KR100999653B1 - Content playing system for having a smart card and the smart card - Google Patents

Abstract

According to one aspect of the invention, a content playback system is disclosed. The content playback system according to an embodiment of the present invention releases the DRM (Digital Right Management) applied to the N (natural number) packet of the content provided by the streaming method, and the NRM original packet from which the DRM is released to the content playback terminal. And a content reproducing terminal receiving the N th original packet from the smart card to be delivered and the smart card, and requesting the N + 1 th packet to the content providing server. According to the present invention, it is possible to achieve a thicker content protection by applying DRM technology without adding a separate process between the server providing the existing streaming service and the receiving terminal, streaming based on the smart card web server function By applying DRM to a service, there is an advantage in that it can propose a technique for supplementing an area not defined in the OMA standard.

Streaming, DRM, Permissions, Smart Card Web Servers

Description

Content playing system and smart card including the smart card {Content playing system for having a smart card and the smart card}

The present invention relates to a content reproduction system for receiving and playing content to which DRM is applied in a streaming manner, and more specifically, to release and play DRM of streaming service content by using a permission stored in a smart card mounted on a content reproduction terminal. A content reproduction system.

Due to the development of Internet-related technologies, the distribution of digitally produced contents is becoming active. However, these digitally produced contents have difficulty in sanctioning illegal use, ie illegal copying and dissemination.

Accordingly, digital rights management (hereinafter referred to as "DRM") technology has emerged as a technology for solving this problem.

In general, DRM is a technology for securely protecting and systematically managing rights object (RO) for digital content. It is used to prevent illegal copying of content and to acquire the right to use content, to create and distribute content, and to use the content. Provide a set of protection and management mechanisms for

DRM technology can protect content from users who do not have access rights. Specifically, the content provider provides the content protected using a specific encryption key, and the user is issued a use right required to decrypt the encrypted content.

On the other hand, rather than a download method of storing and playing content directly to the terminal, a method of preventing unfair use of digital content through a streaming method capable of real-time playback only and the content is not stored in the terminal after playback. It has emerged.

However, in the related art, when content is provided by a streaming method, it is difficult to apply DRM to content.

On the other hand, smart cards are recognized as an essential component in 3G mobile communication. However, although the possibility of using a smart card installed in a communication terminal is increased due to the development of communication technology and integrated technology, the use example has a problem of only a basic part.

Accordingly, an object of the present invention is to provide a content reproducing system that is provided to solve the above-mentioned problems, and receives and plays content provided by a DRM applied streaming method.

In addition, another object of the present invention is to provide a streaming service using a smart card to perform a smart card web server function, the content playback system for playing the content by releasing the DRM applied to the streaming service content using the stored permissions To provide.

According to one aspect of the invention, a content playback system is disclosed.

The content reproduction system according to an embodiment of the present invention releases DRM (Digital Right Management) applied to the N (natural number) packet of the content provided by the streaming method, and reproduces the content of the N-th original packet from which the DRM is released. Smart card to deliver to the terminal; And a content playback terminal that receives and plays the Nth original packet from the smart card and requests an N + 1th packet to the content providing server.

According to another aspect of the invention, a smart card is disclosed.

The smart card according to another embodiment of the present invention receives a connection request from the content playback terminal to a content providing server that provides a streaming service, and connects to the content providing server via the content playback terminal according to the access request. A smart card web server module; And a DRM agent for releasing Digital Right Management (DRM) applied to an N (natural number) packet of the content provided by the content providing server in a streaming manner via the content reproducing terminal, wherein the DRM is released. The second packet is delivered to the content reproduction terminal and reproduced.

Therefore, the present invention has a better content protection effect by applying the DRM technology without adding a separate process between the server providing the existing streaming service and the receiving terminal.

In addition, the present invention has the effect of providing a technology that supplements the area not defined in the OMA standard by applying DRM to the streaming service based on the smart card web server function.

