CN1934852A - Method and system for selectively providing access to content - Google Patents

Abstract

A method of operating a digital program playback device, comprising: receiving, over a first communications network, a data stream representing a program comprising encrypted data portions; identifying an identifier associated with said program from the received data stream; transmitting the program identifier and a device identifier associated with the digital program playback device to an authorizing device by a second communications network; receiving the decryption key over the second communications network in response to the transmission; and , using the decryption key to decrypt the data stream and generate an output signal for playback of the program.

Description

Systems and methods for selectively providing access to content

technical field

The present invention relates to a method and system for restricting access to content such as computer programs, audio programs and audio/video programs.

Background technique

Wide distribution of content such as computer programs, audio programs and audio/video programs via eg transmission and/or pre-recorded media like CDs and DVDs is common. However, preventing unauthorized access to distributed high-value content proves to be problematic, especially in the case of over-the-air broadcasts and pre-recorded media. Current approaches use a variety of access protection techniques, including the use of, for example, smart cards, keys contained in the content that can be decrypted using a public key, and keys that must be entered to unlock the computer program.

Typically, digital rights management is not combined with copy protection systems to provide a comprehensive solution. For example, while copy protection schemes exist for closed systems (eg, satellite providers), these systems do not effectively incorporate digital rights management. Furthermore, digital rights management systems do not exist effectively for computer programs, nor have effective solutions been developed for mobile devices. Furthermore, there is effectively no means to provide specific keys for specific content. Finally, many systems have no means of reliably ensuring access to a two-way or two-way communication network to manage the copy protection process and associated digital rights. Improved mechanisms and techniques to overcome the above problems are highly desirable.

Contents of the invention

The present invention proposes a method of operating a digital program playback device, the method comprising: receiving over a first communication network a data stream comprising encrypted data portions representing a program; identifying from the received data stream the an identifier for the program; transmitting the program identifier and a device identifier associated with the program execution device to an authorizing device via a second communication network; in response to the transmission, receiving a decryption key via the second communication network; and using The decryption key decrypts the data stream and generates an output signal for program playback.

Description of drawings

An understanding of the invention will be facilitated by considering the following detailed description of the preferred embodiments of the invention when considered in conjunction with the accompanying drawings, wherein like numerals indicate like parts, and:

Fig. 1 shows the structural representation of the system according to the scheme of the present invention;

Figure 2 shows a schematic block diagram of a system well suited for use with computer software content in accordance with the aspects of the present invention;

Figure 3 shows a schematic block diagram of a system well suited for use with audio/video content according to the inventive arrangements;

FIG. 4 shows a block diagram of an exemplary playback process suitable for use with the system of FIG. 3;

5A and 5B show a schematic structural diagram of a structure that can be used for a client device according to the solution of the present invention;

Fig. 6 shows according to the solution of the present invention, a representative illustration of the mechanism for solving the time delay in network transmission;

Figure 7 illustrates a method according to an aspect of the present invention.

Detailed ways

It will be appreciated that while many other elements of a typical copy protection and digital rights management system and method have been removed for purposes of clarity, the drawings and description of the present invention have been simplified to illustrate the essentials that are relevant to a clear understanding of the invention element. Those of ordinary skill in the art will recognize that other elements and/or steps are desirable and/or required in the practice of the present invention. However, since such elements and steps are well known in the art and do not facilitate the understanding of the present invention, a detailed discussion of such elements and steps is not provided here.

According to the solution of the invention, it is possible to provide, using multiple delivery methods, a centralized mechanism of a communication network, such as a two-way paging network, as a means of accessing a decryption key to replay distributed encrypted content. The system can implement digital rights management (DRM) and copy protection (CP) mechanisms, and provide wireless access to support fixed location and mobile devices (for example, desktop personal computers, laptop computers, and fixed and mobile set-top boxes and display screen). In addition, the network used may provide an "always on" feature.

