WO2000004688A1 - Procede et appareil permettant d'utiliser un filigrane et une reference dependant du recepteur a des fins de protection contre la copie - Google Patents

Procede et appareil permettant d'utiliser un filigrane et une reference dependant du recepteur a des fins de protection contre la copie Download PDF

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Publication number
WO2000004688A1
WO2000004688A1 PCT/EP1999/004930 EP9904930W WO0004688A1 WO 2000004688 A1 WO2000004688 A1 WO 2000004688A1 EP 9904930 W EP9904930 W EP 9904930W WO 0004688 A1 WO0004688 A1 WO 0004688A1
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WO
WIPO (PCT)
Prior art keywords
ticket
receiver
content
source device
receiver dependent
Prior art date
Application number
PCT/EP1999/004930
Other languages
English (en)
Inventor
Michael Epstein
Original Assignee
Koninklijke Philips Electronics N.V.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US09/320,806 external-priority patent/US20030159043A1/en
Application filed by Koninklijke Philips Electronics N.V. filed Critical Koninklijke Philips Electronics N.V.
Priority to KR1020007002681A priority Critical patent/KR20010023966A/ko
Priority to EP99932875A priority patent/EP1034648A1/fr
Priority to JP2000560702A priority patent/JP2002521868A/ja
Publication of WO2000004688A1 publication Critical patent/WO2000004688A1/fr

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L63/00—Network architectures or network communication protocols for network security
    • H04L63/08—Network architectures or network communication protocols for network security for authentication of entities
    • 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]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/20—Servers specifically adapted for the distribution of content, e.g. VOD servers; Operations thereof
    • H04N21/23—Processing of content or additional data; Elementary server operations; Server middleware
    • H04N21/235—Processing of additional data, e.g. scrambling of additional data or processing content descriptors
    • H04N21/2351—Processing of additional data, e.g. scrambling of additional data or processing content descriptors involving encryption of additional data
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
    • H04N21/41—Structure of client; Structure of client peripherals
    • H04N21/426—Internal components of the client ; Characteristics thereof
    • H04N21/42684—Client identification by a unique number or address, e.g. serial number, MAC address, socket ID
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/60—Network structure or processes for video distribution between server and client or between remote clients; Control signalling between clients, server and network components; Transmission of management data between server and client, e.g. sending from server to client commands for recording incoming content stream; Communication details between server and client 
    • H04N21/65—Transmission of management data between client and server
    • H04N21/658—Transmission by the client directed to the server
    • H04N21/6582—Data stored in the client, e.g. viewing habits, hardware capabilities, credit card number
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/80—Generation or processing of content or additional data by content creator independently of the distribution process; Content per se
    • H04N21/83—Generation or processing of protective or descriptive data associated with content; Content structuring
    • H04N21/835—Generation of protective data, e.g. certificates
    • H04N21/8355—Generation of protective data, e.g. certificates involving usage data, e.g. number of copies or viewings allowed
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/80—Generation or processing of content or additional data by content creator independently of the distribution process; Content per se
    • H04N21/83—Generation or processing of protective or descriptive data associated with content; Content structuring
    • H04N21/835—Generation of protective data, e.g. certificates
    • H04N21/8358—Generation of protective data, e.g. certificates involving watermark
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L2463/00—Additional details relating to network architectures or network communication protocols for network security covered by H04L63/00
    • H04L2463/103—Additional details relating to network architectures or network communication protocols for network security covered by H04L63/00 applying security measure for protecting copy right

