KR20070089582A - Method of managing a sek and a pek for a pay-per view based and service based broadcast subscriber and communication system thereof - Google Patents

Abstract

A method for managing SEK(Service Encryption Key) and PEK(Program Encryption Key) for a pay-per view based and service based broadcast subscriber and a communication system thereof are provided to enable a service only subscriber to access programs excepting PPV(Pay-Per View) service and a PPV only subscriber to access only PPV program and premium service subscriber to access all programs. A method for managing SEK(Service Encryption Key) and PEK(Program Encryption Key) for a pay-per view based and service based broadcast subscriber comprises the following steps of: receiving at least one encrypted key when a first service is served and receiving at least two encrypted keys when a second service is served; and connecting first service contents by using the one encrypted key and connecting second service contents by using the at least two encrypted keys.

Description

METHOD OF MANAGING A SEK AND A PEK FOR A PAY-PER VIEW BASED AND SERVICE BASED BROADCAST SUBSCRIBER AND COMMUNICATION SYSTEM THEREOF}

1 is an exemplary diagram showing a key scheme for conventional service protection and content protection.

FIG. 2 is another exemplary diagram illustrating a key usage procedure showing a procedure for using PEK and SEK in a PPV and a service-based subscription in a conventional BCAST service and content protection.

3 is an exemplary diagram illustrating the use of a program-specific key in a conventional BCAST channel.

4 is an exemplary diagram illustrating improved use of a program-specific key in a BCAST channel in accordance with the present invention.

5 is an exemplary view showing a key (KEY) system showing a procedure for using PEK and SEK according to the present invention.

The present invention relates to the management of service encryption keys and program encryption keys for BroadcastCAST (BCAST) services, and more particularly, to a key management method for pay-per view and service-based subscribers.

In general, BCAST refers to providing a broad broadcast service to a specific or unspecified number by shortening a mobile broadcast service in progress in the Open Mobile Alliance (OMA). That is, the BCAST service is a service for providing over-the-air broadcasting or various additional information to the mobile terminal. The BCAST service may provide useful information to a service provider to all users who subscribe to the service, or only to a specific user group that has already subscribed to a specific content or topic.

Here, the BCAST considers various IP-based networks currently being considered in broadcasting services in order to pursue an independent bearer. For example, the BCAST of 3GPP, BCMCS of 3GPP2, and DVB-T / H and the like are bearers being considered in the terminal broadcasting service of digital contents.

There are many functions that are considered within the BCAST, and manages the user's subscription service before providing the service so that the user can receive the broadcast service, and manages the service to be provided only to the user who subscribes to the specific service. The function of charge charging (fee charging) related to this, or the function to protect the specific service and content before the broadcast or in the transmission phase, and to broadcast the content or service encrypted in order to provide the service only to a user who has been authenticated in advance, or There are functions to manage users who have subscribed to BCAST service as a whole or manage user's subscription information and service preference information.

Here, more efficient service protection and content protection functions are required for safe protection of the contents provided by the BCAST service.

In order to understand such a conventional service protection and content protection function, it will be described with reference to FIG.

FIG. 1 is an exemplary diagram showing a key system for conventional service protection and content protection.

As illustrated in FIG. 1, in a registration step of a first layer, an authorization procedure of a device or a subscriber is performed. In this case, when the authentication procedure is associated with a Digital Rights Management (DRM) based profile, the right encryption key (Rights Encryption Key (REK)) is used by using the public key of the device. Pass by encrypting If the authentication procedure is related to a smartcard based profile, the subscriber management key (SMK) is used by using a smartcard key stored in a secure storage. ) Is encrypted and delivered.

In the second layer, a long-term key message is transmitted through a broadcast or interactive channel. A service encryption key (SEK) or a program encryption key (PEK) is encrypted by using the REK or SMK received from the first layer, and then transmitted.

In the third layer, a short-term key message is transmitted through the broadcast or interactive channel. A traffic encryption key (TEK) is encrypted and transmitted using the SEK or PEK received from the second layer.

