KR20070096530A - Method and system for transmitting infromation btween entity in mobile broadcast system - Google Patents

Abstract

A method and a system for delivering information between network entities in a portable broadcasting system are provided to employ various business models by defining an interface between network entities forming a server in the portable broadcasting system. A BCAST subscription management(BSM) for managing subscriber information transmits a message requesting a traffic encryption key(TEK) to a BCAST service application(BSA) for generating broadcasting service data. A TEK response message is transmitted to the BSM after the BSA creates the TEK. The BSA transmits a TEK transmission message to the BSM. The BSM transmits a TEK confirmation message to the BSA. The messages are transmitted by using a tag field.

Description

Method of transmitting information between objects in mobile broadcasting system and system therefor {METHOD AND SYSTEM FOR TRANSMITTING INFROMATION BTWEEN ENTITY IN MOBILE BROADCAST SYSTEM}

1 is a block diagram showing a network configuration of a general portable broadcasting system;

2 is a block diagram showing a network configuration of a portable broadcasting system to which the present invention is applied;

3 is a diagram illustrating a protocol stack structure used for service protection and content protection in a mobile broadcasting system according to an embodiment of the present invention;

4A and 4B illustrate a procedure in which TEK transmission is performed through a CP-3 interface between a BSA and a BSM according to an embodiment of the present invention;

5A and 5B illustrate a procedure in which STKM transmission is performed through a CP-3 interface between a BSA and a BSM according to an embodiment of the present invention;

6A and 6B illustrate a procedure in which SEAK or PEAK is transmitted through a CP-3 interface between a BSA and a BSM according to an embodiment of the present invention;

7 is a block diagram showing a network configuration of a portable broadcasting system according to another embodiment of the present invention;

8 is a diagram illustrating a protocol stack structure used for service protection and content protection in a mobile broadcasting system according to another embodiment of the present invention;

9A and 9B illustrate a method of transmitting a TEK for content encryption to a BSA through a CP-2-3 interface in BSD / A according to an embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a broadcast service method and a system thereof in a portable broadcasting system, and more particularly, to a method and system for transmitting information for protecting services / content between network entities configuring a broadcast system.

The mobile communication market is continuously demanding the production of new services through recombination or integration of existing technologies. Today, due to the development of communication and broadcasting technologies, mobile terminals such as mobile phones and PDAs in conventional broadcasting systems or mobile communication systems are , A "mobile terminal"). IT is strengthening the mobile communication business by accommodating such potential and actual market demands, rapidly increasing user demands for multimedia services, strategies of operators to provide new services such as broadcasting services in addition to existing voice services, and demands of consumers. With companies' interests in mind, the convergence of mobile communication services and IP technologies is becoming a big trend in the development of next generation mobile communication technologies.

On the other hand, Open Mobile Alliance (OMA), an application standard organization of mobile terminals, is an organization that researches standards for interworking of individual mobile solutions. It is primarily responsible for setting application standards. In particular, the OMA BCAST working group (Open Mobile Alliance Browser and Content Mobile Broadcast Sub Working Group) of the working group of the OMA is studying a technology for providing a broadcast service using a mobile terminal. Hereinafter, a brief description will be given of a broadcast system (hereinafter, referred to as a "mobile broadcast system") discussed in the OMA BCAST working group.

1 is a block diagram showing a network configuration of a general portable broadcasting system.

In FIG. 1, a content provider (CC) 10 is a provider of a broadcast service (hereinafter, referred to as a "BCAST service"), and the BCAST service is a conventional voice / video broadcast service, a file (music file or data file) download service, or the like. The BCAST service application (BSA) 20 receives BCAST service data from the content provider 10 and processes the BCAST service data into a form suitable for the BCAST network of FIG. In addition to the role of generating the role of generating the standardized metadata for the portable broadcast service guide.

In FIG. 1, the BCAST service distribution / adaptation unit (BSD / A) 30 sets a bearer for transmitting BCAST service data supplied from the BCAST service application unit (BSA) 20. And determining a transmission schedule of the BCAST service and generating a portable broadcast guide. The BCAST Subscription Management (BSM) 40 manages subscriber subscription information for receiving the BCAST service, BCAST service provision information, and device information for the mobile terminal receiving the BCAST service.