Definitions

  • This invention generally relates to a system for protecting copyrighted content. Specifically, the present invention pertains to utilizing a ticket, a watermark, and a receiver dependent reference to protect content.
  • a casual attacker is an ordinary consumer that is motivated to copy content for later use (time shifting) or for distribution to friends and relatives.
  • the level sophistication of a casual attacker is low.
  • the casual attacker will typically only use consumer equipment in an unmodified form.
  • a more aggressive casual attack may be mounted if a relatively inexpensive modification to consumer equipment is available. This may take the form of a hardware device such as the equipment used to defeat the Macrovision system.
  • a casual attacker will not open a product to access the internal connections.
  • a hacker is usually motivated to copy protected content just to see if it can be done.
  • the content may then be distributed widely in avoidance or in spite of copy protection laws.
  • An attacker of this type is often highly skilled and may go to great lengths to acquire content.
  • the financial resources of such an attacker are limited but the time resources can be high.
  • the content Once the content is acquired, the content may be distributed to friends and relatives.
  • the Internet may also provide an anonymous method for distributing the illegally copied content.
  • Both small-scale and commercial pirates are interested in defeating copyprotected content in order to produce and sell illegal copies of the content. By avoiding payments to the rightful owner of the copy-protected content, the pirates may reap large profits.
  • the pirate may take advantage of the difference in release windows in order access high value content and distribute it.
  • release windows are utilized to maximize profit from content.
  • the essence of these release windows is to first release the content to a premium service such as a pay-per-view service or a video on demand service. Thereafter, the content may be released on a lower price service such as a home-box-office service. At this time, the content may also be available to a consumer through a purchased storage medium such as a Digital Video Disc (DVD).
  • DVD Digital Video Disc
  • a successful copy protection scheme should at least frustrate a pirates attempt for a sufficient period of time till the legitimate owner of the content may reap their rightful profits.
  • the desired copy protection status may be "copy-once", “no-more-copy”, “copy-never”, and “copy-freely”.
  • Content that has a status of copy-once may be played and copied.
  • the copy- once content is altered such that the content is in the no-more-copy state.
  • Copy-never content is content that may only be played and may not be copied.
  • Copy-freely content may be played and copied without restriction.
  • the additional data may take the form of a digital watermark.
  • the watermark may be embedded directly into the content so that removal of the watermark will degrade the quality of the content.
  • the watermark may be utilized as part of the copy protection scheme.
  • the copy-freely state may be designated by the lack of a watermark within the content.
  • a transmission such as a digital transmission, is sent from a source device and received by a receiving device.
  • a source device is a device that is writing content onto a data bus, initiating a broadcast transmission, initiating a terrestrial transmission, etc.
  • a sink device is a device that reads content from the data bus, etc.
  • FIG. 1 shows a typical system for the transmission of content.
  • the source device is a broadcast initiator 101 that utilizes a transmitting antenna 102 to transmit content.
  • the sink device is a broadcast receiver, such as a set-top-box (STB) 104 that utilizes a receiving antenna 103 for receiving the transmitted content.
  • STB 104 is shown connected to a display device 105, a player 106, and a player/recorder 107, through a bus 108.
  • the term bus is utilized herein to refer to any system for connecting one device to another device.
  • the bus may be a hard wired system such as a coaxial wire, an LEEE 1553 bus, etc., or the bus may be a wireless system such as an infra-red (IR) or radio frequency (RF) broadcast system.
  • IR infra-red
  • RF radio frequency
  • the STB 104 may be a sink for the broadcast transmission and be a source for a transmission on the bus 108.
  • the player/recorder 107 may be a source/sink of a transmission to/from, respectively, the bus 108.
  • a watermark (W) is embedded within transmitted content. A ticket is transmitted along with the transmitted content.
  • the embedded watermark and the ticket together are utilized to determine the copy protection status of the transmitted content.
  • the watermark may be embedded into the content by at least two known methods. One method embeds the watermark (W) in the MPEG coding of the content. Another method embeds the watermark (W) in the pixel data of the content.
  • the ticket (T) is mathematically related to the watermark (W) as discussed in more detail below.
  • Performing one or more one-way functions on the ticket (T) derives the watermark (W).
  • one-way function what is meant is that it is computationally unfeasible to compute the inverse of the function.
  • An example of a publicly known mathematical one-way function is a hashing function, such as secure hash algorithm one (SHA-1) or RACE Integrity Primitives Evaluation Message Digest (RLPEMD).
  • SHA-1 secure hash algorithm one
  • RLPEMD RACE Integrity Primitives Evaluation Message Digest
  • the term unfeasible is intended to mean that the best method will take too long to be useful for a pirate.
  • the time that is required for a pirate to compute the inverse of a hashing function is too long for the pirate to frustrate the intended release window for protected content.
