KR100419432B1 - Copy Protected Optical Disc Manufacturing Method and Copy Protected Optical Disc - Google Patents

Abstract

Disclosed are a method of manufacturing an optical disc with copy protection and a disc thereof. The method of manufacturing a copy-protected optical disc according to the present invention includes (a) a region in which an optical beam cannot be tracked during playback in an optical disc playback device or a region in which significant information is not extracted even when tracking is possible between regions corresponding to contents. And inserting an optical head ditching (OHD) region.

The optical disc manufactured according to the copy-protected optical disc manufacturing method according to the present invention cannot be copied by the recordable optical disc apparatus, and the disc, which is copied by some method, is normally driven by the optical disc reproducing apparatus. I do not lose. Further, in the method of manufacturing a copy-protected optical disc according to the present invention, since a copy-protected optical disc is made by inserting OHD data into a specific area within the optical disc, all processing for copy protection is performed in the manufacturing process of the optical disc. In addition, no further change of the existing optical disc reproducing apparatus is required. In addition, the reliability of copy protection is higher by combining the hardware copy protection structure of the optical disc itself with software encryption and authentication technology.

Description

Copy-protected optical disc manufacturing method and copy protected optical disc

The present invention relates to a method of manufacturing a copy-protected optical disc, and more particularly, to a method of manufacturing a copy-protected optical disc having an optical head ditching (OHD) area that cannot be copied normally in an optical disc recorder. And the disk.

In general, various disks such as optical disks are used to store various types of information in various formats. Also, in recent years, as recordable optical discs such as CD-R, CD-RW, DVD-R, DVD-RW and DVD-RAM have been commercially and popularly distributed, optical discs have been used as personal auxiliary memory memory means. Moreover, as the technology related to the optical disc is developed, the use of a large capacity DVD (DVD) has become common.

In addition, in the past, optical disc devices generally played a role of distributing large-capacity contents as a play-only type device, but recently, as recordable optical disc-related devices have become popular, they have become an important auxiliary memory device. I'm going. However, as the recordable optical disc device is widely used personally, there is a problem that such an optical disc device can be used as a tool for illegal copying.

In addition, since the duplication using the recordable optical disc device is basically based on digital duplication, the signal of the duplicated disc is not deteriorated or deformed compared to the original disc signal. Therefore, the duplicated disc has almost the same quality as the content or file of the original disc, thereby causing a serious damage to the content developer and the original disc manufacturer.

Moreover, the recent rapid development of various hardware or software capable of copying is expected to cause serious economic and social problems due to illegal copying and distribution of disks. Therefore, there is a need for an appropriate copy protection technology that can prevent such illegal copying at the source.

On the other hand, the recordable area of a general recordable optical disc is divided into a plurality of sectors. Each sector is assigned a logical block address (LBA) regardless of whether data is recorded or not. An optical disc apparatus that reads data recorded in an optical disc reads a logical address from the optical disc, and enters and reads a beam therein while traveling the tracks of the optical disc. At this time, the intensity of the reflected light is large on the mirror surface without pit in each track of the disk, while the intensity of the reflected light is small on the pit of the track. The optical pickup converts the difference in intensity of the light reflected from the optical disc into an electrical digital signal, and extracts meaningful information by decoding the sequence of the converted digital signal. Incident of the optical beam into the written pit and detection of the light beam reflected from the recording pit is performed by optical pick-up. At this time, the optical pickup not only detects the difference in the intensity of the reflected light and converts it into electrical digital data, but also uses the thread servo of the optical disc device to output the electrical signal obtained by detecting the difference in the intensity of the reflected light in order to control the rotation speed of the optical disc. send it to the sled servo.