According to the solution of the present invention, the system can typically incorporate content and key servers, hardware implementations of security modules into client devices; key provisioning to facilitate copy protection and/or digital rights management schemes. According to the solution of the present invention, such a system and method can encourage content encryption since it is in fact unprofitable for "pirates" to copy content containing media that is encrypted but lacks the necessary decryption key itself. copying.

Referring now to FIG. 1 , there is shown a system 100 in accordance with aspects of the present invention. Generally, system 100 includes content server 110, key server 120, content distribution means 130 (e.g., wireless and/or wireline transmission systems, such as terrestrial and satellite television networks, global interconnection of computers with a computer network commonly referred to as the Internet, and wireline television and computer networks; and media distribution channels, such as retail distribution chains), client devices 140, and communications network 150.

Content (eg, computer software, audio and/or video programming) is typically created, digitized (if necessary), and stored on a content server (110). In an exemplary configuration, metadata about the content is associated with the content to uniquely identify the content. Key server 120 includes the following non-limiting examples: a database including content encryption/decryption keys, a unique content identifier, information about what device 140 is an authorized device, what device is playing or recording, or has the right to play or record content, and how many times each device 140 has played or recorded that particular content. Device 140 may be used to execute, play and/or record content, provided content server 110 allows it. Access to encrypted content occurs after client playback device 140 securely obtains the corresponding decryption key from key server 120 . The license may be transmitted over network 150, for example.

In an exemplary embodiment, the content may be provided through a content distribution facility 130, eg, through a broadcast or media distribution network. To record content, license lookup device 140 may securely contact key server 120 over network 150 to determine whether the device may copy subject content. For example, the subject content may be identified by companion metadata, broadcast channel/time information, or the content itself. Key server 120 may contact content server 110 via communication link 115 to determine digital rights management (DRM) information associated with the subject content, eg, whether requesting device 140 is authorized to play and/or record the subject content. If permissible, key server 120 may securely return the unique content identifier and recording key to requesting device 140 over network 150 . The requesting device may then use the information returned by the key server 120, eg, decryption and/or encryption keys, to record the subject content. Such an encryption key may be used to encrypt recorded content for storage. The storage key may be different from the key used to store the content on the content server 110 and/or protect the content from access until authorized by the key server 120 . Alternatively, received content can be stored in encrypted form, and the decryption key securely stored for later use.

As a non-limiting example, network 150 may take the form of a wireless communications network, such as a two-way pager network. Communications over network 150, such as a pager network (eg, between device 140 (FIG. 1) and key server 120 (FIG. 1), may be encrypted. Although not critical, a two-way pager network may be particularly advantageous for use as at least a portion of network 150 due to cost considerations. It is expected that such a network will provide a relatively low cost per transaction while providing widespread access over a wide geographic area. However, such a network introduces inherent latency in communications between device 140 and key server 120 . For example, delays of like 1, 5 or even 10 minutes may be experienced. However, a two-way pager network solves the connection problem for fixed-location client devices, eliminating the need for telephone modems and other broadband connections. Additionally, the same system can be used to provide connectivity for mobile client devices. For example, unauthorized access to communications over the network 150 may be secured by encrypting communications using a network 150 security key, or key pair.

Referring now to FIG. 2, there is shown a system 200 well suited for use with computer software content in accordance with aspects of the present invention. In FIGS. 1 and 2 , like reference numerals identify like elements. System 200 also includes a program/program creation system 210, which typically includes a number of elements of hardware/software for creating computer-executable code. The content can then be provided to content server 110 which can encrypt and store the content. Corresponding encryption/decryption keys and content identifiers may be provided to the key server 120 . Symmetric keys, or public/private key pairs can be used. Program identifiers can be in clear text, ie not encrypted. Encrypted content may be distributed using content distribution means 130, such as via CD, DVD or broadband network. Execution of the computer program may start at the personal computer 140 upon obtaining the corresponding decryption key from the key server 120 via the network 150 .