  • the most efficient method known to find such an x 0 may be to exhaustively search all possible bit combinations of x 0 and to compute and verify F(x 0 ) for each attempt. In other cases, there may be a more efficient method than an exhaustive search to compute an inverse of a one-way function, yet these methods are still too time consuming to be feasible for the pirate.
  • the bit content of the ticket (T) is generated from a seed (U).
  • the content owner provides the seed (U).
  • a physical mark (P) is created.
  • the physical mark (P) may be embedded on a storage medium such as a Read-Only Memory (ROM) disk. Performing one or more one-way functions on the physical mark (P), produces the ticket (T).
  • the number of functions performed on the physical mark (P) to create the ticket (T) depends on the copy protection intended for the content.
  • the ticket (T) changes state during every passage of a playback device (e.g., a source device) and a recording device (e.g., a sink device).
  • a playback device e.g., a source device
  • a recording device e.g., a sink device
  • the state modifications are mathematically irreversible and reduce the remaining copy and play rights of the content that are granted by the ticket (T).
  • the ticket (T) indicates the number of sequential playback and recordings that may still be performed and acts as a cryptographic counter that can be decremented but not incremented.
  • the copy protection scheme only protects content on compliant systems.
  • a compliant system is any system that obeys the copy protection rules described above and hereinafter.
  • a non-compliant system may be able to play and copy material irrespective of the copy protection rules.
  • a compliant system should refuse to play copies of content illegally made on a non-compliant system.
  • a physical mark (P) (e.g., data) is embedded on a storage medium and is not accessible by other user equipment.
  • the physical mark (P) data is generated at the time of manufacturing of the storage medium as described above and is attached to the storage medium in a way in which it is difficult to remove the physical mark (P) data without destroying the storage medium.
  • a one-way mathematical function such as a hashing function
  • the watermark is embedded in the medium (e.g., containing video, audio, or data) in such a way that it is infeasible to remove the watermark without destroying the material.
  • the watermark should be imperceptible when the medium is used in the usual manner, such as when content from the medium is displayed.
  • a watermark by itself may indicate whether or not content stored on the storage medium is copy-once or copy-never. For instance, the absence of a watermark may indicate that the content may be copied freely. The presence of the watermark without a ticket on a storage medium may indicate copy-never content.
  • the watermark is checked to see if the material is copy-freely, copy-once, or copy-never. When there is no watermark, the content is copy-freely and may be copied freely as discussed above. When the content contains a watermark but no ticket, the content is copy-never and a compliant recorder will refuse to copy the content. When the content is copy-once, the content contains both a watermark and a ticket, a compliant recorder will hash the ticket twice and compare the twice-hashed ticket to the watermark.
  • the content may be recorded along with a once-hashed ticket and the watermark, thereby creating copy- no-more content (e.g., content with a once-hashed ticket and a watermark).
  • the physical mark will be different on a writable disc and thus, even if an illegal copy is made of copy-never content via a non-compliant recording device, a compliant player will refuse to play the content recorded on the writable disc.
  • a copy-never state may be indicated by the presence of a once-hashed ticket and a watermark. Both copy-no-more stored content and copy-never broadcast content are treated by a compliant system similarly.
  • the content containing the once-hashed ticket may be played but may not be recorded in a compliant system.
  • a compliant recorder will first twice-hash the once-hashed ticket and compare the result (e.g., a thrice-hashed ticket) with the watermark. Since the thrice- hashed ticket will not match the watermark, the compliant recorder will refuse to record the content.
  • a non-compliant recorder receives content containing a ticket (a twice-hashed physical mark) and a watermark.
  • a non-compliant recorder does not alter the ticket upon receipt or recording (e.g., the non-compliant recorder makes a bit-for-bit copy)
  • the non-compliant recorder may make multiple copies of the ticket and the watermark that may be recorded on a compliant recorder.
  • a non-compliant recorder receives content containing a once-hashed ticket (a thrice-hashed physical mark) and a watermark indicating copy-no-more content. In this case, the non-compliant recorder may make multiple copies of the once-hashed ticket and the watermark that will play on the compliant player.
  • a physical mark can be embedded in the physical medium of the CD-ROM that is produced by an authorized manufacturer. The player may then check the physical mark to ensure that the content is being received from an authorized medium. In this way, if a pirate makes an unauthorized copy, the physical mark will not be present on the unauthorized copy and a compliant player will refuse to play the content.
  • this method of copy protection is unavailable.
  • a non-compliant player may deceive a compliant display device. Accordingly, it is an object of the present invention to overcome the disadvantages of the prior art.
  • the display device, etc. is the gatekeeper that disallows recordings that are made and played back on non-compliant player/recorders.
  • a copy protection system for protecting content, such as content containing a watermark embedded therein (e.g., watermarked content).
  • a receiver dependent ticket is created at a source device preferably utilizing a receiver dependent reference.
  • the receiver dependent reference is combined with a ticket utilizing a concatenation function and a oneway function (e.g., a hashing function).
