KR20070011101A - Data reproducing method and data reproducing apparatus, recording medium and data reproducing method and data recording apparatus - Google Patents

Abstract

It is an object of the present invention to provide a data reproducing method and reproducing apparatus, a recording medium and a data recording method and a recording apparatus which protect contents provided by a true content provider from illegal copying, distribution, and the like.

The present invention provides a data reproducing method and a reproducing apparatus, which generate a forensic mark using identifiable information of a player, insert the forensic mark into a stream, and decode the forensic mark.

According to the present invention, it is possible to track a data reproducing apparatus illegally copying content by using the forensic mark, thereby protecting the content.

Description

Data reproducing method and data reproducing apparatus, recording medium and data reproducing method and data recording apparatus {Method and apparatus for reproducing data, recording medium and method and apparatus for recording data}

Figure 1 is shown to aid the conceptual understanding of the present invention, it is shown to show an example of the integrated use between the optical recording and reproducing apparatus.

2 shows a data file structure of the present invention.

3 shows an example of the overall configuration of the optical recording and reproducing apparatus of the present invention.

Figure 4 shows an embodiment of a recording medium reproducing apparatus utilizing the playback system of the present invention.

5 shows an optical recording / playback apparatus playback system model for implementing the data playback method of the present invention.

6A shows an embodiment of a memory unit provided in the optical recording and reproducing apparatus according to the present invention.

Figure 6b illustrates one embodiment of a memory unit structure in accordance with the present invention.

Figure 7 illustrates one embodiment of a player model for implementing forensic marking according to the present invention.

8 shows a flowchart of a data reproduction method according to the present invention.

* Explanation of symbols for main parts of the drawings

11 pickup 12 control unit

13: signal processor 15: local storage

17: playback system

171: User Event Manager

171a: UO Controller

172: Module Manager

173: Metadata Manager

174: HDMV module (Movie Module)

175: BD-J Module

175a: Java Virtual Machine

175b: Application Manager

176: Playback Control Engine

176a: Playback control function

176b: Player registers

177: Presentation Engine

178: Security Virtual Machine

19: Decoder

40: Virtual File System

The present invention relates to the reproduction of data provided by a content provider, and more particularly to a data reproducing method and reproducing apparatus capable of protecting the data, and a recording medium and a data recording method and a recording apparatus.

As a recording medium, an optical disk capable of recording a large amount of data is widely used. Most recently, new high-density recording media, such as Blu-ray Discs (BDs) and high-density digital video discs (HD-DVDs), can record and store high-quality video data and high-quality audio data for a long time. High Definition Digital Versatile Disc) and the like are being developed.

High-density recording media, the next-generation recording media technology, are next-generation optical recording solutions that can contain data that significantly surpasses existing DVDs.

In relation to this, development of the optical recording and reproducing apparatus applying the high density recording medium standard has also begun, but it is true that the development of the optical recording and reproducing device is difficult due to the fact that the high density recording medium standard is not completely completed yet.

However, in reproducing an external input signal and a high density recording medium as described above, there is no known method for protecting the content provided by the content provider. Therefore, there are many limitations in developing an optical recording and reproducing apparatus based on a high density recording medium in earnest. This is true.

The present invention was created in view of the above circumstances, and an object thereof is to protect content provided by a true content provider from illegal copying, distribution, and the like.

Accordingly, an aspect of the present invention is to provide a data reproducing method and reproducing apparatus, a recording medium and a data recording method and a recording apparatus capable of inserting a player's identifiable information into a content to be reproduced to protect content provided by a content provider. .

In order to achieve the above object, the present invention provides a data reproduction method comprising generating a forensic mark using identifiable information of a player, and inserting the forensic mark into a stream and decoding the same.

In addition, the insertion of the forensic mark may use the forensic mark ID, which is generated by using the information identifying the player by executing the content code in the recording medium.

In addition, the insertion of the forensic mark may use a fixup table generated through an exclusive OR between a secret parameter generated by execution of content code stored on a recording medium and a masked fixup table stored on the recording medium.

The fixup table may include information for identifying a process using the fixup table, and when the process identification information indicates forensic marking, the forensic mark may be inserted into the stream.

In addition, when the forensic mark is inserted, the process identification information indicates forensic marking, and the bit designated by the forensic mark bit information included in the fixup table among the bits of the forensic mark ID is set to '1'. An overwrite value included in a fixup table is overwritten in the stream, the process identification information indicates a forensic marking, and a forensic mark included in the fixup table among bits of the forensic mark ID. When the bit specified by the ID bit information is set to '0', the bit may be performed by not overwriting the stream with the overwrite value included in the fixup table.

Further, the player identifiable information can be stored in a memory unit indicating the playing state of the player.

In addition, the information identifying the player may be a player ID assigned according to the player.

In addition, the player identifiable information may be a serial number assigned according to the player.

In addition, the information identifying the player may be a player producer ID.

In addition, the present invention may include a control unit for generating a forensic mark using information identifying the player, and a forensic mark inserter for inserting the forensic mark into a stream.

The control unit may generate the forensic mark ID using the information for identifying the player, and control the forensic mark inserter to insert the forensic mark into the stream using the forensic mark ID.

The forensic mark inserter may further include the forensic mark using a fixup table generated through an exclusive OR between a secret parameter generated by execution of content code stored on a recording medium and a masked fixup table stored on the recording medium. Can be inserted into the stream.

The forensic mark inserter may insert the forensic mark into the stream when information identifying a process using the fixup table included in the fixup table indicates forensic marking.

The forensic mark inserter may include the fixup table when the process identification information indicates forensic marking and a bit designated by the forensic mark bit information included in the fixup table among the forensic mark IDs is set to '1'. Overwrites an overwrite value included in the stream, the process identification information indicates forensic marking, and is specified by forensic mark bit information included in the fixup table among the forensic mark IDs. If the bit is set to '0', the forensic mark may be inserted into the stream by not overwriting the stream with an overwrite value included in the fixup table.

