KR100926910B1 - Method and system for providing multi room based on downloadable conditional access system - Google Patents

Abstract

PURPOSE: A method and a system for providing a multi room based on a downloadable conditional access system are provided to descramble a scrambled transport stream that a set top box retransmits even in a PC. CONSTITUTION: A transmission processor descrambles a scrambled transport stream received from a head end(200). A retransmitting unit retransmits the received scrambled transport stream to the PC(206) included in a home network. The PC to which an external secure processor(210) including an SM(Secure Micro) module is connected downloads a DCAS host module and a CAS(Conditional Access System) client to descramble the retransmitted transport stream.

Description

Method and System for providing Multi Room based on Downloadable Conditional Access System

The present invention relates to a method and system for providing a multi-room service based on DCAS. More particularly, the present invention relates to a method and system for enabling a user to watch cable broadcasting or satellite broadcasting through a personal computer as well as a set-top box provided in a home. It is about.

In the past, broadcast services were provided in an analog manner, but digital services have been provided due to the development of video compression technology and an increase in network transmission bandwidth.

In accordance with the digital conversion of broadcast services, a set-top box dedicated to digital broadcasting has recently been provided, and the set-top box processes broadcast signals received from the head-end of a cable, satellite or terrestrial broadcaster. To play the function.

In accordance with the provision of digital broadcasting service, a conditional access system (hereinafter referred to as 'CAS') has been applied to allow only a legitimate subscriber to access a specific broadcast program (content).

This is because digital content, unlike analog content, is not only capable of perfect copying but also easy to edit and distribute.

In particular, CAS is essential for cable or satellite broadcasting that has paying subscribers.

CAS works in conjunction with Subscriber Management System (SMS) so that only authorized users can receive and play specific content.

In a typical CAS, the headend scrambling content and data using a control word (CW), wherein the control word is encrypted with an authentication key and the authentication key is encrypted with a distribution key.

When the set-top box receives the scrambled transport stream (scrambled content), the set-top box decrypts the authentication key with the distribution key, obtains a control word with the decrypted authentication key, and descrambles the scrambled transport stream through the obtained control word to view it. The signal will be output as possible.

In general, the set-top box has a built-in module for supporting the CAS function is embedded (embedded) it is possible to descramble the transport stream as described above.

For example, the OpenCable method, which is an American standard for cable broadcasting, is equipped with a Point of Deployment (POD) module for supporting CAS functions, and such a POD module works with a smart card containing subscriber information to Perform descrambling.

At this time, the smart card and the POD module are provided to be separated / installed from the set-top box, and even if the subscriber changes the cable station, only the POD module is replaced so that the previous set-top box can be used as it is.

The descrambling process of the conventional open cable-based set-top box is described in detail as follows.

In the conventional open cable based set-top box, as shown in FIG. 1, a transport stream received from the tuner 100 is input to an independent POD module (Point of Deployment) 104 connected to the smart card 102. .

Here, the POD module 104 is a CAS module of the receiving end that processes the security function and the reception restriction function, and performs descrambling of the received transport stream using the subscriber information stored in the smart card 102.

The stream descrambled by the POD module 104 is reproduced through a decoder included in the system-on-chip (Soc) 106.

A typical set-top box includes a transport processor for descrambling a transport stream in the system on chip 106, but conventionally, a descrambling is performed in the POD module 104 that is independent of the system on chip 106 without using a transport processor. To perform.

In addition, CAS modules are built into the set-top box according to other standards, thereby descrambling the transport stream provided by the cable or satellite broadcasting service provider.

On the other hand, in recent years, as the Internet Protocol TV (IPTV) service is started, the use of the broadcast service is also available in personal computers provided in general homes.

However, the conventional personal computer does not have a built-in CAS module for descrambling content provided by a cable or satellite broadcasting service provider, thereby limiting the range of broadcast services that can be provided.

Recently, since the user mainly provides content with high interest in cable broadcasting or satellite broadcasting, the user wants to watch cable broadcasting even on a personal computer, but according to the related art, there is a problem that does not satisfy the needs of the user.

The present invention is to propose a method and system for providing a DCAS-based multi-room service to enable viewing of scrambled content even in a personal computer constituting a set-top box and a home network.

Another object of the present invention is to enable descrambling of a transport stream based on DCAS to the personal computer without replacing the existing set-top box, and further, the set-top box itself can perform descrambling based on DCAS without changing hardware. It is to provide a method and system for providing a DCAS-based multi-room service.