In addition, the present invention has the effect of storing the usage rights in the smart card, to utilize the mobility of the smart card in streaming services.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms including ordinal numbers, such as second and first, may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the second component may be referred to as the first component, and similarly, the first component may also be referred to as the second component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

It is intended to clarify that the division of the components in the present specification is only divided by the main function of each component. That is, two or more components to be described below may be combined into one component, or one component may be provided divided into two or more for each function. Each of the components to be described below may additionally perform some or all of the functions of other components in addition to the main functions of the components, and some of the main functions of each of the components are different. Of course, it may be carried out exclusively by. Therefore, the presence or absence of each component described through this specification will be to be functionally interpreted.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, and the same or corresponding components will be denoted by the same reference numerals regardless of the reference numerals and redundant description thereof will be omitted.

Prior to the detailed description of the drawings, the content playback terminal and the smart card of the present invention will be described first.

The content reproduction terminal is a PDA (Personal Digital Assistant), cellular phone, PCS (Personal Communication Service) phone, WCDMA phone, CDMA-2000 phone, MBS (Mobile Broad and System) phone, PC (Personal Computer), handheld PC (Hand) It includes a communication terminal for transmitting and receiving data with the wired and wireless communication network 120, such as a Held PC) and a notebook PC (Notebook PC).

Hereinafter, an example in which the content reproducing terminal is equipped with a smart card and performs a packet communication with a specific server through a communication network or performs a circuit or packet communication with another communication terminal will be described as a representative example.

Smart cards are UMTS Subscriber Identity Module (USIM) used in Wideband Code Division Multiple Access (WCDMA) technology, User Identity Module (UIM) or Removable User Identity Module (R-UIM) used in Code Division Multiple Access (CDMA) technology. Various names, such as the name that may include the Universal Identity Card (UICC) used in the Subscriber Identity Module (SIM) used in Global System for Mobile Communications (GSM) technology and a comprehensive technology including all three technologies. Can be used as

The communication terminal may be provided with a third generation mobile communication service using a smart card. This can be applied to not only a communication terminal but also a portable communication terminal such as a notebook.

The smart card of the present invention can be used not only for the mobile communication service entering the third generation but also for the wireless portable Internet service that can be represented by Wibro (Wireless Broadband). However, the following description will focus on the case where the smart card is mounted in the communication terminal.

The function of the smart card basically stores subscriber information for identifying and authenticating subscribers when a mobile communication service or an Internet service is provided, and identifies and authenticates subscribers in a communication network by reading and transmitting the subscriber's information. Do it. Accordingly, the communication service subscriber can be provided with a communication service that is not dependent on the communication terminal, in particular a mobile communication service. That is, when any communication terminal connects the smart card of the communication service subscriber to the communication terminal, the communication service can be provided due to the subscriber identification information stored in the smart card.

However, due to the recent development of integrated circuit and smart card manufacturing technology, smart cards have been added to arithmetic processing functions, auxiliary arithmetic processing functions, and large-capacity memory in addition to these basic functions, and are now capable of performing functions as independent terminals. .

The smart card of the present invention is a smart card equipped with a processor having such a large memory and arithmetic processing function. Based on the hardware basis of such a smart card, by executing various applications in the smart card itself and transmitting the result to the communication terminal, it is possible to receive the execution result of the application offline in the communication terminal.

Among them, a smart card web server (SCWS) is one that emerges as a means of receiving a performance result of an application of a smart card from a communication terminal.

The smart card performs the function of the smart card web server as defined in the Open Mobile Alliance (OMA) standard, and basically communicates web page documents (Static or Dynamic HTML pages) at the request of the browser (client) of the communication terminal. Can be delivered to the terminal.

In this case, the smart card needs an environment for exchanging data with the mobile communication terminal, which can exchange data by TCP / IP using a bearer independence protocol (BIP) or a USB environment.

BIP is a protocol that allows data communication between an external node and a smart card mounted in a communication terminal using a packet network (GPRS / UMTS packet bearer, Bluetooth, IrDA, etc.) supported by the network. For data communication using BIP, all communication terminals, smart cards, and external nodes must support BIP.