The apparatus may further include a memory unit storing information identifying the player.

The apparatus may further include a security virtual machine in which the content code is executed.

The present invention also provides a recording medium comprising a stream area in which a stream is recorded and a program area in which a content code used in the decoding process of the stream is recorded.

The apparatus may further include a masked fixup table used for media transformation of the stream.

In addition, the masked fixup table may be multiplexed into the stream.

In addition, the masked fixup table may be recorded on the recording medium as an independent file.

In addition, the present invention records a stream on a recording medium, and generates a content code, which is decoding software for the stream to record on the recording medium, wherein the content code inserts a forensic mark using information identifying the player in the stream. It provides a data recording method characterized in that it is used to.

Also, the stream is a stream modified by a media transform, and the content code may be used to recover the modified stream.

The present invention also includes a recording unit for recording a stream on a recording medium and a control unit for generating a content code which is decoding software for the stream and controlling the recording unit to record the content code on the recording medium. The content code provides a data recording device, characterized in that it is used to insert a forensic mark into the stream using the identifiable information of the player.

Also, the stream is a stream modified by a media transform, and the content code may be used to recover the modified stream.

Therefore, according to the present invention, by inserting a forensic mark using special information in a recording medium into a stream, it becomes possible to track a player who illegally copied the content after the content has been leaked.

Hereinafter, the present invention will be described using an optical disc, in particular, a "Blu-ray Disc (BD)" as a recording medium for convenience of explanation, but the technical concept of the present invention can be applied to other recording media including HD-DVD. Equally applicable is obvious.

In this regard, in the present invention, "local storage" is a kind of storage means provided in the optical recording / reproducing apparatus (FIG. 1), and means an element that a user can arbitrarily store and utilize necessary information and data. do. That is, the local storage currently used generally may be a "hard disk", "system memory (system memory)", "flash memory" and the like, but the present invention is not limited thereto. It is not.

In particular, in the context of the present invention, "local storage" is also utilized as a means for storing data associated with a record carrier (e.g. Blu-ray Disc), and associated with the record carrier Data stored therein is generally data downloaded from the outside.

In this regard, it is also possible to read some permitted data directly from the recording medium, or to generate system data (e.g., metadata, etc.) related to the recording and reproduction of the recording medium and store it in the local storage.

In this regard, in the present invention, for convenience of description, data recorded in the recording medium is referred to as " original data ", and data related to the recording medium among the data stored in the local storage is " additional data " additional data) ".

In addition, in the present invention, the term "Title" refers to a playback unit that forms an interface with a user. Each title is linked to a specific object. In particular, a stream related to the title recorded in the disc is reproduced in accordance with a command or a program in the object. In particular, in the present invention, for the convenience of description, titles that support seamless multi-angle, multi-story, language credits, director cuts, etc. among the titles in which high-definition video information is recorded by the in-MPEG compression method are particularly referred to. HDMV Title (Title). Also, among the titles in which high-definition video information is recorded by MPEG compression, a title in which Java program information is recorded that enables high interactivity by supporting update of a title in a recording medium or connectivity with a network. BD-J Title. "

Figure 1 is shown to aid the conceptual understanding of the present invention, it is shown to show an example of the integrated use between the optical recording and playback apparatus 10 and the peripheral device.

In relation to this, the "optical recording and reproducing apparatus 10" of the present invention is a device capable of recording or reproducing optical discs of various standards, and depending on the design, only an optical disc of a specific standard (e.g., BD) can be recorded and reproduced It may also be possible to play back without recording. However, in consideration of the linkage between the optical disc and the peripheral device to be solved in the present invention, an optical disc player or an optical disc recorder for recording and reproducing an optical disc will be described below. . In this regard, it is well known that the "optical recording and reproducing apparatus 10" of the present invention can be a "drive" that can be embedded in a computer or the like.

In addition to the function of recording and reproducing the optical disk 30, the optical recording and reproducing apparatus 10 of the present invention receives an external input signal, processes the signal, and delivers the signal to the user through another external display 20. Will have In this case, there is no particular limitation on the external signals that can be input, but digital multimedia broadcasting and the Internet will be representative external input signals. In particular, the Internet can be easily accessed by anyone at present. As a medium, specific data on the Internet can be downloaded and utilized through the optical recording / reproducing apparatus 10.

In this regard, a person providing content as an external input source is collectively called a "content provider (CP)".

In addition, in the present invention, content refers to data provided by an author of a recording medium as content constituting a title.

In particular, the present invention provides a method and apparatus for minimizing damage to a content provider by tracking an optical recording / reproducing apparatus that has performed unauthorized copying or distribution of content even if the content is to be distributed without unauthorized copying. Through this, the purpose is to prevent the plunder of the content caused by malicious existence, such as unauthorized copying, distribution of the content.

The original data and the local data will be described in detail. For example, the multiplexed AV stream for a specific title is recorded as the original data recorded in the optical disc, and the original data is used as the international data on the Internet. If you provide an audio stream (e.g. English) that is different from the audio stream (e.g. Korean) of the user, the user may download an audio stream (e.g. English), which is an international data on the Internet, depending on the user. There may be a request to play with the AV stream, or to play only the local data. To enable this, the association between the original data and the local data is defined, and the data is managed / played according to the user's request. A systematic method is needed.

For convenience of explanation, the signal recorded in the disk is referred to as the original data, and the signal existing outside the disk is referred to as the local data, but this is classified according to the method of acquiring the respective data. National data is not necessarily limited to specific data. Thus, data of any attribute existing outside the optical disk and associated with the original data is possible as the local data. The local data may be downloaded for each index file, playlist file (* .m2ts), clip information file (*, clpi), or may be downloaded in content unit or title unit. .

In this regard, in order to realize the needs of the user, it is essential to have a file structure associated with the original data and the international data. Hereinafter, the file structure and data recording structure available on the optical disc will be described with reference to FIG. The detailed description is as follows.

First, Fig. 2 shows the data file structure of the present invention.

