KR100606115B1 - Method for session setup and method for channel change in conversions system of broadcasting and communication - Google Patents

Abstract

The present invention provides a method for establishing a session of a channel change server for receiving a broadcast service in a broadcast communication convergence system providing a broadcast service to each of a plurality of subscriber devices through an optical communication network using a switching scheme. When the session setup message for receiving the broadcast service from the device is received, performing an authentication process for the subscriber device through an authentication server, and a challenge value for encrypting the password of the subscriber device after performing the authentication process Transmitting a session setup challenge message to the subscriber device, receiving password information encrypted with a password of the subscriber device from the subscriber device by using the challenge value, and decrypting the received password information to decrypt the received password information. Of subscriber device Confirming the password, and transmitting the session establishment approval message according to the verification result. The present invention has the effect of maintaining the security by encrypting the password exchanged between the STB and the CCP server when establishing the session in the broadcast communication convergence system.

Broadcast Communication Convergence System, Session Setup, Channel Change, CCP Protocol

Description

Session establishment method and channel change method in broadcasting communication convergence system {METHOD FOR SESSION SETUP AND METHOD FOR CHANNEL CHANGE IN CONVERSIONS SYSTEM OF BROADCASTING AND COMMUNICATION}             

1 is a view for explaining the authentication scheme in a typical xDSL network

2 is a message flow diagram between an STB and a CCP server and an AAA server during session establishment and channel change in a conventional broadcast communication convergence system.

3 is a block diagram of a broadcast communication convergence system according to an exemplary embodiment of the present invention.

4 is a message flow diagram when a session is established and a channel is changed between an STB and a CCP server and an AAA server in a broadcast communication convergence system according to an embodiment of the present invention.

5 is a diagram illustrating a ClientSessionSetupChallenge message format according to an embodiment of the present invention.

6 is a diagram illustrating a ClientSessionSetupRequest message format according to an embodiment of the present invention.

7 is a diagram illustrating a ProgramSelectRequest message format according to an embodiment of the present invention.

The present invention relates to a broadcast communication convergence system, and more particularly, to a session establishment method and a channel change method in a broadcast communication convergence system.

In general, in the video broadcasting service environment, the control channel between the SetTop Box (hereinafter referred to as STB) and the broadcasting service providing server is defined in the DSM-CC and DAVIC standards. It is divided into Channel Change Protocol (CCP) channel.

These session control protocols and CCP protocols are used for broadcast services in xDSL network environments based on ISD / IEC 13818-6 and DAVIC1.2 standards.

The session control channel is responsible for establishing and releasing sessions between the STB and the broadcast service providing server, and the channel change protocol (CCP) channel is used by the STB to select a channel provided from the broadcast service providing server.

However, looking at the DSM-CC and DAVIC standards, the session control protocol and the CCP protocol are defined to operate on different protocol stacks. Session control protocol is defined based on TCP / UDP protocol, and channel change protocol is based on MAC (AAL5 / ATM) protocol. That is, the stack of the session control protocol is TCP / UDP-IP-MAC (AAL5-ATM)-PHY, and the stack of the channel change protocol is MAC (AAL5-ATM)-PHY.

1 is a view for explaining an authentication scheme in a typical x Digital Subscriber Line (xDSL) network. Referring to FIG. 1, in an xDSL network environment, a Password Aauthentication Protocol (PAP) or Challenge Handshake Authentication (PAP) is performed between a STB and a server through a Point-to-Point Protocol (PPP) and Point-to-Point Protocol over Ethernet (PPPoE) layer. Protocol) authentication method. PAP performs an authentication process using an ID or a password, and CHAP performs an authentication process using a hash. PAP and CHAP are protocols that aid in the authentication process by assisting PPP to enable the transfer of IP data over a serial line.

In such xDSL network environment, a broadcast service providing server transmits broadcast programs to a replication unit and broadcast control unit (RU / BCU), and the RU / BCU transmits broadcast programs to the corresponding STB. That is, in xDSL network environment, only one serial line is used to transmit a broadcast program. Therefore, even if there is a flaw in the PAP or CHAP authentication method through PPP, there is no security problem. In other words, there is no room for crackers to steal.

However, in the broadcasting communication convergence system, the session control protocol stack and the channel change protocol stack between STB, CCP server, and AAA server are used identically, and the two protocols are collectively called CCP, which has a TCP / UDP-IP-PHY stack. In the broadcast communication convergence system, all broadcast programs provided from the broadcast service providing server transmit a broadcast program selected by the STB to the corresponding STB through a switching operation. That is, in a broadcast communication convergence system, a broadcast program is transmitted through a switching method without using one serial line.

