KR100936533B1 - Digital Content Encryption Method using Bad Pattern, Digital Content Recording / Playback Method Using the Same, and Digital Content Storage Media - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital copyright protection method using a bad pattern, a digital content recording / reproducing method using the same, and a digital content storage medium thereof, which are physical characteristics of a memory device such as a flash memory (for example, a NAND flash memory). Digital copyright protection method, digital content recording / reproducing method using the same, and digital content storage medium using the same (bad block, bad page, bad bit, etc.) as an encryption key to protect the copyright of digital content, the method To provide a computer readable recording medium having recorded thereon a program for realizing them.

To this end, the present invention provides a digital rights protection (DRM) method, the method comprising: checking the bad pattern for each unit area of the memory device constituting the digital content storage medium, and determining the bad pattern extraction area; Recording a code value of the determined bad pattern extraction area in a table selection code field of a card ID; Inspecting an area corresponding to an area code recorded in the table selection code field and constructing a bad pattern DRM table based on bad pattern information; And generating a bad pattern encryption key based on the bad pattern information.

Digital Content, DRM, Bad Pattern, Bad Block, Bad Page, Memory Device, Physical Characteristics

Description

Digital content encryption method using bad pattern, digital content recording / playback method and digital content storage medium {DRM method using bad pattern, and digital contents recorder / player and method using that}

The present invention relates to a digital copyright protection method using a bad pattern, a digital content recording / reproducing method using the same, a digital content storage medium thereof, and a computer-readable recording medium having recorded thereon a program for realizing the methods. For example, it is possible to protect the copyright of digital content by utilizing bad patterns (bad blocks, bad pages, bad bits, etc.), which are physical characteristics of memory devices such as flash memories (for example, NAND flash memories) as encryption keys. The present invention relates to a digital copyright protection method, a digital content recording / reproducing method using the same, a digital content storage medium thereof, and a computer-readable recording medium having recorded thereon a program for implementing the above methods.

Flash memory refers to a memory in which data may be continuously stored in the memory even when there is no power supply. In addition, data storage / deletion is free. Such flash memory is divided into NOR type and NAND type according to the internal method. NOR type has a structure in which cells are connected in parallel, and NAND type has a structure in which cells are connected in series. Have

Therefore, NAND flash memory is mainly used in SD cards or memory sticks of memory cards, and NOR flash memory is mainly used in MMC cards or compact flash memory.

As such, the flash memory has a small power consumption, and the stored information does not disappear even when the power is turned off. It is a non-volatile memory that is continuously supplied with power. Unlike DRAM, it can not only preserve the stored information but also freely input and output information. Digital TV, digital camcorder, mobile phone, digital camera, personal It is widely used in PDAs, game machines, MP3 players and the like.

However, with the recent increase in the speed of the Internet infrastructure, the improvement of the performance of personal computers, and the increase in the capacity of storage devices, more and more digital contents such as illegally copied music, video, and educational contents have not been paid a fair value. It is a situation that is exposed to, shared with each other, and illegally used. As a result, digital content is soon becoming a free and free consciousness among the general users, which has led to a contraction of the music media, video media, and education media markets.

With the expansion of illegal use, the issue of copyright protection of digital contents is seriously raised, but for those who already have free usage and know how to prevent the spread and use of illegally copied digital contents, pay and use the right copyright value. It is a situation near force majeure. As part of such efforts, in recent years, services that provide digital contents through the network have been converted to paid services, but network paid services have been copyrighted by copyright owners in the situation where digital contents with the same contents are flooded with illegal free digital contents on the Internet. The impact on the protection and contraction of the shrinking offline media market is not significant. This means that if a lot of users know how to use pirated digital content as a paid service or obtain and use pirated free digital content, if it is possible to make piracy, even if a little effort is put into it, the pirated free This is because digital content is obtained and used on the Internet.

For example, suppose that a singer A has released his first album as a CD record, the songs contained in that singer A's first album can be sold to users at the same time as the CD. This will result in the sound source being exposed without any protection device for copyright protection in the internet market where digital content sharing is possible. After a user's music is exposed to the illegal copy market through CD recording (sound storage media), even if any paid service or national policy encourages users to pay a fair royalty fee and use digital content music, It will be difficult to reap.

The same situation applies to DVD, which is a video storage medium. Although DRM (Digital Rights Management) has been applied by region codes or other methods, all of them have been released and illegally copied DVD digital contents are now being used by users without just paying royalty.

In other words, CD or DVD, a digital contents storage medium that is widely used at present, allows copyright holders to record and release their contents on a storage medium and illegally copy their contents without any copyright protection equipment in a market where illegal copying is possible. Is no different from making it public.

Therefore, in the current technical field, the storage media such as CDs and DVDs have rights to contents stored on storage media such as CDs and DVDs due to illegal copying through users' computers and sharing and theft using high-speed Internet infrastructure. Infringement cannot be adequately protected, and there is an urgent need for a thorough protection of the rights of content owners in a vicious cycle of record music, video and multimedia education, which in turn leads to a decline in creative activities. It is a problem of the present invention to meet these demands.

