Content providing system, content reproducing device, content reproducing method, and computer program

• US 10,097,347 B2
• Filed: 03/30/2006
• Issued: 10/09/2018
• Est. Priority Date: 04/07/2005
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Nagao, Yutaka
• Primary Examiner(s): OBEID, MAMON A
• Application Number:
  US11/392,729
• Publication Number:
  US 20070198413A1
• Time in Patent Office: 4,576 Days
• Field of Search: 705 50, 705 51, 705 54, 705 26
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 2209/603 Digital right managament [DRM]
• CPC Class Codes: H04L 2463/101 applying security measures for digital rights management data processing systems or methods, specially adapted for commerce, e.g. marketing, shopping, billing, auctions or e-commerce G06Q30/00
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 9/0822 using key encryption key
• CPC Class Codes: H04L 9/0894 Escrow, recovery or storing of secret information, e.g. secret key escrow or cryptographic key storage

Abstract

A content reproducing device decrypts and outputs an encrypted content encrypted by a content key received from a content transmitting device. The content reproducing device includes a content key obtaining unit for obtaining the content key, and a storage unit for storing the key unique to the content transmitting device, usage restriction information to restrict the usage of the key unique to the content transmitting device, and link information indicating linking of the content transmitting device and the content reproducing device. The content reproducing device also includes a key decryption unit for decrypting the content key with the key unique to the content transmitting device in the event that the content reproducing device is included in the stored link information unit, and a usage control unit for restricting usage of the key unique to the content transmitting device, based on the stored usage restriction information.

Claims

1. A content providing system comprising:

a copyright management server configured to perform registration processing of a user and one or more content reproducing devices owned by one or more users, link the one or more users with the one or more content reproducing devices, and link the one or more content reproducing devices with one another, encrypt, and transmit a content key to the one or more content reproducing devices;

a content transmitting device configured to distribute digital contents purchased by one of the one or more users via a network to one of the one or more content reproducing devices; and

the one or more content reproducing devices owned by the one or more users, at least one of the one or more content reproducing devices coupled via the network with the copyright management server and the content transmitting device, the one or more content reproducing devices being linked together, the one or more content reproducing devices configured to reproduce the digital contents, the one or more content reproducing devices including at least a laptop, a boom box, a portable device with a headphone set, a set of portable audio players, and

at least one or more content reproducing devices being commonly owned by more than one users, the digital contents purchased by a first user of the more than one users being allowed to be used by a second user, who does not purchase the digital contents, among the more than one users, wherein

a transmitter of one of the one or more content reproducing devices configured to transmit an encrypted content encrypted by the content key and a receiver of another of the one or more content reproducing devices configured to receive the encrypted content, the transmitter comprising circuitry that;

encrypts a first device key unique to the transmitter with a second device key unique to the receiver, the first device key unique to the transmitter being based on a unique identification number of the transmitter; and

generates a path having an origin at the transmitter and a destination at the receiver based on identification information of the transmitter and the receiver, and provides the receiver with link information that represents the path and that identifies the transmitter and receiver as being linked and owned by a same user, the first device key, the content key encrypted with the first device key, content usage restriction information, and hop count information indicating a number of generations the link information can be issued; and

the receiver comprising circuitry that;

obtains the content key encrypted with the first device key;

stores the first device key, a usage restriction information to restrict the usage of the first device key, and the link information;

decrypts the content key with the first device key when the stored link information includes information identifying the receiver;

restricts usage of the first device key based on said usage restriction information; and

when permitted by the usage restriction information, decrypts and reproduces the encrypted content using the content key.

2. A content reproducing device for decrypting and outputting an encrypted content encrypted by a content key received from a content transmitting device, the content reproducing device comprising:

circuitry that

obtains the content key, the content key being encrypted with a first key unique to the content transmitting device and a second key unique to the content reproducing device, the first key being based on a unique identification number of the content transmitting device;

stores the first key, usage restriction information to restrict usage of the first key, link information indicating linking of the content transmitting device and the content receiving device as being linked and owned by a same user, the link information including a path having an origin at the content transmitting device and a destination at the content reproducing device based on identification information of the content transmitting device and the content reproducing device, and hop count information indicating a number of generations the link information can be issued, each issuance of the link information being performed by a different content reproducing device;

decrypts the content key with the first key in the event that the content reproducing device is included in the link information;

restricts usage of the first key based on the usage restriction information; and

when permitted by the usage restriction information, decrypts and reproduces the encrypted content using the content key, wherein

a copyright management server configured to perform registration processing of a user and one or more content reproducing devices owned by one or more users, link the one or more users with the one or more content reproducing devices, and link the one or more content reproducing devices with one another, encrypt, and transmit the content key to the one or more content reproducing devices;

the content transmitting device configured to distribute digital contents purchased by one of the one or more users via a network to one of the one or more content reproducing devices; and

the one or more content reproducing devices owned by the one or more users, at least one of the one or more content reproducing devices coupled via the network with the copyright management server and the content transmitting device, the one or more content reproducing devices being linked together, the one or more content reproducing devices configured to reproduce the digital contents, the one or more content reproducing devices including at least a laptop, a boom box, a portable device with a headphone set, a set of portable audio players, and

at least one or more content reproducing devices being commonly owned by more than one users, the digital contents purchased by a first user of the more than one users being allowed to be used by a second user, who does not purchase the digital contents, among the more than one users.