That is, the file structure of the present invention includes at least one BDMV directory (BDMV) under one root directory. In the BDMV directory (BDMV), an index file ("index.bdmv") and an object file ("MovieObjet.bdmv") exist as general file (parent file) information for ensuring interactivity with a user. . In addition, as a directory having information on the data recorded on the physical disk and a method of playing the same, the playlist directory (PLAYLIST), clip information directory (CLIPINF), stream directory (STREAM), auxiliary directory (AUXDATA), A BD-J object directory (BDJO) is provided. Hereinafter, the directory and the files included in the directory will be described in detail.

The metadata directory META includes a metadata file that is data about a data. That is, a search file, a metadata file for a disc library, and the like exist in the directory.

The BD-J object directory (BDJO) contains a BD-J object file for playing a BD-J title.

The auxiliary directory (AUXDATA) contains additional data files required for disc playback, for example, a "Sound.bdmv" file that provides sound when executing interactive graphics, fonts for disc playback ( font) file "11111.otf".

The stream directory STREAM contains files for an AV stream recorded in a specific format in the disc. The most common case is that each stream is recorded as a well-known MPEG-2 transport packet, and is "* .m2ts" as the extension of the stream file (01000.m2ts, 02000.m2ts). use. In particular, a stream in which all of the video / audio / graphic information is multiplexed is called an AV stream, and a title is configured as at least one or more AV stream files.

The clip information directory CLIPINF is composed of clip stream files (01000.clpi, 02000.clpi) corresponding to each of the stream files ("* .m2ts"). The clip information file is a database file for a clip. In particular, the clip information file ("* .clpi") records attribute information and time information (timing information) of the corresponding stream file ("* .m2ts"). Relatedly, a clip information file ("* .clpi") corresponding to a stream file ("* .m2ts") and a stream file ("* .m2ts") one-to-one is named and named "clip". That is, "clip" is data including both a stream file ("* .m2ts") and a clip information file ("* .clpi").

The playlist directory (PLAYLIST) consists of playlist files ("* .mpls"), which are database files for playlists, and each playlist file ("* .mpls") contains a specific clip to be played. It includes at least one PlayItem (PI) and a SubPlayItem (SPI) that specify a playing interval, and the Playitem (PI) and the subplayitem (SPI) are specific clips to be played. Contains information about the playback start time (IN-Time) and playback end time (OUT-Time) of the (clip).

In this regard, a process played by the at least one playitem PI in a playlist file is referred to as a "main path", and a process played by each subplayitem SPI is referred to as a "sub". "Sub path", and the main path must exist in a playlist file, and at least one sub path is required depending on the existence of a sub-playitem (SPI). Will exist. As a result, the playlist file becomes a basic reproduction management file unit in the entire reproduction management file structure for reproducing a desired clip by combining at least one playitem.

The file structure of the present invention also includes a BDSVM directory (BDSVM) under the root directory. The BDSVM directory is a directory structure for a security virtual machine (Security VM). Under the BDSVM directory, there is a content code file ("ContentCode.svm") that stores content code. The content code file also contains all necessary information (eg, scrambled fixup tables) used by the content code. The recording medium on which the content code is recorded also includes the content code. In addition, the BDSVM directory has a backup directory where a backup file of the content code files is located as a subdirectory. The secure virtual machine will be described in detail with reference to FIG. 4.

In this regard, "Content Code" is a type of decoding software that is recorded on a record carrier and provided to a player, which interacts with the user, or queries or plays back the player and player peripherals or drivers. Control the process If a security problem is detected, the content code delivers an appropriate response or countermeasure. The content code participates in the decoding of the content code and has the ability to modify the content. The modification may include modifications such as planting forensic marks in the clip AV stream, as well as modifications that restore the original form for decoding.

In this regard, it will be apparent that the file structure of the present invention is not limited to the names and locations described above. In other words, the directories and files should be understood by their meaning and not by name and location.

3 shows an example of the overall configuration of the optical recording and reproducing apparatus 10 of the present invention.

First, the pickup 11 for reproducing management information including the original data recorded on the optical disc and the reproduction management file information, the servo 14 for controlling the operation of the pickup 11, and the reproduction signal received from the pickup 11; The signal processor 13 for restoring the signal to a desired signal value or modulating the signal to be recorded into a signal recorded on the optical disk and transmitting the signal to the optical disk is basically configured.

In addition, the controller 12 downloads and stores local data existing in addition to the optical disk by a user command in the local storage 15, and also stores original data in the optical disk and / or anywhere in the local storage 15. Data can be played back according to user requirements.

The playback system 17 finally decodes the data under the control of the controller 12 and provides it to the user. The playback system 17 specifically analyzes a decoder for decoding the AV signal, an object command or application relating to the reproduction of the above-mentioned specific title, and an optical recording for determining the playback direction by analyzing a user command input through the control unit 12. It consists of a playback device model.

In this regard, in the present invention, the control unit 12 serves to insert the optical recording and reproducing apparatus 10 into the stream to be reproduced. The information is used to track the optical recording and reproducing apparatus for illegal copying. This is called forensic marking. When the content is damaged through illegal copying or illegal distribution through forensic marking, it is possible to track an optical recording / reproducing apparatus that has damaged the content, thereby suppressing content copying and distribution. The information is a unique value for distinguishing the optical recording and reproducing apparatus. The information includes a player identifier (player ID), a serial number of the optical recording and reproducing apparatus, and a manufacturer ID. identifiers), combinations thereof, and the like. The control unit 12 may be provided with software as a secure virtual machine 178 for inserting the information into the stream in accordance with the execution of the content code. The information may be stored in " Player Registers 176b ", which is a memory unit that stores the reproduction state of the optical recording and reproducing apparatus. The information is transformed into itself or in a form that can be inserted into the stream and inserted into the stream to be reproduced. The stream with the information inserted is decoded at the decoder and presented to the user. The playback system 17 including the secure virtual machine 178 will be described in detail later with reference to FIG. 4.