However, the smart card of the present invention can support TCP / IP data communication in a universal serial bus (USB) environment as defined in the Open Mobile Alliance (OMA) standard, and in this case, performs data communication at an improved speed compared to BIP. can do.

In addition, the smart card may be controlled by a remote management server (Admin Server, not shown) of the external communication network. The remote management server is an HTTP server and transmits an administrative command to the SCWS module included in the smart card. Manage modules. For example, setting or changing configuration parameters of SCWS or installing or deleting an HTML page can be performed.

1 is a system diagram for a streaming service according to an embodiment of the present invention.

Referring to FIG. 1, a system for streaming service may include a content playing terminal 110 equipped with a smart card 120, a communication network 130, a content providing server 140, and a usage right providing server 140. have.

The present invention relates to a streaming service to which DRM (Digital Rights Management) is applied, and will be described in detail with reference to the operation of each component of the system for the streaming service.

As described above, the content reproduction terminal 110 is a communication terminal capable of receiving a packet service through the communication network 130. Content playback terminal 110 of the present invention is connected to the server providing the content, and receives the content in a streaming (streaming) method. The content reproduction terminal 110 reproduces the corresponding content, that is, the packet constituting the content.

In detail, when the DRM is applied to the content of the streaming service, the content reproducing terminal 110 transmits a packet (DRM applied) constituting the corresponding content to the smart card 120. The smart card 120 releases the DRM of the delivered packet, and delivers the released packet (hereinafter, referred to as an original packet) to the content reproducing terminal 110. The content reproduction terminal 110 reproduces the original packet transmitted and requests the transmission of the next packet.

Here, the content providing in the streaming method (ie, the streaming service) is different from the download method in which the data is directly stored in the device receiving the content and then decoded and reproduced, and the device receiving the content is provided through the communication network 130. A service according to a transmission method capable of receiving data and simultaneously playing back content in real time.

Real-time transport protocol / real-time streaming protocol (hereinafter referred to as RTP / RSTP, RTP / RSTP) is a standard protocol of streaming service. Real Time Streaming Protocol (RSTP) is a protocol that sends and receives commands for stream control through Transport Control Protocol / Internet Protocol (TCP / IP), and Real Time Protocol (RTP) uses User Datagram Protocol (UDP). A protocol for receiving playback audio / video data.

Both RSTP and RTP can be used over TCP and UDP protocols, but in most cases RTSP is TCP-based and RTP is UDP-based. This is because TCP is a slow protocol or a protocol that guarantees transmission between a server and a client, and UDP does not guarantee transmission, but is fast.

The detailed procedure of the streaming service is a known technique, and a detailed description thereof will be omitted.

The communication network 130 includes not only CDMA or WCDMA, but also all wired and wireless communication networks 130 capable of providing content or applications to the communication device 110.

Hereinafter, WCDMA will be described as an example. The WCDMA network may include a radio base station Node B, a radio network controller (RNC), a Serving GPRS Support Node (SGSN), and a Gateway GPRS Support Node (GGSN). Since the WCDMA network is a known technology, detailed descriptions are omitted to clarify the gist of the present invention.

The content providing server 140 provides the content to the content reproducing terminal 110 through the communication network 130. In detail, the content providing server 140 provides content in a streaming manner, and provides DRM to a packet constituting the corresponding content.

Rights Issuer (RI) 140 issues a Right Object for specific content. That is, the usage right providing server 140 provides a usage right to obtain a content encryption key (CEK) with the smart card 120 via the content playback terminal 110. Here, the decryption key is a key for releasing the DRM applied to the corresponding content, that is, decrypting the encrypted content.

The content providing server 140 and the usage right providing server 140 may be implemented in the same device. When the content providing server 140 and the usage right providing server 140 are implemented in the same device, the database may be shared with each other, issue a use right in advance, and provide a streaming service.

