KR20000034451A - Method for preventing reproduction of isochronous data transmitted through high performance serial bus - Google Patents

Abstract

PURPOSE: A method for preventing reproduction of an isochronous data transmitted through an IEEE P1394 standard high performance serial bus is provided so that a CONSTITUTION: A code showing that a currently-transmitted data is a data which needs authorization is designated in a tag field of an isochronous packet. An authorization code is designated in a synchronous code field. A key code necessary for the authorization process is inputted from each receiving node(S604), and compared with the authorization code in the synchronous code field of the isochronous packet(S605). As a result, the isochronous packet is transmitted to the receiving node inputting the key code identical to the authorization code(S606), thereby preventing illegal reproduction of the data. That is, the isochronous data of the transmitting node can be selectively transmitted to the authorized receiving nodes by employing the tag field and synchronous code field of the isochronous packet as defined in the IEEE P1394 standard.

Description

A method for protecting a copy of isochronous data transmitted through a high performance serial bus

The present invention relates to a data transmission method through a high performance serial bus standardized by IEEE P1394, and more particularly, to a method for preventing isochronous data copying transmitted through a high performance serial bus.

In general, high-performance serial buses that overcome the problems of parallel buses have been widely studied in order to implement high-speed buses required by computer technology.

The high performance serial bus is a digital serial bus standardized by IEEE P1394, and is defined as a node, a module, and a unit.

In the above, the node is an addressable entity, and reset and recognition may be performed independently. A module consists of one or more nodes. A node is a logical addressing concept, whereas a module is a physical package.

In addition, a node is a logical entity with a unique address, which can be independently reset with an ID ROM and a series of standardized control registers. The address space provided by a node may be mapped to one or more units. A unit is a logical object, such as a disk controller, that corresponds to its own I / O driver software.

Meanwhile, the IEEE P1394 standard high performance serial bus may be applied to various systems. For example, a program provider may provide a program developed by the user to a large number of users so that the user may conveniently use the various programs. It can be applied to a program transmission / reception system.

However, in the IEEE P1394 standard, there is no protocol for preventing unauthorized copying of data when transferring data between applications, so that the copyright of the program provider cannot be properly protected when applied to such a program transmission / reception system. there was.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and selectively uses only isochronos data of a transmitting node selectively to receiving nodes using a tag field and a sync code field of an isochronous packet defined in the IEEE P1394 standard. The purpose of the present invention is to provide an isochronous data copy protection method that is transmitted through a high-performance serial bus that can prevent the isochronous data of a transmitting node from being copied and used without permission.

In order to achieve the above object, an isochronous data copy prevention method transmitted through a high performance serial bus according to the present invention transmits isochronous data to at least one receiving node through a high performance serial bus in the form of an isochronous packet. The method of claim 1, further comprising: specifying a code in the tag field of the isochronous packet indicating that the data to be transmitted is data to be authorized, and assigning an authorization code to the sync code field of the isochronous packet; Checking the code specified in the tag field to determine whether the data to be transmitted is data requiring approval; if the determination result indicates that the data requires approval, receiving a key code necessary for the approval process from each receiving node; Each receiving node Comparing the key code received from the authorization code contained in the sync code field of the isochronous packet, and transmitting the isochronous packet only to the receiving node that inputs the key code that matches the authorization code as a result of the comparison Characterized in that it comprises a step of preventing copying.

1 is a physical topology of an IEEE P1394 standard high performance serial bus according to the present invention;

2 is a protocol stack of the IEEE P1394 standard high performance serial bus according to the present invention;

3 is an exemplary diagram of an isochronous subaction applied to the present invention;

4 is a format of an isochronous data block packet applied to the present invention;

5a is a schematic structural diagram of a program transmission and reception system to which the present invention is applied;

5B is a detailed configuration diagram of a transmitting node and a receiving node shown in FIG. 5A;

FIG. 6 is a flowchart of a data transmission procedure of the IEEE P1394 interface device shown in FIG. 5B.

<Description of the symbols for the main parts of the drawings>

10: sending node 10-1: program provider system

10-2, 21-2: IEEE P1394 Interface Device

21 to 27: Received node 21-1: User system

31 to 37: IEEE P1394 standard high performance serial bus

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

First, the high performance serial bus standardized by IEEE P1394 will be briefly described to help understand the present invention.

The physical topology of the IEEE P1394 standard high performance serial bus according to the present invention is divided into a serial bus in a backplane environment and a serial bus in a cable environment, as shown in FIG. 1, and a serial bus in a different environment is a bridge (BRIDGE, 120). , 140).