Accordingly, in a broadcast communication convergence system, an authentication method using PAP or CHAP through PPP used in a serial line cannot be used. Therefore, in the broadcast communication convergence system, when the STB requests the session establishment using the MAC address to change the channel, the CCP server requests authentication from the AAA server and the AAA server authenticates the session.

Specifically, FIG. 2 is a message flow diagram between an STB, a CCP server, and an AAA server during session establishment and channel change in a conventional broadcast communication convergence system. Referring to FIG. 2, the STB 10 transmits a ClientSessionSetupRequest message requesting session establishment to the CCP server 20 in step 22. Then, the CCP server 20 transmits an Access-Request message requesting authentication of the STB 10 to the AAA server 30 in step 24. The AAA server 30 performs authentication of the requested STB 10, and if authentication succeeds, in step 26, the AAA server 30 transmits an Access-Accept message, which is an authentication acceptance message, to the CCP server 20. The CCP server 20 transmits a ClientSessionSetupConfirm message to the STB 10 informing that the authentication is accepted in step 28. When the authentication is completed as described above, the STB 10 may request the CCP server 20 to change the channel according to the channel change request of the user. If there is a channel change request from the user, the STB 10 transmits a ProgramSelectRequest message for the channel change request to the CCP server 20 in step 30. Then, the CCP server 20 performs a channel change and transmits a ProgramSelectConfirm message to the STB 10 to accept the channel change in step 32.

By the way, in the session setup and channel change process as described above, the serial line is used between the CCP server 20 and the AAA server 30, and thus, the switching method is used between the STB 10 and the CCP server 20. There is a problem that each user's channel can be changed by another user's malicious channel change request. In addition, there is a problem that information about a broadcast channel being used by a user of each STB 10 may be known to other users of the STB 10.

Therefore, an object of the present invention for solving the above problems is a session setup method and channel change method to add a password function when performing the session setup and channel change process in a broadcast communication convergence system using a broadcast switch To provide.

According to the above object, in the broadcast communication convergence system for providing a broadcast service to each of a plurality of subscriber devices through an optical communication network using a switching scheme in the session establishment method of the channel change server for receiving the subscriber service When the session establishment message for receiving the broadcast service is received from the subscriber device, performing an authentication process for the subscriber device through an authentication server; and, after performing the authentication process, a challenge for encrypting the password of the subscriber device. Sending a session setup challenge message including a value to the subscriber device, receiving password information from the subscriber device encrypted password of the subscriber device using the challenge value, and receiving the received password information. Decode the Check the password of own apparatus, and transmitting a session establishment acknowledgment message in accordance with the check result.

In addition, the present invention provides a method for establishing a session of a subscriber device for receiving a broadcast service in a broadcast communication convergence system that provides a broadcast service to each of a plurality of subscriber devices through an optical communication network using a switching scheme, the broadcast service request from a subscriber And transmitting a session setup request message for receiving a broadcast service to the channel change server, and for the session setup request message, a session setup challenge message including a challenge value from the channel change server. Receiving password, generating password information using the challenge value included in the received session setup challenge message, and transmitting the generated password information to the channel change server, and transmitting the password information from the channel change server. The password of the subscriber device is confirmed via According to a step of being set up a session receives a session establishment acknowledgment message accordingly.

A channel change method of a channel change server for changing a channel of a broadcast service provided to a subscriber device in a broadcast communication convergence system that provides a broadcast service to a subscriber device through an optical communication network using a switching scheme, the channel change method of the subscriber device. Transmitting a session setup challenge message to the subscriber device, the session setup challenge message including a challenge value for performing an authentication process and encrypting the password of the subscriber device, and receiving a password encrypted from the subscriber device using the challenge value; Confirming the password of the subscriber device through the received password and establishing a session with respect to the subscriber device; receiving a channel change request message from the subscriber device after setting up the session, and receiving a channel number from the channel change request message. By checking And a step of changing the channel.