So far, the system for the streaming service according to the exemplary embodiment of the present invention has been described with reference to FIG. 1. Hereinafter, a content reproduction system according to an embodiment of the present invention will be described in detail with reference to FIG. 2.

2 is a block diagram of a content reproducing system according to an embodiment of the present invention.

2, the content reproducing system includes a smart card 120 and a content reproducing terminal 110.

The content reproducing terminal 110 receives the content to which the DRM is applied in a streaming manner. When the DRM is released by the smart card 120, the corresponding content is played.

Hereinafter, the detailed operation of the content playback terminal 110 is divided into functional units to be described in detail.

The communication unit 240 transmits and receives all data and signals for receiving a streaming service from the content providing server 140 (or the usage right providing server 140) through the communication network 130.

The input / output unit 250 may include an input device such as a keypad, a touch screen, a microphone for controlling the content playback terminal 110, and an output device such as a speaker or an LCD window for providing a user with data necessary for using a voice call service or data service. Include.

The terminal browser 260 includes a service request unit 262, a determination unit 264, and a playback unit 266.

The service request unit 262 requests the provision of a web page document to the smart card 120 that performs the function of the smart card web server. Here, the service request unit 262 transmits a connection request by TCP / IP or BIP in a USB environment according to the OMA standard.

In addition, the service request unit 262 transmits a request for selecting a streaming service target content, starting a streaming service, requesting a next packet after a played packet, etc. according to the control information input by the user to the smart card 120. . This request is transmitted to the content providing server 140 via the content playback terminal 110 by the smart card 120.

The determination unit 264 determines whether DRM is applied to the received packet according to the streaming service. The determination unit 264 transmits the packet to the playback unit 266 when the DRM is not applied and to the smart card 120 when the DRM is applied.

The playback unit 266 plays back the contents of the streaming service. In detail, the playback unit 266 receives the DRM-free packet or the DRM-released packet by the smart card 120 to play the DRM.

The storage unit 270 stores a predetermined program for controlling the overall operation of the content reproducing terminal 110, data input and output, and various data processed. In addition, the storage unit 270 may be implemented to include a buffer (not shown) to temporarily store the received packet for the streaming service.

When there is a connection request from the content playback terminal 110 to the content providing server 140, the smart card 120 connects to the content providing server 140 via the content playing terminal 110. Thereafter, the web page document received from the content providing server 140 is displayed in the display area of the content reproducing terminal 110.

In addition, the smart card 120 releases the DRM applied to the packet of the streaming service from the content providing server 140. The released packet is delivered to the content reproduction terminal 110 and reproduced.

The smart card 120 includes a central processing unit (CPU), a nonvolatile memory, and an active memory area 230 therein. The smart card 120 is capable of storing information in a memory and processing the information or performing some operation using the information.

However, in the present specification, for convenience of description and understanding, specific operations of the smart card 120 will be divided into functional units based on the functions of the smart card 120 with reference to FIG. 2.

The smart card 120 may include a smart card web server module, a DRM agent 220, and a memory area 230.

The smart card web server module (hereinafter referred to as SCWS module 210) performs the function of the smart card web server described above. As described above, the smart card web server delivers the web page document to the content playback terminal 110 in response to a request of the browser of the content playback terminal 110.

In detail, the SCWS module 210 receives a connection request from the content playback terminal 110 to the content providing server 140. The SCWS module 210 accesses the content providing server 140 via the content playback terminal 110 in response to the access request. Here, the SCWS module 210 may receive a connection request from the content playback terminal 110 by TCP / IP or BIP in a USB environment according to the OMA standard.

The SCWS module 210 receives a request for transmission of a web page document as a server and provides the requested web page document to the content playback terminal 110 in relation to the content playback terminal 110. As such, the SCWS module 210 and the content playback terminal 110 operate similarly to the server-client relationship.

The SCWS module 210 of the present invention requests the provision of a streaming service by accessing the content providing server 140 via the content playback terminal 110.

