KR101238195B1 - System and method for intercepting illegality reproduction in eXchangeable Conditional Access System - Google Patents

Abstract

The present invention relates to a system and method for preventing illegal copying in an exchangeable CA system, and more particularly, to efficiently detect and control a set-top box copy by an illegal actor in an exchangeable CA system to effectively detect and control illegal copying. The present invention relates to an illegal copy blocking system and method in an exchangeable CA system for blocking in advance. According to the present invention, the weakening of the security caused by changing the conventional classic CA system into a switchable CA system, that is, the physical device (smart chip, smart card, cable card) in the classic CA system is software-based. By blocking the illegal copying caused by changing the ID through dynamic ID, it can compensate for the weak security that occurs during the registration process of the first set-top box.

Description

System and method for intercepting illegality reproduction in eXchangeable Conditional Access System}

The present invention relates to a system and method for preventing illegal copying in an exchangeable CA system, and more particularly, to efficiently detect and control a set-top box copy by an illegal actor in an exchangeable CA system to effectively detect and control illegal copying. The present invention relates to an illegal copy blocking system and method in an exchangeable CA system for blocking in advance.

Conditional Access System (CAS) is a system for controlling viewing rights of a user so that only subscribers who have obtained a viewing qualification through a legal procedure can watch a paid broadcasting program.

Conventional set-top boxes have been provided in such a way that a physical device containing CAS information, which is a CA application, is detachably coupled to the set-top box in order to apply the CA system that provides broadcasting content only to authenticated users.

The set top box of the related art supports the OCAP standard in order to interface with the physical device and perform the authentication function. The OCAP standard is a standard for supporting functions required for the authentication process of the physical cable card and the set-top box and the exchange and processing of various information required for the authentication process.

The conventional CA system has a disadvantage in that CAS systems cannot be replaced by configuring various types of physical devices (smart chips, smart cards, cable cards) that are not replaceable for viewing authority control. It had to be structured to pay for operating costs with enormous technical fees, and once introduced, the conditional access system was able to exercise exclusive command with an immutable structure.

Accordingly, a software-exchangeable conditional access system (XCAS) has been applied to the set-top box according to the OCAP standard by replacing the hardware CAS system. At this time, the XCAS is a term used in the country as the same meaning as the DCAS (Downloadable CAS), the contents of the present invention described below is not limited by the name.

The XCAS system is characterized by a software separation in which an XCAS host corresponding to the set-top box downloads the CAS client directly from an XCAS headend instead of a hardware separation such as the cable card for CA.

At this time, in the XCAS host constituting the XCAS system, the XCAS host is a security module that supports a protocol for communication with the XCAS headend for a switchable limited reception service, and is downloaded to the security module and the limited reception system It includes a CAS client module that manages key management and control for.

That is, the security module of the XCAS host downloads and stores the CAS client module through authentication with the XCAS headend, and the CAS client module receives the EMM and ECM from the XCAS headend, decrypts the EMM and publishes it. After extracting a key, decrypting the ECM as the public key, extracting a CW, and descrambled scrambled TS packets received from the XCAS headend to the CW to provide broadcast program content.

At this time, in the process of mutual authentication of the XCAS headend and the XCAS host, the security module of the XCAS host requests a certificate from the certification authority through the XCAS headend to download the CAS client module. The security module uses the security module ID included in the unique identification information of the XCAS host issued from the certification authority at the time of initial manufacture of the XCAS host.

Accordingly, the security module performs a certificate issuance request to the certification authority by using the terminal identification information including the security module ID and the public key and the private key generated by the security module. In addition, the certification authority receives the terminal identification information and checks the validity, and when the validity is confirmed, generates the key information necessary for authentication including the security module ID in the XCAS host.

Thereafter, the certification authority updates the key information in the XCAS headend so that the XCAS host and the XCAS headend can mutually authenticate based on the key information. In this case, the corresponding key information may include the information of the XCAS headend that the XCAS host performs mutual authentication, so that the XCAS host can perform the authentication process with the XCAS headend authenticated by the certification authority.

Accordingly, the XCAS host can download the CAS client module by performing mutual authentication with the key information with the XCAS headend, and the CAS client module provides the security module that supports a communication protocol with the XCAS headend. Through receiving the encryption key required for descrambling the broadcast program content through it can provide the broadcast program content to the user.