In FIG. 1, the systems 110 and 130 of the backplane environment are interconnected with the CPU 111, the memory MEMORY 112, the I / O 113, and the CPU 114 through the serial bus 115. Input / output devices (I / O) 150 and 160 in a cable environment are interconnected via serial bus 154, and cable media 152, 153 and 154 connect ports of different nodes. Here, the cable media 152 to 154 are composed of two pairs of conductor cables for signal transmission and one pair of cables for power supply.

2 is a protocol stack of the IEEE P1394 standard high performance serial bus according to the present invention, wherein the high performance serial bus includes a physical layer 220, a link layer 230, a transaction layer, and a transaction layer. 240, and the serial bus management layer 210 manages the layered protocol.

The physical layer 220 includes connectors / media, arbitration, bus initialization, data resynch, signal levels, encode / decode. ) Function.

The link layer 230 includes a packet transmitter, a packet receiver, and a cycle control function.

The serial bus management layer 210 includes a node controller 211 including a standard CSR 211a, an isochronous resource manager 212 including an isochronous CSR 212a, and a management CSR. There is a Bus Manager (213) function, including (213a).

In addition, request (* .req), acknowledgment (* .conf), indication (* .ind), and response (* .resp) primitives are transferred between layers to exchange information. For example, PH_DATA.ind, PH_CLOCK.ind, and PH_ARB.conf primitives are transmitted from the physical layer 220 to the link layer 230, and PH_DATA.req, from the link layer 230 to the physical layer 220. The PH_ARB.req primitive is passed.

In the layered protocol as described above, the link layer 230 provides a half-duplex data packet transmission service. Here, the operation of transmitting one packet is called a subaction, and such subactions include asynchronous subactions and isochronous subactions. The asynchronous subaction carries variable length data and a few bytes of transaction layer information by an explicit address, and a response to the transferred operation is required. On the other hand, the isochronous subaction transmits variable length data at regular intervals by a simple address, and does not need a response to the transferred operation.

In addition, the isochronous subaction occurs only during isochronos cycles that start every 125 ms on average, and one isochronous packet is transmitted over each isochronos channel for one cycle. Here, the isochronous channel refers to a transmission channel between one transmitting node and one receiving node.

FIG. 3 is an exemplary diagram of an isochronous subaction applied to the present invention, wherein the isochronous subaction is arbitrated through one isochronous channel, data prefix, packet, and data end ( The data end is transmitted, followed by another mediation, data prefix, packet, and data end through the next channel through the isochronous gap.

4 is a format of an isochronous data block packet applied to the present invention, wherein the isochronous data block packet corresponds to a sequence of aligned quadlets (32 bits).

As shown in FIG. 4, the isochronous data block packet includes a data length field (data_length), an isochronous data format tag field (tag), an isochronous channel field (channel), a transaction code field (tcode), and a sync code field ( sy), a header CRC field (header_CRC), a data block payload field (data field), and a data block CRC field (data_CRC). The number of bits allocated to each field is shown in Table 1 below.

Packet component About sleeping Size (bits) Data length data_length 16 Isochronos data format tag tag 2 Isochronos Channel channel 6 Transaction code tcode 4 Synchronous code sy 4 Header CRC header_CRC 32 Data block payload data_field - Data block CRC data_CRC 32

The isochronous data provided by the transmitting node to the receiving node is defined in the data block payload field shown in FIG. 4.

Details of such high performance serial buses are described in the IEEE P1394 standard book published in November 1995.

5A is a schematic configuration diagram of a program transmission / reception system to which the present invention is applied, and the program transmission / reception system is composed of one transmitting node 10 and a plurality of receiving nodes 21 to 27, and each node 10, 21. The connection between ˜27 is made up of the IEEE P1394 standard high performance serial buses 31 to 37.

FIG. 5B is a detailed configuration diagram of the transmitting node and the receiving node shown in FIG. 5A, wherein the transmitting node 10 includes a program provider system 10-1 and an IEEE P1394 interface device 10-2. The node 21 (only one is shown for convenience) is composed of the user system 21-1 and also the IEEE P1394 interface device 21-2. The IEEE P1394 interface device 10-2 of the transmitting node 10 and the IEEE P1394 interface device 21-2 of the receiving node 21 are interconnected by an IEEE P1394 standard high performance serial bus 31.