In order for data contained in an optical disc to be read normally, three conditions must be satisfied. Firstly, logical block address values assigned to sectors in a data block recorded in an optical disc are incremented sequentially, and the size of the file converted by the logical block address values is used in a computer system linked to the playback apparatus. Do not exceed the maximum size of files supported by the operating system. Secondly, the optical pickup of the optical disc reproducing apparatus must be able to continuously run the track by determining the center of the track consisting of a series of recording pits. Thirdly, the servo must be normally controlled by sending a servo signal of eg, EFM (Eight to Fourteen Modulation) data read from the pit recorded along the track to the spindle servo of the optical disk drive. do. Most optical disc devices and optical discs are manufactured according to physical standards satisfying the above conditions.

According to the conventional copy protection technology, encryption of data is performed using encryption software in an optical disc that satisfies the above physical standard. However, this copy protection technique can cause compatibility problems in which the pre-mastering or mastering process is complicated and the original disk does not run on certain driving devices. In addition, according to the copy protection method, if the encryption algorithm is hacked at least once, there is a problem that the replication is easily performed.

The technical problem to be achieved by the present invention is to duplicate the computer software or digital content contained in the original optical disk using a recordable optical disk device such as a CD-R, CD-RW, DVD-R, DVD-RW and DVD-RAM drive. There is provided a method of manufacturing a copy-protected optical disc which is impossible.

Another object of the present invention is to provide a copy-protected optical disk manufactured by the optical disk manufacturing method.

1 is a flowchart showing main steps of a method of manufacturing a copy protected optical disc according to an embodiment of the present invention.

2 is a view for explaining the structure of the OHD data block.

3 is a view for explaining the structure of the optical disk that can not be duplicated according to the present invention.

4 is a view for explaining the structure of a file including an OHD region.

5 is a structural diagram showing an address discontinuity point of a disc.

6 is a flowchart illustrating a method of reading a non-replicable disc and determining a duplicate disc according to the present invention.

In order to achieve the above technical problem, the copy-protected optical disc manufacturing method according to the present invention (a) makes it impossible to track the optical beam during playback in the optical disc playback device between the areas corresponding to the contents, even if tracking is possible. And inserting an OHD (Optical Head Ditching) area including an area where information is not extracted. The step (a) may include (a-1) a premastering process. An OSH information layer including position information of a sector corresponding to an OSH area to be read next and information on a sector in which valid data to be read next is stored, a driving program distributed and stored in the OSH information layer; And performing formatting to insert a production identifier identifying the content; (a-2) During the mastering process, an OHD area including a region where a formatted signal is used to disable the tracking of the light beam during reproduction in the optical disc player, or where significant information is not extracted even if tracking is possible. Making a stamper comprising; And (a-3) pressing using a stamper. The step (a-1) may include (a-1-1) a position of a sector allocated to the OHD region. Scrambling a logical block address representing a; preferably.

Further, the predetermined OHD region preferably includes successive pits whose difference in reflectance of the light reflected from the pits is less than a predetermined threshold.

Alternatively, the predetermined OHD region more preferably includes a mirror region in which pits are not formed.

Preferably, the predetermined OHD area includes an OHD information data area in which a start address of a sector corresponding to the OHD area to be read next is recorded.

The predetermined OHD area preferably includes an OHD information data area in which position information of a sector in which valid data to be read next is stored is recorded.

In addition, in order to achieve the above technical problem, the copy-protected optical disc according to the present invention does not allow the tracking of the light beam during playback in the optical disc playback device between the regions corresponding to the contents, or significant information is not extracted even if the tracking is possible. It is characterized in that it comprises a; OH D region including a region that does not.

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

1 is a flowchart illustrating main steps of a method of manufacturing a copy protected optical disc according to an embodiment of the present invention. In this embodiment, a DVD (digital versatile disc) disc will be described as an example. Referring to FIG. 1, according to the copy-protected optical disc manufacturing method according to an embodiment of the present invention, first, during the premastering process, position information of a sector corresponding to an OHD region to be read next and valid data to be read next are described. Formatting is performed to insert an OSH information layer including position information of the stored sector, a driving program distributed and stored in the OSD information layer, and a production identifier for identifying content (step 102).