In FIG. 1, the terminal 50 is a terminal capable of receiving a BCAST service, and has a function of being connected to a cellular network according to the capability of the terminal. In the description of the present invention, it is assumed that the terminal can be connected to the cellular network. In addition, in FIG. 1, the broadcast network 60 is a network for transmitting BCAST service, and may be, for example, DVB-H, MBMS of 3GPP, BCMCS of 3GPP2, or the like. The interactive network 70 is a network that transmits BCAST service one-to-one or exchanges control information and additional information related to receiving the BCAST service in both directions, and may be, for example, an existing cellular network.

In general, in the BCAST service, a plurality of mobile terminals receive the encrypted service data when the server managing the broadcast service is transmitted. In this case, the plurality of mobile terminals may use the corresponding service by decrypting encrypted service data provided from the server by using a predetermined encryption key previously stored in the terminal. In this regard, a method of encrypting broadcast content and a service is largely divided into two aspects, service protection and content protection. In this case, the service protection means protection of the transmission channel between the BCAST service distribution / adaptive unit (BSD / A) 30 and the mobile terminal 50, and the content protection is mobile with the BCAST service application unit (BSA) 20. Means end-to-end protection between the terminal (50).

However, in the current portable broadcasting system, specific methods such as encryption key and message transmission procedure for encrypting the broadcast service and / or content between entities constituting the broadcast system for secure transmission of the broadcast service and / or content are not presented. The presentation of the concrete plan is required.

Accordingly, an object of the present invention is to provide a method and system for protecting a broadcast service and / or content in a portable broadcasting system.

Another object of the present invention is to provide a method and system for generating and transmitting an encryption key and a message between entities constituting a broadcast system to protect a service and / or content in a portable broadcast system.

It is still another object of the present invention to provide a method and system for implementing a system that can be applied to various business models by defining interfaces between entities forming a server side in a portable broadcasting system.

In the portable broadcasting system according to an embodiment of the present invention, the information transfer method between entities in the portable broadcasting system includes a broadcast service subscription unit (BSM) that manages subscriber information in an information transmitting method for protecting a broadcast service broadcasted to a mobile terminal. Transmitting a message requesting an encryption key (TEK) to a BCAST service application (BSA) that generates broadcast service data; and after the BCAST service application generates a TEK, a TEK response message is sent to the broadcast service subscription unit. Characterized in that the transmission process.

In the portable broadcasting system according to an embodiment of the present invention, the information transfer system between entities in the portable broadcasting system is an information delivery system for protecting a broadcasting service broadcasted to a mobile terminal, and transmits a message requesting an encryption key (TEK). A broadcast service subscription unit (BSM) that manages subscriber information for transmitting data to a BCAST service application (BSA) generating data and receiving a response message for an encryption key request message from the BSA, and an encryption key request message from the BSM. And a BCAST service application (BSA) for generating a cryptographic key and transmitting a response message to the BSM in response to the TEK request message.

In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

First, a brief description of a basic method of performing service protection and content protection in a portable broadcasting system according to an embodiment of the present invention. The basic configuration of the portable broadcasting system to which the present invention is applied is shown in FIG. A service protection and content protection scheme in the portable broadcasting system will be described with reference to FIG. 2.

The content provided from the content provider (CC) 10 to protect the content is encrypted in the BCAST service application unit (BSA) 20 of FIG. 2 and broadcasted to the mobile terminal 50. The CP-A 22 provided in the BCAST service application unit (BSA) 20 generates a TEK, and transmits the generated TEK to the CP-E (CP-Ecryption) 21 to proceed with encryption of content. . The CP-E encrypts and broadcasts content

Unlike the content protection, the service protection encrypts the transport channel through which the BCAST service is provided by the BCAST service distribution / adaptive unit (BSD / A) 30. The SD (Stream Distribution) 31 provided in the BCAST service distribution / adaptive unit (BSD / A) 30 broadcasts the content in the form of a stream, and the File Distribution (FD) 32 provides the content in the form of a file. Broadcast The BCAST subscription management unit (BSM) 40 performs subscription management of the mobile terminal 50 for both service protection and / or content protection. CP-Management (CP-M) 41 provided in the BCAST subscription management unit (BSM) 40 performs encryption key generation and user terminal subscription management.

