Classifications

• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F15/00—Digital computers in general; Data processing equipment in general
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N5/00—Details of television systems
  • H04N5/76—Television signal recording
  • H04N5/91—Television signal processing therefor
  • H04N5/913—Television signal processing therefor for scrambling ; for copy protection
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F21/00—Security arrangements for protecting computers, components thereof, programs or data against unauthorised activity
  • G06F21/10—Protecting distributed programs or content, e.g. vending or licensing of copyrighted material ; Digital rights management [DRM]
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
  • G11B20/00086—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
  • G11B20/00086—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
  • G11B20/0021—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving encryption or decryption of contents recorded on or reproduced from a record carrier
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
  • H04L9/08—Key distribution or management, e.g. generation, sharing or updating, of cryptographic keys or passwords
  • H04L9/0894—Escrow, recovery or storing of secret information, e.g. secret key escrow or cryptographic key storage
  • H04L9/0897—Escrow, recovery or storing of secret information, e.g. secret key escrow or cryptographic key storage involving additional devices, e.g. trusted platform module [TPM], smartcard or USB
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F2211/00—Indexing scheme relating to details of data-processing equipment not covered by groups G06F3/00 - G06F13/00
  • G06F2211/007—Encryption, En-/decode, En-/decipher, En-/decypher, Scramble, (De-)compress
  • G06F2211/008—Public Key, Asymmetric Key, Asymmetric Encryption
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F2221/00—Indexing scheme relating to security arrangements for protecting computers, components thereof, programs or data against unauthorised activity
  • G06F2221/21—Indexing scheme relating to G06F21/00 and subgroups addressing additional information or applications relating to security arrangements for protecting computers, components thereof, programs or data against unauthorised activity
  • G06F2221/2131—Lost password, e.g. recovery of lost or forgotten passwords
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L2209/00—Additional information or applications relating to cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
  • H04L2209/60—Digital content management, e.g. content distribution
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N5/00—Details of television systems
  • H04N5/76—Television signal recording
  • H04N5/91—Television signal processing therefor
  • H04N5/913—Television signal processing therefor for scrambling ; for copy protection
  • H04N2005/91357—Television signal processing therefor for scrambling ; for copy protection by modifying the video signal
  • H04N2005/91364—Television signal processing therefor for scrambling ; for copy protection by modifying the video signal the video signal being scrambled