  • the receiver dependent reference is transmitted from a receiver, such as a display device, an audio output device, a data output device, etc., to the source device prior to the source device transmitting watermarked content to the receiver.
  • the receiver dependent reference is also stored at the receiver. Thereafter, the source device transmits to the receiver watermarked content, the ticket, and the receiver dependent ticket.
  • the ticket is hashed twice and compared to the watermark in the usual way.
  • the stored receiver dependent identifier is combined with the ticket in the same way that the receiver dependent identifier was combined with the ticket at the source device.
  • a result of the combination is compared to the receiver dependent ticket. If the result equals the receiver dependent ticket, then the receiver is provided with access (e.g., enabled to display) to the watermarked content.
  • the receiver dependent identifier may be a fixed receiver serial number.
  • the serial number may be stored in a memory of the receiver or it may be a serial number, or a portion of a serial number from a component within the receiver, such as a processor serial number.
  • a certificate containing the public key of the source device is sent to the receiver prior to the above described process.
  • a public key known to the receiver may be used to verify the certificate.
  • the manufacturer should build (e.g., store) the public key used to verify the certificate into the receiver as is known in the art.
  • the receiver dependent ticket (the receiver dependent identifier concatenated with the ticket) may be encrypted utilizing a private key of the source device.
  • the encrypted receiver dependent ticket is then transmitted from the source device to the receiver along with the watermarked content and the ticket. Thereafter, prior to the receiver verifying the receiver dependent ticket, the receiver decrypts the receiver dependent ticket utilizing a public key of the source device.
  • the receiver dependent ticket may be signed (as is know in the art, by hashing the receiver dependent ticket and encrypting that hashed result) utilizing a private key of the source device.
  • the resulting signature is sent along with the watermarked content, the receiver dependent ticket, and the ticket to the receiver along with the watermarked content.
  • the receiver verifies the signature on the receiver dependent ticket utilizing a public key of the source device.
  • FIG. 1 shows a conventional system for the transmission of content
  • FIG. 2 shows an illustrative communication network in accordance with an embodiment of the present invention
  • FIG. 3 shows details of an illustrative communication network in accordance with embodiment of the present invention wherein a source device provides content to a sink device;
  • FIG. 4 shows a flow diagram in accordance with an embodiment of the present invention wherein a serial number is utilized as a unique receiver identifier and a private/public key system is utilized to further secure the receiver dependent ticket.
  • FIG. 2 depicts an illustrative communication network 250 in accordance with an embodiment of the present invention.
  • a source device 230 such as Set Top Box (STB), a Digital Video Disc (DVD), a Digital Video Cassette Recorder (DVCR), or another source of content, utilizes a transmission channel 260 to transmit content to a sink device 240.
  • the transmission channel 260 may be a telephone network, a cable television network, a computer data network, a terrestrial broadcast system, a direct broadcast satellite network, some combination thereof, or some other suitable transmission system that is know in the art.
  • the transmission channel 260 may include RF transmitters, satellite transponders, optical fibers, coaxial cables, unshielded twisted pairs of wire, switches, in-line amplifiers, etc.
  • the transmission channel 260 may also operate as a bi-directional transmission channel wherein signals may be transmitted from/to the source device 230, respectively, to/from the sink device 240.
  • An additional transmission channel 261 may also be utilized between the source device 230 and the sink device 240.
  • the transmission channel 260 is a wide-bandwidth channel that in addition to transmitting copy protection content (e.g., copy protection related messages), transmits copy protected content.
  • the transmission channel 261 typically is a low- bandwidth channel that is utilized to transmit copy protection messages.
  • the sink device 240 contains a memory 276 that is utilized for storing a receiver dependent identifier.
  • the memory 276 is a non-volatile storage, such as a programmable read-only memory (PROM), an electrically erasable PROM (EEPROM), a hard-wired electrical circuit, etc.
  • PROM programmable read-only memory
  • EEPROM electrically erasable PROM
  • the receiver dependent identifier in accordance with the present invention, is transmitted to the source device 230 utilizing at least one of the transmission channels 260, 261.
  • the source device 230 utilizes the receiver dependent identifier to change the ticket such that the watermarked content may only be utilized (e.g., played) by a corresponding sink device as described in more detail below.
  • the content may be provided to a device, such as a display device 265, for display thereon.
  • a display device 265 is integral to the sink device 240 such that the display device 265 is the final arbiter in determining whether the copy protected content may be utilized.
  • the device is illustratively shown as the display device 265, in fact the device may be any known device that may be suitably utilized for the copy protected content. For instance, in a case wherein the copy protected content is audio content, the device may be the device that outputs the audio signal.
  • the device may be any suitable device for manipulating the content that may include, video, audio, data, etc., or some combination thereof.