In this way, the interleaved address generating apparatus outputs addresses sequentially in the column direction with respect to the two-dimensional array of 2 ² x 2 ³ by controlling i to be reset whenever i exceeds the maximum value. In addition, since the interleaved address generating device uses the output i 'from the bit inverting device 102 as a read address value for the memory 110, row exchange can also be simultaneously performed in the two-dimensional array.

Hereinafter, a process of manufacturing a copy-protected disc by inserting OSD information into an original DVD file will be described in more detail. For example, the original file is composed of 10 blocks. In this embodiment, 10 blocks of OHD blocks are inserted every two blocks of the original file. The OHD block includes three blocks of OHD data blocks, four blocks of OHD blocks, and three blocks of ODP data blocks. The physical OHD block is composed of a mirror area in which pits are not formed. Alternatively, it is also possible to include successive pits whose difference in reflectance of the reflected light from the pits is below a predetermined threshold at which tracking of the light beam is impossible, and it is possible to include pits of a standard different from the standard specification.

FIG. 2 is a diagram for explaining the structure of OHD data block. The data structure shown in FIG. 2 corresponds to one sector 22. Sixteen sectors form one OHD data block. Referring to FIG. 2, the OHD data includes a header field (Header filed), an ID field (244), a current block display field (Curr. Block Ind.), An address information field (248), and the following. A OHD layer start address 250, a next effective data start address 252, and a reserved field 254 are reserved. In addition, driving programs are distributed in the data area 260 of the OHD data block. Further, an ID required for the execution of a drive program of the optical disc drive device can be inserted into the data area 260 in the OHD data block.

Through the processes described with reference to FIGS. 1 and 2, an optical disk capable of copying according to the present invention is manufactured. 3 shows an example of a structure inside the optical disc that is not replicable according to the present invention. Referring to FIG. 3, a physical and artificial error structure is formed in a predetermined region 31 in the non-replicable disk 30 according to the present invention. That is, the OHD area 32 is formed which includes an area where no meaningful information is extracted even if it is inaccessible or accessed by the general optical disk device as described above. The OHD region 32 logically corresponds to an OHD block. Regions 322 and 324 correspond to an OHD data block, and region 326 corresponds to a physical OHD block. In this embodiment, the physical OHD block is composed of a mirror area in which pits are not formed. Alternatively, the physical OHD block may consist of successive pits in which the difference in reflectance of the reflected light from the pits is below a predetermined threshold at which tracking of the light beam is impossible. Alternatively, it is also possible to construct continuous pits with lengths that do not meet the specifications. A valid data area that can be normally accessed is formed next to the OHD area 32 including an area where normal access is impossible or no significant information is extracted even if the normal access is impossible. They are mutually repetitive and alternately formed. The OHD data block corresponding to the areas 322 and 324 as described above is called dummy data because it is not valid data that is content. That is, dummy data including address information of the next read sector is stored on the inner and outer circumferential sides of the physical OHD block corresponding to the area 326. In addition, the dummy data contained in the optical disc transfers the virtual data capacity to the operating system of a computer connected to the optical disc reproducing apparatus, thereby allowing the operating system to be a disc whose size of the duplicated disc is considerably larger than the original data size of the original disc. Recognize. If the size of a file stored in the copied optical disc is recognized as 4 gigabytes, the file cannot be recognized using an operating system of a 32-bit computer.

The file stored in the optical disc having the above physical structure has a structure as shown in FIG. It is assumed that the structure of the file is read sequentially from the inner circumference to the outer circumference. As shown in Fig. 5, the file includes an O.D. information data field 402, a physical O.D. field 404, and an O.D. information data field 406 written before the valid data field 408. Next, the O.D. information data field 410, the physical O.D. field 412, and the O.D. information data field 414 are recorded before the valid data field 416. Finally, the O.D. information data field 420, the physical O.D. field 422, and the O.D. information data field 424 are recorded. The physical OHD fields 404, 412, 422 are physical OHD blocks, i.e., data blocks read from a mirror area where pits are not formed (these blocks will be described later with reference to FIG. May be perceived as an error).

