or copying, e.g. piracy indicating unauthorised use of record carriers in general G11B23/28; scrambling for television signal recording H04N5/913; network architectures or network protocols for network security H04L63/00; cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
• CPC Class Codes: G11B 20/0021 involving encryption or decryption of contents recorded on or reproduced from a record carrier
• CPC Class Codes: H04N 2005/91364 the video signal being scrambled
• CPC Class Codes: H04N 21/2347 involving video stream encryption
• CPC Class Codes: H04N 21/631 Multimode Transmission, e.g. transmitting basic layers and enhancement layers of the content over different transmission paths or transmitting with different error corrections, different keys or with different transmission protocols
• CPC Class Codes: H04N 21/63345 by transmitting keys key distribution for secret or secure communication H04L9/08; network support of key management H04L63/06
• CPC Class Codes: H04N 5/913 for scrambling ; for copy protection
• CPC Class Codes: H04N 7/162 Authorising the user terminal, e.g. by paying; Registering the use of a subscription channel, e.g. billing
• CPC Class Codes: H04N 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58
• CPC Class Codes: H04N 7/17345 Control of the passage of the selected programme

Abstract

A data delivery system providing multipoint delivery of encrypted digital data to specific destinations. A plurality of pieces of key information are generated on the basis of an encryption key specific to each digital data item to be delivered. The multiple pieces of key information are delivered over routes which differ from the routes used to deliver the digital data and which further differ from each other. Physically different media or transmission over a network at different times are used to separately transmit different sets of key information.

Claims

1. A digital data delivery method for use in delivering digital data from an upstream system to a downstream system, said upstream system providing multipoint delivery of encrypted digital data to specific destinations, and said downstream system decrypting the delivered digital data, said method comprising the steps of:

encrypting digital data at said upstream system using an encryption key;

generating on the basis of said encryption key, sets of passkeys, each set having at least two passkeys and each set of passkeys specific to a respective one of said specific destinations by dividing said encryption key by a division pattern that is;

(a) unique to each of said specific destinations and (b) based on the content of said digital data;

generating a plurality of partial keys based on a portion of the passkeys in said set or a portion of passkey information from which said passkeys may be reproduced;

delivering either said plurality of partial keys or partial key information, from which said partial keys may be reproduced, and delivering the remaining passkeys in a set not used to generate said partial keys or the remaining passkey information, to a respective one of said specific destinations over a plurality of delivery routes which differ from routes for delivering said digital data and which are further different from each other;

delivering the encrypted digital data;

restoring said encryption key by using said downstream system using either said plurality of partial keys or said partial key information and using either said remaining passkeys or said remaining passkey information in a set delivered over said plurality of delivery routes; and

using the restored encryption key to decrypt the encrypted digital data.

2. The method of claim 1, wherein a set of said partial keys is generated by dividing a portion of said set of passkeys specific to a destination by a predetermined division pattern specific to the destination of said set of partial keys.

3. A signal processing method for use with an upstream system providing multipoint delivery of encrypted digital data to specific destinations, said method comprising the steps of:

encrypting digital data at said upstream system using an encryption key;

generating on the basis of said encryption key, sets of passkeys, each set having at least two passkeys and each set of passkeys specific to a respective one of said specific destinations by dividing said encryption key by a division pattern that is;

(a) unique to each of said specific destinations and (b) based on the content of said digital data;

generating a plurality of partial keys based on a portion of the passkeys in said set or a portion of passkey information from which said passkeys may be reproduced;

delivering either said plurality of partial keys or partial key information, from which said partial keys may be reproduced, and delivering the remaining passkeys in a set not used to generate said partial keys or the remaining passkey information, to a respective one of said specific destinations over a plurality of delivery routes which differ from routes for delivering said digital data and which are further different from each other; and

delivering the encrypted digital data.

4. The method of claim 3 wherein a set of said partial keys is generated by dividing a portion of said set of passkeys specific to a destination by a predetermined division pattern specific to the destination of said set of partial keys.

5. A digital data delivery system comprising an upstream system providing multipoint delivery of encrypted digital data to specific destinations and a downstream system decrypting the delivered digital data;

said upstream system including;

an encrypting element for encrypting digital data using an encryption key;

a first key information generator for generating, on the basis of said encryption key, sets of passkeys, each set having at least two passkeys and each set of passkeys specific to a respective one of said specific destinations by dividing said encryption key by a division pattern that is;

(a) unique to each of said specific destinations and (b) based on the content of said digital data;

a second key information generator for generating a plurality of partial keys based on a portion of the passkeys in said set or a portion of passkey information, from which said passkeys may be reproduced;

a key information delivery element for delivering either said plurality of partial keys or partial key information, from which said partial keys may be reproduced, and for delivering the remaining passkeys in a set not used to generate said partial keys or the remaining passkey information, to a respective one of said specific destinations over a plurality of delivery routes which differ from routes for delivering said digital data and which are further different from each other; and

a digital data delivery element for delivering the encrypted digital data;

and said downstream system including;

an encryption key restoring element for restoring said encryption key using either said plurality of partial keys or said partial key information and using either said remaining passkeys or said remaining passkey information in a set delivered over said plurality of delivery routes; and

a decrypting element for decrypting the encrypted digital data using the restored encryption key.

6. An upstream system for providing multipoint delivery of encrypted digital data to specific destinations, comprising:

an encrypting element for encrypting digital data using an encryption key;

a first generator for generating on the basis of said encryption key, sets of passkeys, each set having at least two passkeys and each set of passkeys specific to a respective one of said specific destinations by dividing said encryption key by a division pattern that is;

(a) unique to each of said specific destinations and (b) based on the content of said digital data;

a second generator for generating a plurality of partial keys based on a portion of the passkeys in said set or a portion of passkey information from which said passkeys may be reproduced;

a key information delivery element for delivering either said plurality of partial keys or partial key information, from which said partial keys may be reproduced, and delivering the remaining passkeys in a set not used to generate said partial keys or the remaining passkey information, to a respective one of said specific destinations over a plurality of delivery routes which differ from routes for delivering said digital data and which are further different from each other; and

a digital data delivery element for delivering the encrypted digital data.

7. The system of claim 6, wherein said second key information generator generates a set of said partial keys by dividing a portion of said set of passkeys specific to a destination by a predetermined division pattern specific to the destination of said set of partial keys.

8. A storage medium which stores a computer-readable program for controlling the steps of:

encrypting digital data using an encryption key;

generating on the basis of said encryption key, sets of passkeys, each set having at least two passkeys and each set of passkeys specific to a respective one of specific destinations by dividing said encryption key by a division pattern that is;

(a) unique to each of said specific destinations and (b) based on the content of said digital data;

generating a plurality of partial keys based on a portion of the passkeys in said set or a portion of passkey information from which said passkeys may be reproduced;

delivering either said plurality of partial keys or partial key information, from which said partial keys may be reproduced, and delivering the remaining passkeys in a set not used to generate said partial keys or the remaining passkey information, to a respective one of said specific destinations over a plurality of delivery routes which differ from routes for delivering said digital data and which are further different from each other; and

performing multipoint delivery of the encrypted digital data to said specific destinations.

9. The storage medium of claim 8, wherein a set of said partial keys is generated by dividing a portion of said set of passkeys specific to a destination by a predetermined division pattern specific to the destination of said set of partial keys.