Still by way of non-limiting example, key server 120 may create corresponding entries in one or more databases reflecting program encryption/decryption keys, unique program identifiers, information about what devices are authorized devices information, what device is executing the content, and how many times the device has executed or is authorized to execute the specific content. The present invention envisions many possible implementations. In a simplified embodiment, the device may re-query the key server for each install, execution or replay. Optionally, permanent or time-based digital rights management information can be provided in the security processor. In such a case, the key may be valid for one or more installations, executions, or replays until the key expires, times out, or a predetermined number of allowed plays occur.

Since the encryption program does not contain an activation key, the encryption program can be provided for free copying. Encrypted content may be distributed using any type of content distribution means (eg, loading on DVD, Internet files, etc.). Computer execution of the encryption program takes place only after the same decryption, which requires the personal computer device 140 to obtain the decryption key from the key server 120 via the network 150 .

Referring now to FIG. 3, there is shown a system 300 well suited for use with audio/video content in accordance with aspects of the present invention. In FIGS. 1 and 3 , like reference numerals still identify like elements. System 300 also includes program/program creation system 310, which typically includes a camera, microphone, and hardware/software typically used to record audio/visual presentations like audio recordings, movies, and television. The system 310 can be used to create and digitize audio/video content. The content can then be provided to the content server 110 which can encrypt and store the content. A unique content identifier may be associated with encrypted content as metadata and provided in the clear. The corresponding encryption/decryption keys and content identifiers may be provided to and stored by the key server 120 . Encrypted content may be distributed using content distribution means 130, such as via CD, DVD or broadband network. Upon obtaining a corresponding decryption key from the key server 120 over the network 150, playback may occur at a playback device 140, such as a digital receiver or DVD player.

Still by way of non-limiting example, key server 120 may create corresponding entries in one or more databases reflecting program encryption/decryption keys, unique program identifiers, information about what devices are authorized devices information, what devices are authorized to play/record content, and how many times a device has accessed or is authorized to access specific content. Since an encrypted program does not contain an activation key, the encrypted program can be provided for free copying. Encrypted content may be distributed using any type of content distribution means (eg, broadcast transmission, loading on DVD, Internet file, etc.). Computer copying or playback of the encrypted program takes place only after the same decryption, which requires the personal computer device 140 to obtain the decryption key from the key server 120 via the network 150 .

Referring now to FIG. 4 , a block diagram of an exemplary playback process 400 suitable for use with the system 300 of FIG. 3 is shown. Playback device 140 determines the content identifier associated with the content to be played, for example, by reading the content to be played from a medium, such as a DVD or CD, that contains clear text identifiers and encrypted content. Playback device 140 may then contact key server 120 over network 150, which may take the form of a two-way pager network, for example. Key server 120 authenticates player device 140 and the unique program identifier. If replay is allowed, for example, if the content still has playback rights, the key server 120 uses the network 150 in a secure manner, and the corresponding decryption key (as a non-limiting example, may be a symmetric key, or a key corresponding part of the pair) to the playback device 140. Playback device 140 may use the obtained key to decrypt the replayed content and generate program content for decryption on the display device, such as via a display device communicatively coupled to the playback device (e.g., via an RCA cable or HDMI interface). The output signal 145 is reproduced.

Referring now to FIG. 5A, there is shown a schematic diagram of an architecture 500A that may be used with a client device, such as device 140 of FIGS. 1-4, in accordance with aspects of the present invention. For example, structure 500A may be used to enforce all security policies related to content recording by client device 140, and may even be incorporated into the device's audio/video decoder.