In the above-described process, the key information issued through the mutual authentication process between the XCAS host and the certification authority has a process that is issued when validity is authenticated through the unique identification information of the XCAS host. Since the unique identification information of the terminal including the ID can be duplicated together, the above-described security process itself is problematic.

In other words, the conventional XCAS is mainly researched and implemented only for the method of safely downloading the CA to the XCAS host, thereby revealing a weakness in the illegal copying of the terminal itself of the XCAS host. Therefore, the conventional XCAS was insufficient to meet the security requirements.

The present invention seeks to improve the security of an exchangeable CA system by providing a method for efficiently detecting and controlling a set-top box constituting an XCAS host by an illegal actor. It aims to provide stable services and guarantee the profits of broadcasters.

The piracy blocking system in the interchangeable CA system that blocks piracy through mutual authentication of an XCAS headend and an XCAS host that receives key information required for authentication from a certification authority for achieving the above object is the XCAS. Provides the CAS client module to the XCAS host performing mutual authentication based on the headend and the key information and downloading the CAS client module from the XCAS headend after authentication, and the XCAS host authenticated based on the key information. If a dynamic ID is assigned to the XCAS host, the dynamic ID is matched with the security module ID included in the key information, and is periodically stored. Determination of piracy is made by comparing with ID, and in case of piracy, the security module ID Blocks the connection to the XCAS host, and if not illegal copying includes an XCAS headend to update the dynamic ID to transmit to the XCAS host, and match and store the security module ID with the updated dynamic ID.

At this time, the XCAS headend stores the key information, allocates a dynamic ID to the XCAS host corresponding to the security module ID included in the key information, and periodically requests a security module ID and a dynamic ID from the XCAS host. An authentication server for determining whether the illegal copy is compared with a previously stored security module ID and a dynamic ID, and a download server for storing the CAS client module, wherein the XCAS host is mutually associated with the authentication server based on the key information. And a security module for authenticating, downloading and storing a CAS client module from the download server, and transmitting the security module ID and the dynamic ID according to the request of the authentication server.

In addition, the authentication server stores and blocks the security module ID and dynamic ID of the illegally cloned XCAS host when it is determined to be illegal copying, and deletes key information of the XCAS host corresponding to the same security module ID as the illegally cloned XCAS host. And, it may be characterized by transmitting a message for renewing the authentication authority and the authentication authority to the XCAS host.

In accordance with the present invention for achieving the above object, illegal copy blocking in an exchangeable CA system that blocks illegal copying through mutual authentication of an XCAS headend and an XCAS host that have received key information necessary for authentication from a certificate authority. The method may further include a first step in which the security module of the XCAS host storing the key information and the authentication server of the XCAS headend perform mutual authentication based on the key information, and the security module in which the authentication server is authenticated. A second step of allocating and transmitting a dynamic ID with a CAS client module and matching the dynamic ID with a security module ID included in the key information, and storing the dynamic ID from the authentication server by the security module; A third step of receiving and storing the authentication server periodically requesting a security module ID and a dynamic ID to the security module; A fourth step of receiving the security module ID and the dynamic ID from an existing security module, and comparing the security module ID and the dynamic ID previously stored in the authentication server with the security module ID and the dynamic ID received from the security module to determine whether illegal copying is possible. The fifth step of determining.

In this case, the fourth step includes the step of sending a duplicate confirmation Announce message for receiving the currently stored dynamic ID and the secure module ID from the security module, and the security module receives the duplicate confirmation Announce message, and has already been allocated. And adding the received dynamic ID and security module ID to the duplication confirmation request message, and sending the dynamic ID and security module ID included in the duplication confirmation request message to the database. The method may further include checking whether the data is replicated according to whether the stored dynamic ID and the security module ID match.

In addition, if the authentication server is normal after the fifth step after the confirmation whether the replication, the new dynamic ID different from the existing dynamic ID is generated to update the existing dynamic ID, and including it in the updated dynamic ID issuing message. When the security module receives the updated dynamic ID issuance message and extracts the new dynamic ID and replaces the existing dynamic ID with the new dynamic ID, or when the authentication server is replicated after checking whether the authentication server is duplicated. Adds the security module ID and the existing dynamic ID to the security module revocation list of the database to prevent downloading of the CAS client module, and deletes key information of the XCAS host corresponding to the same security module ID as the illegally cloned XCAS host. The method may further include a sixth step of transmitting a message for renewing a certificate to the XCAS host.