In order to achieve the above object, according to a preferred embodiment of the present invention, in an apparatus for providing a multi-room service on a home network, a scrambled transport stream received from a head-end (Scrambled Transport Stream) A transport processor descrambling the data; And a retransmission unit retransmitting the received scrambled transport stream to a personal computer included in a home network, wherein the personal computer to which an external security processor including a Secure Micro (SM) module is connected is a downloadable conditional access system (DCAS). A DCAS-based multi-room service providing apparatus for downloading a DCAS host module and a CAS (Conditional Access System) client from a server and descrambling the retransmitted transport stream is provided.

According to another aspect of the present invention, a method for providing a multi-room service in a server connected to a personal computer included in a home network, the USB (Universal Serial Bus) dongle type including a Secure Micro (SM) module Receiving a connection request of a personal computer to which the secure processor is connected; And transmitting a downloadable conditional access system (DCAS) host module and a conditional access system (CAS) client to the personal computer, wherein the personal computer is based on the DCAS host module, SM module, and CAS client. A DCAS-based multi-room service providing method for descrambling a scrambled transport stream retransmitted from a set-top box included in the present invention is provided.

According to another aspect of the invention, a set-top box for receiving a scrambled transport stream from the headend, and retransmitting the transport stream on a home network; And a USB (Universal Serial Bus) dongle type security processor including a Secure Micro (SM) module connected thereto, and downloading a DCAS host module and a CAS (Conditional Access System) client from a downloadable conditional access system (DCAS) server. And a personal computer that descrambles a scrambled transport stream retransmitted in the set-top box based on the DCAS host module, the SM module, and the CAS client. .

According to the present invention, the descramble of the scrambled transport stream retransmitted by the set-top box in the personal computer by connecting the SM (Secure Micro) module that performs the DCAS protocol and generates and stores the key and secret information to the personal computer in the USB dongle type There is an advantage to it.

In addition, according to the present invention can be applied to the DCAS without changing the hardware of the existing set-top box has the advantage that can be provided multi-room service without replacing the set-top box.

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. In describing the drawings, similar reference numerals are used for similar elements.

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.

 Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, the same reference numerals will be used for the same means regardless of the reference numerals in order to facilitate the overall understanding.

2 is a diagram illustrating a system for providing a multi-room service based on a DCAS according to an embodiment of the present invention.

As shown in FIG. 2, the system according to the present invention includes a head-end 200, a downloadable conditional access system (DAS) server 202, and a set-top box included in a home network: STB 204 and personal computer 206.

The headend 200 receives content from cable broadcasting, satellite broadcasting, terrestrial broadcasting, and IPTV broadcasting service providers, and encodes the contents into a preset format.

In particular, the headend 200 performs scrambling (encryption) of the content according to a CAS (Conditional Access System) algorithm that is set so that only a legitimate subscriber can access the cable or satellite broadcast, and the scrambled content (Scrambled) Transport stream) to the set-top box 204.

According to one preferred embodiment of the present invention, the scrambled content sent to the set-top box 204 is re-sent to the personal computer 206 constituting the home network with the set-top box 204.

In this case, retransmission of the content may be performed via the router 208 provided in the home network.

According to the present invention, an external security processor for descrambling of scrambled content is connected to the personal computer 206, and a DCAS including the security processor is applied.

Preferably, the external security processor may be a security processor 210 of a universal serial bus (USB) dongle type.

The personal computer 206 is a terminal capable of decoding and playing content including audio and video. The personal computer 206 may include a general desktop and a laptop, but is not limited thereto. An external processor of a USB dongle type is connected to descramble content. If the device is capable of performing and playing it, it can be applied without limitation.

The DCAS method is a method of downloading from a DACS server, rather than embedding a CAS client that performs core functions for descrambling in an embedded manner as in the related art.

In the case of applying the DCAS, the device for receiving and playing the content is not dependent on a specific CAS provider, and there is no need to replace the device even if the CAS provider is changed later.

The personal computer 206 must be provided with a DCAS host module and a Secure Micro (SM) module for downloading and descrambling of the CAS client.

The SM module executes the DCAS protocol, generates and stores key and secret information for descrambling (descrambling), and SM client related data and code such as a CAS client and a Digital Rights Management (DRM) client as described below. Save it.

