KR20120072030A - The apparatus and method for remote authentication - Google Patents

Abstract

PURPOSE: A remote authenticating system and a method thereof are provided to eliminate mutual authentication between servers by directly authenticating between a broadcast receiving terminal and a visited CAS authenticating server. CONSTITUTION: An authentication server encodes content. The authentication server transmits the encoded content. The authentication server transmits an ECM(Entitlement Control Message) and an EMM(Entitlement Management Message) for decoding the encoded content. A broadcast receiving terminal(120) produces control words based on the ECM and EMM. The broadcast receiving terminal decodes the encoded content using the produced control words.

Description

System and method for performing remote authentication {The Apparatus and Method for remote authentication}

The present invention relates to a roaming (mobility) support technology of a conditional access system (CAS), and more particularly, stops even when an existing broadcast (multimedia data) receiving terminal is located in another area according to a user's movement. The present invention relates to a remote authentication method and apparatus for a conditional access system capable of receiving a broadcast (multimedia data) service.

If the user wants to watch service programs such as cable network, IPTV network and satellite broadcasting, the conditional access system determines whether to provide the service based on user (subscriber) authentication so that only authorized users can receive and view the program. It is a system to control.

CA system uses different standards for each manufacturer, which is why it is not compatible with other company's equipment. Therefore, broadcast service provider directly provides subscriber with receiving terminal with CA system, increasing the burden of broadcasting service provider. It was difficult to update the CA system.

In order to solve this problem, the OpenCable standard in North America has released a standard for separating a conditional access system from a subscriber receiving terminal. As a result, the conditional access system separated from the receiving terminal has been standardized as a PCMCIA card type cable card. As in the past, it was possible to provide a paid broadcasting service by providing only a cable card to a subscriber without renting a receiving terminal to a subscriber, but OpenCable did not achieve the desired result such as an increase in the price of a cable card and an increase in management cost.

In this situation, a downloadable conditional access system (DCAS) technology has been introduced that enables a paid broadcast service by downloading a conditional access software to a subscriber receiving terminal without requiring a hardware conditional access system.

On the other hand, the conventional CA system head-end system can access the network to download the CA software to the authorized receiving terminal, and the user can install the program on the receiving terminal to receive the program access qualification information to view the program.

However, when the receiving terminal moves to access the network of another authentication server for the first time, a mechanism for continuously providing the program access credential information corresponding to the network of the authentication server previously connected to the receiver in the network of the authentication server newly connected to the receiver. This situation is not specified. At this time, although the user has moved to the authentication server network of the same service provider, there is a problem that viewing of the program is impossible.

In addition, there is a problem that communication resources are wasted because the program access credential information is continuously transmitted to the previous network due to the movement of the corresponding receiving terminal, and thus the use efficiency of the network is reduced.

Therefore, there is a need for a technology capable of supporting the mobility of the CA system more efficiently.

Meanwhile, in order to download the conventional CA system, mutual authentication between the authentication server and the receiving terminal should be performed. In addition, if the CA system mounted on the receiving terminal does not mutually authenticate with the authentication server located in the CA system headend, various attacks may be received from the server impersonating the authentication server.

Therefore, there is a need for an effective mutual authentication method for solving a security problem in a downloadable CA system.

On the other hand, in the conventional CA system, the CA system service provider can directly assign the master key to the terminal and at the same time, the authorization of the key can be reflected in the entitlement management message (EMM). The master key is provided to the terminal via the downloadable CA system, not the receiving system service provider. Accordingly, there is a need for a method of providing a master key to a receiving terminal authenticated to a downloadable CA system headend and a method of managing an entitlement management message (EMM).

On the other hand, in the conventional downloadable conditional access system, the receiving terminal is provided with a Secure Micro (SM) module in the form of an on-board, and the receiving terminal is provided from the conditional access system headend on the SM module. The downloaded CA system client is saved.

The SM module executes the downloadable CA system protocol, generates and stores the key and secret information, and receives the credential control message (ECM) and the credential management message (EMM) from the headend. Interpret the message to get the control word.

