KR100950596B1 - Broadcasting receiving apparatus based on downloadable conditional access system and method for reinforcing security thereof - Google Patents

Abstract

PURPOSE: A broadcast reception device based on DCAS and a security reinforcing method thereof are provided to exactly confirm the forgery or modification of a DCAS(Downloadable Conditional Access System) host module by verifying the integrity of DCAS host module through block unit division about components. CONSTITUTION: An SM(Secure Micro) module(300) obtains a control word through an ECM(entitlement control message) or EMM(entitlement management message). The SM module performs authentication related functions of a broadcasting receiver. A DCAS host module(310) performs message routing with the SM module and network resource management function. A first verifying unit(330) verifies the integrity of the DCAS host module through the connection with a second verifying unit(334) according to a challenge-response algorithm.

Description

Broadcasting receiving Apparatus based on Downloadable Conditional Access System and method for reinforcing security

The present invention relates to a DCAS-based broadcast receiving apparatus and a method for enhancing security thereof, and more particularly, to an apparatus and a method capable of preventing forgery or tampering of a DCAS host module.

Broadcasting services have been provided in the past in the analog way, but recently, due to the development of video compression technology and the increase of network transmission bandwidth, the digital service has been provided.

In accordance with the provision of digital broadcasting service, a conditional access system (hereinafter referred to as "CAS") has been applied to allow only legitimate subscribers to access specific contents.

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

CAS works in conjunction with Subscriber Management System (SMS) so that only authorized subscribers 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.

Thereafter, the control word and the authentication key are included in a predetermined message (eg, a qualification control message or a qualification management message) and transmitted to the set-top box.

When the set-top box receives the scrambled transport stream (scrambled content), the set-top box decrypts the authentication key with the distribution key and obtains a control word with the decrypted authentication key. The set-top box descrambles the scrambled transport stream through the obtained control word and outputs the signal as a viewable form.

In general, the set-top box has a module for supporting the CAS function in an embedded manner to perform descrambling of the transport stream as described above.

Recently, a core function for descrambling, namely, a downloadable conditional access system (DCAS) method, which provides a CAS client that obtains a control word through a credential control message or a credential management message provided through a data channel, is downloaded from a server. have.

In the DCAS, a secure Micro (SM) module is provided on-board in a set-top box, and a CAS client downloaded from a server is stored in the SM module.

In this case, the SM module executes the DCAS protocol, generates and stores key and secret information, and acquires a control word by interpreting the message through a CAS client when a credential control message or credential management message is received from the headend.

In addition, the set-top box is provided with a DCAS host module in software form that manages the DCAS function as a whole and performs routing of messages transmitted from the SM module or messages transmitted to the SM module.

In general, since SM modules are provided in a secured form, they are less likely to be exposed to external intrusions. However, since DCAS host modules are provided in software form, they are exposed to malicious forgery or tampering by other users.

Therefore, there is a need to check and counteract forgery or modulation of the DCAS host module in the DCAS-based set-top box.

Meanwhile, DCAS is currently defined for digital cable broadcasting, and it is necessary to provide a new set-top box equipped with a DCAS host module and an SM module for DCAS application, and the user has to replace the set-top box to use DCAS service. There is this.

Digital cable broadcasting now follows the American standard OpenCable.

The open cable method stipulates that smart card and POD (Point of Deployment) module containing subscriber information can be separated / installed from the set-top box.

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

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 by 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 transmission processor for descrambling a transport stream in the system on chip 106. However, in the prior art, the descrambling is performed in the POD module 104 that is independent of the system on chip 106, without using a transmission processor. To be done.

In the conventional open cable-based set-top box, the POD module 104 has a built-in CAS module of a specific operator, and thus there is a problem that the set-top box itself should be replaced when the CAS operator is changed in the future.

DCAS (Downloadable CAS) has been proposed to solve this problem, but until now, DCAS has been proposed by providing an SM module on a separate chip with security guarantee and mounting it on-board. It is becoming.

Therefore, in order to apply the DCAS to the conventional open cable-based set-top box, a hardware change is required, and thus a new set-top box is required.

Therefore, there is a demand for a method of applying DCAS without replacing the existing set-top box while enhancing the security of the DCAS host module in the DCAS-based set-top box.

In order to solve the problems of the prior art as described above, the present invention is to propose a DCAS-based broadcast receiving apparatus and a security enhancement method thereof that can verify the integrity of the DCAS host module.