3. The content reproducing device according to claim 2, wherein the circuitry decrypts the first key using the second key;

wherein the circuitry decrypts the first key if-when the link information identifies the content reproducing device and the content transmitting device.

4. The content reproducing device according to claim 2, wherein the usage restriction information includes decryption restriction information which restricts decryption of the content key.

5. The content reproducing device according to claim 2, wherein the usage restriction information includes transmission restriction information that restricts transmission of the first key to another content reproducing device.

6. The content reproducing device according to claim 2, wherein the circuitry further:

issues the link information to another content reproducing device; and

encrypts a second key unique to the content transmitting device with a third key unique to the another content reproducing device; and

provides the another content reproducing device with the link information for generating a path having an origin at the content reproducing device and a destination at the content transmitting device, a second device key, the usage restriction information, and hop count information indicating a number of generations the link information can be issued unique to the another content reproducing device.

7. The content reproducing device according to claim 6, wherein the circuitry further:

generates a second usage restriction information based on the usage restriction information; and

provides the second usage restriction information to the other content reproducing device.

8. A content transmitting device for transmitting an encrypted content encrypted by a content key to a content reproducing device, the content transmitting device comprising:

circuitry that;

encrypts a first device key unique to the content transmitting device with a second device key unique to the content reproducing device, the first device key being based on a unique identification number of the content transmitting device; and

provides the content reproducing device with link information for generating a path having an origin at the content transmitting device and a destination at the content reproducing device based on identification information of the content transmitting device and the content reproducing device, the first device key, the content key encrypted with the first device key, content usage restriction information, and hop count information indicating a number of generations the link information can be issued, the link information including an indication that the content transmitting device and the content reproducing device are linked and owned by a same user,

wherein the content reproducing device uses the content usage restriction information to determine whether decryption of the encrypted content is permitted, and the content reproducing device decrypts and reproduces the encrypted content using the content key when permitted by the usage restriction information;

a copyright management server configured to perform registration processing of a user and one or more content reproducing devices owned by one or more users, link the one or more users with the one or more content reproducing devices, and link the one or more content reproducing devices with one another, encrypt, and transmit the content key to the one or more content reproducing devices;

the content transmitting device configured to distribute digital contents purchased by one of the one or more users via a network to one of the one or more content reproducing devices; and

the one or more content reproducing devices owned by the one or more users, at least one of the one or more content reproducing devices coupled via the network with the copyright management server and the content transmitting device, the one or more content reproducing devices being linked together, the one or more content reproducing devices configured to reproduce the digital contents, the one or more content reproducing devices including at least a laptop, a boom box, a portable device with a headphone set, a set of portable audio players, and

at least one or more content reproducing devices being commonly owned by more than one users, the digital contents purchased by a first user of the more than one users being allowed to be used by a second user, who does not purchase the digital contents, among the more than one users.

9. A content reproducing device for decrypting and outputting an encrypted content encrypted by a content key received from a content transmitting device, the content reproducing device comprising:

circuitry that;

obtains the content key encrypted with a first key unique to the content transmitting device and a second key unique to the content reproducing device, the first key being based on a unique identification number of the content transmitting device;

stores the first key, usage restriction information to restrict usage of the first key, link information indicating linking of the content transmitting device and the content reproducing device as being linked and owned by a same user, the link information including a path having an origin at the content transmitting device and a destination at the content reproducing device based on identification information of the content transmitting device and the content reproducing device, and hop count information indicating a number of generations the link information can be issued;

decrypts the content key with the first key in the event that the content reproducing device is included in the link information;

restricts usage of the first key based on the usage restriction information; and

when permitted by the usage restriction information, decrypts and reproduces the encrypted content using the content key, wherein

a copyright management server configured to perform registration processing of a user and one or more content reproducing devices owned by one or more users, link the one or more users with the one or more content reproducing devices, and link the one or more content reproducing devices with one another, encrypt, and transmit the content key to the one or more content reproducing devices;

the content transmitting device configured to distribute digital contents purchased by one of the one or more users via a network to one of the one or more content reproducing devices; and

the one or more content reproducing devices owned by the one or more users, at least one of the one or more content reproducing devices coupled via the network with the copyright management server and the content transmitting device, the one or more content reproducing devices being linked together, the one or more content reproducing devices configured to reproduce the digital contents, the one or more content reproducing devices including at least a laptop, a boom box, a portable device with a headphone set, a set of portable audio players, and

at least one or more content reproducing devices being commonly owned by more than one users, the digital contents purchased by a first user of the more than one users being allowed to be used by a second user, who does not purchase the digital contents, among the more than one users.