Since the optical disk configured as described above includes a mirror area in which pits are not formed, tracking of a normal light beam is impossible when using a general optical disk reproducing apparatus. Therefore, data stored in the optical disc cannot be read normally in that area. However, it may be assumed that the mirror area is jumped to read and copy data stored in the original disk.

Therefore, according to an embodiment of the present invention, the logical block address indicating the position of the sector allocated to the OHD region is scrambled. If the logical block address forms one or more scrambled OHD areas consecutively, the logical block address value assigned to the sector in the data block recorded in the optical disc does not increase sequentially. In the optical disk manufactured as described above, logical block addresses of sectors are discontinuously arranged as shown in FIG. Therefore, when a copy-protected optical disc manufactured according to the manufacturing method according to the present invention is reproduced using a general optical disc reproducing apparatus, the pickup of the optical disc apparatus cannot access the OHD area without the address information of the sector. The sequence of addresses is discontinuous by the OHD area. Accordingly, when, for example, reading an optical disc in the optical disc reproducing apparatus, since the optical disc reproducing apparatus expects or expects a sequential address to appear for normal driving, When a drive traverses or tracks a discontinuous address, a so-called 'back track jump' occurs with a discontinuous offset to find the address that the drive or system expects. However, it continues to encounter the OHD area, that is, it encounters a discontinuous address, so that the OHD area cannot be read, and as a result, the OH area of the corresponding original disk cannot be read normally and cannot be copied. Even if the original disk is copied by the copying device, the copying disk on which data is recorded is written at an address different from the original address so that it cannot be normally driven during the driving. In addition, on the duplicated disc after tracking of one OSD area is completed, an address is formed as long as the OSD area is recorded as a normal address, and this address is used for recording subsequent valid data.

In addition, the mirror area included in the OHD area formed in the copy protected optical disc according to the embodiment of the present invention prevents the center line position information of the track from being found by the general optical disc reproducing apparatus. That is, since the optical disc reproducing apparatus cannot maintain normal tracking by servo in the mirror area, data reading is impossible. In addition, since the FM signal is not normally detected in the OHD region, the FM signal is not provided to the spindle servo. Therefore, the spindle servo motor is not normally controlled. Therefore, tracking and data reading in the playback apparatus are interrupted, so that normal reading of data is not performed in the OHD area.

It will now be described that the copy protected optical disc according to the present invention cannot be copied using the recordable optical disc apparatus. For example, even if duplication of one OHD area is completed by the recordable optical disk device, the address of another OHD area following the discontinuous address occupying a considerable period is presented, and the other After the OHD region is copied, another OHD region is presented at the end of the OHD region beyond the discontinuous address of a considerable period. If this process is repeated several times, copying of the original by the optical disk device is difficult, and even if the optical disk is attempted to be copied, the copied optical disk may not have the same OHD structure and address structure as the original optical disk.

6 is a flowchart illustrating a process of reading a non-replicable disc and determining a duplicate disc according to the present invention. Referring to Fig. 6, first, when a copy-protected optical disc is inserted into an optical disc reproducing apparatus, the drive program stored in the optical disc is read and automatically executed (step 602). Such a drive program can be loaded and executed by a control means such as a microcomputer in the optical disc reproducing apparatus or by an operating system executed in a user computer to which the optical disc reproducing apparatus is attached. The drive program includes a routine for determining whether an OHD region has been detected. When the drive of the disc starts, it is possible to determine whether the OHD area has been detected from the optical disc by injecting a light beam into the optical disc while the optical disc is being driven (step 604). Alternatively, step 604 may be a step of determining whether the sector structure is a predefined structure by referring to the sector structure of the OHD region. If the OHD region is detected in step 604, the OHD data block is extracted (step 606). If the OHD data block has been extracted, the ID is extracted (step 608). It is possible to recognize a pattern of an error occurring due to the mirror area as an ID. Next, it is identified whether the extracted ID and the ID obtained from the driving program match (step 610). If the extracted ID and the ID obtained from the drive program are identified to match, the disc is normally driven (step 612). That is, the optical disc, which is copied from the copy protection disc manufactured according to the copy-protected optical disc manufacturing method according to the present invention, Since the normal driving is stopped initially in the optical disc reproducing apparatus, the identification of the copy is performed at an early stage, thereby preventing a user's misuse and time damage in advance.