Another object of the present invention is to apply a DCAS without changing the hardware in the existing open cable-based set-top box, DCAS-based broadcast receiving device and security enhancement method that can enhance the security through the integrity verification of the DCAS host module after the DCAS is applied To provide.

In order to achieve the above object, according to an embodiment of the present invention, a security enhancement method of a downloadable conditional access system (DCAS) -based broadcast receiving apparatus, (a) a hash value for a component included in the DCAS host module Storing; (b) generating a random number of preset bits; (c) receiving hash value calculation information for one or more components designated according to the random number; And (d) verifying the integrity of the DCAS host module using the hash value calculation information and the stored hash value.

According to another aspect of the present invention, a program of instructions that can be executed by a digital processing device is tangibly implemented and read by the digital processing device to enhance security of a downloadable conditional access system (DCAS) based broadcast receiving device. A recording medium, comprising: storing a hash value for a component included in a DCAS host module; And verifying the integrity of the DCAS host module using the hash value operation information and the stored hash value for one or more components designated according to a random number of preset bits. Possible recording media are provided.

According to another aspect of the present invention, there is provided a downloadable conditional access system (DCAS) -based broadcast receiving apparatus, comprising: a first number verifying unit and a random number generator for generating a random number of predetermined bits; A SM (Secure Micro) module for acquiring a control word from a message received through the controller; And a DCAS host module including a component for a DCAS protocol and performing routing of messages delivered from the secure micro module, wherein the first verifier stores a hash value for a component included in the DCAS host module. In addition, a DCAS-based broadcast receiving apparatus for verifying the integrity of the DCAS host module using hash value calculation information for a component designated according to the random number is provided.

According to another aspect of the present invention, a method for providing a security enhancement service in a server connected to a broadcast reception device, comprising: transmitting an image for a DCAS host including a downloadable conditional access system (DCAS) host module to the broadcast reception device; step; Sending a Conditional Access System (CAS) client for descrambling of a transport stream after authenticating the broadcast receiving device in which a Secure Micro (SM) module transmitting and receiving a message with a DCAS host module is stored. step; And transmitting a verification application for verifying the integrity of the DCAS host module to the broadcast receiving device, wherein the verification application stores a hash value for a component included in the DCAS host module and random numbers of preset bits. Provided is a method for providing a security enhancement service that verifies the integrity of the DCAS host module by using hash value operation information for the one or more components specified according to a random number and the stored hash value.

According to the present invention, there is an advantage that the integrity of the DCAS host module can be verified in the SM (Secure Micro) module that performs the DCAS protocol and generates and stores key and secret information.

In addition, according to the present invention, since the components included in the DCAS host module is divided into block units and the integrity thereof is verified through this, there is an advantage in that the user can accurately check whether the DCAS host module is forged or tampered with by an unfair user.

Furthermore, according to the present invention, there is an advantage that the security-enhanced DCAS can be applied without changing the hardware of the existing open cable-based 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. Like reference numerals are used for like elements in describing each drawing.

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, unless expressly defined in this application, are construed in ideal or excessively formal meanings. It doesn't work.

 Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In order to facilitate a thorough understanding of the present invention, the same reference numerals are used for the same means regardless of the number of the drawings.

2 is a diagram illustrating a security service providing system of a DCAS-based broadcast receiving apparatus according to an embodiment of the present invention.

As shown in FIG. 2, the system according to the present invention may include a head-end 200, a downloadable conditional access system (DCAS) server 202, and one or more broadcast receiving devices 204.

The head-end 200 receives content from a cable broadcaster, satellite broadcaster, terrestrial broadcaster, and an IPTV broadcaster, and encodes the content in a preset format.

The headend 200 encodes the video received from the broadcaster into a transport stream according to MPEG-2, and scrambling (encrypts) the video so that only the right subscriber can watch the content and transmits it to the broadcast receiving device 204. do.

In addition, the headend 200 transmits an entitlement control message (ECM) and an entitlement management message (EMM) for descrambling the transport stream to the broadcast receiving device 204 through a predetermined data channel. do.

The DCAS server 202 performs an authentication function of the transmission and broadcast reception device 204 of the CAS (Conditional Access System) client.

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.

The broadcast reception device 204 receives a credential control message and a credential management message, obtains a control word by interpreting the credential control message, and performs descrambling (decoding) of the transport stream through the obtained control word.

According to the present invention, the broadcast reception device 204 is a device that operates based on DCAS, and may include a Secure Micro (SM) module, a DCAS host module, and a transmission processor, as shown in FIG. 3.