As a non-limiting example, structure 500A may include input 510 adapted to receive encrypted content from content distribution facility 130 (FIG. 1). For example, input 510 may take the form of an audio/video data decoder, or buffer, for receiving a data stream from an antenna or network connection, or a media drive. Received data may be stored in a storage device 540 such as a hard drive and read therefrom using the read/write interface 530 . The received data may be provided to encrypter/decryptor 520 . Content key register 550 may store keys used by encryptor/decryptor 520 and corresponding content identifiers. Structure 500A may also include modem 560 for communicating over network 150 ; and device identifier and network 150 security key storage 570 . Memory 570 may store a device identifier for a particular device 140 , as well as a network security key for network 150 . Architecture 500A may operate security processor 580 responsively. A/V or content data may be provided from any suitable source used as medium 130, such as a satellite tuner/demodulator, home network, or cable TV/demodulator. Network 150 communications (eg, wireless pager transmissions) are received through modem 560 (eg, a pager network modem).

In general, it is not desirable to store A/V content on device 540 in the clear in accordance with aspects of the present invention. Therefore, it is often desirable to encrypt A/V content prior to storage. The corresponding encryption key and unique content ID may be provided by key server 120 and sent over network 150 using modem 560 . Encryptor/decryptor 520 may use the encryption key to encrypt content before placing the encryption key in storage device 540 .

Referring now to FIG. 5B, there is shown a schematic diagram of an architecture 500B that may be used for a client device, such as device 140 of FIGS. 1-4, in accordance with aspects of the present invention. In FIGS. 5A and 5B , like reference numerals identify like elements. According to aspects of the invention, for example, structure 500B may be used to enforce all security policies associated with content playback by client device 140, and may even be incorporated into the device's audio/video decoder. Furthermore, structure 500B includes A/V decoder 515 and encrypter/decryptor 525 , which may optionally be the same encrypter/decryptor element 520 . Again, security processor 580 controls authentication and key handling. Public/private key pair encryption techniques may be used. After authenticating device 140 and specific content, security processor 580 receives (via network 150 and modem 560) an encrypted content key from key server 120 in response to the device and content identifier sent to key server 120. key. The content decryption key can then be written into register 550 (typically, register 550 is inaccessible except for secure processor 580) and used to decrypt the associated content using encryptor/decryptor 525 for use in The content of the decoder 515 is decoded. For example, the content may be recovered from memory 540 and decrypted.

Referring now to FIG. 6, FIG. 6 shows a representative diagram of a mechanism for addressing delays in network transmissions according to an aspect of the present invention. As previously mentioned, network 150 introduces latency into communications between device 140 and key server 120 . If there is too much latency in the system, users will not find the system usable. To hide transmission delays, access (e.g., execution, playback, and/or recording) of audio such as the first few minutes (e.g., 5-10 minutes) may be permitted before the content is identified by the key server 120 and/or the content server 110 /video program and return the result to device 140. Such execution may correspond to limited functionality of the computer program product. Such playback or recording can be used to implement the pause feature associated with digital video recorders (DVRs) (thus setting limits on how long content can be paused without permission to record the content). Recordings of the programming content may be stored in the clear during this interval, or encrypted using a common encryption key, which may be stored in multiple devices 140 .

As another non-limiting example, prior to retrieving the key from the key server 120, it is possible to allow A first portion 610 of the program/program content 600 is executed, played and/or recorded. Alternatively, portion 610 may correspond to limited functions according to the timing of computer program content or program functions. In the case of audio and/or video content, portion 610 may correspond to a portion of all programs/programs, such as the first few minutes. After some point 620, a portion of the content is secured 630 (eg, encrypted) using a key obtained from key server 120 .

Such a mechanism would present a number of advantages. Third-party content distribution may be encouraged. Furthermore, the content is identified prior to recording the content. This prevents unauthorized execution, playback and/or recording of the content. Digital rights management (DRM) is integrated at the heart of the key server. The key server can track the allowable permissions of each individual server device, or group of devices. If the allowable execute, play and/or record rights have been exceeded for a particular device or group of devices, the key will not be sent to the requesting client device. Additionally, DRM can be managed on a per customer basis (rather than a device basis) if customer billing information is provided. Finally, content encryption can be graded by any scale level. For example, each recorded segment of content may have a unique encryption key. To reduce latency, a large number of keys can optionally be stored in a secure structure.