In this regard, the content code executed in the secure virtual machine may participate in the decoding process of the content to transform the content. This is called a media transform. The process of inserting information identifying the optical reproducing apparatus into a stream may occur as part of the media transform. The involvement of the content code in the decoding process means that an illegally copied title or media key cannot be simply transmitted over the Internet because the content code operates in the form of converting the content.

In addition, the AV encoder 18 converts an input signal into a signal of a specific format, for example, an MPEG2 transport stream, under the control of the control unit 12, in order to perform a function of recording a signal on an optical disk. ). In the present invention, the AV encoder 18 may provide a signal processing unit 13 by multiplexing a fix-up table used for media transformation into a clip AV stream. The fixup table may be multiplexed into the clip AV stream in a scrambled form, and the scrambled fixup table is called a masked fixup table.

Figure 4 shows an embodiment of a recording medium reproducing apparatus utilizing the playback system of the present invention.

The term " playback system " refers to collective playback processing means composed of a program (software) and / or hardware provided in the optical recording / reproducing apparatus. A system for reproducing a recording medium loaded in the optical recording / reproducing apparatus 10 as well as reproducing and managing data stored in storage (for example, downloaded from the outside) in association with the recording medium.

In particular, the playback system 17 includes "User Event Manager 171", "Module Manager 172", "HDMV Module 174", "BD-J Module 175", "Playback control engine 176). "," Presentation engine 177 "and" Virtual File System 40 ". In the present invention, the playback system includes a "Security Virtual Machine 178" that provides additional security for titles associated with the record carrier. This will be described in detail as follows.

First, as separate playback processing management means for reproducing the HDMV title and the BD-J title, "HDMV Module 174" for the HDMV title and "BD-J Module 175" for the BD-J title, respectively. It is configured independently. The "HDMV Module 174" and the "BD-J Module 175" particularly have a control function for receiving a command or a program in the above-described object (Movie Object or BD-J Object) and processing the same. Have The "Metadata Manager 173" can perform title selection at any time under the control of the user and provide the recording medium and title metadata to the user. The " HDMV Module 174 " and " BD-J Module 175 " separate commands or applications from the hardware configuration of the playback system, thereby enabling portability of the commands or applications. As a means for receiving and processing the command or application, the "Command processor 174a" in the "HDMV Module 174" and the "Application in which the application is executed in the" BD-J Module 175 "are executed. "Java VM 175a" which is a "Virtual Machine" and an "Application manager 175b" including an application management function that manages the lifecycle of an application are provided.

In addition, the user command is transmitted to the "HDMV Module 174" and the "BD-J Module 175" as well as the operations of the "HDMV Module 174" and the "BD-J Module 175" are controlled. "Module Manager 172" is provided. The "Playback Control Engine 176" which interprets the playlist file information recorded in the actual disc and performs the playback function according to the playback commands of the "HDMV Module 174" and the "BD-J Module 175". Is provided. In addition, a "Presentation Engine 177" is provided to decode a specific stream managed by the "Playback Control Engine 176" and display it on the screen. In particular, the " Playback Control Engine 176 " is a " Playback Control Functions 176a " that manages all playbacks and the playback status and playback environment of the optical recording / playback device 10 " Player status registers (PSR) " And "Player Registers 176b" for storing "General purpose register (GPR)". In some cases, "Playback Control Functions (176a)" may mean "Playback Control Engine (176)". "Playback Control Functions 176a" handles static scenarios contained in the playlist.

In this regard, the HDMV title and the BD-J title each receive a user command of a separate method, and the method of performing the user command is independent of each other. A means for receiving a user command and delivering it to either "HDMV Module 174" or "BD-J Module 175" is required, which is in charge of "User Event Manager 171". Thus, for example, the "User Event Manager 171" may refer to the "Module Manager 172" or the "UO Controller 171a" if the received command is a user command by the "User Operation (UO) 171a". If the received command is a user command by "Key Event", it is transmitted to "Java VM 175a" in the "BD-J Module 175" for execution.

In addition, the playback system 17 of the present invention may include a "Metadata Manager 173", in which the "Metadata Manager 173" provides a user with a disc library and an enhanced search metadata application. application).

In the above-described playback system of the present invention, the "Module Manager 172", "HDMV Module 174", "BD-J Module 175", and "Playback Control Engine 176" are software-based. Processing is possible. Software processing is more useful in design than actual hardware configuration. However, the "Presentation Engine 177", the decoder 17b, and the plane are generally designed in hardware. In particular, the components that are processed in software (for example, reference numerals 172, 174, 175, and 176) may be configured as one part of the control unit 12 described above. The configuration of the present invention should be understood as meaning, and is not limited to hardware configuration or software configuration.

Recently, with the development of a reproducing apparatus capable of playing or copying content and the Internet, illegal copying and distribution of content has been a problem. In addition, in the case of high-resolution / high-quality content, the risk of hacking, etc. is also high, the need for protection is increasing. Accordingly, various methods for protecting content have been raised. In the present invention, to provide a content protection method using the "Security Virtual Machine (178)".

5 shows an optical recording and reproducing system reproducing system model for implementing the data reproducing method of the present invention, wherein the system model includes a secure virtual machine (178).

The Security VM of the system model of the present invention provides additional security to titles recorded on the recording medium of the present invention. Titles to which the additional security is applied are also referred to as self-protecting digital content (SPDC). The main feature of the additional security is renewability, whereby the security mechanism of content playback for each content can be updated by the use of the secure virtual machine 178. The updateability is realized by content code running on the secure virtual machine 178. Hereinafter, the security virtual machine 178 will be described in detail.

The secure virtual machine 178 provides the content owner with discovery, media transform, forensic mark, run native, application layer communication, and the like. A security tool such as an optical recording / reproducing device storage slot or the like is provided.