In addition, the SCWS module 210 may access the usage right providing server 140 via the content playback terminal 110. When there is no right to use the content provided by the streaming method, it is to receive the right to use the corresponding content.

When the DRM is applied to the content provided by the streaming method, the DRM agent 220 releases the corresponding DRM.

Hereinafter, the operation of the DRM agent 220 will be described in detail by dividing it into functional units. The DRM agent 220 may include an extractor 222, a key manager 224, and a decryptor 226.

When the content reproduction terminal 110 is provided with a streaming service, the extractor 222 receives a packet constituting the corresponding content. The extractor 222 extracts identification information of the content from the delivered packet.

The key manager 224 selects a usage right corresponding to the identification information extracted by the extractor 222. The key manager 224 then obtains a decryption key from the selected usage right.

The decryption unit 226 decrypts the packet transmitted from the content reproduction terminal 110 using the decryption key obtained by the key management unit 224. That is, the decoder 226 releases the DRM applied to the packet by using the decryption key. Here, the decoded packet will be referred to as an original packet.

In addition, the decoder 226 transmits the original packet to the content playback terminal 110. In this case, the original packet may be delivered to the content playback terminal 110 through the SCWS module 210.

In addition, when the packet to which the same DRM is applied is continuously transmitted by the streaming service, the decoder 226 decodes the packet by using the obtained decryption key. That is, the function of extracting the identification information of the extraction unit 222 and the key management unit 224, selecting a use right, and obtaining a decryption key may be performed only once for packets to which the same DRM is applied.

Specifically, when receiving the first packet of the streaming service, the DRM agent 220 performs the above-described identification information extraction, usage right selection, and decryption key acquisition, and releases the DRM of the first packet with the obtained decryption key. Here, the decoder 226 releases the DRM of the first packet by using the Advanced Encryption Stadard (AES) algorithm. Here, the AES algorithm is well known to those skilled in the art to which the present invention pertains, and a detailed description thereof will be omitted for the convenience of understanding the present invention.

According to an embodiment of the present invention, the decryption unit 226 releases the DRM using the same AES algorithm with the previously obtained decryption key for the second and third packets which are subsequently received.

According to another embodiment of the present invention, the decoder 226 does not use the AES algorithm from the second packet, but performs the XOR operation with the second packet, in particular with the data region to which the DRM is applied. Of course, the content providing server according to the present embodiment should encrypt the packet so that the original packet can be generated only by the XOR operation with the decryption key from the second packet. According to this embodiment, the security of the streaming service may be somewhat weakened, but there is an effect that can increase the real-time of the streaming service itself.

According to another embodiment of the present invention, the decoder 226 uses the decryption key (CEK ₂ ) derived by applying a predetermined hash function to the decryption key (CEK ₁ ) previously obtained for the second packet. To decode the second packet. The decoding unit 226 decodes the third packet by using a decryption key CEK ₃ derived by applying a hash function to CEK ₂ again, that is, a key for decoding the second packet. That is, according to the present embodiment, the decoder 226 derives the decryption key CEK _{N + 1} for decoding the N + 1 th packet through the following equation.

[Equation]

(CEK _{N +1} ) = hash (CEK _N )

Here, CEK _N means a decoding key for decoding the N-th packet, and hash () means applying a preset hash function.

This embodiment is more effective than the embodiment using the above-described XOR operation, and has the effect of enhancing the real-time than the embodiment of performing the AES algorithm for all packets.

In the memory area 230 of the present invention, usage rights for playing content are stored. Stored usage rights are provided to the DRM agent 220 on request.

The memory area 230 may be divided into a user data area and a secure data area. The user data area stores subscriber information (e.g., International Mobile Station Identity (IMSI)). The above-described usage rights may be stored in the secure data area, which is a memory area 230 in which unauthorized access (reading / writing) is not allowed from the outside.

The memory area 230 may store a predetermined program for controlling the overall operation of the smart card 120, data input and output, and various data processed.

