Receiving device for securely storing a content item, and playback device

• US 20020174354A1
• Filed: 03/08/2002
• Published: 11/21/2002
• Est. Priority Date: 03/12/2001
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Engelen, Dirk Valentinus Rene, Lokhoff, Gerardus Cornelis Petrus, Breugom, Michel Ronald, Bel, Hendrik Jan, Van De Poel, Peter
• Granted Patent: US 7,124,304 B2
• Time in Patent Office: Days
• US Class Current: 713/193
• CPC Class Codes: G06F 21/109 by using specially-adapted hardware at the client
• 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: G11B 20/00768 wherein copy control information is used, e.g. for indicating whether a content may be copied freely, no more, once, or never, by setting CGMS, SCMS, or CCI flags
• CPC Class Codes: G11B 20/00855 involving a step of exchanging information with a remote server
• 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 63/0442 wherein the sending and receiving network entities apply asymmetric encryption, i.e. different keys for encryption and decryption cryptographic mechanisms or cryptographic arrangements for public-key encryption H04L9/30
• CPC Class Codes: H04L 63/10 for controlling access to devices or network resources
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04N 21/2541 Rights Management protecting software against unauthorised usage in a vending or licensing environment G06F21/10; security in data switching network management H04L41/28; security management or policies for network security H04L63/20; access security in wireless networks H04W12/08
• CPC Class Codes: H04N 21/4367 Establishing a secure communication between the client and a peripheral device or smart card
• CPC Class Codes: H04N 21/4788 communicating with other users, e.g. chatting arrangements for providing for computer conferences, e.g. chat rooms, to substation in data switching networks H04L12/1813; distributed application using peer-to-peer [P2P] networks H04L67/104
• CPC Class Codes: H04N 21/632 using a connection between clients on a wide area network, e.g. setting up a peer-to-peer communication via Internet for retrieving video segments from the hard-disk of other client devices broadcast-related systems characterised by transmission among terminal devices H04H60/80; distributed application using peer-to-peer [P2P] networks H04L67/104
• CPC Class Codes: H04N 21/835 Generation of protective data, e.g. certificates protecting software against unauthorised usage in a vending or licensing environment G06F21/10
• CPC Class Codes: H04N 21/8355 involving usage data, e.g. number of copies or viewings allowed
• 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

Abstract

A receiving device (110) for securely storing a content item (102) on a storage medium (111). The content item (102) is stored in a secure format, and has an associated license file. The license file (141) is encrypted using public key associated with a group of playback devices (120, 121), so that each playback device (121) in the group can decrypt the license file (141) and play the content item (102), but devices outside the group cannot. A playback device (121) can provide a device-specific public key to a Content Distribution Management System (CDMS). The CDMS then returns the secret key for the group encrypted with the public key of the playback device (121). The playback device (121) then securely obtains the secret key of the group and is subsequently able to decrypt the license file (141).

Claims

1. A receiving device (110) for securely storing a content item (102), comprising

downloading means (201) for downloading the content item (102),

writing means (203) for writing the downloaded content item (102) to a storage medium (111), and

licensing means (204) for obtaining a license file (141) from a license server (140), the license file (141) at least comprising a permission to write the downloaded content item (102) to the storage medium (111), characterized by

license locking means (205) for encrypting the license file (141) with an encryption key associated with a group (G1, G2, G3) of playback devices, and for providing the encrypted license file (141) to the writing means (203) for writing the encrypted license file (141) to the storage medium (111).

2. The receiving device as claimed in claim 1, whereby the license locking means (205) are arranged for encrypting the license file (141) with a License Locker Encryption Key (LLEK), encrypting the LLEK with the encryption key associated with the group (G1, G2, G3) of playback devices, and additionally providing the encrypted LLEK to the writing means (203) for writing the encrypted LLEK to the storage medium (111).

3. The receiving device (110) as claimed in claim 1, whereby the encryption key is the public key of a public/secret key pair.

4. The receiving device (110) as claimed in claim 1, wherein the content item (102) comprises at least one of audio and video data.

5. The receiving device (110) as claimed in claim 1, wherein the license locking means (205) are further arranged for receiving a selection of an identifier of the group (G1, G2, G3) and for obtaining the encryption key associated with the selection from a keyserver (130).

6. A playback device (121) for playing a content item (102) stored on a storage medium (111), comprising

playback means (305) for playing back the content item (102) in accordance with a permission in a license file (141) for the content item (102), stored on the storage medium (111), characterized in that

the license file (141) is stored encrypted on the storage medium (111), and in that the playback device (121) further comprises

secure storage means (309) for storing one or more decryption keys, each decryption key being associated with a respective group (G1, G2, G3) of playback devices,

decoding means (302) for checking whether a stored decryption key is suitable for decrypting the encrypted license file (141), and if so,

decrypting the license file (141) using the stored decryption key and providing the decrypted license file (141) to the playback means (305).

7. The playback device (121) as claimed in claim 6, whereby the license file (141) is stored encrypted with a License Locker Encryption Key (LLEK), said LLEK being stored on the storage medium (111) encrypted with an LLEK encryption key, the one or more decryption keys are LLEK decryption keys, and the decoding means (302) are arranged for checking whether a stored LLEK decryption key is suitable for decrypting the encrypted LLEK, and if so, obtaining the LLEK from the encrypted LLEK using the stored LLEK decryption key, and decrypting the license file (141) using the LLEK.

8. The playback device (121) as claimed in claim 6, wherein the content item (102) comprises at least one of audio and video data.

9. The playback device (121) as claimed in claim 6, whereby the stored decryption key is the secret key of a public/secret key pair.

10. The playback device (121) as claimed in claim 6, further comprising registration means (306) for registering a public key of a public/secret key pair associated with the playback device (121) at a Content Distribution Management System (CDMS) (310), the secret key of said public/secret key pair being stored in the secure storage means (309), and for receiving a decryption key associated with a group (G1, G2, G3) of playback devices encrypted with said public key, decrypting said encrypted decryption key and storing said decryption key in the secure storage means (309).

11. A computer program product (200) for enabling a programmable device when executing said computer program product to function as a receiving device (110), comprising

downloading means (201) for downloading the content item (102),

writing means (203) for writing the downloaded content item (102) to a storage medium (111), and

licensing means (204) for obtaining a license file (141) from a license server (140), the license file (141) at least comprising a permission to write the downloaded content item (102) to the storage medium (111), characterized by

license locking means (205) for encrypting the license file (141) with an encryption key associated with a group (G1, G2, G3) of playback devices, and for providing the encrypted license file (141) to the writing means (203) for writing the encrypted license file (141) to the storage medium (111).

12. A computer program product (300) for enabling a programmable device when executing said computer program product to function as a playback device (121), comprising

playback means (305) for playing back the content item (102) in accordance with a permission in a license file (141) for the content item (102), stored on the storage medium (111), characterized in that

the license file (141) is stored encrypted on the storage medium (111), and in that the computer program product further comprises

decoding means (302) for checking whether a stored decryption key is suitable for decrypting the encrypted license file (141), and if so,

decrypting the license file (141) using the stored decryption key and providing the decrypted license file (141) to the playback means (305).