Referring now to FIG. 7, there is shown a schematic block diagram representative of a method or process flow 700 in accordance with aspects of the present invention. Method 700 may well be used with the system of FIG. 3 and the processor of FIG. 4 . For example, similar methods can be used to record content, or to execute content.

Method 700 includes receiving 710 a data stream indicative of a program over a first communication network. In block 720, an identifier associated with the program is identified from the received data stream. The program identifier is then transmitted to the authorizing device over the second communications network, along with the device identifier associated with the accessing device (block 730). In block 740, in response to transmission 730, a decryption key is received over the second communications network. Then in block 750, the data stream is decrypted using the received decryption key and an output signal indicative of the decrypted data stream is output.

The received data stream may include a data portion representing a first portion of the program, and an encrypted data portion representing a second portion of the program. Typically, the first portion of data is accessible by a receiving device for processing and for outputting a signal indicative of the first portion of the program (block 760), independent of receipt of a decryption key for the second portion of the program. In an exemplary embodiment, a portion of data representing a first portion of the program is decrypted. In an alternative exemplary embodiment, the data portion may be encrypted using a public key that the receiver already has access to. Thus, in block 760, as prior to receiving the decryption key in block 740, the first data portion may be used to output a signal indicative of the first portion of the program. The steps of transmitting 730 and receiving 740 may be accomplished using a two-way pager network.

It is to be understood that the forms of the invention shown are exemplary embodiments only. Various changes may be made in the function and arrangement of parts; equivalent means may be substituted for those shown and described; and independent changes may be made without departing from the spirit and scope of the invention as defined in the claims. Use specific features with other features.

Claims (27)

1, a kind of method of operand word program playback device comprises:

By first communication network receive represent program, comprise enciphered data partial data stream;

The identifier that identification is associated with described program from the data flow that is received;

By the second communication network, described program identifier and described digital program playback device associated device identifier are transferred to authorisation device;

Respond described transmission, come the receiving and deciphering key by the second communication network; And

Use described decruption key that described data flow is decrypted, and generate the output signal that is used for described program playback.

2, the method for claim 1 also comprises: receive and represent program to begin the clear data stream of part, and also comprise: before receiving described decruption key, response clear data stream generates the step of output signal.

3, the method for claim 1 also comprises: receive and represent program to begin the public key encrypts data stream of part, and also comprise: before receiving described decruption key, respond public key encrypts data stream, generate the step of output signal.

4, the method for claim 1, wherein described digital playback device comprises mobile subscriber terminal, and described second communication medium comprises two-way pager network.

5, a kind of method that is used to be transmitted in the program of resetting on the digital playback device may further comprise the steps:

Encrypt the data flow of representing program;

The decruption key that will be used for decrypted data stream is stored in key server;

The playback right limit information that will be associated with digital playback device is stored in the database;

Transmit institute's data stream encrypted by first communication network;

By the second communication network, receive the request that described digital playback device is visited described program, described request comprises identifier related with described program and the identifier that is associated with digital playback device;

Response database determines whether described digital playback device has the access rights to described program; And

Respond described determining step, described decruption key is transferred to described digital playback device.

6, method as claimed in claim 5 also comprises by described first communication network, the clear data stream of the beginning part of the described program of transmission representative.

7, method as claimed in claim 5 also comprises by described first communication network, the public key encrypts data stream of the beginning part of the described program of transmission representative.

8, method as claimed in claim 5, wherein, described digital playback device comprises mobile subscriber terminal, and described second communication medium comprises two-way pager network.