The SD-C (SD-Client) 52 provided in the terminal 50 transmits the encrypted stream content transmitted from the SD 31 to the CP-D (CP-D) 54 and decrypts the FD. File Distribution (-C) forwards the encrypted file content transmitted from FD 32 to CP-D 54 for decryption. The CP-C (CP-Client) 51 performs registration and subscription through an association with the CP-M 41, and obtains an encryption key for decrypting the encrypted content through the CP-D (CP-D). 54).

Related information of the encryption key used for the service protection and / or content protection and how to use is as follows.

The mobile terminal 50 registers as a service subscriber with the BCAST subscription management unit (BSM) 40 in order to use the services and contents broadcast from the broadcasting system of FIG. 1 and receives registration key data (RKM). . Thereafter, the mobile terminal 50 acquires a long-term key message (LKM) while subscribing to a service, and then uses a short-term key message (SKM) used to decrypt the actual encrypted service and content. ) Can be obtained.

In addition, the mobile terminal 50 may decrypt the LKM using the RKM, and as a result of the decryption, the mobile terminal 50 obtains a service encryption key (SEK) and a service authentication key (SAK). The SEK and SAK are included in the LKM and delivered to the mobile terminal 50 in an integrated form called a service encryption authentication key (SEAK).

The SKM includes a traffic encryption key (TEK), and the SKM is encrypted by the SEAK and a MAC (Message Authentication Code) function is applied to protect the TEK. The TEK obtained by decrypting by the SEAK may be used to decrypt an actual encrypted service and content.

The service protected through the encryption key is transmitted from the BCAST service distribution / adaptive unit (BSD / A) 30 to the mobile terminal 50 as shown in FIG. 2, and the protected content through the encryption key. Is transmitted from the BCAST service application unit (BSA) 20 to the mobile terminal 50.

Hereinafter, descriptions of the message schema table of the present invention as shown in Tables 1 to 6 are as follows. In <Table 1> to <Table 6>, "name" indicates a name for an element value and an attribute value configuring a corresponding message. "Type" means whether the name is in the form of an element value or an attribute value, the element value having the same value as E1, E2, E3, E4, E1 means the upper element value for the whole message, and E2 Is a lower element value of E1, E3 is a lower element value of E2, and E4 is a lower element value of E3. The attribute value is represented by A, where A represents the attribute value of the element. For example, A below E1 indicates an attribute value of E1. "Category" is used to distinguish whether the element or attribute value is mandatory or not, and M value if required and O value if optional. "Cardinality" represents a relationship between elements and has a value of 0, 0..1, 1, 0..n, 1..n. 0 means optional, 1 means mandatory, and n means that it can have multiple values. For example, 0..n means that there may be no element value or n values. "Description" indicates what the element or attribute value means, and "Data Type" indicates the data type for the element or attribute value.

Tables 1 to 6 below show the field configuration of the message defined in the present invention in order, and descriptions of each field of the message are specified in the corresponding table. And Table 7 below shows in which situation each of these messages apply. Hereinafter, an encryption key and a message for encrypting a service and content used in an embodiment of the present invention will be referred to as a traffic encryption key (TEK) and a short term key message (STKM), respectively.

Table 1 below defines the request message format Req-1.

<Table 2a> and <Table 2b> define the response message format Res-1.

Table 3 below defines the response message format Res-2.

Table 4 below defines the transmission message format Tra-1.

Table 5 below defines the confirmation message format Con-1.

Table 6 below defines the confirmation message format Con-2.