On the other hand, it is possible to insert a routine for processing the optical disc to be normally operated by receiving a disposable use key, for example, from a remote server via the Internet, in a drive program distributed in the OHD area. In this case, the user computer connects to the remote server (step 614) and requests an authenticated use key. If it is determined that the use key is provided (step 614) and it is determined that the authenticated use key is provided, the normal drive of the disc may be performed. However, the drive program does not detect an OHD area in step 606, If the OHD area is detected in step 606, but the OHD data block is not detected in step 606, and an authenticated use key is not provided in step 616, the operation is disabled. Adding a routine to receive a one-time use key from the server prevents the user from using the optical disc because the ID is not generated normally on the computer even though the client has the original disc. That is, if the user generates an access code without the user's recognition by executing the driving program and provides the generated access code to the authenticated user through the Internet, the user must put the same ID as the generated ID in the computer. Can be used. Thus, one optical disc can be used completely normally for one client.

The optical disc manufactured by the method for manufacturing a copy-protected optical disc according to the present invention is included in the OHD area in a drive program distributedly stored in the OHD area in the optical disc when reproduced in a general optical disc reproducing apparatus. By referring to whether a mirrored area has been detected, the replica can be turned off and the replica can be distinguished from the original.

In addition, when driving the original disk according to the present invention, with reference to the information stored in the OHD information data block, extracting and extracting the password, ID, access address, etc. necessary for the execution of the drive program of the optical disk drive device; The original optical disc can be driven normally or can not be driven according to various judgments based on the received information. Therefore, the sectors in the optical disk manufactured according to the copy-protected optical disk manufacturing method according to the present invention can reproduce the content data normally even though the logical block addresses are discontinuously arranged. Thus, the copy-protected optical disc can be normally driven without attaching additional hardware to a device such as an optical disc drive device.

In addition, it is possible to program to generate a different access code each time a running program is executed. That is, some of the internal information that can be read from the individual user computer can be extracted, and the combined data can be used as an access code by combining the extracted information and the error data read from the specific OHD area. In such a case, only when the information of the OHD area is present at a position exactly coincident with the OHD area in the original optical disc, a normal access code is generated and the driving program continues to run normally, thereby achieving stronger copy protection.

Alternatively, it is also possible to insert some essential data of contents to be executed on the optical disk into the OHD area formed in the optical disk according to the present invention. In this way, when a part of the content is inserted into the OSD area, it is possible to effectively prevent the hacked program from being driven by an algorithm that does not refer to the OSD area.

In addition, since the data stored in the OHD area can be distributed and stored in a predetermined amount in a certain section of the entire content file, the composition of each copy protection data can vary according to the contents of the optical disk, and accordingly the result of encryption It can be generated differently. Therefore, according to the present invention, an individual copy protection service can be provided to a content copyright holder recorded on an optical disc.

It is impossible to copy an optical disk manufactured according to the copy-protected optical disk manufacturing method according to the present invention as described above, and a disk which is copied by some method is not normally driven by the optical disk reproducing apparatus. Further, in the method of manufacturing a copy-protected optical disc according to the present invention, since a copy-protected optical disc is made by inserting OHD data into a specific area within the optical disc, all processing for copy protection is performed in the manufacturing process of the optical disc. In addition, no further change of the existing optical disc reproducing apparatus is required. In addition, the reliability of copy protection is further enhanced by combining the hardware copy protection structure of the optical disc itself with software encryption and authentication technology.