The program provider system 10-1 of the transmitting node 10 sends the program data in the form of an isochronous packet to the IEEE P1394 standard interface device 10-2. At this time, the program provider system 10-1 designates a "10" code in a tag field of the isochronous packet shown in FIG. An authorization code is specified in the code field sy and sent to the IEEE P1394 interface device 10-2. The acknowledgment code is a 4-bit binary code, and various codes such as "1101" and "1010" may be used if only an appointment is made with an authorized user in advance. On the other hand, in the case where it is desired to transmit a program which is irrelevant even if it is used without unauthorized copying, "1" code is designated in the tag field of the isochronous packet and transmitted to the IEEE P1394 interface device 10-2. That is, codes assigned to tag fields of the isochronous packet and their meanings are shown in Table 2 below.

code meaning 0 0 Data field is not formatted 0 1 Copyable Data 1 0 Data that requires approval 1 1 Reserved

When the IEEE P1394 interface device 10-2 of the transmitting node 10 receives the isochronous packet from the program provider system 10-1, first checks the code specified in the tag field tag of the corresponding packet, and checks the code. Is 1, the isochronous packet is transmitted to the three receiving nodes 21, 24, and 25 via the IEEE P1394 standard high performance serial buses 31, 34, and 35, respectively. Here, the isochronous packets transmitted to the three receiving nodes 21, 24, and 25 are sequentially transmitted to the remaining receiving nodes 22, 23, 26, and 27. On the other hand, if the code specified in the tag field (tag) is "10", Isochronos receives a key code for approval from all receiving nodes 21 to 27 through the IEEE P1394 standard high performance serial bus (31, 34, 35). The isochronous packet is transmitted only to the receiving node which has entered the key code matching the acknowledgment code, compared to the acknowledgment code specified in the sync code field sy of the packet.

That is, when transmitting a free program, the program provider system 10-1 sets the tag field tag of the isochronous packet to "1" so that all receiving nodes 21 to 27 can receive and use the program. For example, when transmitting a paid program, the tag field is set to "10" so that the program is transmitted only to a receiving node that is pre-approved by the program provider. Therefore, a receiving node that is not approved by the program provider does not receive the program.

A process of preventing isochronous data copying of a transmitting node in the program transmission / reception system configured as described above will be described in more detail with reference to the flowchart shown in FIG. 6.

FIG. 6 is a flowchart of a data transmission procedure of the IEEE P1394 interface device shown in FIG. 5B.

First, the program provider system 10-1 of the transmitting node 10 sends the program data to be transmitted in the form of isochronous packet to the IEEE P1394 interface device 10-2. At this time, the program provider system 10-1 designates a "10" code indicating that the data to be transmitted is data to be approved in the tag field of the isochronous packet when the program to be transmitted is a paid program. In addition, an acknowledgment code pre-appointed with the user is specified in the sync code field sy, while a "1" code is assigned to a tag field of the isochronous packet when the current program to be transmitted is a free program.

The IEEE P1394 interface device 10-2 receives the isochronous packet from the program provider system 10-1 (S601) and checks the code specified in the tag field (S602) among them (S602).

After the step S602, the IEEE P1394 interface device 10-2 determines whether the code specified in the tag field tag is "10" (S603). If the code is "10", the IEEE P1394 interface device 10-2 receives approval from the receiving nodes 21 to 27. The required key code is input (S604). Here, the program provider notifies the program license number only to the users who have paid the fee so that only the authorized user side receiving node can input the correct key code.

After the step S604, the IEEE P1394 interface device 10-2 checks the acknowledgment code specified in the sync code field sy of the isochronous packet received from the program provider system 10-1, and receives each of the receiving nodes 21-27. Compared to the key code received from the (S605).

After step S605, the IEEE P1394 interface device 10-2 transmits the isochronous packet only to a receiving node that has input a key code that matches the acknowledgment code confirmed in the sync code field sy of the isochronous packet. It is possible to use the paid program, thereby preventing the illegal copy of the paid program (S606).

On the other hand, if the code specified in the tag field tag of the isochronous packet is not "10" as a result of the determination in step S603, the IEEE P1394 interface device 10-2 again returns the code specified in the tag field "1". In operation S607, if the corresponding code is “1”, the isochronous packet is transmitted to all receiving nodes 21 to 27 so that all users can copy and use the free program (S608).

As described above, the present invention is applicable to a program transmission / reception system because it is possible to selectively transmit isochronous data of a transmitting node to only pre-approved receiving nodes using a tag field and a synchronization code field of an isochronous packet defined in the IEEE P1394 standard. In this case, the program provider is prevented from being transmitted to unauthorized users so that the program provider can receive copyright protection.

Claims (1)

A transmitting node transmits isochronous data in the form of an isochronous packet to one or more receiving nodes via a high performance serial bus. Designating a code indicating that data to be transmitted is data to be approved in a tag field of the isochronous packet; Designating an authorization code in the sync code field of the isochronous packet; Checking the code specified in the tag field to determine whether the data to be transmitted is data requiring approval; Receiving a key code necessary for an approval process from each of the receiving nodes if the result of the determination requires data; Comparing a key code received from each receiving node with an acknowledgment code included in a sync code field of the isochronous packet; Preventing unauthorized copying of data by transmitting the isochronous packet only to a receiving node that inputs a key code corresponding to an approval code as a result of the comparison, wherein the isochronous data copy prevention method is transmitted through a high performance serial bus. .