KR20010008479A - Method for managing connection of digital interface - Google Patents

Abstract

PURPOSE: A method for connecting digital interfaces is provided to control access from a third apparatus to a bit stream in transfer while connecting digital apparatuses by using a digital interface such as IEEE1394. CONSTITUTION: A source digital apparatus(310) decides content of a bit stream to be transferred to a synchronizing digital apparatus(320). By selecting a specific option for the decided bit stream, communication between digital apparatuses(330) begins to form a coding channel. Then, coding/decoding keys to be used in the coding channel are decided. Bit stream between the source digital apparatus and the synchronizing digital apparatus is coded and decoded according to the decided coding/decoding keys.

Description

Method for managing connection of digital interface

The present invention relates to a digital interface connection method, and more particularly, to a connection management method between digital devices connected through a digital interface such as IEEE1394.

Digital devices such as digital TVs, digital VCRs, and digital set-top boxes are emerging, and IEEE 1394, a network that allows these digital devices to interface with each other, is being introduced (see IEEE1394-1995 High Performance Serial Bus, IEC 61883, etc.). .

In systems where multiple digital devices are interconnected through digital interfaces such as IEEE 1394, the IEC61883 standard specifies connection management between these digital devices. The IEC61883 standard defines an input plug and an output plug as an inlet and an outlet for a bitstream for each digital device, and also includes an output master plug register (oMPR) contained within each digital device. ) manages input and output plugs to manage connection between digital devices by managing output plug control registers (oPCRs), input master plug registers (iMPRs), and input plug control registers (iPCRs).

There are two types of connection between digital devices: point-to-point connection and broadcast connection. A point-to-point connection is a connection consisting of an output plug, an input plug, and a channel between them, allowing any digital device to establish / overlay the connection and establish the connection. One device is responsible for all the management of the connection. A broadcast connection is divided into a broadcast-in connection and a broadcast-out connection. The broadcast connection is a connection between an input plug and a channel, and the broadcast connection is a connection between an output plug and a channel. Connection. The broadcast connection can only be established by the device that actually inputs and outputs the bitstream by this connection, and the release of the connection can be established by any device on the network. All management, including the establishment or release of point-to-point and brocast connections, uses registers such as iMPR, oMPR, iPCR, and oPCR.

An embodiment of a digital interface connection management method between digital devices according to the prior art will be described with reference to FIGS. 1 and 2A and 2B.

First, device 1 110 is called a source device (e.g. DVCR), device 2 120 is called a sink device (e.g. DTV), and device 3 130 is another sink device (e.g. DTV in another room). When device 1 110 and device 2 120 are connected through a point-to-point connection, the content of oPCR of device 1 110 is oPCR.P-2-P_Connection_Counter = 1, oPCR.Channel_Number = 33, The contents of the iPCR of 2 120 are iPCR.P-2-P_Connection_Counter = 1 and iPCR.Channel_Number = 33.

Accordingly, as shown in FIG. 1, the IEEE 1394 module is controlled between the device 1 110 and the device 2 120 according to the information setting, so that the device 2 120 may receive the output of the device 1 110. have.

At this time, if the device 3 (130) wants to see the current output of the device 1 (110) while the connection between the device 1 (110) and the device 2 (120) is set, the device 3 (130) is the device 1 currently set The point-to-point connection between the device 110 and the device 2 120 is overlaid to establish a point-to-point connection or a broadcast-in connection. When the point-to-point connection between the device 3 130 and the device 1 110 is set to overlap, the content of oPCR of the device 1 110 is oPCR.P-2-P_Connection_Counter = 2, oPCR.Channel_Number = 33, and the device The contents of iPCR of 3 130 are iPCR.P-2-P_Connection_Counter = 1 and iPCR.Channel_Number = 33.

Accordingly, as shown in FIG. 1, the IEEE 1394 module is controlled between the device 3 130 and the device 1 110 according to the information setting, so that the device 3 130 can receive the output contents of the device 1 110. have.

However, in the related art, device 3 (130) attempts to access the bit stream in a state where a bit stream is being transmitted because a point-to-point connection or a broadcast connection exists between device 1 (110) and device 2 (120). There is no user control. For example, if device 1 (110) and device 2 (120) are DVCR and DTV in the parent's room and device 3 (130) is the DTV in the child's room, the children control access to the bitstream contents of the VCR watched by their parents. Can not. Therefore, in the related art, the connection between the digital devices is not private and a third party device may access randomly.

The technical problem to be achieved by the present invention is a connection management method of a digital interface that can control the access of the third-party device to the bit stream transmitted through this connection when establishing a connection between digital devices through a digital interface such as IEEE 1394 To provide.

1 illustrates a digital interface connection management method according to the prior art.

FIG. 2A is a detailed view of the oPCR of device 1 of FIG. 1.

FIG. 2B is a detailed view of iPCR of device 2 of FIG. 1.

3 is a block diagram illustrating digital interface connection management according to the present invention.

4 is a flowchart illustrating a digital interface connection management method according to the present invention.