So far, the content reproduction system according to an embodiment of the present invention has been described with reference to FIG. 2. Hereinafter, a content reproduction method according to an embodiment of the present invention will be described in detail with reference to FIG. 3.

3 and 4 are call processing diagrams for a content reproduction method according to an embodiment of the present invention.

The present invention relates to a streaming service to which DRM is applied based on a smart card web server (SCWS).

3 illustrates a case where the smart card 120 stores usage rights in advance as a first embodiment of the present invention, and FIG. 4 illustrates a streaming service by the smart card 120 as a second embodiment of the present invention. In this case, you need to download the permission.

Hereinafter, a first embodiment of the present invention will be described with reference to FIG. 3.

In step S302, the content playback terminal 110 requests the streaming service to the content providing server 140. In detail, when the content playback terminal 110 requests the provision of a web page document to the SCWS module 210 of the smart card 120, the SCWS module 210 provides the content providing server via the content playback terminal 110. (140).

Thereafter, the SCWS module 210 requests the streaming service of the specific content to the content providing server 140 according to the request transmitted from the content playback terminal 110.

Next, in step S304 and step S306, the content providing server 140 applies the DRM to the packet of the corresponding content (S304). In operation S306, the DRM-applied packet is transmitted to the content reproduction terminal 110.

Here, the content providing server 140 may apply DRM to all packets constituting the content, or may apply and transmit DRM only to packets to be transmitted according to a streaming service.

Hereinafter, a case in which the content providing server 140 transmits the Nth packet according to the streaming service will be described in detail.

Subsequently, in step S308, the content reproducing terminal 110 determines whether DRM is applied to the N-th packet received in step S306.

If it is determined that the DRM is not applied, the content reproduction terminal 110 performs steps S320 and S322. That is, the content playback terminal 110 plays back the N th packet through the terminal browser 260 and requests the content providing server 140 to transmit the N + 1 th packet.

On the other hand, when it is determined in step S308 that the DRM is applied to the N-th packet, the content playback terminal 110 includes the DRM agent 220 through the SCWS module 210 (including the smart card 120) in the N-th packet. (Included in the smart card 120).

Subsequently, in step S310, the DRM agent 220 extracts identification information from the Nth packet. Here, the identification information may be a content ID for identifying the content.

Subsequently, in step S312, the DRM agent 220 determines whether there exists a usage right corresponding to the extracted identification information.

In this embodiment, it is assumed that the use right is issued in advance, and the DRM agent 220 will determine that the use right is available. On the other hand, if it is determined that the DRM agent 220 does not have permission to use the second embodiment of the present invention, it will be described in detail in the description of FIG.

Subsequently, in step S314, the DRM agent 220 extracts the stored usage right to obtain a decryption key (CEK) from the usage right. The decryption key is a key that can release the DRM applied to the content.

Subsequently, in step S316, the DRM agent 220 decodes the DRM applied to the delivered Nth packet using the decryption key.

The DRM agent 220 decodes the N th packet to generate an N th original packet from which the DRM applied to the N th packet is released.

Here, the method of decoding the DRM-applied packet with the decryption key is a technique well known to those skilled in the art (symmetric key encryption, asymmetric key encryption, AES algorithm, etc.), and thus the detailed description thereof will be omitted. .

Subsequently, in steps S318 and S320, the DRM agent 220 delivers the generated N-th original packet to the content playback terminal 110 through the SCWC module (S318). The content reproduction terminal 110 reproduces the delivered Nth original packet (S320).

As a result, the content reproduction terminal 110 may reproduce the DRM application packet provided by the streaming method.

Thereafter, in step S322, the content playback terminal 110 requests the N + 1 th packet to the content providing server 140 using the smart card web server function.

Steps S306 to S320 may be repeatedly performed on the N + 1 th packet. When the above process is performed for all packets constituting the corresponding content, the content reproduction terminal 110 may eventually receive and reproduce the content to which the DRM is applied in a streaming manner.