10. A content transmitting device for transmitting an encrypted content encrypted by a content key to a content reproducing device, the content transmitting device comprising:

circuitry that;

encrypts a first device key unique to the content transmitting device with a second device key unique to the content reproducing device, the first device key being based on a unique identification number of the content transmitting device; and

provides the content reproducing device with link information for generation a path having an origin at the content transmitting device and a destination at the content reproducing device based on identification information of the content transmitting device and the content reproducing device, the first device key, content usage restriction information, and hop count information indicating a number of generations the link information can be issued, the link information including an indication that the content transmitting device and the content reproducing device are linked and owned by a same user,

wherein the content reproducing device uses the content usage restriction information to determine whether decryption of the encrypted content is permitted, and the content reproducing device decrypts and reproduces the encrypted content using the content key when permitted by the usage restriction information;

a copyright management server configured to perform registration processing of a user and one or more content reproducing devices owned by one or more users, link the one or more users with the one or more content reproducing devices, and link the one or more content reproducing devices with one another, encrypt, and transmit the content key to the one or more content reproducing devices;

the content transmitting device configured to distribute digital contents purchased by one of the one or more users via a network to one of the one or more content reproducing devices; and

the one or more content reproducing devices owned by the one or more users, at least one of the one or more content reproducing devices coupled via the network with the copyright management server and the content transmitting device, the one or more content reproducing devices being linked together, the one or more content reproducing devices configured to reproduce the digital contents, the one or more content reproducing devices including at least a laptop, a boom box, a portable device with a headphone set, a set of portable audio players, and

at least one or more content reproducing devices being commonly owned by more than one users, the digital contents purchased by a first user of the more than one users being allowed to be used by a second user, who does not purchase the digital contents, among the more than one users.

11. A non-transitory computer-readable medium encoded with computer-readable instructions that, when executed by a computer, cause the computer to perform a method of decrypting and outputting encrypted content encrypted by a content key received from a content transmitting device, the method comprising:

performing, by a copyright management server, registration processing of a user and one or more content reproducing devices owned by one or more users;

linking the one or more users with the one or more content reproducing devices, and linking the one or more content reproducing devices with one another, encrypting, and transmitting the content key to the one or more content reproducing devices;

distributing, by the content transmitting device, digital contents purchased by one of the one or more users via a network to one of the one or more content reproducing devices, wherein the one or more content reproducing devices owned by the one or more users, at least one of the one or more content reproducing devices being coupled via the network with the copyright management server and the content transmitting device, the one or more content reproducing devices being linked together, the one or more content reproducing devices reproducing the digital contents, the one or more content reproducing devices including at least a laptop, a boom box, a portable device with a headphone set, a set of portable audio players, at least one or more content reproducing devices being commonly owned by more than one users;

allowing the digital contents, which is purchased by a first user of the more than one users, to be used by a second user, who does not purchase the digital contents, among the more than one users;

obtaining the content key encrypted with a first key unique to the content transmitting device and a second key unique to a content reproducing device among the one or more content reproducing devices, the first key being based on a unique identification number of the content transmitting device;

storing the first key, usage restriction information to restrict usage of the first key, link information indicating a linking of the content transmitting device and the content reproducing device as being linked and owned by a same user, the link information including a path having an origin at the content transmitting device and a destination at the content reproducing device based on identification information of the content transmitting device and the content reproducing device, and hop count information indicating a number of generations the link information can be issued;

decrypting the content key with the first key when the content reproducing device is included in the link information;

restricting usage of the first key based on the usage restriction information; and

when permitted by the usage restriction information, decrypting and reproducing the encrypted content using the content key.