Finally, Table 7 below is used to classify each message type using "Tag" used in the message format defined in Tables 1 to 6. The "Tag" value defined below is not always fixed, but merely identifies the type of message and may change depending on the situation. In the response and acknowledgment messages, the Status field is generally "0" to indicate that the request and transmission message has been successfully received and performed. If "1", this indicates that the request or transmission message has not been received or performed. it means.

In addition, <Table 7> shows message type and applied message format according to Tag value, and each message has a shortened form using CKeyReqid or CKeyDeliveryid as shown in 'Applied message format' of <Table 7>. You can get performance improvements by using Res-2 or Con-2 messages.

3 is a diagram illustrating a protocol stack structure used for service protection and content protection in a portable broadcasting system according to an embodiment of the present invention. In particular, FIG. 3 illustrates a protocol stack that configures an interface for TEK delivery between the BSA 20 and the BSM 40 in content protection.

The BSA 20 and the BSM 40 may exchange data with each other by using a predetermined protocol. Data transmission protection between the BSA 20 and the BSM 40 can realize data protection regardless of the protocol and data on the top using HTTPS. Above the IPSec is the TCP protocol and HTTP, and above it, the CP-E 21 of the BSA 20 and the CP-M 41 of the BSM 40 for sending and receiving messages and related work on the interface. You can use HTTPS (HTTP over TLS) instead of HTTP to protect the interface. You can use either IPSec or HTTPS, and in some cases, both can be used to protect the interface.

4A and 4B illustrate a procedure in which TEK transmission is performed through a CP-3 interface between a BSA and a BSM according to an embodiment of the present invention.

Referring to FIG. 4A, the BSM 40 transmits a TEK request message to the BSA 20 requesting a TEK in step 401. The BSM 40 designates the Tag value of Table 1 as 1 to indicate that it is a TEK request message. After receiving the TEK request message, the BSA 20 generates a TEK in step 403 and transmits a TEK response message to the BSA 20. The BSA 20 transmits a TEK response message by designating Tag values of <Table 2a>, <Table 2b>, or <Table 3> to 2.

4B illustrates how the BSA 20 transmits a TEK without the request of the BSM 40.

Referring to FIG. 4B, the CP-A 22 of the BSA 20 designates a TEK transmission message as a tag value of 3 in Table 405 and includes the TEK in the data field in step 405. ) To the CP-M 41. In step 407, the BSM 40 designates the Tag value of <Table 5> or <Table 6> as 4 and sends it to the BSA 20.

In connection with FIG. 4, the TEK is passed to the BSM 40 and used to generate the STKM. In addition to TEK, other information may be required to generate the actual STKM. Thus, in Figure 4 it is specified that the STKM partially filled with TEK and other information in the data field of the message can be transmitted instead of TEK.

5A and 5B illustrate a procedure of performing STKM transmission through a CP-3 interface between a BSA and a BSM according to an embodiment of the present invention.

Referring to FIG. 5A, the BSA 20 transmits an STKM request message to the BSM 40 requesting the STKM in step 501. In order to indicate that the BSA 20 is a STKM request message, the BSA 20 transmits the Tag value of <Table 1> as 1. Then, the CP-M 42 of the BSM 40 generates an STKM in step 503, and then transmits an STKM response message to the BSA 20. When transmitting the STKM response message, the BSM 40 designates and transmits a Tag value of <Table 2a>, <Table 2b>, or <Table 3> to 2.

5B illustrates how the BSM 40 transmits STKM without requesting the BSA 20.

Referring to FIG. 5B, the CP-M 42 of the BSM 40 transmits an STKM transmission message to the CP-E 21 of the BSA 20 in step 505. When transmitting the STKM transmission message, the CP-M 42 of the BSM 40 transmits the STKM in the data field by designating 3 as a tag in Table 4. In step 507, the BSA 20 designates a Tag value of 4 in Table 5 or Table 6 as a confirmation message and transmits the Tag value to 4 to the BSM 40.

In order to generate the STKM message shown in FIGS. 5A and 5B, the BSM 40 must first receive the TEK from the BSA 20 according to the method of FIG. 4. However, for this purpose, the following method may be used in addition to the method of FIG. 4.