Discovery tools provide information about the playback environment to detect malicious environments and attacks. One of the most serious attacks on content owners is that the imitator pretends to be a legitimate player and plays the content in an incorrect way. To counter this kind of attack, secure virtual machine 178 uses discovery and discovery random access memory (RAM) to distinguish legitimate players from mimics. Once the copycat is detected, other security tools can prevent playback of the content.

The content code may use media transform to define modifications to be applied to the content stream as part of the decoding process. This allows the secure virtual machine 178 to provide additional layers to the copy protection system for the record carrier according to the present invention. During authoring of the record carrier, the content on the record carrier is deliberately corrupted and can be reduced to its normal form by the secure virtual machine 178 during playback of the record carrier. Once the copycat is detected by the discovery, the secure virtual machine 178 has no action for the media transform, so that content cannot be played back normally in the copycat. In other words, the content recorded on the recording medium may be intentionally damaged during authoring. The secure virtual module of the present invention can restore the damaged content, that is, the content to which the media transform has been applied, to its original form during playback. As a result, the content cannot be reproduced normally in the copying machine, thereby protecting the content.

A forensic mark is a signal embedded in the content that is not recognized by the user when the content is played but can be detected by a special detector. In the present invention, a forensic mark using identifiable information is inserted into a stream to be reproduced to present the optical recording and reproducing apparatus. Forensic marks themselves do not prevent attacks on content owners. However, by inserting player-specific information into the output content played back in the player, and identifying the forensic mark in the leaked content when the content is leaked into the air, the content owner may have identified the forensic mark. The pirated content can only be detected and revoked.

In this regard, the identifiable information of the optical recording / reproducing apparatus may include manufacturer information such as a manufacturer's name, identifier, manufacturing region, manufacturing date, etc., production line, serial number, model number, firmware / software version of the optical recording / reproducing apparatus Device information such as a certificate or the like, or reproduction state information of the optical recording / reproducing apparatus may be used.

In addition, the secure virtual machine 178 detects or corrects a security flaw in the optical recording / reproducing apparatus so that content code running in the native and secure virtual machine 178 can exchange data with the application layer. Application storage communications capabilities, and Player Storage Slots, which are nonvolatile storage used by content code.

Through such a security tool, the secure virtual machine 178 can provide updateability to protect content from various types of attacks. In addition, the use of discovery can detect the copying machine and restore the combination of the optical recording and reproducing apparatus.

In this regard, the secure virtual machine 178 may be implemented as part of a control unit as software, or may be implemented as an independent module as hardware.

The playback system model of FIG. 5 is defined based on the security tool of the secure virtual machine 178 described above, and illustrates the playback system and the secure virtual machine 178 of the recording medium navigation system. The secure virtual machine 178 includes a background virtual machine (VM) process, an interrupt interrupt VM process, a virtual machine memory space, a discovery memory space, and a transform function.

Specifically, the secure virtual machine 178 of the present invention is composed of two virtual machine processes, a background VM process and an interrupt VM process. If there is no time-critical operation (eg, security checks) at the time that the secure virtual machine 178 should perform, then the secure virtual machine 178 is the timing at which the content code is fixed. It works in background mode without. In the background mode, the secure virtual machine 178 need not operate over time, and the optical record / playback apparatus may alternate between providing processor time to the secure virtual machine 178 and performing other actions.

The two virtual machine processes share a fixed size memory area. The memory area is called a virtual machine memory space. The virtual machine memory space is a working memory for a background virtual machine process and an interrupt virtual machine process, in which content code and its data or variables are stored. The content code recorded on the recording medium at the start of playback of the title is loaded into the virtual machine memory space, and the background virtual machine process and the interrupt virtual machine process read / write to the virtual machine memory space. Secure virtual machines include a random access memory (RAM) in addition to the normal virtual machine memory space. Discrete RAM reads data from non-confidential portions of the actual memory space of the optical recorder software.

In this regard, before the data of the content code file is stored in the virtual machine memory space, the secure virtual machine verifies the signature of the content code file. The content code must be signed by the private key of the owned trusted certificate authority. If the verification fails, the virtual machine does not read the data of the content code file.

An interrupt virtual machine process is provided for the optical recording and reproducing apparatus to perform operations requiring a result from the secure virtual machine 178 within a limited period of time. For example, as described above in Media Transform, the clip AV stream may be provided in a transformed manner. In order to transform the clip AV stream to its original state, a secret parameter and associated values are required. The secret parameter is provided by an interrupt virtual machine process of the secure virtual machine 178. In this case, "Playback Control Functions" (176a) invokes the interrupt virtual machine process and activates it. In the active mode, the interrupt virtual process process calculates the assigned content code to provide a secret parameter to the transform function and returns to the non-active mode. In this case, the background virtual machine process is resumed.

In this regard, the execution mode of the secure virtual machine 178 includes a media initialization mode, a background mode, a title initialization mode, a secret parameter calculation mode, an application request mode, and a title termination mode. When the recording medium is loaded, the secure virtual machine 178 operates in the media initialization mode. In media initialization mode, the interrupt virtual machine process is activated and media access occurs. When the content code initializes the entire recording medium, it enters the background mode. In background mode, the background virtual machine process runs.

When execution results from content code running on the secure virtual machine 178 are required, the "Module Manager 172", "Playback Control Function (176a)" and "Command Processor (174a)" interrupts ( interrupt). When an interrupt occurs, the state moves to that mode. For example, when the "Module Manager 172" attempts to start playing a title, it is in the title initialization mode. When the "Playback Control Engine 176a" requires the calculation of a secret parameter, it is in the secret parameter calculation mode. When " Command Processor 174a " wants to change the status of " Player Status Registers ", it enters the application request mode. When the "Module Manager 172" wants to stop the playback of the entire recording medium, it enters the media termination mode. When an interrupt occurs in the background mode, the background virtual machine process is stopped and the interrupt virtual machine process is activated. When the content code finishes processing the interrupt, it returns to the background mode state, the interrupt virtual machine process is terminated, and the background virtual machine process is resumed.