The present invention also provides a channel change method for changing a channel of a broadcast service provided by a subscriber device in a broadcast communication convergence system providing a broadcast service to each of a plurality of subscriber devices through an optical communication network using a switching scheme. Transmitting a session setup request message for receiving a broadcast service to a channel change server according to a broadcast service request, and receiving a session setup challenge message including a challenge value from the channel change server; After generating password information by using the challenge value included in the challenge message, transmitting the generated password information to the channel change server, and receiving a session set up as the password by the password information is confirmed from the channel change server After receiving the session, If the channel change request from the subscriber comprises the step of transmitting a channel change request message to the server to change the channel to the channel is changed by the channel change server.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the same components in the drawings are represented by the same reference numerals and symbols as much as possible even though they are shown in different drawings. In addition, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

3 is a block diagram of a broadcast communication convergence system according to an embodiment of the present invention. Referring to FIG. 3, a broadcast communication convergence system according to an embodiment of the present invention includes STB-1 to STB-N (100-1 to 100-N), ONU 200, OLT 300, and CCP server 400. And an AAA server 500.

Each of the STB-1 to STB-N (100-1 to 100-N) is a digital broadcast receiver located in each home, receives a broadcast service through an optical communication network, and provides the broadcast video signal to a user through a TV. To help.

More specifically, each of STB-1 to STB-N (100-1 to 100-N) is an electronic box placed on a TV set to receive cable or satellite broadcasting at home. It can be a device that connects to a TV in order to do so. Each of the STB-1 to STB-N (100-1 to 100-N) can use its own content or the general Internet through a dedicated browser, and can obtain information about news, weather, stocks, education, cooking, etc. Make sure you have an Internet phone.

According to an embodiment of the present invention, each of STB-1 to STB-N (100-1 to 100-N) encrypts and transmits a password so that security is maintained when establishing a session for receiving a broadcast service. In addition, each of the STB-1 to STB-N 100-1 to 100-N encrypts and transmits a channel number to be changed when a channel change request is received from a user while receiving a broadcast service.

The ONU (Optical Network Unit) 200 is an end device of an optical communication network that provides a service interface to each of STB-1 to STB-N (100-1 to 100-N). The ONU 200 is implemented to be highly accessible to users by accommodating fiber to the building (FTTB), fiber to the floor (FTTF), fiber to the office (FTTO), and fiber to the home (FTTH). . The ONU 200 is connected to each of the STB-1 to STB-N (100-1 to 100-N) devices in each home for implementing the FTTH according to an embodiment of the present invention through a switching signal received And provide a communication signal. At this time, each of the ONU 200 and STB-1 to STB-N (100-1 to 100-N) may be connected by bidirectional hybrid fiber coaxial (HFC).

OLT (Optical Line Terminal) 300 receives an all-optical signal and a communication signal received from a broadcasting company and a communication provider to provide broadcasting communication services such as digital broadcasting, analog broadcasting, voice telephone, video service, and high-speed Internet. After the conversion, it is bundled with one optical signal and transmitted to the ONU 200 through the optical cable.

The AAA server 400 performs authentication with each of the STB-1 through STB-N 100-1 through 100-N and provides an authentication result.

The CCP server 500 receives the session establishment request from each of the STB-1 through STB-Ns 100-1 through 100-N, via the AAA server 400, through the STB-1 through STB-Ns 100-1 through 100-N. N) Perform authentication for each. The CCP server 500 receives the session establishment request message including the encrypted password from each of the STB-1 through STB-N 100-1 through 100-N, and performs session establishment. In addition, the CCP server 500, if there is a channel change request from each of the STB-1 to STB-N (100-1 to 100-N) after the session setup process as described above, the channel change request message including the encrypted channel number Receives the channel change process.

4 is a message flow diagram when a session is established and a channel is changed between an STB and a CCP server and an AAA server in a broadcast communication convergence system according to an embodiment of the present invention. Hereinafter, a session establishment and channel change process in a broadcast communication convergence system according to an embodiment of the present invention will be described with reference to FIGS. 3 and 4. Hereinafter, each of STB-1 to STB-N (100-1 to 100-N) is referred to as STB 100.

Referring to FIG. 4, in step 702, the STB 100 transmits a ClientSessionSetupRequest message requesting session establishment to the CCP server 500. Then, the CCP server 500 transmits an Access-Request message requesting authentication of the STB 100 to the AAA server 400 in step 704. The AAA server 400 performs authentication of the STB 100 requested for authentication, and transmits an Access-Response message, which is a message indicating the authentication result, to the CCP server 500 in step 706. At this time, the access-response message may include information on whether the authentication is successful and authenticator information.