12. A non-transitory computer-readable encoded with computer-readable instructions thereon that, when executed by a computer, cause the computer to perform a method of transmitting an encrypted content encrypted by a content key to a content reproducing device, the method comprising:

performing, by a copyright management server, registration processing of a user and one or more content reproducing devices owned by one or more users;

linking the one or more users with the one or more content reproducing devices, and linking the one or more content reproducing devices with one another, encrypting, and transmitting the content key to the one or more content reproducing devices;

distributing, by a content transmitting device, digital contents purchased by one of the one or more users via a network to one of the one or more content reproducing devices, wherein the one or more content reproducing devices owned by the one or more users, at least one of the one or more content reproducing devices being coupled via the network with the copyright management server and the content transmitting device, the one or more content reproducing devices being linked together, the one or more content reproducing devices reproducing the digital contents, the one or more content reproducing devices including at least a laptop, a boom box, a portable device with a headphone set, a set of portable audio players, at least one or more content reproducing devices being commonly owned by more than one users;

allowing the digital contents, which is purchased by a first user of the more than one users, to be used by a second user, who does not purchase the digital contents, among the more than one users;

encrypting a first device key unique to the content transmitting device with a second device key unique to a content reproducing device among the one or more content reproducing devices, the device first key being based on a unique identification number of the content transmitting device; and

providing the content reproducing device with link information for generating a path having an origin at the content transmitting device and a destination at the content reproducing device based on identification information of the content transmitting device and the content reproducing device, the first device key, content usage restriction information, and hop count information indicating a number of generations the link information can be issued, the link information including an indication that the content transmitting device and the content reproducing device are linked and owned by a same user,

wherein the content reproducing device uses the content usage restriction information to determine whether decryption of the encrypted content is permitted, and the content reproducing device decrypts and reproduces the encrypted content using the content key when permitted by the usage restriction information.

13. A method for decrypting and outputting an encrypted content encrypted by a content key received from a content transmitting device, the method comprising:

performing, by a copyright management server, registration processing of a user and one or more content reproducing devices owned by one or more users;

linking the one or more users with the one or more content reproducing devices, and linking the one or more content reproducing devices with one another, encrypting, and transmitting the content key to the one or more content reproducing devices;

distributing, by a content transmitting device, digital contents purchased by one of the one or more users via a network to one of the one or more content reproducing devices, wherein the one or more content reproducing devices owned by the one or more users, at least one of the one or more content reproducing devices being coupled via the network with the copyright management server and the content transmitting device, the one or more content reproducing devices being linked together, the one or more content reproducing devices reproducing the digital contents, the one or more content reproducing devices including at least a laptop, a boom box, a portable device with a headphone set, a set of portable audio players, at least one or more content reproducing devices being commonly owned by more than one users;

allowing the digital contents, which is purchased by a first user of the more than one users, to be used by a second user, who does not purchase the digital contents, among the more than one users;

obtaining, with circuitry, the content key, the content key being encrypted with a first key unique to the content transmitting device and a second key unique to a content reproducing device among the one or more content reproducing devices, the first key being based on a unique identification number of the content transmitting device;

storing, with the circuitry, the first key, usage restriction information to restrict the usage of the first key, link information indicating linking of the content transmitting device and the content reproducing device as being linked and owned by a same user, the link information including a path having an origin at the content transmitting device and a destination at the content reproducing device based on identification information of the content transmitting device and the content reproducing device, and hop count information indicating a number of generations the link information can be issued;

decrypting, with the circuitry, the content key with the first key when the content reproducing device is included in the link information;

restricting, with the circuitry, usage of the first key based on the usage restriction information; and

when permitted by content usage restriction information, decrypting and reproducing the encrypted content using the content key.

14. A method for transmitting an encrypted content encrypted by a content key to a content reproducing device, the method comprising:

performing, by a copyright management server, registration processing of a user and one or more content reproducing devices owned by one or more users;

linking the one or more users with the one or more content reproducing devices, and linking the one or more content reproducing devices with one another, encrypting, and transmitting the content key to the one or more content reproducing devices;

distributing, by a content transmitting device, digital contents purchased by one of the one or more users via a network to one of the one or more content reproducing devices, wherein the one or more content reproducing devices owned by the one or more users, at least one of the one or more content reproducing devices being coupled via the network with the copyright management server and the content transmitting device, the one or more content reproducing devices being linked together, the one or more content reproducing devices reproducing the digital contents, the one or more content reproducing devices including at least a laptop, a boom box, a portable device with a headphone set, a set of portable audio players, at least one or more content reproducing devices being commonly owned by more than one users;

allowing the digital contents, which is purchased by a first user of the more than one users, to be used by a second user, who does not purchase the digital contents, among the more than one users;

encrypting, with circuitry, a first device key unique to the content transmitting device with a second device key unique to a content reproducing device among the one or more content reproducing devices, the device first key being based on a unique identification number of the content transmitting device; and

providing, with the circuitry, the content reproducing device with link information for generating a path having an origin at the content transmitting device and a destination at the content reproducing device based on identification information of the content transmitting device and the content reproducing device, the first device key, content usage restriction information, and hop count information indicating a number of generations the link information can be issued, the link information including an indication that the content transmitting device and the content reproducing device are linked and owned by a same user,

wherein the content reproducing device uses the content usage restriction information to determine whether decryption of the encrypted content is permitted, and the content reproducing device decrypts and reproduces the encrypted content using the content key when permitted by the usage restriction information.