9, a kind of method of operand word program recording apparatus comprises:

Come receiving data stream by first communication network, described data flow comprises first data division of the first that represents described program and the enciphered data part of representing the second portion of described program;

The identifier that identification is associated with described program from the data flow that is received;

By the second communication network, described program identifier and described digital program playback device associated device identifier are transferred to authorisation device;

Respond described transmission, come the receiving and deciphering key by described second communication network; And

Use described decruption key that described data flow is decrypted, and generate the output signal that is used to write down described program.

10, method as claimed in claim 9, wherein, the first of described program is the beginning part of described program, and also comprises: before receiving described decruption key, respond the step that described first data division generates output signal.

11, method as claimed in claim 9, wherein, described first data division is unencrypted or uses public-key encryption.

12, method as claimed in claim 9, wherein, described second communication medium comprises two-way pager network.

13, a kind of method of operational computations machine program execution apparatus comprises:

Data are conducted interviews, and described data comprise first data division of the first that represents described program and the enciphered data part of representing the second portion of described program;

The identifier that identification is associated with described program from the data of being visited;

By the second communication network, described program identifier and described program execution apparatus associated device identifier are transferred to authorisation device;

Respond described transmission, come the receiving and deciphering key by described second communication network; And

Use described decruption key to decipher the described enciphered data part of described program, and generate the output that is used to carry out described program.

14, method as claimed in claim 13, wherein, the described output that is used to carry out described program comprises: be used to activate the output with the part of the corresponding described computer program of described second portion.

15, method as claimed in claim 13, wherein, the described first of described program is the function limitation version of described computer program, and also is included in before the described decruption key of reception, response first generates the step of output signal.

16, method as claimed in claim 12, wherein, described first data division is unencrypted or uses public-key encryption.

17, method as claimed in claim 12, wherein, described second communication medium comprises two-way pager network.

18, a kind of computer program is stored on the computer-readable medium and with computing equipment and uses, and described computer program comprises:

First data division is represented the first of described computer program;

The enciphered data part is represented the second portion of described computer program;

Code is used for the program identifier that is associated with described computer program product from the identification of described first data division, and with described computing equipment associated device identifier;

Code is used for described program identifier and device identifier are transferred to authorisation device;

Code is used to respond described transmission, comes the receiving and deciphering key; And

Code is used to use described decruption key to decipher the described enciphered data part of described computer program, and generates the output that is used to carry out described computer program.

19, product as claimed in claim 18, wherein, the described output that is used to carry out described computer program comprises: activate the output with the function of the corresponding described computer program of described second portion.

20, product as claimed in claim 19, wherein, the described first of described computer program represents the function limitation version of described computer program, and also is included in before the described decruption key of reception, responds the step that first data division generates output signal.

21, product as claimed in claim 18, wherein, described first data division is unencrypted or uses public-key encryption.

22, product as claimed in claim 18, wherein, described second communication medium comprises two-way pager network.

23, a kind of method of client devices that optionally provide to the visit of content, described method comprises:

First data division of the first of the described content of visit representative and the enciphered data part of representing the second portion of described content;

The identifier that identification is associated with described content from the data of being visited;

Transfer to authorisation device with described program identifier with described client devices associated device identifier;

Respond described transmission and come the receiving and deciphering key;

Before receiving described decruption key, respond described first data division and generate output signal, so that visit the first of described content; And

Use described decruption key to decipher the encryption section of described data, and respond described decryption portion and generate output signal, for use in the second portion of the described content of visit.

24, method as claimed in claim 23, wherein, described content comprises at least one in representing of computer program, audio representation and audio/video.

25, method as claimed in claim 23, wherein, described provide visit comprise following at least one: computer program product, audio plays are represented, audio plays/representation of video shot, record audio is represented and record audio/representation of video shot.

26, method as claimed in claim 23, wherein, described transmission and reception are by two-way pager network.

27, method as claimed in claim 23, wherein, described first data division is unencrypted or uses public-key encryption.

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