Definitions

• This invention relates to the field of consumer electronics, and in particular to the recovery of published material that is recorded in an encrypted form.
• Digital recordings have the unique property that copies of the content material have the same quality as the original. As such, the need for an effective copy protection scheme is particularly crucial for the protection of content material that is digitally recorded.
• a number of protection schemes have been developed or proposed that record the content material in an encrypted form.
• Other protection schemes have been developed or proposed that record an encrypted key that controls the playback, or rendering, of the content material.
• a "smartcard" is used to decrypt the encrypted information.
• the smartcard contains a master key that is used to encrypt and decrypt the content material or to encrypt or decrypt another key that controls the rendering of the content material.
• the master key is contained within the recording or playback device, or within a content-access-module that is used to decrypt the content material.
• a smartcard or content- access-module is typically preferred, so as to allow the use of alternative or replacement recording or playback devices.
• a conventional method for alleviating the inconvenience and impact associated with the loss of a smartcard is to maintain a registry of each smartcard and its associated master key. Such a system, however, requires that the user have a means for identifying the particular smartcard after it is lost, or requires that the registry contain an identification of each user of each smartcard.
• the content material is intended to be published for use by the general public.
• This published material is encrypted to prevent it from being copied or used by persons other than those who have acquired the right to access the published material, and those who have acquired the right to access the material have no privacy rights or concerns regarding access to the material.
• the encryption process inconveniences those who have acquired the right to access the published material.
• the success of imposing the proposed encryption schemes for safeguarding copy protected published material will be highly dependent on the general public's acceptance of this inconvenience, and in particular, to any loss of value incurred due to a misplaced or defective decryption device.
• This objective and others are achieved by including an encryption of a master key with each recording that contains encrypted published material that requires the master key for decryption and subsequent processing.
• the master key is encrypted using a public key associated with a trusted authority. Should the smartcard be lost, or the decryption device become inoperative, any one of the recordings containing the encrypted master key is sent to the trusted authority for a retrieval of the master key.
• the trusted authority uses the private key corresponding to the public key that was used to encrypt the master key to determine the master key.
• the trusted authority is the vendor of the smartcard or other encryption decryption device, and provides a replacement smartcard or device containing the retrieved master key, typically for a fee, for subsequent use by the user to decrypt other recorded material in the user's collection.
• FIG. 1 illustrates an example block diagram of a system for recording encrypted published material in accordance with this invention.
• FIG. 2 illustrates an example flow diagram of a system for recording encrypted published material in accordance with this invention.
• FIG. 3 illustrates an example flow diagram for the retrieval of a master key in accordance with this invention.
• FIG. 1 illustrates an example block diagram of a system 100 for recording encrypted published material, such as audio content, audio-visual content, virtual-reality content, multi-media content, and the like, in accordance with this invention.
• published material is used in the general sense of content material that is recorded by one party for distribution to other parties, typically the general public. That is, the encryption of the material is not to preserve the secrecy of the content material, but rather to preserve the copy and viewing rights to the published material.
• An encryption device 110 receives the content material 101 and provides encrypted material to a recording device 130 for recording onto a medium 140.
• the content material 101 is often communicated from a source, such as a "pay-per-view" broadcaster, in encrypted form and decrypted locally.
• a source such as a "pay-per-view" broadcaster
• this decryption stage is not illustrated in FIG. 1 and is not discussed further in this disclosure.
• the encryption device 110 encrypts the content material using either a master key M 121 to produce an encryption E M (CM) 112, or a session key K to produce an encryption E (CM) 114.
• the master key M 121 is intended to remain constant for all encryptions of the particular system 100, and is commonly provided by, for example, a smartcard, illustrated in FIG. 1 as an access device 120.
• the access device 120 may be embodied within a separate access module, such as a set-top-box or other device.
• the session key K may change for each particular content material, or each content material classification, and may contain, for example, a ticket or other item that identifies the display or copy rights to the content material.
• the access device 120 that provides the master key M 121 also provides a public key P 122 that is associated with a trusted authority, such as the vendor of the access device 120.
• the public key P 122 is part of a public-private key-pair, the private key of the key-pair being a secret kept at the trusted authority. An item that is encrypted using the public key of the key-pair can only feasibly be decrypted by the private key of the key-pair.
• the encryption device 110 encrypts the master key M 121 using the public key P 122, and communicates the encrypted master key Ep(M) 111 to the recording device 130 for inclusion on the medium 140 with the encrypted content material E M (CM) 112 or E (CM) 114. If the encrypted content material is encoded using the session key K, the encryption device 110 also encrypts the session key K using the master key M, and provides an encrypted session key E M (K) 113 to the recording device 130 for inclusion on the medium 140 as well.
• a playback device 150 communicates the encrypted material 111, 112 or 111, 113, 114 from the medium 140 to the decryption device 160.
• the medium 140 may be any of a variety of recording mediums including magnetic tape, magnetic disks, laser disks, CDs, DVDs, and so on.