According to the present invention, the SM module is provided through the USB dongle type security processor 210, and the DCAS host module is provided by downloading from the DCAS server 202.

The DCAS server 202 transmits and receives a predetermined message with the set-top box 204 and the personal computer 206, and performs security management of the message.

Although the DCAS server 202 is shown separately from the headend 200 in FIG. 2, this is for convenience of description only, and the DCAS server 202 may belong to the infrastructure of the headend 200. It will be obvious to you.

3 is a flowchart illustrating a process of providing a multi-room service according to the present invention, and illustrates a process of driving a personal computer as a DCAS host between a DCAS server and a personal computer.

Referring to FIG. 3, first, a USB dongle type security processor is connected to a personal computer 206 (step 300).

With the secure processor connected as above, the personal computer 206 connects to the DCAS server 202 via the network (step 302).

The DCAS server 202 sends an interface for user authentication to the connected personal computer 206 (step 304).

In this case, the interface for authenticating a user may be a request for input of a pre-registered ID and password to the corresponding user. Alternatively, the interface for authenticating a user may require input of registered key information to the security processor 210.

The personal computer 206 sends the user's input information to the DCAS server 202 (step 306), and the DCAS server 202 performs user authentication via the user input information (step 308).

After the user authentication is completed, the DCAS server 202 transmits an application that enables the personal computer 206 to provide the same broadcast service as the set top box 204 (step 310).

The application transmitted by the DCAS server 202 may include an electronic program guide (EPG), middleware for a personal computer, an audio / video (A / V) player, and the like.

DCAS server 202 then sends the DCAS host module to personal computer 206 (step 312).

In this case, the DCAS host module manages all DCAS functions in the personal computer, and transmits and receives a predetermined message with the SM module to transmit a control word for descrambling to a predetermined processor.

The DCAS host module will be described in detail below.

After the storage of the DCAS host module is completed in the personal computer 206 (step 314), the DCAS server 202 performs a process of authenticating the SM module in association with a USB dongle type security processor connected to the personal computer 206. (Step 316).

If authentication of the SM module is complete (step 318), the DCAS server 202 sends a CAS client to the personal computer 206 (step 320).

The transmitted CAS client 320 is stored in a USB dongle type security processor 210 (step 322).

Thereafter, the personal computer 206 determines whether scrambled content is received from the set-top box 204 (324).

The personal computer 206 has an Entitlement Management Message (EMM) and an Entitlement Control Message (ECM) that receive scrambled content from the set-top box 204 and further resend from the set-top box 204. If received (step 326), descrambling of the content is performed based on the DCAS host module, SM module and CAS client (step 328).

In step 328 the personal computer 206 descrambles the content via the control words obtained from the ECM and EMM.

4 is a diagram illustrating components of the DCAS. Referring to FIG. 4, the SM module 400 may include a DCAS monitor 402 and an SM bootloader 404.

The DCAS monitor 402 performs message routing between the SM boot loader 404 or CAS client and the SMD (SM Driver) 416 of the DCAS host module 410.

The SM boot loader 404 checks an SM client such as a CAS client and transmits and receives a message for authentication with the DCAS server 202 while the SM module is driven.

The DCAS host module 410 may include a conditional access network handler (CAN) 412, a DCAS manager 414, and a SMD driver 416.

The conditional access network handler 412 controls the connection establishment with a network capable of supporting CAS, and controls the network processing environment required for a particular network to send a message to a DCAS host to process the message.

The DCAS manager 414 manages all DCAS functions in the set top box 204 corresponding to the DCAS host. The DCAS manager 414 interfaces with the SMD 416 and the conditional access network handler 412 and controls the connection setup for the SM bootloader 404 and CAS clients. In addition, the DCAS manager 414 performs routing, filtering, and queuing functions of the messages destined for the SM module 400.

In addition, the DCAS server 202 may transmit a Digital Rights Management (DRM) client and an Authorized Service Domain (ASD) client to the personal computer 204.

In the above, the DCAS including the USB dongle type security processor is applied to the personal computer 206.

In addition, DCAS may also be applied to the set-top box 204 according to the present invention. Preferably, the set top box 204 according to the present invention may be a set top box complying with an open cable standard, which is an American cable broadcasting standard.

According to the present invention, the open cable-based set-top box 204 is applied to DCAS to operate as a DCAS host.