When the Access-Response message is received, the CCP server 500 generates and transmits a ClientSessionSetupchallenge message to the STB 100 in step 708 regardless of whether the authentication succeeds or fails. The ClientSessionSetupchallenge message is a message including the challenge value required for the STB 100 to generate a password in the session control message.

5 is a diagram illustrating a ClientSessionSetupchallenge message format according to an embodiment of the present invention. Referring to FIG. 5, the ClientSessionSetupchallenge message format includes 'Protocol Discriminator', 'DSM-CC Type', 'Message ID', 'Trangection ID', 'Reserved', 'Adaptation Length', 'challenge', 'Message Length', It consists of 'Session ID', 'Response', and 'Reserved' area.

The 'Protocol Discriminator' area consists of 1 byte and contains protocol identifier information. The DSM-CC Type 'area consists of 1 byte and the format information of DSM-CC (Digital Storage Media Command & Control) This area is included. The 'Message ID' area consists of 2 bytes and contains the message identifier information. The 'Trangaction ID' area consists of 4 bytes and the area containing the translation identifier information is ekl. The 'Reserved' area contains 1 byte. Configured and reserved area. The 'Adaptation Length' area consists of 1 byte and contains the length information of the Adaptation area, and the 'Adaptation' area consists of 16 bytes and is an adaptation area. The 'Message Length' area consists of 2 bytes and contains a message length value, and the 'Session ID' area consists of 10 bytes and contains session identification information. The 'Response' area is composed of 2 bytes and contains response information, and the 'Reserved' area is a reserved area composed of 20 bytes.

According to an embodiment of the present invention, a challenge value for generating a password is included in an 'Adaptation' area as shown at 50 of the above areas. At this time, the challenge value may be an authenticator value or a random value included in the authentication result received from the AAA server 400.

Referring back to FIG. 4, in step 710, the STB 100 receives a ClientSessionSetupchallenge from the CCP server 500, and includes a challenge value included in the received message, a pre-stored user password, and a shared secret key. Create a password using. At this time, the STB 100 generates a challenge value, a password, and a shared secret key as a password through the MD5 function, which is a kind of hash function.

In step 712, the STB 100 transmits a ClientSessionSetupRequest message including the generated password to the CCP server 500 again.

Referring to the ClientSessionSetupRequest message according to an embodiment of the present invention in more detail, Figure 6 is a view showing a ClientSessionSetupRequest message format according to an embodiment of the present invention.

Referring to FIG. 6, the password generated by the STB 100 is included in the 'Adaptation' area 60 among areas of the ClientSessionSetupRequest message. At this time, if the cipher is 16 bytes or less, the cipher may be included in 16 bytes in a zero padding manner.

Referring back to FIG. 4, the CCP server 500 receives a ClientSessionSetup Request message transmitted from the STB 100 in step 714 and checks the password included in the ClientSessionSetup Request message. If the user confirms that the password is correct, the CCP server 500 transmits a ClientSessionSetupConfirm message to the STB 100 informing the session establishment approval in step 716.

As described above, if there is a channel change request by the user after the session establishment is approved, the STB 100 transmits a ProgramSelectRequest message for the channel change request to the CCP server 20 in step 716.

That is, the STB 100 encrypts the channel number to be changed by using the challenge value received in the session setup process and the shared secret key stored in advance according to the channel change request by the user, and includes the encrypted channel number in the ProgramSelectRequest message. Send it. At this time, the STB 100 generates an encrypted channel number by compressing the challenge value, the shared secret key, and the channel number to be changed through the MD5 function, which is a kind of hash function.

7 is a diagram illustrating a ProgramSelectRequest message format including an encrypted channel number according to an embodiment of the present invention.

Referring to FIG. 7, the encrypted channel number generated by the STB 100 is included in the 'Adaptation' area 70 among areas of the ProgramSelectRequest message. A random value is included in the 'Broadcast Program ID' area set to include broadcast program identification information.

Then, the CCP server 500 receives the ProgramSelectRequest message from the STB 100 in step 720, decrypts the encrypted channel number included in the ProgramSelectRequest message, and checks the channel number to be changed by the user to change the channel.

In operation 722, the CCP server 500 transmits a ProgramSelectConfirm message indicating the approval of the channel change to the STB 100.

In the above description of the present invention, specific embodiments have been described, but various modifications may be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be defined by the described embodiments, but should be determined by the equivalent of claims and claims.

As described above, the present invention has an effect of maintaining security by encrypting a password transmitted and received between the STB and the CCP server when establishing a session in a broadcast communication convergence system.