As described above, an optical disc manufactured according to the copy-protected optical disc manufacturing method according to the present invention cannot be copied by a recordable optical disc apparatus, and a disc which is copied by some method is normally driven by an optical disc reproducing apparatus. This is not done. Further, in the method of manufacturing a copy-protected optical disc according to the present invention, since a copy-protected optical disc is made by inserting OHD data into a specific area within the optical disc, all processing for copy protection is performed in the manufacturing process of the optical disc. In addition, no further change of the existing optical disc reproducing apparatus is required. In addition, the reliability of copy protection is high by combining the hardware copy protection structure of the optical disc itself with software encryption and authentication technology.

Claims (16)

(a) Optical Head Ditching (OHD) including an area between the areas corresponding to the contents, an area in which the optical beam cannot be tracked during playback in the optical disc reproducing apparatus, or an area where no significant information is extracted even if tracking is possible. A method of manufacturing an optical disc comprising inserting one or more regions) Step (a) is (a-1) an OHD information layer including position information of a sector corresponding to an OHD region to be read next and a position information of a sector storing valid data to be read next during the premastering process, and the OHD information Performing formatting to insert a drive program distributed and stored in a hierarchy, and a production identifier identifying content; (a-2) During the mastering process, an OHD area including a region where a formatted signal is used to disable the tracking of the light beam during reproduction in the optical disc player, or where significant information is not extracted even if tracking is possible. Making a stamper comprising; And (a-3) pressing using a stamper; characterized in that it comprises a, copy-protected optical disk manufacturing method. The method of claim 1, wherein the predetermined OHD region, A method of manufacturing a copy protected optical disc, characterized in that it comprises successive pits whose difference in reflectance of reflected light from the pits is below a predetermined threshold. The method of claim 1, wherein the predetermined OHD region, A method of manufacturing a copy protected optical disc, characterized in that it comprises a mirror area in which pits are not formed. The method of claim 1, wherein the predetermined OHD region, And an OSD information data area in which a start address of a sector corresponding to an OHD area to be read next is recorded. In FIG. 6, i and j represent the row number and column number output from the counter control part 101, and i 'represents the row number output from the bit inversion apparatus 102. In FIG. In addition, α ⁱ⁰ And α ^j Denotes vector data output from the memory 110 and the memory 111, and ⁱ⁰ + α ^j Denotes the result of the calculation in the exclusive-OR operator 112. log _α (α ⁱ⁰ + α ^j Denotes data output from the memory 113, and the offset addition result represents the result of adding the offset address output from the shift register 104 in the adder 105. delete The method of claim 1, wherein step (a-1) comprises: (a-1-1) scrambling a logical block address indicating a position of a sector allocated to the OHD region. Among the areas corresponding to the content, an optical head ditching (OHD) area including an area that disables the tracking of the light beam during playback in the optical disc player or does not extract significant information even when tracking is possible. But And a logical block address indicating a position of a sector allocated to the OHD area is scrambled. 9. A copy protected optical disc as claimed in claim 8, wherein the predetermined OHD region includes successive pits whose difference in reflectance of reflected light from the pits is less than a predetermined threshold. The method of claim 8, wherein the predetermined OHD region, And a mirrored area in which pits are not formed. The method of claim 8, wherein the predetermined OHD region, And an O.D information data area in which the start address of the sector corresponding to the O.D area to be read after the current sector is recorded. The method of claim 8, wherein the predetermined OHD region, And an O.D information data area in which position information of a sector in which valid data to be read after the current sector is stored is recorded. The method of claim 8, wherein the predetermined OHD area, And a drive program for performing control according to the positional information of the sector corresponding to the next OHD area to be read and the positional information of the sector in which valid data to be read next is stored. delete The method of claim 1, wherein the predetermined OHD region, A method of manufacturing a copy protected optical disc, characterized in that it comprises pits of a standard different from the standard specification. 10. The copy protected optical disc of claim 8, wherein the predetermined OHD area includes pits of a standard different from a standard standard.