The fourth layer encrypts the contents delivered through the broadcast channel using a traffic encryption key (TEK). In this case, the encryption may include a network layer (eg, IP), a transport layer (eg, UDP), a session layer (eg, RTP), or a content layer (AU encryption). Is performed in

2 is another exemplary diagram illustrating a key usage procedure showing the PEK and SEK usage procedures in the PPV and service-based subscription in the conventional BCAST service and content protection. This may also apply to DVB-H.

First, a registration layer performs a device authentication procedure. A right encryption key (REK) is encrypted and transmitted using a public key of the device.

In addition, service subscribers are issued SEKs and PPV subscribers are issued PEKs through a rights management layer.

Thereafter, the traffic encryption key (TEK) is transmitted in the form of E {PEK} (TEK) || E {SEK} (PEK) through a key stream layer. That is, in case of service subscriber, D {SEK} (E {SEK} (PEK)) is decrypted through SEK to get PEK and D {PEK} (E {PEK} (TEK)) is restored through PEK. (Decryption) to get TEK.

Finally, the traffic encryption layer encrypts the content delivered through the broadcast channel using a traffic encryption key (TEK).

3 is an exemplary diagram illustrating the use of a program-specific key in the conventional BCAST channel.

In general, in terms of BCAST protection, a service is one or more IP flows that are expected to be represented simultaneously. By way of example, the IP flows may be audio or video or other kind of service. Here, a program can be logically defined as a service with distinct start and end. In other words, the service can be viewed as a set of programs. The program can be classified into a general program accessible by subscribing to the service and a PPV program accessible by paying a separate fee for each program.

In general, all broadcast service subscribers can select and receive three types of services. The first is a general service (Service Only), the service subscriber can access only the general program provided in the channel, the PPV program is not accessible. The second is the PPV service (PPV Only), the service subscriber can access only the PPV program provided in the channel, the general program is not accessible. Finally, the Premium Service (Service & PPV) allows the subscriber to access both the general program and the PPV program.

3 shows that general programs and PPV programs are simultaneously serviced in one channel. At this time, in FIG. 3, when looking at the key management for each program of the BCAST channel, the general service subscriber can also access the PPV program. Because Short Term Key Message (STKM) is E {SEK} (PEK) || Since it is in the form of E {PEK} (TEK), general service (Service Only) and premium service (Service & PPV) are decoded PEK from SEK in the form of A case and then access program by decoding TEK from PEK. Because there is. In the case of the paper view (PPV Only) service, the program is accessed by decoding the TEK from the PEK in the B case. Therefore, when using the above STKM can not distinguish the premium service (Service & PPV) and the general service (Service Only). Therefore, it is not possible to distinguish between services of general service (Service Only), paper view service (PPV Only), and premium service (Service & PPV) through one BCAST channel.

Similarly, in OMA BCAST, general service subscribers and premium service subscribers receive SEK encrypted with REK in the case of DRM Based Profile through Long-Term Key message and then decrypt it with REK to obtain SEK. For Smartcard based profile, use SMK. SEK is encrypted and received through Long-Term Key message, and then decrypted with SMK to obtain SEK. In the case of the DRM Based profile, the PPV service subscriber receives the PEK encrypted with the REK through a Long-Term Key message and decrypts it with the REK to obtain the PEK. In the case of Smartcard based profile, the PEK is encrypted using the SMK, received through a long-term key message, and then decrypted with the SMK to obtain the PEK.

If the general program is being serviced on the channel, the general service subscriber and the premium service subscriber decode the TEK by decrypting the short-term key message, STKM: E {SEK} (TEK), which is encrypted by SEK with the SEK already owned. You can get this and access the program by decrypting the service with this TEK. Since the PPV service subscriber does not have a SEK, it cannot decrypt the delivered STKM and thus cannot obtain the TEK and thus cannot access the program.

If the PPV program is being serviced on the channel, the PPV service subscriber receives the short-term key message, STKM: E {PEK} (TEK) || E {SEK} (PEK) can be decrypted with a PEK already owned to get TEK, and the TEK can decrypt the service to access the program. The premium service subscriber can access the program by first obtaining the PEK from the SEK owned by the delivered STKM, obtaining the TEK from the PEK, and decrypting the service with the TEK. In this case, the general service subscriber should not be able to access the PPV program from the viewpoint of BCAST service protection and content protection. Available and access to the PPV program.