In the present invention, the clip AV stream of the content is inserted with a forensic mark, decoded, and presented. Insertion of the forensic mark may be in the form of a media transform. In a security tool called media transform, transform functions play an important role. Transform functions are an important part of the record carrier update mechanism. The transform function is located outside of the virtual machine, and the secreted fixer (SPs) and forensic mark IDs (FM_ID) that are masked fix-up table entries are enumerated by the virtual machine. ) To apply the media transform to the clip AV stream. The transform function may be included in the control unit 12 in software, but may be designed in hardware as a separate device for inserting a forensic mark.

In the present invention, the forensic mark is generated using information that can identify the optical recording and reproducing apparatus (player). The information can be stored in a memory unit which stores the reproduction state of the optical recording and reproducing apparatus. Hereinafter, the information will be referred to as 'Player ID', and the case where the 'Player ID' is stored in the 'Player Status Register' will be described as an example.

FIG. 6A illustrates an embodiment of a memory unit included in the optical recording and reproducing apparatus according to the present invention, and FIG. 6B illustrates an embodiment of the memory unit structure according to the present invention.

The optical recording and reproducing apparatus of the present invention is provided with " Player Registers " The " Player Registers " 176b includes " Player Status Registers (PSRs) ", which store variables used to indicate player status, and variables used for sharing and programming data between HDMV applications and BD-J applications. Can be classified as "General Purpose Registers (GPRs)". 6A to 6B illustrate an example in which the information for identifying the optical recording and reproducing apparatus of the present invention is stored in the "Player Status Register" (hereinafter referred to as PSR).

Referring to FIG. 6A, 'Player ID' may be stored in the PSR32 501 which is one of "Player Status Registers (PSRs)". The Player ID is information for identifying the optical recording and reproducing apparatus. The secure virtual machine of the present invention may generate a forensic mark to be inserted into a clip AV stream in the process of playing content using the 'Player ID'. When transmitting data through the network, it can be used to limit the distribution of data depending on the player. It may also be used for tracking the optical recording / reproducing apparatus which reproduces, reproduces or distributes the unauthorized data of the optical recording / reproducing apparatus. Referring to FIG. 6B, the 'Player ID' is stored using a predetermined bit of the PSR32 501. It is apparent that the above information identifying the optical recording / reproducing apparatus may be stored in a register other than the PSR32 501.

In this regard, the " Player Status Register " is a " Playback Status Registers " that stores playback status parameters such as a playback title number and chapter number, and a " Player Setting " that stores optical recording / playback device configuration parameters such as audio language codes or country codes. Registers ". In view of the object of the present invention to protect the data provided by the content provider, the optical recording / reproducing apparatus preferably does not allow the user to set the 'Player ID' value. Therefore, when the 'Player ID' is stored in one of the "Player Status Registers", it is stored in the "Player Setting Register" of the "Playback Status Registers" and "Player Setting Registers" that constitute the "Player Status Registers". Would be desirable. This is because the values included in the "Player Setting Registers" are not affected by an initialization process or navigation commands that initialize the "Playback Status Registers."

Regarding the above example, it has been described that the 'Player ID' is stored in the 'Player Status Register', but a memory unit capable of storing information on the optical recording and reproducing apparatus is sufficient. In addition to the 'Player ID' as the information for identifying the optical recording and reproducing apparatus, the serial number of the optical recording and reproducing apparatus, the ID of the optical recording and reproducing apparatus, and the like can be used.

Figure 7 illustrates one embodiment of a player model for implementing forensic marking according to the present invention.

In the present invention, the forensic mark may be inserted during media transformation of the stream. Fix-up tables are used in the media transform, which is divided into a series of fix-up table entries. One way to implement the media transform is to use a masked fixup table multiplexed onto the clip AV stream, and another method is to use a masked fixup table stored as a separate file on a recording medium.

 When a masked fixup table multiplexed onto a clip AV stream is used for media transformation, the actual fixuptable entry (unmasked fixuptable entry) is provided by the masked fixuptable entry and the virtual machine. It can be calculated by a logical operation between secret parameters (eg, an XOR operation). The fixup table entry used in the forensic marking of the present invention is a program map table (PMT) in a masked form by a logical operation (for example, exclusive logic) with a secret parameter provided by a secure virtual machine. ) Is stored in the descriptor of the packet. The fixup table entry includes a secret parameter identifier (SP_ID) of a secret parameter segment (SP Segment) to which the program map table packet belongs. The secret parameter identifier is not masked and is the same as the secret parameter identifier for the secret parameter segment in which the fixup table entry exists. The fixup table entry also includes information identifying a process that uses the fixup table. The process identification information (type_identifier) indicates whether media transformation or forensic marking is performed. For example, when the process identification information is set to '00b', it means that no media transform is applied, and if it is set to '01b', it means to apply a media transform, and '11b' performs forensic marking. Can mean.

The fixup table may include information indicating a bit position FM_ID_bit_position of a forensic mark ID for the forensic marking. When the forensic mark ID bit position is set to a specific value (for example, '1'), the overwrite operation on the fixup entry is performed. However, when the bit designated by the forensic mark ID bit position information included in the fixup table is set to '0' among the bits of the forensic mark ID, an overwrite value included in the fixup table is determined. It is not overwritten by the stream.

The fixup table may also include a relative packet number from the program map table to the first modified packet, a relative packet number from the modified packet to the second modified packet, and an overwrite to be overwritten to the modified packets, respectively. Contains a value.

In this regard, the clip AV streams of the present invention are divided into secret parameter segments (SP Segments), and a secret parameter identifier is assigned to each secret parameter segment in each clip AV stream. The content code generates a secret parameter for each secret parameter segment and provides it to the secure virtual machine 178. The secret parameter is used to calculate the actual fixup table entries through a logical operation with the masked fixup table entries. The number of secret parameters for each clip is equal to the number of secret parameter segments in that clip and applies to all fixuptable entries in one secret parameter segment. .