That is, in FIG. 5, when the BSA 20 adds new fields to the STKM request message transmitted to the BSM 40 and includes related information such as TEK, the BSA 20 transmits the STKM from the BSM 40 without performing the method of FIG. 4. It can be created. Alternatively, by adding one field and transmitting STKM partially filled with TEK, it is possible to prevent the addition of multiple fields.

6A and 6B illustrate a procedure in which SEAK or PEAK is transmitted through a CP-3 interface between a BSA and a BSM according to an embodiment of the present invention.

Referring to FIG. 6A, the BSA 20 transmits a SEAK / PEAK request message for requesting a SEAK / PEAK (Program Encryption Authentication Key) to the BSM 30 in step 601. At this time, the BSA 20 designates the Tag value of Table 1 as 1 to indicate that it is a SEAK / PEAK request message. Upon receiving the SEAK / PEAK request message, the BSM 40 generates a SEAK or PEAK in step 603 and transmits a SEAK / PEAK response message to the BSA 20. At this time, the BSM 40 transmits a Tag value of <Table 2a> and <Table 2b> or <Table 3> to 2 when transmitting a SEAK / PEAK response message.

6B illustrates how the BSM 20 sends SEAK / PEAK without requesting the BSA 40.

Referring to FIG. 6B, in step 605, the CP-M 42 of the BSM 40 includes a TEK in the data field by designating a SEAK / PEAK transmission message as a Tag value of 3 in Table 1 and including the TEK in the data field. Send to the CP-A 22. In step 607, the BSA 20 assigns the Tag value of <Table 5> or <Table 6> to 4 as a confirmation message and transmits the Tag value to the BSM 20.

7 is a block diagram illustrating a network configuration of a portable broadcasting system according to another embodiment of the present invention. A service protection and content protection scheme in the portable broadcasting system will be described with reference to FIG. 7.

In the portable broadcasting system of FIG. 7, the BSD / A 30 includes a CP-KD 33 for generating a TEK. The CP-KD 33 generates a TEK and transmits the TEK to the CP-E 21 of the BSA 20.

8 is a diagram illustrating a protocol stack structure used for service protection and content protection in a portable broadcasting system according to another embodiment of the present invention. In particular, FIG. 8 illustrates a protocol stack between CP-2-3 interfaces between BSA 20 and BSD / A 30 in content protection.

It uses IPSec to protect the safety between interfaces and transmits protocols related to service protection methods through TCP and HTTP. It manages the information transmitted between the BSA 20 and the BSD / A 30. The information includes a Traffic Encryption Key (TEK). You can use HTTPS (HTTP over TLS) instead of HTTP to protect the interface. You can use either IPSec or HTTPS, and in some cases, you can use both to protect the interface. You can use HTTPS (HTTP over TLS) instead of HTTP to protect the interface. You can use either IPSec or HTTPS, and in some cases, you can use both to protect the interface.

9A and 9B illustrate a method of transmitting a TEK for content encryption to a BSA through a CP-2-3 interface in BSD / A according to another embodiment of the present invention. In another embodiment of the present invention, when encrypting the content in the BSA 20 in the content protection method, it is used to receive the TEK from the BSD / A 30 and use the content for encryption.

Referring to FIG. 9A, the BSA 20 transmits a TEK request message to the BSD / A 30 requesting a TEK in step 901. In order to indicate that the BSA 20 is a TEK request message, the Tag value of Table 1 is set to 1. After receiving the TEK request message, the CP-KD 32 of the BSD / A 30 generates a TEK in step 903 and then transmits the TEK response message to the BSA 20 as a response message. When transmitting the TEK response message, the CP-KD 32 of the BSD / A 30 designates and transmits a Tag value of <Table 2a> and <Table 2b> or <Table 3> to 2.

9B illustrates how BSD / A transmits a TEK without requesting a BSA.

9B, the BSD / A 30 and 30 transmit a TEK transmission message to the CP-E 21 of the BSA 20 in step 905. When transmitting the TEK transmission message, the BSD / A 30 and the 30 specify a Tag value of 3 in Table 4 and transmit the TEK in the data field.