As described above, since the downloadable CA is provided with a download method of the CA system which acquires the control word from the credential control message and the credential management message, it is possible to freely change the CA system without being dependent on the specific CA system provider. .

Here, in order to apply the downloadable CA system to the conventional open cable-based set-top box, a hardware change is required, and thus a new receiving terminal needs to be developed.

Therefore, the user's demand for a system capable of supporting roaming based on the downloadable CA system without replacing the existing receiving terminal is further increased.

On the other hand, in providing a mutual authentication function between the authentication server and the receiving terminal, the certificate-based solution is not vulnerable to duplication because it does not include device hardware information loaded with authentication information. The hardware-based recognition solution recognizes a terminal only with hardware information, and thus there is insufficient interworking and security between the terminal and the user.

The smart card (USIM, SIM) technology is mounted on various terminals to provide user authentication and secure storage. Pre-shared key is used for user authentication.

In addition, when smart card technology is a removable token, the Trusted Computing Group (TCG) standard Mobile Trusted Module (MTM) is a hardware token in the form of a fixed token. Therefore, in addition to the user authentication provided by the smart card technology attached to the terminal provides a strong security functions such as device and platform authentication, secure key generation and management, remote device authentication and public key authentication method.

According to the present invention, when mutual authentication is completed between the security module of the CA host and the visiting authentication server, the user provides the service without interruption by instructing the restricted receiving server to transmit the credential management message to the network of the visiting authentication server. Policy server that supports the mobility of CAS hosts that can be received, and the method of authentication between the broadcast receiving terminal and the visited CAS authentication server, which requires no mutual authentication between servers, and additionally, no need for a policy server. Provide techniques.

In addition, the present invention provides a method for receiving a secure broadcast service because it provides a strong security functions such as device and platform authentication, secure key generation and management, remote device authentication and public key certificate method in addition to user authentication. .

In addition, the present invention, in the downloadable limited reception system (DCAS), by limiting such as paid broadcast reception and update of information by simply performing remote authentication to the subscriber terminal and the subscriber terminal that has already purchased the paid broadcasting service Provides a method of supporting a receiving service.

In addition, the present invention provides a simple apparatus and method for providing a broadcast service to a user who has moved to another broadcaster's area based on a downloadable CA system without replacing a broadcast receiving terminal.

In a roaming support method of a CA using a remote authentication according to an aspect of the present invention, a remote authentication request of a broadcast receiving terminal is received by accessing a CAS authentication server in a headend of a visiting broadcaster. Checking and authenticating related information When authentication of a broadcast receiving terminal is completed, transmitting authentication completion information to the broadcast receiving terminal, and transmitting a CAS image defined for the visiting broadcaster to a broadcast receiving terminal. do.

In addition, roaming-related information uses ID PubKey and Certificates generated by the broadcast receiving terminal requesting roaming service, and by verifying roaming related information, identification information of a broadcasting company subscribed to the authenticated broadcasting receiving terminal, visited broadcasting company identification information, and Roaming service use period information includes at least one.

In a roaming method of a CA system in a server of a visiting broadcaster according to an aspect of the present invention, a roaming related information is generated by an unsubscribed broadcast receiving terminal, and the roaming related information is transmitted to a CAS authentication server by an unsubscribed broadcast receiving terminal. Requesting remote authentication, receiving an authentication result of the unsubscribed broadcast receiving terminal from the CAS authentication server, establishing a connection with the unsubscribed broadcast receiving terminal, and transmitting a CAS image to the authenticated unsubscribed broadcast receiving terminal. .

According to an aspect of the present invention, there is provided a roaming apparatus of a CA according to an aspect of the present invention, wherein the roaming apparatus of a CAS receives a roaming-related information of a broadcast receiving terminal according to a roaming service request of a user, and updates roaming information. And a first CAS authentication server for authenticating the roamed broadcast receiving terminal in cooperation with the first DCAS authentication server according to a preset protocol and transmitting a CAS image to the MTM platform of the broadcast receiving terminal.