In order to solve the above technical problem, the present invention provides a method for managing a connection of a digital interface for controlling access of another digital device while the digital device for a source and the sink digital device are connected by a digital interface. Determining, by the digital device, the content of the bitstream to be transmitted by establishing a connection to the sink digital device; When a predetermined option is selected for the bitstream determined in the process, starting a predetermined communication between the digital devices to form an encryption channel; Promising an encryption and decryption key for use in the encryption channel formed in the process; And encrypting, decrypting, and accessing the bitstream between the source digital device and the sink digital device according to the encryption and decryption key promised in the above process.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

The method of managing the digital interface connection of the present invention will be described by combining the configuration diagram of FIG. 3 and the flowchart of FIG.

Referring to FIG. 3, device 1 310, device 2 320, and device 3 330 are connected to an IEEE 1394 bus. Device 1 310 is called a source device (e.g. DVCR), Device 2 320 is called a sink device (e.g. DTV), and Device 3 330 is another sink device (e.g. DTV). An encryption module is built in the device 1 310 and the device 2 320 for an encryption request and response.

First, a connection is established between the device 1 310 and the device 2 320 in step 410. Herein, the connection between the device 1 310 and the device 2 320 may be a point-to-point connection or a broadcast-out / broadcast-in connection. For example, when the connection between the device 1 310 and the device 2 320 is established through the point-to-point connection, the content of the oPCR of the device 1 310 is oPCR.P-2-P_Connection_Counter = 1, oPCR.Channel_Number = 33, iPCR contents of the device 2 320 are iPCR.P-2-P_Connection_Counter = 1 and iPCR.Channel_Number = 33.

At this time, if the device 3 (330) wants to see the current output of the device 1 (310) while the connection between the device 1 (310) and the device 2 (320) is established, the device 3 (330) is currently set device 1 The point-to-point connection between the 310 and the device 2 320 is overlaid to establish a point-to-point connection or a broadcast-in connection. Therefore, when the point-to-point connection between the device 3 330 and the device 1 310 is set to overlap, the content of oPCR of the device 1 310 is oPCR.P-2-P_Connection_Counter = 2, oPCR.Channel_Number = 33, The contents of iPCR of device 3 330 are iPCR.P-2-P_Connection_Counter = 1 and iPCR.Channel_Number = 33. If the broadcast-in connection is overlapped between the device 3 330 and the device 1 310, the contents of the oPCR of the device 1 310 are oPCR.P-2-P_Connection_Counter = 1 and oPCR.Broadcast_Connection_Counter = 1. , oPCR._Channel_Number = 33, iPCR contents of the device 3 (330) is iPCR.Broastcast_Connection_Counter = 1, iPCR.Channel_Number = 33.

In step 420, it is checked whether the bitstream to be accessed between the device 1 310 and the device 2 320 is a specific content. In general, the device 1 310 manipulates and outputs a bit stream by referring to copyright control information (CCI) of the bit stream to be output. That is, if the copyright information is copy-free, the original bitstream (clear plaintext) is output without any illegal copy prevention process (for example, 5C DTCP, XCA, etc.), and vice versa. If the copy-never, copy-once, no-more-copy, etc., the scrambled through the encryption channel through the sink and the predetermined anti-piracy process Output a bitstream (scrambled bitstream, encrypted ciphertext). Therefore, step 420 is a case where the bitstream is specified specifically for the case where the copyright information is copy-free.

In a state in which the connection between the device 1 310 and the device 2 320 is performed in step 430, the user has a special content of the bitstream transmitted through the connection so that the device 3 330, which is another third party, cannot access the device. The operation selects a predetermined option.

If the option that the bitstream is special content is selected by the user in step 440, the device 1 310 and the device 2 320 related to the existing connection initiate a predetermined communication to form an encryption channel. Such communication may be a newly defined AV / C CTS (AV Control Command and Transaction Set) command or may be a newly defined protocol.

In operation 450, the device 1 310 and the device 2 320 promise an encryption / decryption key to use through an encryption module included therein.

In operation 460, the device 1 310 encrypts and outputs the bitstream using the encryption / decryption keys promised to each other, and the device 2 320 decrypts the received bitstream.

Therefore, as shown in FIG. 3, since the device 330 knows nothing about the encryption / decryption key promised between the device 1 310 and the device 2 320, access from the device 1 310 is impossible. Also, even if a bitstream is received, the contents thereof cannot be interpreted and displayed. Device 1 310 and Device 2 320 maintain their own encryption channels only if they refuse to attempt Device 3 330 to find out the encryption / decryption key or if they have contacted an existing user and allowed their use. do.

As described above, according to the present invention, when a connection is established between digital devices through a digital interface such as IEEE 1394, a user of such an existing connection is connected to another third party digital device for the bit stream being transmitted through the connection. Can control access.

Claims (2)

In the connection management method of the digital interface for controlling the access of other digital devices while the digital device for the source and the digital device for the sink is connected to the digital interface, Determining, by the source digital device, the content of the bitstream to be transmitted by establishing a connection to the sink digital device; When a predetermined option is selected for the bitstream determined in the process, starting a predetermined communication between the digital devices to form an encryption channel; Promising an encryption and decryption key for use in the encryption channel formed in the process; And encrypting, decrypting, and accessing the bitstream between the source digital device and the sink digital device according to the encryption and decryption key promised in the step. The method of claim 1, wherein the connection of the digital interface is applied in the IEEE 1394 interface standard.