  • the content may be provided from the source device 230 in the form of a Moving Picture Experts Group (MPEG) compliant transport stream, such as an MPEG-2 compliant transport stream.
  • MPEG Moving Picture Experts Group
  • the present invention is not limited to the protection of an MPEP-2 compliant transport stream.
  • the present invention may be suitably employed with any other data stream that is known in the art for transmitting content.
  • the source device 230 may be a conditional access (CA) device.
  • the transmission channel 260 is a conditional access module bus.
  • FIG. 3 depicts details of an illustrative communication network 350 in accordance with an embodiment of the present invention.
  • a source device 330 provides content, including copy protected content, to a sink device 340, over a transmission channel 360.
  • the transmission channel 360 may be a wide bandwidth transmission channel that may also have a bi-directional capability, such as a CA module bus.
  • the sink device 340 contains a copy protection status determination circuit 370 for creating/storing a unique receiver identifier and for determining the copy protection status of received content.
  • unique is not necessarily intended to denote unique in an absolute sense. It is sufficient that there is a pool of numbers of sufficient size (e.g., the integers between 0 and 2 ⁇ 129), that the likelihood of a random selection of a particular one of the numbers is sufficiently small for a given application. Of a course, a smaller or larger pool of numbers may suffice for any particular application.
  • the copy protection status determination circuit 370 contains a memory device 376 for storing a unique receiver identifier.
  • the source device 330 may request the unique receiver identifier from the sink device 340 prior to transmitting copy protected content.
  • the sink device 340 may transmit the unique receiver identifier to the source device 330 as a portion of a request for the source device 330 to begin transmission of copy protected content to the sink device 340.
  • the sink device 340 may utilize either of the transmission channels 360, 361 for transmission of the request for copy protected content and/or for transmission of the unique receiver identifier.
  • the transmission channel 360 may be unidirectional and may only be utilized for the transmission of content to the sink device 340 from the source device 330.
  • the transmission channel 361 is utilized for the transmission of the unique receiver identifier from the sink device 340 to the source device 330.
  • the transmission channel 361 may also be utilized for transmitting a request for copy protected content from the sink device 340 to the source device 330.
  • the transmission channel 360 has bi-directional capability and may be utilized for transmissions both to and from the source device 330, and to and from the sink device 340.
  • the transmission channel 361 may not be present or it may be utilized solely for the transmission of content requiring low bandwidth.
  • the source device 330 may transmit to the sink device 340 a request for the transmission of the unique receiver identifier.
  • the source device 330 is a conditional access
  • the transmission channel 360 is a CA module bus 360
  • the sink device 340 is a display device 340.
  • the CA device 330 transmits a request for a unique receiver identifier (e.g., a receiver serial number (S)) from the display device 340.
  • the display device 340 transmits a unique serial number (S), that is stored in a memory 376, to the CA device 330 over the CA module bus 360.
  • S unique serial number
  • the serial number (S) is illustratively shown as stored in a memory, in fact, the serial number (S) may be stored or resident in any portion of the display device 340.
  • the serial number (S) may be a serial number of a processor, such as processor 314 (discussed in more detail below), the serial number (S) may be a fixed hardware configuration that may be interrogated by the processor 314, or the serial number (S) may be any other unique display device identifier that may be known in the art.
  • the serial number (S) should be unique (as discussed above) to a given display device, such as display device 340, such that the likelihood is high that another randomly selected display device has a different unique serial number.
  • the processor 314 utilizes a ticket and the serial number (S), received from the display device 340, to create a receiver dependent ticket (RDT) as discussed in more detail below.
  • RDT receiver dependent ticket
  • the processor 314 may simply be a fixed hardware device that is configured for performing functions, such as mathematical functions, including a concatenation function, a one-way function, such as a hashing function. In alternate embodiments, the processor 314 may be a microprocessor or a reconfigurable hardware device.
  • the copy protected content is received via an input 305 as an audio/video (A/V) signal.
  • the A/V signal contains a watermark (W) and a ticket (T).
  • the watermark (W) is embedded into the copy protected content. In this way, removal of the watermark (W) from the copy protected content will result in the copy protected content becoming largely degraded.
  • the ticket accompanies the content. However, in alternate embodiments the ticket may also be embedded into the watermarked content without affecting the inventive features of the present invention.
  • the copy protected content is read from a physical medium, such as a digital video disc (DVD).
  • DVD digital video disc
  • the DVD may contain a physical mark (P) as described Linnartz.
  • content contained on the DVD e.g., A/V content
  • W watermark embedded therein
  • the physical mark (P), the ticket (T), and the watermark (W) on the disk are related as follows:
  • the serial number (S) is combined with the ticket (T), utilizing for instance concatenation and hashing functions, thereby creating a receiver dependent ticket (RDT) as follows:
  • the watermarked content, containing a watermark (W) embedded therein, the receiver dependent ticket (RDT), and the ticket (T), are then transmitted via the CA module bus 360 to the display device 340.
  • the copy protection status determination circuit 370 extracts the watermark (W) from the watermarked content.
  • the copy protection determination circuit 370 retrieves the serial number (S) from the memory 376 (or from any other suitable location as discussed above) and combines the ticket (T) with the serial number (S), utilizing the same operation that was utilized at the source device 330 for creating the receiver dependent ticket (RDT). For instance, concatenation and hashing functions may be utilized at the display device 340 for combining the ticket (T) with the serial number (S). A result of the combination is then compared to the receiver dependent ticket (RDT):
  • the content is discarded and any selected operation at the display device 340 (e.g., play, record, etc.) regarding the content is disabled. This may happen, for instance, in a case wherein an improper display device (e.g., a display device other than the display device that requested the content) has received the content. If the result does equal the receiver dependent ticket (RDT), then access to the content is enabled in accordance with the access granted by the ticket.
  • RDT receiver dependent ticket
  • a trusted source should be utilized to create the recorded content or the real time transmitted content (e.g., received over the input 305).
  • a CA device such as the CA device 330, which is inherently designed to be tamper resistant is an example of a trusted real time source.
  • any trusted source that is known in the art may be suitably utilized.
  • the CA device 330 it may be assumed that the CA device 330 decrypts the watermarked content so that prior to the arrival of the watermarked content at the CA device 330, the watermarked content cannot be recorded.
  • the copy protected content is discarded.
  • the copy protection status determination process fails, no operation regarding the copy protected content is enabled at the display device 340.
  • a private/public key system is utilized to further secure the copy protected content in accordance with the present invention.
  • the display device 340 has a public key that is trusted, e.g., secure for example by being installed in part of the display device 340 hardware, such as stored in the memory 376.
  • the public key corresponds to a private key of the manufacturer of the display device 340.
  • the private key is stored, for instance, in a memory 322 at the CA device 330.
  • the private key is utilized to sign certificates of each CA device manufacturer, as is known in the art.
  • a certificate containing the CA device 330 public key is sent to the display device 340.
  • the public key of this CA device is stored at the display device 340.
  • the CA device 330 may digitally sign the receiver dependent ticket (RDT). For instance, a signature may be calculated by hashing the receiver dependent ticket (RDT) and encrypting the result utilizing the private key of the CA device 330.
  • the signature is sent from the CA device 330 to the display device 340 together with the watermarked content, the ticket, and the receiver dependent ticket (RDT).
  • the signature is verified utilizing the public key of the CA device 330.
  • the watermarked content, the ticket, the receiver dependent ticket (RDT), and the serial number (S) are utilized as described above.
  • the receiver dependent ticket (RDT) may be encrypted utilizing the private key of the CA device 330.
  • the encrypted receiver dependent ticket (RDT) is then transmitted from the CA device 330 to the display device 340 along with the watermarked content and the ticket (T). Thereafter, prior to the display device 340 verifying the serial number (S), the display device 340 decrypts the receiver dependent ticket (RDT) utilizing the public key of the CA device 330. Thereafter, the receiver dependent ticket (RDT) may be utilized as discussed above.
  • FIG. 4 shows a flow diagram 400 of an illustrative protocol for use of a serial number (S) and a private/public key system in accordance with an embodiment of the present invention.
  • step 405 in accordance with the present invention, after a CA device is connected to a receiver, the CA device sends a certificate containing the CA device public key to the display device.
  • an expiration date may also be attached to the certificate, although the use of an expiration date may not be practical in a consumer environment, where there is often no way to upgrade the certificate.
  • step 410 the display device verifies the certificate utilizing the embedded public key of the manufacturer and in step 415, stores the verified public key of the CA device.
  • step 420 in response to a request for copy protected content from the display device, the CA device requests a serial number (S) (the unique receiver identifier) from the display device.
  • step 425 the display device sends the serial number (S) to the CA device.
  • step 430 the CA device combines the serial number (S) with the ticket (T) utilizing concatenation and hashing functions to produce a receiver dependent ticket (RDT).
  • step 435 the CA device encrypts the receiver dependent ticket (RDT) utilizing the CA device private key.
  • the encrypted receiver dependent ticket (RDT) is then sent to the display device along with the watermarked content and the ticket (T).
  • the display device utilizes the public key of the CA device to decrypt the receiver dependent ticket (RDT).
  • the display device combines the ticket (T) with the serial number (S) utilizing concatenation and hashing functions and compares a result to the receiver dependent ticket (RDT). If the result is not equal to the receiver dependent ticket (RDT), then in step 475 access to the content is disabled. If the result is equal to the receiver dependent ticket (RDT), then in step 480, the ticket and watermark are compared in the usual way.