• the playback device 150 is a co ⁇ esponding device for reading the material on the medium. If the medium 140 is a hard disk drive, for example, the playback device 150 may be a computer system that reads files that are stored on a hard disk drive.
• the decryption device 160 can receive the master key from the access device 120, if required.
• the decryption device 160 If the content material CM 101 is encrypted using the session key K, as E ⁇ (CM) 114, and the decryption device 160 is privy to the session key K, it does not need the master key M 121 to decrypt a copy 1 O of the content material CM 101. If, on the other hand, the decryption device 160 does not have direct access to session key K, or the content material CM 101 is encrypted using the master key M 121, as E M (CM) 112, the decryption device 160 receives the master key M 121 from the access device 120 and provides thereafter a copy 101' of the content material CM 101. This copy 101' of the content material CM 101 is provided to a conventional rendering device 170 for presentation to the user in a suitable form.
• FIG. 2 illustrates an example flow diagram for recording encrypted content material in accordance with this invention, as may be effected by the encryption device 110 of FIG. 1.
• the use of a session key K, and the encryption of the session key K using the master key M is not illustrated in FIG. 2; the details for adding this option will be evident to one of ordinary skill in the art in view of this disclosure.
• the process commences upon receipt of the content material CM, at 210.
• the encryption device 110 receives a master key M and a public key P, at 220, typically from an access device 120 in FIG. 1.
• the encryption device 110 encrypts the master key M using the public key P, at 230, and records the encrypted master key Ep(M), at 240.
• the content material is encrypted, at 250, using the master key M, and the encrypted content material E M (CM) is similarly recorded, at 260.
• the recording of the encrypted master key Ep(M) and the encrypted content material E M (CM) is preferably stored on the same medium 140.
• FIG. 3 illustrates an example flow diagram for the retrieval of a master key M in accordance with this invention.
• FIG. 3 illustrates example actions that occur at a provider's locale and at a user's locale.
• the provider provides a master key M and a public key P to the user, the master key M and public key P being typically provided on a smartcard that is used to facilitate the encryption of copy-protected material via a conforming system 350.
• the master key M may be generated randomly on the smart card, and not known to the provider.
• a conforming system 350 effects and enforces the encryption and copy protection in accordance with these standards.
• the user Via the conforming system 350 that includes encryption, decryption, recording, and playback capabilities, the user is able to create a collection 360 of encrypted content material CM that conforms to the appropriate standards, and is able to decrypt and playback the encrypted content material CM, via the use of the provided master key M.
• the provider provides the user with a replacement master key M, via the following process, illustrated in FIG. 3.
• the user selects an individual encrypted recording 361 from the collection 360 and sends it to the provider.
• a copy of the recording 361 can be sent, provided that the copy contains an unmodified copy of the encrypted master key Ep(M).
• the provider decrypts the encrypted master key Ep(M), using the co ⁇ esponding private key p, at 320, and provides a replacement copy of the master key M and public key K, at 330, typically by sending the user a replacement smartcard in return for a servicing fee.
• FIG. 4 illustrates an example block diagram of a system for providing a replacement access device 120' in accordance with this invention.
• the playback device 410 accesses the encrypted recording 361 from the user's collection 360 of FIG. 3 to provide the encrypted master key Ep(M) to a decryption device 420.
• the decryption device 420 uses the private key p 401 to decrypt the encrypted master key Ep(M) to provide the master key M.
• a programming device loads the decrypted master key M, and the public key P co ⁇ esponding to the private key p 401 into the duplicate access device 120' that is sent back to the user, typically with the encrypted recording 361.
• the foregoing merely illustrates the principles of the invention. It will thus be appreciated that those skilled in the art will be able to devise various a ⁇ angements which, although not explicitly described or shown herein, embody the principles of the invention and are thus within its spirit and scope.
• controls may be incorporated into the process illustrated in FIG. 3 to assure that the number of copies of the master key M is limited.
• a simple record of the number of times a master key M is provided can be maintained, and further copies of the master key M may be precluded.
• providing each copy of the master key M can have an increasingly higher fee charged, or some other procedure employed, so as to make an unauthorized mass distribution of the same master key M economically infeasible, or highly inefficient.
• the access device 120 may be a programmable device that is downloaded with a master key M upon activation. Thereafter, the aforementioned process of replacing the access device 120 may include the downloading of a copy of the master key M, based on a transmission of encrypted master key Ep(M) to the downloading entity.
• Ep(M) encrypted master key

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• Engineering & Computer Science (AREA)
• Theoretical Computer Science (AREA)
• Computer Security & Cryptography (AREA)
• Signal Processing (AREA)
• Software Systems (AREA)
• Computer Hardware Design (AREA)
• Physics & Mathematics (AREA)
• General Engineering & Computer Science (AREA)
• General Physics & Mathematics (AREA)
• Multimedia (AREA)
• Technology Law (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing For Digital Recording And Reproducing (AREA)
• Storage Device Security (AREA)
• Television Signal Processing For Recording (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=23539874

Family Applications (1)

Country Status (5)

Families Citing this family (14)

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• 2000
  • 2000-08-16 EP EP00965881A patent/EP1145242A3/en not_active Withdrawn
  • 2000-08-16 KR KR1020017005512A patent/KR100748867B1/ko not_active IP Right Cessation
  • 2000-08-16 CN CN00801828A patent/CN1327586A/zh active Pending
  • 2000-08-16 JP JP2001522536A patent/JP2003509881A/ja not_active Withdrawn
  • 2000-08-16 WO PCT/EP2000/008054 patent/WO2001018807A2/en not_active Application Discontinuation

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