Referring to FIG. 7, a media transform using a fixup table multiplexed on a clip AV stream is described. The optical recording and reproducing apparatus 10 reads a clip AV stream including a masked fixup table from a recording medium. The content may be encrypted and provided to the optical recording / reproducing apparatus 10. In this case, the content must be decoded before it can be decoded. Encryption refers to a type of copy protection method that prevents illegal duplication, distribution, and editing of content provided by a content provider by modifying data using a specific algorithm. It serves as a kind of lock that prevents unauthorized access to the decrypting content of the content, and the particular algorithm serves as a key to lock the lock. Therefore, the specific algorithm used for encrypting the content may be referred to as an encryption key. In order to play the encrypted content, a means for decrypting a specific algorithm used to encrypt the content should be provided. The specific algorithm decryption means serves as a kind of key to unlock the lock. When a key is provided, the key is used to decrypt the algorithm used for content encryption and to restore the content to its original form, which is called decryption. When the content is encrypted in units of titles, a key used for encrypting and decrypting the title is called a title key Kt. The optical recording / reproducing apparatus 10 decrypts the clip AV stream encrypted using the title key Kt.

The content code in the recording medium is provided to the secure virtual machine 178. The content code is executed in the secure virtual machine 178 and uses the clip ID (Clip_ID), secret parameter ID (SP_ID) and player ID (Player_ID) provided by the "Playback Control Engine 176". The secret parameter ID and forensic mark ID (FM_ID) are displayed along with the parameters. In the present invention, the forensic mark ID is generated based on the player identifiable information, and the forensic mark is inserted into the clip AV stream using the forensic mark ID.

In this regard, the clip ID provided from the "Playback Control Engine 176" to the secure virtual machine 178 is equal to the number used for the file name of each clip. For example, 'Clip_ID = 123' indicates a clip referring to the clip information file '00123.clpi' and the stream file '00123.m2ts'.

The content may be intentionally corrupted and then encrypted and recorded on the recording medium. The optical recording and reproducing apparatus 10 restores the content to its original form through the media transform. A transform function is used for the media transform, and the transform function causes a masked fixup table to be extracted from the decoded clip AV stream by a demultiplexer (Demux). The actual fixup table entry is calculated by a logical operation of the extracted masked fixup table entry and the secret parameter output by the content code.

The optical recording / reproducing apparatus 10 sets the process identification information included in the fixup table to perform media transformation (for example, '01b'), or sets the process identification information to perform forensic marking ( For example, it is checked whether the bit of the forensic mark 11b) and indicated by the forensic mark ID bit position is set to '1'. In such a case, the media transform process continues, and the overwrite values included in the fixup table are overwritten on the packets specified in the fixup table in the transport stream, and modified. If the process identification information is set not to perform media transformation (for example, '00b'), the clip AV stream is not modified. In addition, when the forensic marking is set to perform forensic marking but the bit of the forensic mark indicated by the forensic mark ID is not '1' (when set to '0'), the overwrite values are not overwritten in the designated packet. As a result, depending on the forensic mark ID, the overwrite operation may or may not occur at a designated position, and the stream of content may have a unique pattern that varies depending on whether or not there is an overwrite. The unique pattern becomes a forensic mark to track the player who processed the leaked content.

The processes of extracting the masked fixup table from the decoded clip AV stream in the above-described process to calculate an actual fixup table, and overwriting an overwrite value in a specific packet using the fixup table may be performed for the entire clip AV stream. Will be repeated for. As a result, according to the present invention, whether or not to overwrite the position specified in the fixup table entry for each secret parameter segment of each clip AV stream is determined according to the forensic mark ID generated by using the player identification information. Therefore, since the overwrite pattern is different for each player, when the content is leaked, the player who illegally leaks the content can be tracked by analyzing the overwrite pattern.

In this regard, the optical recording / reproducing apparatus 10 may also insert the player identifiable information directly into the clip AV stream. In this case, information specifying the position at which the information is inserted will have to be defined.

Referring to FIG. 7, a media transformation using a fixup table multiplexed onto a clip AV stream will be described. The optical recording / reproducing apparatus 10 secures a masked fixup table from a recording medium before starting content playback. It is preloaded from the machine 178. The masked fix-up table may be obfuscated and recorded on a recording medium, and the secure virtual machine 178 de-obfuscates the masked fix-up table to start playback. Sends the masked fixup table for the title to the transform function module.

The masked fixup table has a block structure to be logically operated with each secret parameter. Each Fix-up entry in the FUT block is masked by an exclusive OR of the associated secret parameter values specified by the secret parameter ID. The optical recording / reproducing apparatus 10 scans the masked fix-up table to find a necessary fix-up table to be used for the current reproduction position in the clip AV stream. Content recorded on the recording medium is executed in the secure virtual machine to output a secret parameter ID and a forensic mark ID together with each secret parameter in response to a command invoked by the "Playback Control Engine 176". A logical operation (eg, exclusive OR) of the secret parameter value from the secure virtual machine 178 and the masked fixup table is used to obtain a cleared fixup table. The above process of finding the fixup table block necessary for the current playback position of the clip AV stream and calculating the cleared fixup table is repeated for the entire clip AV stream. In this regard, if the secret parameter value changes after the duration of the secret parameter segment, the secret parameter must be newly calculated.

The clip AV stream on the recording medium is read by the optical recording / reproducing apparatus 10 and decoded using a title key. The optical recording / reproducing apparatus 10 sets the process identification information included in the fixup table to perform media transformation (for example, '01b'), or sets the process identification information to perform forensic marking ( For example, it is checked whether the bit of the forensic mark 11b) and indicated by the forensic mark ID bit position is set to '1'. In the above case, the overwrite values are overwritten at a specified position per fixup table. In other cases, the media transform defined in the fixup table is not applied, and the process returns to the process of reading the clip AV stream from the recording medium and decrypting it using the title key.

8 shows a flowchart of a data reproduction method according to the present invention.