As such, in the conventional broadcast service connection, the general service subscriber should not be able to access the PPV program when using a program-specific key, but as with the premium service subscriber, the problem is accessible and thus the contents of the content in the broadcast service. There is a problem of poor protection

In the above-described prior art, access of the provided services is allowed or restricted according to a program subscriber's use of a program-specific key among the services provided by the broadcast service, as described above. Because no subscribers were identified, service subscribers had access to both PPV and general programs.

That is, in the related art, the general service subscriber may access the program encryption key PEK using the service encryption key received after the service encrypted key SEK is owned. However, changing the delivery method of the service encryption key and the program encryption key makes it possible to distinguish between general service subscribers and premium service subscribers. In addition, if the service encryption key and the program encryption key is managed as described above, the service provider may provide a service segmented into a PPV subscriber, a general service subscriber, and a premium service subscriber through one broadcast channel.

An object of the present invention is to solve the above problems, the present invention is to receive a service encryption key and a program encryption key to the premium service subscriber in the broadcast service access method. The present invention provides a method for managing a service encryption key and a program encryption key, the method for managing an encryption key for accessing a broadcast service,

Receiving one encrypted key if the user wants to receive the first service or at least two encrypted keys if the user wants to receive the second service; Accessing content of the first service using the one encrypted key or accessing content of the second service using the at least two encrypted keys. It may provide a method.

Preferably, the first service may be a service only or a pay-per view service.

Preferably, the second service may be a premium service including both the service only and the pay-per view service.

Preferably, the method may include registering the first service or the second service before the receiving process.

On the other hand, the present invention provides an encryption key management method for accessing a broadcast service in order to achieve the above object, comprising the steps of: checking the type of service subscribed to the terminal; After the verifying step, if the first broadcast service is provided to the terminal, one encrypted key is transmitted or if the second broadcast service is provided to the terminal, at least two or more encrypted keys are provided. It may provide a broadcast service method comprising the step of.

The type of the first broadcast service and the second broadcast service may include at least one service only, a pay-per view service, or the general service and a paper view service. It may be a premium service that includes all.

Preferably, the first broadcast service and the second broadcast service may be transmitted through one broadcast channel.

Preferably, the one encrypted key may be at least one service encryption key (SEK) or program encryption key (PEK).

Preferably, the at least two encrypted keys may include both the service encryption key SEK and the program encryption key PEK.

Preferably, a traffic encryption key (TEK) may be generated using the one encryption key or the at least two encryption keys for the first broadcast service or the second broadcast service.

Preferably, according to each broadcast type, the TEK may be encrypted using the SEK, or the TEK may be encrypted using the PEK.

Preferably, contents may be encrypted using the traffic encryption key (TEK) in a network layer, a transport layer, a session layer, or a content layer.

Preferably, the one encryption key may be generated using at least one Rights Encryption key (REK) or Subscriber Management Key (SMK).

Preferably, the right encryption key (REK) can be encrypted using the device's public key for a DRM-based profile.

Preferably, the subscriber management key (SMK) may be encrypted using the device's private key for a smart card based profile.

Preferably, the one encryption key may be transmitted through at least one broadcast channel or an interactive channel.

In addition, the present invention, in the encryption key management method for accessing the broadcast service in order to achieve the above object, a premium service including both a general service (service only) and a pay-per-view service (PPV) A broadcast service characterized in that a format of a Short Term Key Message (STKM) is transmitted by encrypting a TEK using a SEK or an encrypted TEK by using a PEK according to the type of a program currently being broadcast. It may provide a method.

One of the features of the present invention is that the inventors recognize the problems of the prior art described and described above, and have implemented the present invention based on such recognition.

Hereinafter, with reference to the accompanying drawings an embodiment according to the present invention will be described in detail.

4 is an exemplary diagram illustrating improved use of a program-specific key in a BCAST channel according to the present invention.