According to the present invention, the weakening of the security caused by changing the conventional classic CA system into a switchable CA system, that is, the physical device (smart chip, smart card, cable card) in the classic CA system is software-based. By blocking the illegal copying caused by changing the ID through dynamic ID, it can compensate for the weak security that occurs during the registration process of the first set-top box.

In addition, the present invention ensures the reliability of the security that is concerned when supplying the product to the limited receiving company, broadcast service providers have the effect of effectively blocking the reduction in revenue caused by the replica set-top box.

1 is a block diagram of an exchangeable CA system.
2 is a flow chart for a new dynamic ID issuance of an illegal copy blocking system in a switchable CA system according to the present invention.
Figure 3 is a flow chart for the illegal copy confirmation of the illegal copy blocking system in the interchangeable conditional access system according to the present invention.
Figure 4 is a flow chart of the illegal copy blocking method in the interchangeable CA system.

The present invention is used during the authentication process between the initial certification authority and the XCAS host, and the unique identification information of the terminal, including the security module ID set at the time of manufacture of the subscriber terminal constituting the XCAS host, is copied together at the time of duplication of the subscriber terminal by an illegal actor. The authentication process used to issue certificates is obsolete, so that subsequent security processes between the XCAS host and the XCAS headend can also easily detect whether or not the XCAS host is pirated, in order to address the security vulnerability. The invention can be proposed.

To this end, in addition to the security module ID between the XCAS host and the XCAS headend, a separate dynamic ID for detecting whether the XCAS host is illegally copied by the XCAS headend is assigned to a legitimately authenticated XCAS host. This makes it easy to detect when replicating an XCAS host.

Hereinafter, the XCAS host described in the present invention refers to a subscriber station including a set-top box, and the communication mechanism for protocols and procedures for messages transmitted and received between the certification authority, the authentication server, and the security module of the present invention is referred to as XCAS protocol. define.

First, Fig. 1 shows a step-by-step interchangeable CA system.

Referring to FIG. 1, the overall configuration diagram of the XCAS may include a certification authority 140, an XCAS headend 130, an XCAS host 120, and a security module 110.

The certification authority 140 provides key information generated in the authentication process with the security module to the XCAS headend 130, and the XCAS headend may extract the security module ID of the XCAS host from the key information. have. In addition, the authentication server 131 of the XCAS headend 130 transmits the key information necessary for authentication received from the certification authority 140 to the security module 110 of the XCAS host 120 through a cable network, and authentication. The server 131 and the security module 110 perform mutual authentication based on the key information, and all the keys generated at this time may be stored in the key management server 132.

At this time, the XCAS host transmits a public key and a private key generated by the XCAS host for the subscriber terminal authentication of the certification authority together with the security module ID to the authentication authority based on the security module ID, the public key and the private key. The certificate generated by the certification authority may be used as the key information.

Meanwhile, after the mutual authentication is normally completed, the security module may download the CAS client module 111 from the download server of the XCAS headend. After performing the above procedure, the CAS client module 111 receives the scrambled broadcast program content through the XCAS headend to perform the descrambling process, and through this, the subscriber can normally watch the broadcast program to which the restricted reception is applied. .

Based on the above-described configuration, the terminal illegal copy blocking system in the interchangeable CA system according to the present invention is an additional XCAS between the authentication server 131 and the security module 110 of the XCAS headend system shown in FIG. By adding a protocol, it can be configured as shown in FIG.

Referring to FIG. 2, the security module 110 authenticates based on the key information from the authentication server 131, and then the CAS client module 111 from the download server 133 of the XCAS headend 130. ) Has been downloaded and installed.

In this case, the authentication server 131 of the XCAS headend 130 may allocate a dynamic ID to the XCAS host 120 when the CAS client module 111 is provided, and the dynamic ID is included in the key information. By matching the security module ID of the XCAS host and storing it in the database, the XCAS host to which the dynamic ID is assigned can be identified.