The first DCAS authentication server may determine whether a roaming service is available using the user roaming request information, and when the roaming service is available, a request processing module for storing roaming related information, and receiving a roaming request of a user, and requesting an authentication request. Check the authentication processing module and the received authentication completion information for authenticating the SM module of the user and the MTM platform using the information contained in the information, and if the user and the broadcast receiving terminal is authenticated, the relevant information for CAS update to the broadcast receiving terminal It includes a CAS update module for transmitting.

In addition, the broadcast receiving terminal includes a multimedia processor that outputs a decoded output by inputting a scrambling stream, a control processor that controls descrambling of the scrambling stream in the multimedia processor, and a CAS image and an SM module in the MTM platform to be stored. And an MTM platform for providing control words to the multimedia processor to perform descrambling.

In addition, the MTM platform includes an Endorsement Key (EK), an MTM and an Endorsement Cert, a Platform Cert, and a Conformance Cert that includes a plurality of Attestation ID Keys according to the number of services provided and generates an ID SubKey by a remote authentication request. , ID SubKey and Certificates.

A CA system according to an aspect of the present invention encrypts and transmits a content, and transmits a credential control message (ECM) and a credential management message (EMM) for decrypting the encrypted content, and an credential control message (ECM). And a terminal that calculates a control word based on the entitlement management message EMM and decrypts the encrypted content by using the calculated control word.

In a method for performing remote authentication between an authentication server and a terminal according to an aspect of the present invention, a terminal generates an ID request bundle for an authentication request of a terminal and transmits the bundle to an authentication server based on the ID request bundle in an authentication server. Performing verification of the terminal, generating a Signed ID for the terminal and transmitting it to the terminal, connecting the authentication server and the communication link using the Signed ID in the terminal, and providing a service to the terminal through the communication link connected from the authentication server. Transmitting service information for providing, and receiving and storing the service information at the terminal.

According to another aspect of the present invention, a method for performing remote authentication between an authentication server and a terminal generates roaming related information including identification information of a terminal, subscriber and operator identification information for a service, and roaming period information for a service. In the step of, the terminal transmits roaming-related information to the authentication server to request authentication, authenticating the terminal using the roaming-related information in the authentication server, and if the terminal is authenticated in the authentication server, providing a service to the terminal Transmitting service information for the service.

The present invention can provide an efficient roaming scheme of the CA system by eliminating the mutual authentication between the servers by the authentication between the direct broadcast receiving terminal and the visited authentication server, and further eliminating the need for a policy server.

In addition, the mobile credit module (MTM) of the present invention provides a secure broadcasting service because it provides a strong security functions such as device and platform authentication, secure key generation and management, remote device authentication and public key certificate method in addition to user authentication It can provide a way to receive it.

In addition, the present invention in the downloadable limited reception system (DCAS), by simply performing remote authentication to the existing subscriber terminal that purchased the pay-TV service and the reserve subscriber terminal that has not yet purchased, such as limitations such as paid broadcast reception and information update A method of supporting a reception service may be provided.

In addition, the present invention can be provided as a simple apparatus and method that can provide a broadcast service to a user who has moved to another broadcaster's area based on a downloadable limited reception system (DCAS) without replacing the broadcast receiving terminal.

1 is a view showing a CA system for performing remote authentication according to an embodiment of the present invention.
Figure 2 is a block diagram showing an authentication server of the CA system for performing remote authentication according to an embodiment of the present invention.
Figure 3 is a block diagram showing a terminal of a CA system for performing remote authentication according to an embodiment of the present invention.
4 is a block diagram illustrating an authentication module of the terminal of FIG. 3 according to an exemplary embodiment of the present invention.
5 is a view showing a method for performing remote authentication in a CA system according to an embodiment of the present invention.

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

1 is a view showing a CA system for performing remote authentication according to an embodiment of the present invention. Referring to FIG. 1, the CA includes a certificate server 100 and 110 and a terminal 120.

As shown in FIG. 1, a CA system according to an aspect of the present invention may include a first headend 100 belonging to a first broadcaster and a second headend 110 belonging to a second broadcaster. It may include.

The first and second headends 100 and 110 may encode the video received from the content provider into a transport stream according to MPEG-2, and broadcast by scrambling and encrypting the video so that only the right subscriber can watch the content. Transmit to the receiving terminal 120.