The present invention provides a service for a BCAST service that can provide a general service (Service Only, non PPV service), Paper View service (PPV Only), premium service (two or more services: Example) Service & PPV) in one channel A key management method can be provided. As described above, a service type provided through one BCAST channel may be classified into three types: general service (Service Only), paper view service (PPV Only), and premium service (Service & PPV). Of course, in addition to the three types of services may be further divided, for convenience of description, only the three types of cases are described herein. In the case of the general service (Service Only) subscriber, access to the general program except the PPV program is possible. In the case of the PPV Only subscriber, only the PPV program is accessible. The premium service (Service & PPV) subscribers can access all programs including the PPV program.

The general service (Service Only) subscriber may be issued an SEK through a long-term key message. Here, the traffic encryption key (TEK) can be delivered in the SEK encrypted Short-Term Key Message (STKM: E {SEK} (TEK)), so that the subscriber uses the SEK to transmit the TEK. Can be obtained. In addition, a program except for PPV may be transmitted after being encrypted by the TEK, and the subscriber may access by decrypting the corresponding program. The PPV Only subscriber cannot obtain the TEK from the STKM since the SEK is not issued, thereby restricting access to the general program.

The PAV subscriber can be issued a PEK through a Long-Term Key Message. Here, since the traffic encryption key (TEK) can be delivered as a short-term key message (STKM: E {PEK} (TEK)) encrypted with a PEK, the subscriber uses the PEK to transmit the TEK. You can get it. The PPV program can be delivered encrypted by the TEK, and the subscriber can access the program by decrypting the program. Service Only A subscriber cannot obtain the TEK from the STKM because the PEK is not issued, and thus access to the PPV program can be restricted.

The premium service (Service & PPV) subscriber may be issued a SEK and PEK through a Long-Term Key Message. The premium service (Service & PPV) subscriber may use the SEK-encrypted short-term key message (STKM: E {SEK} (TEK)) or the PEK-encrypted short-term key message (Short-Term Key Message). , STKM: E {PEK} (TEK)) can both decrypt. Therefore, both TEK used to encrypt a general program and TEK used to encrypt a PPV program can be obtained. The premium service (Service & PPV) subscriber can access both the general program and the PPV program using the TEKs.

Figure 5 is an exemplary view showing a key (KEY) system showing the PEK and SEK using procedures according to the present invention.

As illustrated in FIG. 5, an authentication procedure of a device or a subscriber may be performed in the registration step of the first layer. In this case, when the authentication procedure is associated with a Digital Rights Management (DRM) based profile, a right encryption key (Rights Encryption Key) may be used using a public key of a device. REK)) can be encrypted and delivered. If the authentication procedure is related to a smartcard base profile, a subscriber management key (SMK) is used by using a smartcard key stored in a secure storage. ) Can be encrypted and delivered.

In the second layer, a long-term key message may be transmitted through a broadcast or interactive channel. Here, the service encryption key (SEK) or program encryption key (PEK) may be encrypted and transmitted using the REK or SMK received from the first layer. Herein, the SEK subscriber may receive the SEK, the PAV subscriber may receive the PEK, and the premium service (Service & PPV) subscriber may receive the SEK and the PEK, respectively.

In the third layer, a short-term key message may be transmitted through the broadcast or interactive channel. A traffic encryption key (TEK) may be encrypted and transmitted using the SEK or PEK received from the second layer. That is, the access rights of the BCAST channel may be restricted so that only the subscriber who owns the SEK or PEK can view the TVAST channel according to a time and a broadcast program. The Service Only subscriber can decrypt only the TEK encrypted with the SEK, and the PPV Only subscriber can only decrypt the TEK encrypted with the PEK. The premium service (Service & PPV) subscriber can decode all the TEK since both the SEK and the PEK have been received. The TEK encrypted with the SEK and the PEK encrypted with the PEK are transmitted separately according to the nature of the program and are not transmitted simultaneously.

In the fourth layer, a content transmitted through the broadcast channel may be encrypted using a traffic encryption key (TEK). The encryption may include a network layer (eg, IP), a transport layer (eg, UDP), a session layer (eg, RTP), or a content layer (content layer). AU encryption).

Here, the present invention can be applied to various services or various additional services using the BCAST service as well as the BCAST service. That is, the BCAST supplementary services such as web casting, game delivery, or software update also manage web encryption, game contents, software services, and the like related thereto. The method may be modified, changed or improved in various ways.