The DCAS host module performs the overall management and control functions for the DCAS function.

The SM module executes the DCAS protocol, generates and stores key and secret information for acquiring control words, and stores SM client related data and codes such as a CAS client and a digital rights management (DRM) client as described below.

The SM module may be provided in the form of an on-board type chip, but preferably may be provided from the DCAS server 202 in a download manner or in an external security processor (eg, a USB dongle type security processor). This will be described in detail below.

3 is a diagram illustrating a detailed configuration of a security enhanced DCAS-based broadcast receiving apparatus according to the present invention.

Referring to FIG. 3, the DCAS-based broadcast receiving apparatus according to the present invention may include an SM module 300, a DCAS host module 310, and a transmission processor 320.

The SM module 300 obtains the control word through the entitlement control message or the entitlement management message, transfers the control word to the DCAS host module 310, and performs a function related to authentication of the broadcast reception device 204.

The SM module 300 may include a DCAS monitor 302 and an SM bootloader 304.

The DCAS monitor 302 performs message routing between the SM boot loader 304 or CAS client 306 and the SMD (SM Driver) 316 of the DCAS host module 310.

The SM boot loader 304 checks an SM client such as the CAS client 306 and transmits and receives a message for authentication with the DCAS server 202 while the SM module is driven.

The SM boot loader 304 receives and stores the changed CAS client 306 when the CAS operator is changed through communication with the DCAS server 202.

Meanwhile, the DCAS host module 310 performs a function of routing and network resource management of messages destined for the SM module 300 or messages transmitted from the SM module 300.

The DCAS host module 310 may include a Conditional Access Network Handler (CANH) 312, a DCAS Manager 314, and a SMD Driver 316.

The conditional access network handler 312 controls a connection setup with a network capable of supporting CAS, and controls a network processing environment required for processing a message by a specific network that transmits a message to the broadcast reception device 204.

The DCAS manager 314 manages all DCAS functions in the broadcast reception device 204 corresponding to the DCAS host. The DCAS manager 314 interfaces with the SMD 316 and the conditional access network handler 312 and controls connection settings for the SM bootloader 304 and the CAS client 306. In addition, the DCAS manager 314 performs routing, filtering, and queuing functions of the message destined for the SM module 300 or the messages transmitted from the SM module 300.

In addition, the DCAS manager 314 transfers the control word obtained from the SM module 300 to the transmission processor 320.

In a general DCAS-based broadcast receiving apparatus, the SM module 300 is provided in a state where security is guaranteed.

However, since the DCAS host module 310 does not go through a separate authentication process, it may be relatively vulnerable to external intrusion.

According to an exemplary embodiment of the present invention, the first verification unit 330 and the random number generator 332 are additionally added to the SM module 300 which is secured to determine whether the DCAS host module 310 is forged or tampered with. Is provided.

In addition, a second verification unit 334 is provided in the DCAS host module 310 to transmit and receive a predetermined message with the first verification unit 330.

The first verifier 330, the random number generator 332, and the second verifier 334 may be provided in the form of an application from the DCAS server 202.

The first verifier 330 according to the present invention verifies the integrity of the DCAS host module by interworking with the second verifier 334 according to a challenge-response.

4 illustrates a detailed configuration of the first verification unit and the second verification unit according to the present invention.

Referring to FIG. 4, the first verifying unit 330 according to the present invention may include a hash value list storing unit 400, a message transmitting and receiving unit 402, and an integrity verifying unit 404, and a second verifying unit. 334 may include a hash value calculator 410, a hash value logic operator 412, and a message transceiver 414.

According to the present invention, the hash value list storage unit 400 calculates a hash value for each component included in the DCAS host module 310 according to a preset hash algorithm and stores the calculated hash value.

Here, the hash algorithm is a function that maps an arbitrary bit string to a fixed bit string.

As described above, the components included in the DCAS host module 310 may include a conditional access network handler 312, a DCAS manager 314, and an SM driver 316, in addition to driving the transmit processor 320. It may include a transport processor driver (TPD) for.

According to an exemplary embodiment of the present invention, in order to more reliably verify the integrity of the DCAS host module 310, the entire component included in the DCAS host module 310 is divided into n blocks, where n is one or more natural numbers. Can be.

In this case, n blocks are assigned numbers from 1 to n, and the hash value list storage unit 400 calculates hash values for each of the n blocks, and hashes the assigned numbers and hash values for each block. Store in a list of values.