The BSA 20 transmits an acknowledgment message to the BSD / A 30 and 30 in step 907. When the BSA 20 transmits an acknowledgment message, the BSA 20 assigns a Tag value of 4 to the BSD / A 30 and 30.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications may be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the scope of the following claims, but also by those equivalent to the scope of the claims.

In the present invention operating as described in detail above, the effects obtained by the representative ones of the disclosed inventions will be briefly described as follows.

The present invention can protect broadcast services and / or content in a portable broadcast system.

In addition, the present invention may generate and transmit an encryption key and a message between entities constituting the broadcast system to protect a service and / or content in the portable broadcast system.

In addition, the present invention can implement a system that can be applied to a variety of business models by defining the interface between each entity forming the server side in the portable broadcasting system.

Claims (11)

In the information transmission method for the protection of a broadcast service broadcasted to a mobile terminal in a portable broadcasting system, Transmitting, by a broadcast service subscription unit (BSM) managing subscriber information, a message requesting an encryption key (TEK) to a BCAST service application (BSA) generating broadcast service data; And transmitting, by the BCAST service application, the TEK, and then transmitting a TEK response message to the broadcast service subscription unit in a portable broadcasting system. The method of claim 1, Transmitting, by the BCAST service application, an encryption key (TEK) transmission message to a broadcast service subscription unit; And transmitting, by the broadcast service subscription unit, a TEK confirmation message to the BCAST service application. The method of claim 1, The information transmission method for the protection of a broadcast service broadcasted to a mobile terminal in a mobile broadcasting system, characterized in that the transmission using the tag field. In the information transmission method for the protection of a broadcast service broadcasted to a mobile terminal in a portable broadcasting system, Transmitting a message requesting a message (STKM) to a broadcast service subscription unit (BSM) that manages subscriber information by a BCAST service application (BSA) generating broadcast service data; And transmitting a response message to the broadcast service subscription unit by the broadcast service subscription unit to a message requesting STKM. The method of claim 4, wherein Transmitting, by the BCAST service application, a message (STKM) transmission message to a broadcast service subscription unit; And transmitting, by the broadcast service subscription unit, a message (STKM) confirmation message to the BCAST service application. The method of claim 4, wherein And transmitting the messages using a tag field. In the information transmission method for protection of a broadcast service broadcast to a mobile terminal in a portable broadcasting system, Transmitting, by a broadcast service subscription unit (BSM) managing subscriber information, a message requesting a service encryption and authentication key (SEAK / PEAK) to a BCAST service application (BSA) generating broadcast service data; And transmitting, by the BCAST service application, a response message to the broadcast service subscription unit in response to the message requesting TEK to the broadcast service subscription unit. The method of claim 7, wherein Transmitting, by the BCAST service application, an encryption key (TEK) transmission message to a broadcast service subscription unit; And transmitting, by the broadcast service subscription unit, a TEK confirmation message to the BCAST service application. The method of claim 7, wherein And transmitting the messages using a tag field. In the information transmission method for protection of a broadcast service broadcast to a mobile terminal in a portable broadcasting system, Transmitting, by a BCAST service application (BSA) generating broadcast service data, a message requesting an encryption key (TEK) to a broadcast service distribution / adaptive unit (BSD / A) that transmits broadcast service data; Generating a TEK in the broadcast service distribution / adaptive unit, and then transmitting a TEK response message to a BCAST service application; and a method of transmitting information for protecting a broadcast service broadcast to a mobile terminal in a portable broadcasting system. . An information delivery system for protecting a broadcast service broadcast from a portable broadcasting system to a mobile terminal, Broadcast service subscription unit for transmitting a message requesting the encryption key (TEK) to the BCAST service application (BSA) for generating broadcast service data, and manages subscriber information for receiving a response message to the encryption key request message from the BSA ( BSM), And receiving a cryptographic key request message from the BSM, generating an encryption key, and transmitting a response message to the BSM requesting the TEK to the BSM. system.

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