In order to apply DCAS to the open cable-based set-top box 204, the DCAS server 202 according to the present invention establishes a connection with the open cable-based set-top box 204 to allow the set-top box 204 to operate as a DCAS host. Send an image for the DCAS host.

Here, the image for the DCAS host is a modified platform code, middleware (OpenCable Application Platform Stack) and porting layer for changing the set-top box 204 to the DCAS host, as shown in FIG. And DCAS host module.

Here, the modified platform code, middleware, and porting layer may include a DCAS interface for supporting communication with the DCAS host module.

Platform code, also known as glue code, is the code that connects the porting layer and hardware.

The porting layer defines a platform-independent middleware-side application program interface (API), and provides an API for hardware control such as a real time operating system installed in the set-top box 204, a CPU, and a decoder.

On the modified porting layer, a POD porting layer (POD PL) for a POD module that interworks with a smart card in the open cable-based set-top box 204 is removed, and a DCAS interface is added.

DCAS server 202 according to the present invention transmits the SM module to the open cable-based set-top box 204 is installed DCAS host module.

According to the present invention, since the SM module for DCAS support is provided by software instead of an on-board chip, the existing open cable-based set-top box can be used as it is.

As described above, the set-top box 204 in which the download of the DCAS host module and the download of the SM module are completed performs a function as a DCAS host, and then the DCAS server 202 according to the present invention stores the SM stored in the set-top box 204. The module is authenticated, and then the CAS client is transmitted to the set-top box 204.

Meanwhile, in the above description, the open cable-based set-top box 204 downloads the image and the SM module for the DCAS host from the DCAS server 202.

However, one of ordinary skill in the art understands that the SM module including the image and software for the DCAS host may be downloaded to the memory of the open cable-based set-top box 204 using near field communication (eg, USB communication method) without being limited thereto. Should.

In addition, although the SM module is described as being provided to the set-top box 204 in software form, the present invention is not limited thereto, and the SM module may be stored and provided in an external (USB dongle type) security processor as in the personal computer 206. .

Through the above process, the DCAS having the configuration as shown in FIG. 4 may be applied to the set-top box 204 according to the present invention.

5 is a view showing the configuration of a set-top box according to an embodiment of the present invention.

As shown in FIG. 5, after DCAS is applied to the open cable-based set-top box, the scrambled content output by the tuner 500 is directly input to the system on chip 504 without passing through the POD module 502.

As described above, the system-on-chip 504 is a chip that has a module for reproducing the transport stream transmitted from the headend 200, and decodes audio and video included in the signal output from the tuner 500. It may include a decoder 510.

In addition, the system-on-chip 504 includes a transmission processor 420 as in a typical open cable-based set-top box.

According to the present invention, the transport stream output from the tuner 500 is directly input to the transport processor 420, and the transport processor 420 is a decryption key provided by the SM module 400 stored in software according to the present invention. Descrambling of the input transport stream is performed using (eg, a control word).

Meanwhile, the transmission processor 420 according to the present invention may further include a demux for extracting audio, video, and data from the signal output from the tuner 500.

As shown in FIG. 5, the control unit 520 included in the set-top box 204 according to the present invention does not allow the scrambled content based on the downloaded DCAS host module and the SM module to pass through the POD module 502. It is controlled so that descrambling is performed directly in the system on chip 504.

In addition, the controller 520 controls the memory 522 to store the DCAS host image and the SM module.

Meanwhile, according to the present invention, the set top box 204 may further include a retransmitter 530.

The retransmitter 530 may be configured to transmit the scrambled content output from the tuner 500 to another personal computer 206 existing on the home network according to a preset short range communication protocol (eg, Zigbee, Bluetooth, WLAN, binary CDMA). To send).

In addition, the retransmitter 530 transmits the entitlement control message and the entitlement management message for the descrambling of the content to the personal computer 206.

According to the present invention, the controller 520 may manage a list of personal computers 206 included in the home network, and control to retransmit the scrambled content to one or more personal computers 206 included in the list. Do this.

As described above, when the scrambled content and messages are transmitted to the personal computer 206 constituting the set-top box 204 and the home network, the personal computer 206 is connected to the DCAS host module, the CAS client, and the USB client downloaded from the DCAS server. Content descrambling is performed using an SM module stored in a dongle type security processor.