In addition, the present invention has the effect of maintaining the security by encrypting the channel number exchanged between the STB and the CCP server when changing the channel in the broadcast communication convergence system.

Claims (16)

In the broadcast communication convergence system for providing a broadcast service to each of a plurality of subscriber devices through an optical communication network using a switching scheme, the method for establishing a session of a channel change server for receiving a broadcast service in a subscriber device, When the session establishment message for receiving the broadcast service is received from the subscriber device, performing an authentication process for the subscriber device through an authentication server; Transmitting a session setup challenge message to the subscriber device after the authentication process, the session setup challenge message including a challenge value for encrypting the password of the subscriber device; Receiving password information encrypted with a password of the subscriber device using the challenge value from the subscriber device; Confirming the password of the subscriber device by decrypting the received password information, and transmitting a session establishment approval message according to the verification result, And wherein the challenge value is an authenticator value included in an authentication result value for the subscriber device delivered from the authentication server when the authentication process is performed. The method of claim 1, And the session setup challenge message comprises the challenge value in an adaptation field of a session control message format defined in a CCP protocol. The method of claim 1, The password information is characterized by compressing the challenge value and the password and the shared secret key of the subscriber device previously stored in the subscriber device using a Message Digest (MD) 5 function. delete A session establishment method of a subscriber device for receiving broadcast service in a broadcast communication convergence system that provides a broadcast service to each of a plurality of subscriber devices through an optical communication network using a switching scheme, Transmitting a session establishment request message for receiving a broadcast service to a channel change server according to a broadcast service request from a subscriber; Receiving, for the session establishment request message, a session setup challenge message including a challenge value from the channel change server; Generating password information using the challenge value included in the received session setup challenge message, and transmitting the generated password information to the channel change server; Setting up a session as a password of the subscriber device is confirmed from the channel change server through the password information, and receiving a session establishment approval message accordingly; And wherein the challenge value is an authenticator value included in an authentication result value for the subscriber device delivered from the authentication server when the authentication process is performed. The method of claim 5, And the session setup challenge message comprises the challenge value in an adaptation field of a session control message format defined in a CCP protocol. The method of claim 5, And the cipher is a compressed value of the challenge value, a password previously stored in the subscriber device, and a shared secret key using a message digest 5 function. delete A channel change method of a channel change server for changing a channel of a broadcast service provided to a subscriber device in a broadcast communication convergence system that provides a broadcast service to a subscriber device through an optical communication network using a switching scheme, Performing a authentication procedure for the subscriber device and sending a session setup challenge message to the subscriber device including a challenge value for encrypting the password of the subscriber device; Receiving a password encrypted with a password from the subscriber device using the challenge value and confirming the password of the subscriber device using the received password to establish a session with the subscriber device; Receiving a channel change request message including channel number information that a subscriber wants to change from the subscriber device after the session establishment; Confirming the channel number to be changed by the subscriber from the channel number information included in the channel change request message, and changing the channel; The channel number information is characterized in that the challenge value, the shared secret key stored in advance in the subscriber device and the channel number to be changed by the subscriber is compressed using a Message Digest (MD) function. . delete The method of claim 9, The channel change request message is configured to include channel number information in an adaptation field of the session control message format defined in the CCP protocol. delete A channel change method for changing a channel of a broadcast service provided by a subscriber device in a broadcast communication convergence system providing a broadcast service to each of a plurality of subscriber devices through an optical communication network using a switching scheme, Transmitting a session establishment request message for receiving a broadcast service from a subscriber to a channel change server according to a broadcast service request from a subscriber, and receiving a session setup challenge message including a challenge value from the channel change server; After generating password information using the challenge value included in the received session setup challenge message, the generated password information is transmitted to the channel change server, and as the password by the password information is confirmed from the channel change server. Receiving a session, Generating channel number information using a channel number requested by the user when a channel change is requested from the subscriber after receiving the session; Transmitting a channel change request message including the generated channel number information to the channel change server; And checking the channel number to be changed by the subscriber from the channel number information included in the channel change request message by the channel change server to change the channel. The channel number information is characterized in that the challenge value, the shared secret key stored in advance in the subscriber device and the channel number to be changed by the subscriber is compressed using a Message Digest (MD) function. delete The method of claim 13, The channel change request message is configured to include channel number information in an adaptation field of the session control message format defined in the CCP protocol. delete

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