In addition, a part of step S308 (determination of whether to apply DRM) and steps S310 to S314 may be omitted for the N + 1 th packet. The present invention applies the DRM technology to the streaming service, and it is necessary to appropriately balance the real-time requirements of the streaming service and the security requirements of the DRM technology. In other words, in the present invention, if the security is enhanced, the real-time is weakened, and if the real-time is enhanced, the security may be weak.

Subsequently, it is assumed that the N th packet is the first packet of the corresponding streaming service.

Decoding method for packets continuously received after the first packet. The first method is to maximize security. According to the first method, real-time performance may be guaranteed only when the computing capability of the smart card 120 is greater than or equal to a predetermined value.

The first method is a method of releasing DRM in the same way even when the second packet is received. That is, the DRM is also released for the second and third packets by using the above-described AES algorithm.

The second method is to prioritize real time over security. The DRM agent 220 decodes the second packet by performing an XOR operation on the decryption key and the second packet (particularly, the data area) that have already been obtained in response to the first packet. The DRM agent 220 also decodes the third packet by performing an XOR operation with the obtained decryption key.

Because XOR operations are very simple, they are less secure than the first method, but they also improve real-time.

The third method is to enhance security than the second method using the XOR operation. The DRM agent 220 may use the decryption key (CEK ₂ ), which is previously obtained to decrypt the first packet, to decode the second packet CEK ₂ . It is derived by applying the hash function to CEK ₁ ). The DRM agent 220 releases the DRM of the second packet with the derived CEK ₂ . Subsequently, the DRM agent 220 derives a decryption key CEK ₃ corresponding to the third packet by applying a hash function to CEK ₂ , and decodes the third packet with the derived CEK ₃ .

Therefore, the third method can enhance the real-time compared to the first method described above, and has an effect of enhancing security than the second method.

Hereinafter, a second embodiment of the present invention will be described with reference to FIG. 4.

The second embodiment of the present invention is a case where the usage right is not stored in advance in the smart card 120 mounted on the content reproducing terminal 110. Therefore, when the decoding of the received packet is requested, the smart card 120 needs to download the right to use the corresponding content. That is, the second embodiment is a case where the DRM agent 220 determines that there is no permission to use in step S312 of the first embodiment described above.

If the DRM agent 220 determines that there is no permission to use in step S312, it performs steps S410 to S430.

In step S410, the DRM agent 220 delivers a permission request to the SCWS module 210. The SCWS module 210 performs a smart card web server function and transmits a usage right request to the usage right providing server 140 via the content playback terminal 110.

That is, the SCWS module 210 transmits the permission request transmitted from the DRM agent 220 to the permission providing server 140 according to the OMA standard. Of course, the usage right request is merely transmitted via the content playback terminal 110 according to the OMA standard, and is not transmitted under the control of the content playback terminal 110.

On the other hand, the usage right request may include content identification information and IMSI. That is, the permission to use the request is information necessary for authenticating the legitimate use of the content, and may include identification information for identifying the content and IMSI for authenticating the user requesting the use of the content.

Subsequently, in step S420 and step S430, the usage right providing server 140 generates a usage right (or selects a stored usage right) in response to the received usage right request (S420). In addition, the DRM agent 220 downloads the usage rights generated from the usage right providing server 140 (S430). That is, the usage right providing server 140 transmits the generated usage right to the DRM agent 220 via the content playback terminal 110 and the SCWS module 210. At this time, the usage rights providing server 140 may also transmit the usage rights to the DRM agent 220 according to the OMA standard.

The process of the second embodiment after this is the same as the steps S314 to S322 described in the description of FIG. 3. Therefore, the subsequent steps will be omitted.

The invention can also be embodied as computer readable code on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored.

For example, the computer-readable recording medium may include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like.

It may also include the implementation in the form of a carrier wave (for example, transmission over the Internet).