As shown in FIG. 5, when a plurality of components are divided into n blocks, a unit component such as a DCAS manager 314 may be divided into one or more blocks DCAS Manager 1 and DCAS Manager 2.

For integrity verification, the random number generator 332 generates a random number of preset bits, and the message transceiver 402 transmits the random number to the second verifier 334.

In this case, when the entire component of the DCAS host module is divided into n blocks, the random number generator 332 may generate a random number of n bits.

The hash value calculator 410 of the second verifier 334 calculates a hash value of a specified component according to a random number, and the hash value logic calculator 412 logically calculates the calculated hash value according to a preset method. Generate hash value calculation information.

According to the present invention, when the whole component is divided into n blocks and n bits of random numbers are transmitted from the first verification unit 330, the hash value calculator 410 of the second verification unit 334 is n. Identifies the designated block number according to the bit random number and calculates a hash value for the block corresponding to the number.

For example, when the entire component is divided into 10 blocks, and the random number is composed of 10 bits such as "1001001100", the hash value calculator 410 checks the position of the bit represented by "1" in the random number. Hash values for blocks 1, 4, 7, and 8 can be calculated.

That is, when the n-bit random number according to the present invention includes k bits corresponding to "1" (where 1≤k≤n), the hash value calculation unit 410 is located at the position 1 in the random number. Therefore, hash value is calculated for k blocks.

However, the present invention is not limited thereto, and a hash value may be calculated for a block of bits corresponding to "0" according to a setting method.

The hash value logic calculating unit 412 generates hash value calculation information by performing a logical operation on the calculated one or more hash values according to a preset method.

Here, as the calculation method, a known logical operation method such as AND, OR, or XOR may be applied.

The hash value calculation information is transmitted to the first verifier 330 through the message transceiver 414.

In the meantime, the integrity verification unit 404 of the first verification unit 330 extracts a hash value for a block designated according to a random number from a hash value list at the time when integrity verification is required, and the hash value described above with respect to the extracted hash value. The logic operation is performed in the same manner as the value logic operation unit 412.

Thereafter, the integrity verification unit 404 compares the hash value calculation information that is performed by the hash value calculation information transmitted from the second verification unit 334 as described above, and determines whether the two match. Verify the integrity of

If the integrity is verified, since the DCAS host module 310 is not forged or tampered with, the normal process of the SM boot loader 304 may be performed, for example, a CAS client download or a control word obtained from the CAS client.

According to the present invention, the integrity verification of the DCAS host module 310 may be performed at every boot of the broadcast reception device 204. Therefore, since the integrity of any block is verified through a random number randomly generated at every boot, it is possible to prevent a third party from invading the DCAS host module 310 and hacking the secret information of the user.

Meanwhile, according to an exemplary embodiment of the present invention, the DCAS-based broadcast receiving device 204 may be a set-top box conforming to the open cable standard, which is an American cable broadcasting standard.

According to the present invention, the open cable-based set-top box operates as a DCAS host by applying DCAS to an open cable-based set-top box.

Hereinafter, for convenience of description, the DCAS-based broadcast receiving apparatus 204 will be described as being an open cable-based set-top box.

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 set-top box 204 for the DCAS host to operate the set-top box 204 as a DCAS host Send the image.

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 APIs for hardware control such as a real time operating system, a CPU (controller), and a decoder installed in the set-top box 204. to provide.

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.

The DCAS server 202 according to the present invention transmits the SM module 300 to the open cable-based set-top box 204 in which the DCAS host module is installed.

According to the present invention, since the SM module 300 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 where the download of the DCAS host module 310 and the download of the SM module 300 are completed is defined as a DCAS host. Thereafter, the DCAS server 202 according to the present invention authenticates the SM module 300 stored in the set-top box 204, and then transmits the CAS client 306 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 can download the SM module including the image and software for the DCAS host to the memory of the open cable-based set-top box 204 using near field communication (eg, a USB communication method). You will have to understand.

6 is a view showing the configuration of a set-top box according to an embodiment of the present invention. Referring to Figure 6 describes the processing path of the transport stream according to the present invention.

As shown in FIG. 6, after DCAS is applied to the open cable-based set-top box, the scrambled transport stream output by the tuner 600 is directly input to the system-on-chip 604 without passing through the POD module 602. .

As described above, the system-on-chip 604 is a chip having a module for reproducing the transport stream transmitted from the headend 200, and decodes audio and video included in a signal output from the tuner 600. A decoder 610 may be included.

In addition, like the general open cable-based set-top box, the system-on-chip 604 includes a transmission processor 320.