According to the present invention, the personal computer 206 also provides the SM module for applying the DCAS as a USB dongle type, and authenticates the same through the DCAS server 202 so that the SM module is secured. 206).

Through this, scrambled content can be viewed not only on the TV connected to the set-top box, but also on the personal computer 206 to provide various contents to many family members in the home.

On the other hand, the above described the transmission of the content provided by the cable broadcast provider to the personal computer in the open cable-based set-top box to which the DCAS is applied, but not limited to the case of transmitting the scrambled content not only cable broadcasting but also satellite broadcasting It may be included in the scope of the invention.

Preferred embodiments of the present invention described above are disclosed for purposes of illustration, and those skilled in the art will be able to make various modifications, changes, and additions within the spirit and scope of the present invention. Additions should be considered to be within the scope of the following claims.

1 is a view showing a transport stream path of a conventional open cable-based set-top box.

2 is a diagram illustrating a multi-room service providing system according to an exemplary embodiment of the present invention.

3 is a flowchart illustrating a multi-room service providing process according to the present invention.

4 illustrates the components of a DCAS.

5 is a view showing the configuration of an open cable-based set-top box to which the DCAS is applied according to the present invention.

6 illustrates a software architecture before and after applying DCAS in a set-top box according to the present invention.

Claims (14)

An apparatus for providing a multi-room service in a home network, the apparatus comprising: A transport processor descrambling a scrambled transport stream received from a head-end; And Retransmitting unit for retransmitting the received scrambled transport stream to a personal computer included in the home network, The personal computer to which an external security processor including a Secure Micro (SM) module is connected downloads a DCAS host module and a Conditional Access System (CAS) client from a downloadable conditional access system (DCAS) server to descramble the retransmitted transport stream. DCAS-based multi-room service providing device. The method of claim 1, The external security processor is a DCAS-based multi-room service providing device which is a USB (Universal Serial Bus) dongle type security processor. The method of claim 1, And the retransmitter retransmits a credential control message and a credential management message for descrambling the transport stream to the personal computer. The method of claim 1, The scrambled transport stream is a DCAS-based multi-room service providing apparatus received from a cable broadcast or satellite broadcast headend. The method of claim 2, The CAS client is a DCAS-based multi-room service providing apparatus stored in the USB dongle type security processor. The method of claim 1, The DCAS host module includes at least one of a limited reception network handler (CANH), a DCAS manager, and a SMD (SM Driver). The method of claim 1, The SM module is a DCAS-based multi-room service providing apparatus including at least one of a DCAS monitor and a SM bootloader (Bootloader). The method of claim 6, When the CAS client changes, the SM bootloader deletes an existing CAS client and downloads the changed CAS client. The method of claim 1, The device is an open cable-based set-top box having a POD module interoperating with a smart card and the transmission processor is included in a System on Chip, Download an image for the DCAS host including a DCAS host module, an SM module and a CAS client for transmitting and receiving a message to and from the DCAS server, and transmit the scrambled data based on the DCAS host module, the SM module, and the CAS client. DCAS-based multi-room service providing device to descramble the stream in the transport processor without passing through the POD module. The method of claim 9, The DCAS host image is a DCAS-based multi-room service providing apparatus comprising a modified platform code, middleware and porting layer for changing the set-top box to a DCAS host. The method of claim 10, At least one of the modified platform code, middleware, and the porting layer includes a DCAS interface supporting communication between the DCAS host modules. A method of providing multiroom services in a server connected to a personal computer included in a home network, Receiving a connection request of a personal computer to which a security processor of a universal serial bus (USB) dongle type including a secure micro (SM) module is connected; And Transmitting a downloadable conditional access system (DCAS) host module and a conditional access system (CAS) client to the personal computer; And the personal computer performs descrambling of the scrambled transport stream retransmitted from the set-top box included in the home network based on the DCAS host module, the SM module, and the CAS client. The method of claim 12, Authenticating the user using at least one of user input information or key information registered for the secure processor; And And transmitting at least one of an electronic program guide, a personal computer middleware, and an audio / video player from the DCAS server to the personal computer after the user authentication. A set top box that receives the scrambled transport stream from the headend and retransmits the transport stream on a home network; And It is connected with a USB (Universal Serial Bus) dongle type security processor that includes a Secure Micro (SM) module. And a personal computer that descrambles a scrambled transport stream retransmitted from the set-top box based on the DCAS host module, an SM module, and a CAS client.

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