In addition, the first and second headends 100 and 110 transmit an entitlement control message (ECM) and an entitlement management message (EMM) for a descrambling (decoding) of the transport stream. Through the transmission to the broadcast receiving terminal 120.

The first headend 100 includes a first CAS authentication server that acts as a proxy for CAS service for the subscribed broadcast receiving terminal 120.

In addition, the second headend 110 also includes a second CAS authentication server that acts as a proxy for CAS service for the subscribed broadcast receiving terminal 120.

The broadcast receiving terminal 120 tunes, descrambles, and decodes the transport streams received from the first and second headends 100 and 110 to display contents.

In addition, when the scrambled transport streams are received from the first and second headends 100 and 110, the broadcast receiving terminal 120 receives the entitlement control message (ECM) and the entitlement management message (EMM), and controls them by interpreting them. A word is obtained and descrambling of the transport stream is performed through the obtained control word.

The first CAS authentication server 100 and the second CAS authentication server 110 communicate with each other according to a preset protocol to provide an uninterrupted broadcasting service to the broadcast receiving terminal 120 of a user roaming to each CAS authentication server.

Hereinafter, a process of providing a roaming service when a user subscribed to a first broadcaster moves to an area of a second broadcaster on the above-described CA system.

First, the first CAS authentication server 100 and the second CAS authentication server 110 communicate with each other according to a preset protocol to share roaming related information in each CAS authentication server.

The roaming related information stores broadcast receiving terminal identification information, subscriber broadcasting company identification information, visiting broadcasting company identification information, and roaming service usage period information.

When there is a connection of the broadcast receiving terminal 120, the second CAS authentication server 110 tests the roaming information of the broadcast receiving terminal 120 received by the authentication request of the broadcast receiving terminal 120, and receives the broadcast. When the terminal 120 is authenticated, the broadcast receiving terminal 120 transmits information for a CAS service.

According to this process, the second CAS authentication server 110 receives a broadcast that is not subscribed to the second CAS authentication server 110 through remote authentication provided by the broadcast receiving terminal 120 without interworking with the first CAS authentication server 100. The broadcast service may be provided to the terminal 120, and thus, the user may not need to replace the broadcast receiving terminal 120.

Figure 2 is a block diagram showing an authentication server of the CA system for performing remote authentication according to an embodiment of the present invention. 2, the authentication server 200 includes a roaming request processing module 210, an authentication processing module 220, and an information updating module 230.

The first or second CAS authentication servers 100 and 110 of FIG. 1 may be implemented in the form of the authentication server 200 of FIG. 2.

The roaming request processing module 210 determines whether roaming service is available using roaming request information when there is a roaming request from a broadcast receiving terminal (user), and stores roaming related information when roaming service is available.

As described above with reference to FIG. 1, the roaming related information may include broadcast receiving terminal identification information, subscriber and visiting broadcaster identification information, and roaming service period information.

The authentication processing module 220 receives a roaming request from the broadcast receiving terminal (user), and authenticates the user and the broadcast receiving terminal using the roaming information included in the authentication request.

The information update module 230 checks the received authentication completion information, and transmits relevant information for updating service information to the broadcast receiving terminal when the user and the broadcast receiving terminal are authenticated.

Through this process, the broadcast receiving terminal (user) may move to a plurality of broadcaster areas and perform a roaming request to receive a desired service.

Figure 3 is a block diagram showing a terminal of a CA system for performing remote authentication according to an embodiment of the present invention. Referring to FIG. 3, the broadcast receiving terminal 120 according to the present invention includes a content processing module (multimedia processor or application processor) 300, a control module 310, and an authentication module 320.

The scrambled transport stream is input to the content processing module 300.

The content processing module 300 is a chip in which a module for reproducing a transport stream transmitted from the authentication servers 100 and 110 of FIG. 1 is embedded. The content processing module 300 processes the transport stream and decodes the audio or video and outputs the same. In addition, descrambling of the input transport stream is performed using the control word provided by the authentication module 320.