According to the present invention, the transport stream output from the tuner 600 is directly input to the transport processor 320, and the transport processor 320 uses the control word provided by the SM module 300 to decode the input stream. Perform scrambling

In this case, the SM module 300 includes a first verification unit 330 for verifying the integrity of the DCAS host module 310, and the first verification unit 330 provides a hash value for a component included in the DCAS host module. And the hash value calculation information for one or more components designated according to a random number of a predetermined bit and the stored hash value to verify the integrity of the DCAS host module.

On the other hand, the controller 620 controls the descrambling of the scrambled transport stream based on the DCAS host module and SM module downloaded as described above directly in the system-on-chip 604 without passing through the POD module 602.

Furthermore, the first and second verification units 330 and 334 stored in the memory 622 monitor whether the DCAS host module is forged or modulated from time to time.

In addition, the controller 620 controls the memory 622 to store the DCAS host image and the SM module.

Meanwhile, in the above description, the SM module is provided in the open cable-based set-top box in the form of software. However, as shown in FIG. 7, the SM module is provided through a USB dongle type security processor to be included in the scope of the present invention. Can be.

As shown in FIG. 7, a security processor 700 including an SM module is provided, and the security processor 700 is configured to be inaccessible without authentication from the outside, and the system-on-chip 604 and the USB interface 702. Is connected through.

In general, since the open cable-based set-top box 204 includes the USB interface 702, even when the USB dongle type security processor 700 including the SM module 300 is provided, the DCAS is not changed without changing the existing hardware. It is possible to apply.

FIG. 9 is a flowchart illustrating a process of applying a DCAS having security to an open cable-based set-top box.

FIG. 9 illustrates a process in which the open cable-based set-top box 204 communicates with the DCAS server 202 via a network to download an image and SM module for the DCAS host and also provide an application for verification of the DCAS host module. .

9, after a connection is established between the open cable-based set-top box 204 and the DCAS server 202 (step 900), the DCAS server 202 transmits an image for the DCAS host to the set-top box 204. (Step 902).

In accordance with the download of the image for the DCAS host, the DCAS host module 310 is stored (step 904), and the modified platform code, the porting layer and the middleware are stored, and at the same time a DCAS interface for supporting communication with the DCAS host module is provided. Saved (step 906).

Thereafter, the DCAS server 202 transmits the SM module 300 to the set top box 204 (step 908).

The DCAS server 202 sends a verification application to the set top box 204 (step 910).

The verification application is program code corresponding to the first verification unit 330 included in the SM module 300 and the second verification unit 334 included in the DCAS host module 310.

Next, the DCAS server 202 transmits secret information for CAS client and user authentication to the set-top box 204 (step 912).

Thereafter, the DCAS initialization process is performed according to the reboot of the set-top box 204 (step 914).

DCAS initialization is already defined in the DCAS standard, and authentication and transmission and reception of a predetermined message are performed between the DCAS server 202 and the SM boot loader 304 included in the SM module 300 during the initialization process.

Thereafter, the first verifier 330 and the second verifier 334 included in the set-top box 204 perform hash value calculation and logical operation on components of the DCAS host module according to a random number of predetermined bits. The integrity of the DCAS host module is verified (step 916).

After the integrity is verified as described above, the SM boot loader 304 in the SM module proceeds with the normal process (step 918).

According to the normal operation of the SM process, when the scrambled transport stream is received from the headend 200, the set-top box 204 acquires a control word through the SM module 300, thereby descrambling the transport stream. To perform.

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 security service providing system of a DCAS-based broadcast receiving apparatus according to an embodiment of the present invention.

3 is a diagram illustrating a configuration for enhanced security in a DCAS-based broadcast receiving apparatus according to the present invention.

4 is a diagram illustrating a detailed configuration of a verification unit according to the present invention.

5 is a flow chart illustrating a security hardening method according to the present invention.

Figure 6 is a view showing the configuration of a set-top box according to an embodiment of the present invention.

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

8 illustrates a software architecture before and after applying DCAS according to the present invention.

9 is a flowchart illustrating a process of applying a security enhanced DCAS to an open cable-based set-top box.