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

Abstract

L'invention concerne un système de protection du droit d'auteur. Un ticket dépendant du récepteur est calculé au niveau d'un dispositif de départ par combinaison d'un identificateur dépendant du récepteur avec un ticket. L'identificateur dépendant du récepteur est transmis du récepteur au dispositif de départ avant que ce dernier ne transmette un contenu filigrané au récepteur. L'identificateur dépendant du récepteur est également mémorisé au niveau du récepteur. Le dispositif de départ transmet ensuite au récepteur le contenu filigrané, le ticket ainsi que le ticket dépendant du récepteur. Au niveau du récepteur, l'identificateur dépendant du récepteur ayant été mémorisé est combiné avec le ticket de la même manière que l'identificateur a été combiné avec le ticket au niveau du récepteur. Le résultat de cette combinaison est comparé au ticket dépendant du récepteur. Si le résultat est égal au ticket dépendant du récepteur, le filigrane et le ticket peuvent être comparés selon la manière habituelle afin de déterminer le statut de protection contre la copie du contenu protégé.
PCT/EP1999/004930 1998-07-14 1999-07-09 Procede et appareil permettant d'utiliser un filigrane et une reference dependant du recepteur a des fins de protection contre la copie WO2000004688A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
KR1020007002681A KR20010023966A (ko) 1998-07-14 1999-07-09 복사방지용 워터마크 및 수신기 의존 레퍼런스를 이용하는방법 및 장치
EP99932875A EP1034648A1 (fr) 1998-07-14 1999-07-09 Procede et appareil permettant d'utiliser un filigrane et une reference dependant du recepteur a des fins de protection contre la copie
JP2000560702A JP2002521868A (ja) 1998-07-14 1999-07-09 ウォーターマークの使用方法及び装置及び、コピープロテクションのための受信機に依存した基準