The control module 310 descrambles the scrambled transport stream in the content processing module 300 based on the CAS service information transmitted from the authentication servers 100 and 110 of FIG. 1 and the information processed by the authentication module 320. descrambling). In addition, the control module 310 controls the authentication module 320 to store the CAS service information and the SM (Secure Micro) module.

4 is a block diagram illustrating an authentication module of the terminal of FIG. 3 according to an exemplary embodiment of the present invention. Referring to FIG. 4, the authentication module 320 according to the present invention includes a mobile credit module (MTM) 400 and certificates 440, 450, and 460.

The mobile credit module 400 includes keys 410, 420, and 430 for authentication of the broadcast receiving terminal and the service.

The Endorsement Key (EK) 410 is a public / private key pair generated by the mobile credit module 400. A size of 2048 bits is recommended. The secret key is unique and mobile according to each mobile credit module 400. Leakage out of credit module 400 is limited.

The Endorsement Key (EK) 410 is generated using its own command within the mobile credit module 400. In addition, the manufacturer of the mobile credit module 400 is generated and injected during the manufacturing process, this characteristic means a state verified by the Endorsement Certificate.

Attestation ID Keys 420 and 430 are used by a service provider to provide self-certification for a provided service, and a plurality of keys may exist in the mobile credit module 400 for each service, such as a CAS service.

When a new service such as CAS is newly received, the ID PubKey of the Attestation ID Key 420 generated by the mobile credit module 400 is used as a value of an ID request bundle, and the first or second CAS certificate server of FIG. 1 is used. This is a key generated by receiving a Signed ID PubKey delivered to the terminal through an authentication process such as verification of the certificates 440, 450, and 460 received at 100 and 110.

In Certificates 440, 450, and 460, the Endorsement Cert 440 includes the public key of the Endorsement Key (EK) 410 and provides an attestation for the mobile credit module 400.

Platform Cert 450 is provided by a platform vendor, and mobile credit module 400 provides authenticity as a security component in authentication module 320.

The Conformance Cert 460 is a security feature provided by an authentication module vendor or an evaluation agency for this field technology, which means that the security property of the authentication module 320 is certified by an authorized evaluation agency.

5 is a view showing a method for performing remote authentication in a CA system according to an embodiment of the present invention.

FIG. 5 illustrates an ID request bundle using a newly generated ID PubKey and certificates 440, 450, and 460 in the authentication module 320 of the terminal to receive a new ID, that is, authentication of a new ID. I want to receive.

In other words, verify the certificates (440, 450, 460), and after the verification is completed, receives a Signed ID from the first CAS certificate server 200 and downloads the image (service information) and SM module for the CAS host The process of changing to a CAS host is shown.

First, using the information of the authentication module 320 generates a bundle of ID request to be used for the authentication request (500). Thereafter, the generated ID request bundle is transmitted to the first CAS authentication server 200 (510).

Next, in the contents of the ID request bundle received as the authentication request, the certificates 440, 450, and 460 are verified by the first CAS certificate server 200 (520).

Thereafter, after verification of the certificates 440, 450, and 460 is completed, a Signed ID to be transmitted as a result of the authentication request is generated (530).

Next, the Signed ID is transmitted to the MTM platform 320 (540). Then, after the connection is established between the authentication module 320 of the broadcast receiving terminal 120 and the first CAS authentication server 200 (550), the first CAS authentication server 200 is an image for the CAS host (service information ) Is transmitted to the authentication module 320 (560).

Next, the CAS host image (service information) is stored in the authentication module 320 (570). Thereafter, the first CAS authentication server 200 transmits the SM module to the authentication module 320 (580).

Next, the first CAS authentication server 200 transmits a CAS image (service information) and secret information for user authentication to the authentication module 320 of the broadcast receiving terminal 120 (590).

When the broadcast receiving terminal 120 is changed to the CAS host through the same process, and the broadcast receiving terminal 120 changed to the CAS host moves to another broadcaster's area, the terminal is not replaced through authentication and downloading of the CAS client. A broadcast service can be provided to a user.

One aspect of the present invention may be embodied as computer readable code on a computer readable recording medium. The code and code segments implementing the above program can be easily deduced by a computer programmer in the field. A computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer system is stored. Examples of the computer-readable recording medium include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical disk, and the like. The computer-readable recording medium may also be distributed over a networked computer system and stored and executed in computer readable code in a distributed manner.