The optical recording and reproducing apparatus 10 according to the present invention reads out data from the recording medium including the content code involved in the decoding process of the clip AV stream and the clip AV stream. The content code is executed in the secure virtual machine 178 (S10) to calculate a secret parameter (Secret Parameter) (S20). In addition, the forensic mark ID is calculated using the information for identifying the player (S20).

The secret parameter is logically calculated with a fixup entry of a masked fixup table stored in the recording medium (S30) and used to calculate an actual fixup table (S40). The calculated fixup table includes process identification information, and forensic marking is determined according to the process identification information (S50). If the process identification information does not indicate forensic marking (e.g., is set to a value other than '10b'), the optical recording / reproducing apparatus 10 decodes without inserting a forensic mark in the corresponding clip AV stream (S70). To present.

When the process identification information indicates forensic marking (for example, when it is set to '10b'), the optical recording / reproducing apparatus 10 clips the forensic mark to the AV stream by using the ID for identifying the player. Insert into (S60). The clip AV stream in which the forensic mark is inserted is decoded (S70) and presented.

In relation to this, the player identifiable information may be stored in the "Player Registers 176a" included in the "Player Control Engine 176", as described in FIGS. 6A-6B, and the secure virtual machine 178. Receives information for identifying a player from the "Player Control Engine 176" to generate a forensic mark ID. The content code may calculate the forensic mark ID by applying the identifiable information to the player to a logic function (eg, exclusive OR, bit extraction, shift / rotation, etc.).

In this regard, it can be said that the forensic mark is inserted into a clip AV stream which is decoded using the forensic mark ID. Since the forensic mark ID is used to insert the forensic mark, in a broad sense, the forensic mark ID itself may be understood as a forensic mark. Since the forensic mark should be used to identify the player, it is preferably generated within the player itself.

According to the present invention described above, the forensic mark using the information for identifying the player is inserted into the reproduced content. When the content provider illegally leaked content is found, the forensic mark inserted in the content can be checked to track the player compromising the content and take responsibility. Therefore, there is an advantage that can prevent illegal copying of the content.

The present invention is not limited to the above-described embodiments, and as can be seen in the appended claims, modifications can be made by those skilled in the art to which the invention pertains, and such modifications are within the scope of the present invention.

According to the data reproducing method, the reproducing apparatus, and the data transmitting method according to the present invention described above, it is possible to track an optical recording / reproducing apparatus that has damaged the contents by illegal copying, distribution, or the like by inserting the identifiable information into the reproduced content. It is possible to protect the content from malicious acts on the content, such as illegal copying and distribution.

Claims (24)

Generate a forensic mark using information identifying the player, And decoding the forensic mark by inserting the forensic mark into a stream. The method of claim 1, Insertion of the forensic mark, And a forensic mark ID generated using information identifying the player by execution of a content code in a recording medium. The method of claim 2, Insertion of the forensic mark, And a fixup table generated through an exclusive OR of a secret parameter generated by execution of the content code and a masked fixup table stored in the recording medium. The method of claim 3, wherein The fixup table includes information identifying a process using the fixup table, And when the process identification information indicates forensic marking, inserting the forensic mark into the stream. The method of claim 4, wherein Insertion of the forensic mark, When the process identification information indicates forensic marking and a bit designated by forensic mark bit information included in the fixup table among the bits of the forensic mark ID is set to '1', an overwrite value included in the fixup table. (overwrite value) overwrite the stream, When the process identification information indicates forensic marking and a bit designated by forensic mark ID bit information included in the fixup table among the bits of the forensic mark ID is set to '0', the overwrite included in the fixup table is included. And overwrite a value not overwritten to the stream. The method of claim 1, And the player identifiable information is stored in a memory unit indicative of the playback state of the player. The method of claim 1, The player identifiable information is a player ID assigned according to the player. The method of claim 1, And the player identifiable information is a serial number assigned according to the player. The method of claim 1, And the player identifiable information is a player producer ID. A control unit for generating a forensic mark using information identifying the player, And a forensic mark inserter for inserting the forensic mark into a stream. The method of claim 10, The forensic mark inserter, Inserting the forensic mark into the stream using a fixup table generated through an exclusive OR of a secret parameter generated by execution of content code stored on a recording medium and a masked fixup table stored on the recording medium. A data reproducing apparatus. The method of claim 10, And the controller controls the forensic mark inserter to generate a forensic mark ID using the identifiable information of the player and to insert the forensic mark into the stream using the forensic mark ID. The method of claim 12, The forensic mark inserter, And inserting the forensic mark into the stream when information identifying a process using the fixup table included in the fixup table indicates forensic marking. The method of claim 13, The forensic mark inserter, When the process identification information indicates forensic marking and a bit designated by forensic mark bit information included in the fixup table among the forensic mark IDs is set to '1', an overwrite value included in the fixup table (overwrite) overwrite value to the stream, When the process identification information indicates forensic marking and a bit designated by forensic mark bit information included in the fixup table among the forensic mark IDs is set to '0', an overwrite value included in the fixup table (overwrite) and a data value is not overwritten in the stream. The method of claim 10, And a memory unit for storing information identifying the player. The method of claim 10, And a security virtual machine for executing the content code. The stream area where the stream is written And a program area in which the content code used in the decoding process of the stream is recorded. The method of claim 17, And a masked fixup table for media transformation of the stream. The method of claim 18, And the masked fix-up table is multiplexed into the stream. The method of claim 18, And the masked fixup table is recorded on the recording medium as an independent file. Record the stream on a record carrier, Generating content code, which is decoding software for the stream, to record on the recording medium; Wherein the content code is used to insert a forensic mark into the stream using information identifying the player. The method of claim 21, The stream is a stream modified by a media transform, And the content code is used to recover the modified stream. A recording unit for recording the stream on the recording medium; A control unit for generating a content code which is decoding software for the stream, and controlling the recording unit to record the content code on the recording medium, And the content code is used to insert a forensic mark into the stream using information identifying the player. The method of claim 23, The stream is a stream modified by a media transform, And the content code is used to recover the modified stream.

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