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US9272598P 1998-07-14 1998-07-14
US60/092,725 1998-07-14
US09/320,806 US20030159043A1 (en) 1999-05-27 1999-05-27 Method and apparatus for use of a watermark and a receiver dependent reference for the purpose of copy pretection
US09/320,806 1999-05-27

Publications (1)

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WO2000004688A1 true WO2000004688A1 (fr) 2000-01-27

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PCT/EP1999/004930 WO2000004688A1 (fr) 1998-07-14 1999-07-09 Procede et appareil permettant d'utiliser un filigrane et une reference dependant du recepteur a des fins de protection contre la copie

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EP (1) EP1034648A1 (fr)
JP (1) JP2002521868A (fr)
KR (1) KR20010023966A (fr)
TW (1) TW431104B (fr)
WO (1) WO2000004688A1 (fr)

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GB2358313A (en) * 1999-12-20 2001-07-18 Ibm Unique watermarking of web documents
WO2002017635A2 (fr) * 2000-08-24 2002-02-28 Canal+ Technologies Societe Anonyme Transmission et traitement de contenu protege
EP1246382A3 (fr) * 2001-03-29 2011-05-18 CLARION Co., Ltd. Dispositif de reproduction de données et système de reproduction de données

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Publication number Priority date Publication date Assignee Title
US7509682B2 (en) * 2001-02-05 2009-03-24 Lg Electronics Inc. Copy protection method and system for digital media
KR100493284B1 (ko) * 2001-05-11 2005-06-03 엘지전자 주식회사 디지털 미디어의 복제 제어 방법 및 시스템

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WO1996027155A2 (fr) * 1995-02-13 1996-09-06 Electronic Publishing Resources, Inc. Systemes et procedes de gestion securisee de transactions et de protection electronique des droits

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US5432850A (en) * 1992-07-02 1995-07-11 Lannet Data Communications Ltd. Method and apparatus for secure data transmission
WO1996027155A2 (fr) * 1995-02-13 1996-09-06 Electronic Publishing Resources, Inc. Systemes et procedes de gestion securisee de transactions et de protection electronique des droits

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MACQ B M ET AL: "CRYPTOLOGY FOR DIGITAL TV BROADCASTING", PROCEEDINGS OF THE IEEE,US,IEEE. NEW YORK, vol. 83, no. 6, pages 944-957, XP000518745, ISSN: 0018-9219 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2358313A (en) * 1999-12-20 2001-07-18 Ibm Unique watermarking of web documents
WO2002017635A2 (fr) * 2000-08-24 2002-02-28 Canal+ Technologies Societe Anonyme Transmission et traitement de contenu protege
WO2002017635A3 (fr) * 2000-08-24 2003-05-22 Canal & Technologies Sa Transmission et traitement de contenu protege
US7848521B2 (en) 2000-08-24 2010-12-07 Thomson Licensing S.A. Transmitting and processing protected content
EP1246382A3 (fr) * 2001-03-29 2011-05-18 CLARION Co., Ltd. Dispositif de reproduction de données et système de reproduction de données

Also Published As

Publication number Publication date
EP1034648A1 (fr) 2000-09-13
JP2002521868A (ja) 2002-07-16
KR20010023966A (ko) 2001-03-26
TW431104B (en) 2001-04-21

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