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. Therefore, the scope of the present invention should not be limited to the above-described embodiments, but should be construed to include various embodiments within the scope of the claims.

100, 110 certificate server
120 broadcast receiving terminals

Claims (14)

In the method of remote authentication of the terminal in the authentication server,
Generating and receiving an ID request bundle for an authentication request of the terminal from the terminal;
Verifying the terminal based on the bundle of ID requests, generating a Signed ID for the terminal, and transmitting the signed ID to the terminal;
Connecting a communication link from the terminal using the Signed ID; And
And transmitting service information to the terminal through the connected communication link. The method of claim 1,
When the terminal moves from an area of a specific authentication server to an area of another authentication server, the other authentication server verifies roaming information of the terminal to authenticate the terminal, and transmits service information for providing a service to the terminal. Remote authentication method further comprising ;. The method of claim 1,
Determining whether roaming to the authentication server is possible by using roaming information received from the terminal when the roaming request is received from the terminal, and storing roaming related information about the terminal when the roaming is possible;
Authenticating the terminal using the roaming related information; And
If the terminal is authenticated, transmitting service information for providing a service to the terminal. The method of claim 3, wherein the roaming related information
Remote identification method including identification information of the terminal, subscriber and operator identification information for the service, roaming period information for the service. In the method for remote authentication of the authentication server in the terminal,
Generating an ID request bundle for an authentication request of a terminal and transmitting the bundle to an authentication server;
Receiving a Signed ID for the terminal generated by verifying the terminal based on the ID request bundle from the authentication server;
Connecting a communication link with the authentication server using the Signed ID;
Receiving service information from the authentication server through the connected communication link;
Storing the service information. The method of claim 5, wherein
Calculating a control word based on the service information; And
And decrypting and decoding the encrypted content received from the authentication server using the control word. The method of claim 5, wherein storing the service information
Generating at least one key for authentication of the terminal and the service;
Remote authentication method for holding the certificate (Certificates) of the terminal credentials, platform, security. The method of claim 7, wherein
Transmitting a set of ID requests generated based on the generated plurality of keys (ID PubKey) and the certificates to the authentication server;
Receiving a Signed ID for the terminal generated by verifying the terminal using the ID request bundle from the authentication server; And
Remote authentication for the authentication server from the Signed ID, and receiving and storing the service information from the authentication server. 8. The method of claim 7, wherein the key is
An endorsement key that is unique to the terminal and includes a secret key restricted to the outside; And
Attestation ID Key for performing a self-authentication for the service. 8. The method of claim 7, wherein the certificates
An endorsement certificate for the terminal;
A platform certificate that proves authenticity as a security component of the terminal; And
Remote authentication method comprising a; (Certification Cert) for authenticating the security characteristics of the terminal. An authentication server for encrypting and transmitting content and transmitting an entitlement control message (ECM) and an entitlement management message (EMM) for decrypting the encrypted content; And
And a terminal for calculating a control word based on the entitlement control message (ECM) and the entitlement management message (EMM) and decrypting the encrypted content using the calculated control word. The method of claim 11, wherein the authentication server
A roaming request processing module for determining whether roaming to the authentication server is possible by using roaming information received from the terminal when the roaming request is received from the terminal, and storing roaming related information for the terminal when the roaming is possible;
An authentication processing module for authenticating the terminal using the roaming related information; And
And an information update module for transmitting service information for providing a service to the terminal when the terminal is authenticated. The method of claim 11, wherein the terminal
A content processing module for decrypting and decoding the encrypted content using the control word;
An authentication module for calculating a control word based on the entitlement control message (ECM) and an entitlement management message (EMM), transmitting the control word to the content processing module, and storing the service information; And
And a control module positioned between the content processing module and the authentication module to control the operation of the two modules. The method of claim 13, wherein the authentication module
And a mobile credit module (MTM) for generating one or more keys for authentication of the terminal and service.
Remote authentication system that holds the certification information (certificates), the credentials, platform, security of the mobile credit module (MTM).

Images