Meanwhile, the security module receives and stores the dynamic ID from the authentication server 131. Thereafter, the authentication server 131 periodically sends a 'replica confirmation Announce message' 151 for receiving the dynamic ID and the security module ID currently stored from the security module to the security module 110.

When the security module 110 receives the 'reply confirmation Announce message' 151, the security module 110 adds the already assigned dynamic ID and security module ID to the 'replica confirmation request message' 152, and the authentication server sends the ' The dynamic ID and the security module ID included in the replication confirmation request message are compared with the dynamic ID and the security module ID stored in the database to check whether the data is duplicated according to the match.

If normal after the confirmation of the replication, the authentication server generates a new dynamic ID different from the existing dynamic ID to update the existing dynamic ID, and includes it in the 'updated dynamic ID issuing message' (153) the security module The security module 110 receives the 'updated dynamic ID issuance message' 153 to extract the new dynamic ID and replaces the existing dynamic ID with the new dynamic ID.

Thereafter, when the authentication server retransmits the 'reply confirmation announce message' 151, the updated dynamic ID and security module ID are added to the 'replica confirmation request message' and may go through the same process as described above. .

On the other hand, the authentication server is a method of confirming whether or not to replicate the pirated XCAS host is as shown in FIG.

Referring to FIG. 3, the authentication server 131 may include a security module ID and a dynamic ID 172 that the security module 110 of an authorized XCAS host includes in the 'replication confirmation request message' 152. For example, the new dynamic ID is generated and the existing dynamic ID is updated (171), and it is included in the 'updated dynamic ID issuance message 153' for the case of matching. Sends to security module of XCAS host.

Through this, the authorized XCAS host replaces and stores the existing dynamic ID with the new dynamic ID included in the 'updated dynamic ID issuance message 153)'.

Thereafter, when the replicated XCAS host 160 transmits the 'replication confirmation request message' 152 in the same manner, the security module ID and the existing dynamic ID 173 are transmitted, and the new dynamic ID stored in the database 170 is stored. And the existing dynamic ID are inconsistent with each other, and thus may be determined as a replicated XCAS host.

In this case, the authentication server may prevent the download of the CAS client module by adding the security module ID and the existing dynamic ID to the security module revocation list of the database, and if the same security module ID and the existing dynamic ID are transmitted later, Locking may be performed to block or stop the function of the security module installed in the replicated XCAS host.

In addition, the authentication server maintains the security module revocation list of the replication terminal until the expired certificate expiration period included in the key information to completely block, and the XCAS host corresponding to the same security module ID as the pirated XCAS host. The key information may be deleted, and a message for renewing the certificate with the certificate authority may be sent to the XCAS host having the right to induce the XCAS host to generate new key information with the certificate authority.

Therefore, the certification authority may take measures to allow a valid user who has passed through a valid procedure to reassign a security module ID through a new certificate to receive service.

4 is a flowchart illustrating a method for blocking illegal copying in an exchangeable CA system according to the present invention. First, a security module of the XCAS host and an authentication server of the XCAS headend receive key information required for authentication from a certification authority. After storing, the mutual authentication is performed based on the key information.

Thereafter, a CAS client module and a dynamic ID are allocated and transmitted to the security module authenticated by the authentication server, and the dynamic ID is matched with a security module ID included in the key information and stored in a database.

The security module receives and stores the dynamic ID from the authentication server, and the authentication server periodically requests a security module ID and a dynamic ID from the security module to the security module ID. Receive a dynamic ID.

Thereafter, the authentication server compares the previously stored security module ID and the dynamic ID with the security module ID and the dynamic ID received from the security module, and determines whether illegal copying is performed. And generating a new dynamic ID different from the existing dynamic ID to update the existing dynamic ID, and transmitting the new dynamic ID to the security module by including it in the updated dynamic ID issuing message, and the security module receives the updated dynamic ID issuing message. After extracting the dynamic ID, the new dynamic ID may replace the existing dynamic ID.