The general service, premium service, and PPV service mentioned in the above description may refer to any channel accessible by using a specific encryption key, rather than a restriction to distinguish a paid program from a specific channel.

In the above described exemplary embodiments of the present invention by way of example, but the scope of the present invention is not limited only to these specific embodiments, the present invention in various forms within the scope of the spirit and claims of the present invention Can be modified, changed, or improved.

The present invention can provide all kinds of services (eg, Service Only, PPV Only, Service & PPV) through one BCAST channel. Service Only subscribers have access to programs excluding PPV services, PPV Only subscribers have access to PPV programs only, and premium service (Service & PPV) subscribers have access to all programs, including PPV programs. Keys can be managed.

That is, according to the present invention, in the encryption key management method for accessing the broadcast service, the PPV subscriber uses the PEK to change the structure in which both the program encryption key and the traffic encryption key can be accessed through the service encryption key. The program can be accessed and general service subscribers can use SEK to access another specific program, and only premium subscribers can use both PEK and SEK to access both of these and other specific programs. By making this possible, the general service subscribers are not allowed to access the PPV service, and the service subscription types are further subdivided into two types: PPV subscribers, general service subscribers, and premium service subscribers. In addition, the three types of services can be serviced through one channel.

Claims (17)

In the encryption key management method for accessing the broadcast service, Receiving one encrypted key if the user wants to receive the first service or at least two encrypted keys if the user wants to receive the second service; Accessing the content of the first service using the one encrypted key or accessing the content of the second service using the at least two encrypted keys. Service method. The method of claim 1, wherein the first service, Broadcast service method, characterized in that the general service (service only) or pay-per view (pay-per view) service. The method of claim 2, wherein the second service, And a premium service including both the general service and the pay-per view service. 4. The broadcast service method according to claim 3, comprising registering the first service or the second service before the receiving process. In the encryption key management method for accessing the broadcast service, Confirming the type of the service subscribed to by the terminal; After the verifying step, if the first broadcast service is provided to the terminal, one encrypted key is transmitted or if the second broadcast service is provided to the terminal, at least two or more encrypted keys are provided. Broadcast service method comprising the step of. 6. The method of claim 5, wherein the first broadcast service and the second broadcast service are of the type: And at least one general service (pay only) or pay-per view service or a premium service including both the general service and the pay view service. 6. The method of claim 5, wherein the first broadcast service and the second broadcast service are of the type: At least one general service (pay only) or pay-per view service, or a premium service including both the general service and the pay-per-view service. . The method of claim 5, wherein the one encrypted key, At least one service encryption key (SEK) or program encryption key (PEK). The method of claim 8, wherein the at least two encrypted keys are: And both the service encryption key (SEK) and the program encryption key (PEK). The method of claim 5, wherein the traffic encryption key (TEK),  And the one encryption key or the at least two encryption keys for the first broadcast service or the second broadcast service. The method according to claim 9 and 10, According to each broadcast type, the TEK is encrypted using the SEK, or the TEK is encrypted using the PEK broadcast service method. The method of claim 10, wherein contents are encrypted using the traffic encryption key (TEK) in a network layer, a transport layer, a session layer, or a content layer. Characterized in that the broadcast service method. The method of claim 5, wherein the one encryption key, A broadcast service method, characterized in that it is generated using at least one Rights Encryption key (REK) or Subscriber Management Key (SMK). The method of claim 13, wherein the right encryption key (REK), Broadcast service method, characterized in that encrypted using the public key of the device for the DRM-based profile. The method of claim 13, wherein the subscriber management key (SMK), Broadcast service method characterized in that the encryption using the private key of the device for the smart card-based profile. The method of claim 13, wherein the one encryption key is The broadcast service method, characterized in that transmitted through at least one broadcast channel (broadcast channel) or an interactive channel (interactive channel). In the encryption key management method for accessing the broadcast service, The format of the Short Term Key Message (STKM) on the premium service, which includes both general service (service only) and paper view service (PPV), is determined by using the SEK. A method of broadcasting services characterized in that the TEK is transmitted by encrypting or transmitting the TEK by encrypting the TEK.

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