Claims (15)

A method for enhancing security of a downloadable conditional access system (DCAS) -based broadcast receiving device, (a) dividing all of the plurality of components included in the DCAS host module into n blocks (n is a natural number of 1 or more), and storing a hash value for each of the n blocks; (b) generating a random number of n bits; (c) receiving hash value calculation information for at least one component block designated according to the random number; And (d) verifying the integrity of the DCAS host module using the hash value calculation information and the stored hash value, The hash value storage, the random number generation, and the integrity verification process are performed in a Secure Micro (SM) module of the broadcast reception device. The method of claim 1, And a component included in the DCAS host module is at least one of a DCAS manager, a restricted reception network handler, a secure micro driver, and a transport processor driver. delete The method of claim 1, The random number generation step generates a random number of n bits, The DCAS host module calculates hash values for k blocks (where 1 ≦ k ≦ n) specified according to the random number and logically computes the calculated hash values according to a predetermined algorithm. . The method of claim 4, wherein The n-bit random number is a bit string including 0 or 1, and includes at least one of k or 0. The method of claim 1, The steps (a) to (d) are performed in a secure micro (SM) module of the DCAS-based broadcast receiving device. In order to enhance the security of a downloadable conditional access system (DCAS) -based broadcast receiving device, a program of instructions that can be executed by the digital processing device is tangibly implemented and can be read by the digital processing device. Dividing all of the plurality of components included in the DCAS host module into n blocks (n is a natural number of 1 or more), and storing a hash value for each of the n blocks; And verifying the integrity of the DCAS host module by using the hash value operation information and the stored hash value of at least one block designated according to a random number of n bits, The hash value storage, the random number generation, and the integrity verification process are performed in a Secure Micro (SM) module of the broadcast reception device. In the downloadable conditional access system (DCAS) -based broadcast receiving device, SM (Secure Micro) module including a first number and a random number generator for generating a random number of n (n is a natural number of one or more) bits, and obtains a control word from a message received through a data channel ; And Includes a component for the DCAS protocol and includes a DCAS host module for performing routing of messages delivered from the SM (Secure Micro) module, The first verification unit divides all of the plurality of components included in the DCAS host module into n blocks, stores a hash value for each of the n blocks, and calculates a hash value for a block designated according to the n-bit random number. DCAS-based broadcast receiving apparatus for verifying the integrity of the DCAS host module using the information, the random number generator generates a random number of n bits. delete The method of claim 8, The first verification unit, A hash value list storage unit for storing hash values for each of the n blocks; The n-bit random number is transmitted to a second verifying unit included in the DCAS host module, and a hash of k blocks (where 1 ≦ k ≦ n) designated from the second verifying unit according to the n-bit random number is provided. A message transceiver for receiving value calculation information; And And an integrity verification unit that verifies the integrity of the DCAS host module by using the hash value list and the hash value calculation information. The method of claim 8, The DCAS-based broadcast receiving device is an open cable-based set-top box having a POD module that interworks with a smart card. The open cable-based set-top box downloads the image for the DCAS host including the DCAS host module and the SM module from the DCAS server, and does not pass the scrambled transport stream based on the DCAS host module and the SM module without passing through the POD module. DCAS-based broadcast reception device descrambling in a transmission processor included in the system on a chip. The method of claim 11, The DCAS host image includes a modified platform code, middleware and a porting layer for changing the open cable-based set-top box into a DCAS-based broadcast receiving device. The method of claim 12, At least one of the modified platform code, middleware and the porting layer includes a DCAS interface supporting communication between the DCAS host modules. The method of claim 8 The DCAS-based broadcast receiving device is an open cable-based set-top box having a POD module that interworks with a smart card. The open cable-based set-top box downloads an image for the DCAS host including the DCAS host module from the DCAS server, and the SM module is provided through a USB dongle type security processor, based on the DCAS host module and the SM module. A DCAS-based broadcast reception device for descrambling a scrambled transport stream in a transport processor included in a system on chip without passing through the POD module. A method for providing a security enhancement service in a server connected to a broadcast reception device, Transmitting an image for a DCAS host including a downloadable conditional access system (DCAS) host module to the broadcast receiving device; Transmitting a CAS (Conditional Access System) client for descrambling a transport stream after authenticating the broadcast receiving device in which a Secure Micro (SM) module transmitting and receiving a message with a DCAS host module is stored. ; And And transmitting a verification application for verifying integrity of the DCAS host module to the broadcast receiving device. The verification application divides the entire plurality of components included in the DCAS host module into n blocks (n is a natural number of 1 or more), stores a hash value for each of the n blocks, and uses a random number of n bits. Verifying the integrity of the DCAS host module by using the hash value calculation information and the stored hash value for one or more blocks designated according to The verification application is included on the Secure Micro (SM) module to provide the security enhancement service providing the hash value storage, the random number generation and the integrity verification.

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