On the other hand, if the authentication server is replicated after determining whether to replicate, the security module ID and the existing dynamic ID is added to the security module revocation list of the database to prevent the download of the CAS client module, and the illegally replicated XCAS host Deletes the key information of the XCAS host corresponding to the same security module ID and sends a message to the XCAS host to renew the authentication with the certification authority, so that the XCAS host is issued a new certificate from the certification authority to obtain the existing security module ID. You can update it.

110: security module 111, 134: CAS client
120: XCAS host 130: XCAS headend
131: authentication server 132: key management server
133: download server 140: certificate authority
151: Announcement Message for Replication Confirmation
152: Replication confirmation request message
153: Updated dynamic ID issuance message

Claims (6)

In the piracy blocking system in the interchangeable CA system that prevents piracy through mutual authentication of the XCAS headend and the XCAS host that receive key information required for authentication from the certification authority,
An XCAS host performing mutual authentication based on the XCAS headend and the key information, and downloading a CAS client module from the XCAS headend after authentication; And
When providing the CAS client module to the XCAS host authenticated based on the key information, a dynamic ID is assigned to the XCAS host, and the dynamic ID is matched with a security module ID included in the key information and stored periodically. By comparing the dynamic ID to the XCAS host and comparing the previously stored security module ID and the dynamic ID to determine whether to illegally copy, and in case of illegal copying, block access to the XCAS host corresponding to the security module ID, and illegally copy. If not, the XCAS headend for updating the dynamic ID and transmits to the XCAS host, and matching and storing the security module ID with the updated dynamic ID,
The XCAS headend,
Stores the key information, allocates a dynamic ID to an XCAS host corresponding to the security module ID included in the key information, periodically requests a security module ID and a dynamic ID from the XCAS host, and stores the previously stored security module ID and dynamic ID. An authentication server for determining whether the illegal copy is compared with an ID; And
A download server for storing the CAS client module;
The XCAS host,
And a security module which mutually authenticates with the authentication server based on the key information, downloads and stores a CAS client module from the download server, and transmits the security module ID and the dynamic ID according to the authentication server's request.
The authentication server stores and blocks the security module ID and dynamic ID of the illegally cloned XCAS host, and deletes key information of the XCAS host corresponding to the same security module ID as the illegally cloned XCAS host. And a message for renewing a certificate with a certification authority to the XCAS host.
delete delete In the piracy prevention method in an exchangeable CA system that prevents piracy through mutual authentication of the XCAS headend and the XCAS host that received the key information required for authentication from the certification authority,
A first step of performing mutual authentication between the security module of the XCAS host storing the key information and the authentication server of the XCAS headend based on the key information;
A second step of allocating and transmitting a CAS client module and a dynamic ID to the secure module authenticated by the authentication server, and matching the dynamic ID with a security module ID included in the key information and storing the dynamic ID in a database;
A third step of the security module receiving and storing the dynamic ID from the authentication server;
A fourth step of the authentication server periodically requesting a security module ID and a dynamic ID from the security module, and receiving the security module ID and the dynamic ID from the security module; And
And a fifth step in which the authentication server compares a previously stored security module ID and a dynamic ID with a security module ID and a dynamic ID received from the security module, and determines whether to be illegally copied.
The fourth step,
Sending a duplicate confirmation Announce message for receiving a dynamic ID and a security module ID currently stored from the security module; And
Receiving, by the security module, the replication confirmation Announce message, adding the already allocated dynamic ID and security module ID to the replication confirmation request message, and sending the same.
The fifth step,
The authentication server further comprises the step of checking whether or not duplication according to the match by comparing the dynamic ID and security module ID included in the replication confirmation request message with the dynamic ID and security module ID stored in the database,
After the fifth step,
If the authentication server is normal after confirmation of the replication, create a new dynamic ID different from the existing dynamic ID to update the existing dynamic ID, include it in the updated dynamic ID issuing message and send it to the security module and the security The module receives the updated dynamic ID issuance message, extracts the new dynamic ID, and replaces the existing dynamic ID with the new dynamic ID,
When the authentication server is replicated after checking whether the replication is performed, the security module ID and the existing dynamic ID are added to the security module revocation list of the database to prevent the download of the CAS client module, and the same security as that of the pirated XCAS host. And deleting a key information of the XCAS host corresponding to the module ID, and transmitting a message for renewing a certificate with the certification authority to the XCAS host. How to block.
delete delete

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