The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

And functional programs, codes and code segments for implementing the present invention can be easily inferred by programmers in the art to which the present invention belongs.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It will be understood that the invention may be varied and varied without departing from the scope of the invention.

1 is a system diagram for a streaming service according to an embodiment of the present invention.

2 is a block diagram of a content playback system according to an embodiment of the present invention.

3 is a call processing diagram for a content reproducing method according to the first embodiment of the present invention.

4 is a call processing diagram for a content reproduction method according to a second embodiment of the present invention;

<Description of the symbols for the main parts of the drawings>

110: content playback terminal 120: smart card

130: communication network 140: content providing server

150: server for providing authorization 210: SCWS module

220: DRM agent 222: extraction unit

224: key management unit 226: decryption unit

230: memory area 240: communication unit

250: input / output unit 260: terminal browser

262: service request unit 264: determination unit

266: playback unit 270: storage unit

Claims (11)

In the content playback system for playing the content provided by the streaming method, When the request for providing the content is received, transmit the provision request to the content providing server via the content playback terminal, A smart card for releasing DRM (Digital Right Management) applied to an N (natural number) packet of the content provided by the streaming method and delivering the N-th original packet from which the DRM is released to the content reproducing terminal; And And a content reproducing terminal receiving the N th original packet from the smart card and playing the request, and requesting the N + 1 th packet to the content providing server. The method of claim 1, The content playback terminal, A service request unit which requests the smart card to access the content providing server; A determination unit which determines whether DRM is applied to an Nth packet received from the content providing server in response to the request, and delivers the Nth packet to the smart card when DRM is applied; And And a playback unit for reproducing the original packet when the N th original packet is received from the smart card. The method of claim 1, The smart card, Downloading a usage right corresponding to the content in advance in the secure data area, and using the usage rights to release the DRM applied to the N-th packet using the content rights. The method of claim 1, The smart card, A content playback system according to any one of a UMTS Subscriber Identity Module (USIM), a User Identity Module (UIM), a Removable User Identity Module (R-UIM), a Subscriber Identity Module (SIM), and a Universal IC Card (UICC). In the smart card mounted on the content playback terminal, A smart card web server module for receiving a connection request from the content reproducing terminal to a content providing server for providing a streaming service and connecting to the content providing server via the content reproducing terminal according to the access request; And A DRM agent for releasing DRM (Digital Right Management) applied to an N (natural number) packet of content provided by the content providing server in a streaming manner via the content reproducing terminal, The N-th packet from which the DRM is released is delivered to the content playing terminal and played. The method of claim 5, The DRM agent, An extraction unit for extracting identification information for distinguishing contents from the N-th packet; A key manager which selects a usage right corresponding to the extracted identification information and obtains a decryption key for releasing the DRM from the selected usage right; And And a decryption unit for releasing the DRM applied to the N-th packet by using the decryption key and delivering the N-th original packet from which the DRM is released to the content playback terminal through the smart card web server module. Smart card. The method of claim 6, The decoding unit, From the N + 1 th packet received from the content playback terminal, the DRM applied to the N + 1 th packet is released using the obtained decryption key for the DRM release of the N th packet, and the smart card web server module is released. The smart card, characterized in that for transmitting the N + 1 st packet from which the DRM is released to the content playback terminal. The method of claim 7, wherein The decoding unit, And applying a hash function preset to the obtained decryption key and releasing the DRM applied to the N + 1 th packet with the decryption key to which the hash function is applied. The method of claim 7, wherein The decoding unit, A smart card, characterized in that to release the DRM through the XOR operation of the obtained decryption key and the N + 1 th packet. The method according to claim 5 or 6, The smart card web server module, And if it is determined by the DRM agent that a usage right corresponding to the content does not exist, the smart card according to claim 1, accessing the usage right providing server and downloading the usage right via the content playback terminal. The method according to claim 5 or 6, The smart card web server module, Smart card, characterized in that for receiving the connection request from the content playback terminal by TCP / IP or BIP.

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