Therefore, the present invention can protect the copyright of digital content by utilizing bad patterns (bad blocks, bad pages, bad bits, etc.), which are physical characteristics of memory devices such as flash memories (for example, NAND flash memories) as encryption keys. It is an object of the present invention to provide a digital copyright protection method, a digital content recording / reproducing method using the same, a digital content storage medium thereof, and a computer-readable recording medium having recorded thereon a program for realizing the above methods.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention which are not mentioned above can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

According to an aspect of the present invention, there is provided a digital rights protection (DRM) method, the method comprising: inspecting a bad pattern for each unit area of a memory device constituting a digital content storage medium, and determining a bad pattern extraction area; Recording a code value of the determined bad pattern extraction area in a table selection code field of a card ID; Inspecting an area corresponding to an area code recorded in the table selection code field and constructing a bad pattern DRM table based on bad pattern information; And generating a bad pattern encryption key based on the bad pattern information.

In addition, the present invention provides a digital rights protection (DRM) method, comprising: inspecting a bad pattern for each unit area of a memory device constituting a digital content storage medium and determining a bad pattern extraction area; Recording a code value of the determined bad pattern extraction area in a table selection code field of a card ID; And examining an area corresponding to the area code recorded in the table selection code field, and constructing a bad pattern DRM table based on the bad pattern table.

In addition, the present invention for achieving the above object, Digital copyright protection (DRM) method, comprising the steps of: extracting the physical characteristics of the digital content storage medium; And generating an encryption key using physical characteristics of the extracted digital content storage medium.

On the other hand, the present invention for achieving the above object, in the digital content recording method, the step of inspecting the bad pattern for each unit area of the memory device constituting the digital content storage medium, and determining the bad pattern extraction area; Recording a code value of the determined bad pattern extraction area in a table selection code field of a card ID; Inspecting an area corresponding to an area code recorded in the table selection code field and constructing a bad pattern digital copyright protection (DRM) table based on the bad pattern table; And recording the digital content on a storage medium by using the bad pattern DRM table as an encryption key.

The present invention also provides a digital content recording method comprising the steps of: extracting the physical characteristics of the digital content storage medium; Generating an encryption key using physical characteristics of the extracted digital content storage medium; And recording the digital content on the digital content storage medium by using the generated encryption key.

In addition, in the digital content recording method, the present invention for achieving the above object is a bad area of a used memory in a header data area, which is an area for recording characteristics of a memory card (digital content storage medium), not a data storage space. Setting and recording an area for recording addresses of the; And extracting an encryption characteristic value by combining addresses of the bad region, and then encrypting the original content data with the encryption characteristic value and recording the content data in the normal region except the bad region of the memory.

In addition, the present invention for achieving the above object, in the digital content recording method, marking the bad area of the used memory at the defined position of the free area corresponding thereto, and encrypts by combining the addresses of the bad area Extracting feature values; And encrypting the original content data using the encryption characteristic value to record the content data in the normal area except the bad area of the memory.

In addition, the present invention for achieving the above object, in the digital content recording method, marking the bad area of the used memory at the defined position of the free area corresponding thereto, and the specified value recorded in the memory Extracting encryption characteristic values; And encrypting the original content data using the encryption characteristic value to record the content data in the normal area except the bad area of the memory.

On the other hand, in the present invention for achieving the above object, in the digital content storage medium, the code value of the bad pattern extraction area is recorded in the table selection code field of the card ID, and the 'field code recorded in the table selection code field'. Digital contents are recorded by using a digital copyright protection (DRM) encryption table based on a bad pattern table as an encryption key by examining a corresponding area.

On the other hand, the present invention for achieving the above object, in the digital content playback method, when inserting the digital content storage medium, by checking the area corresponding to the area code recorded in the table selection code field of the card ID, the bad pattern table Constructing a bad pattern digital copyright protection (DRM) table based on the background; Checking whether patterns having actual bad pattern address values in the bad pattern DRM table are actual bad patterns; And reproducing digital content by using the bad pattern DRM table as a decryption key according to the inspection result.

In addition, the present invention for achieving the above object, the digital content reproduction method, comprising the steps of: extracting the physical characteristics of the digital content storage medium; Generating a decryption key using physical characteristics of the extracted digital content storage medium; And playing the digital content using the generated decryption key.

In addition, the present invention for achieving the above object, in the digital content playback method, when inserting a digital content storage medium, the address of the bad area is read from the header data area, combined with the address of the bad area used to encrypt the content data Calculating an encryption characteristic value; And restoring original content data to the encryption characteristic value while sequentially reading the content data of the memory except the bad region, wherein the encryption characteristic value is unique, such as an address of a bad region different for each memory used. By calculating the combination of values, the complete copy is physically impossible unless the bad memory areas of the original memory and the memory used for copying all match.

In addition, the present invention for achieving the above object, in the digital content playback method, when inserting the digital content storage medium, the memory is read and the addresses of the bad area, combined with the address of the bad area used to encrypt the content data Calculating an encryption characteristic value; And restoring original content data with the encryption characteristic value while sequentially reading data of the memory except the bad region, wherein the encryption characteristic value is a singular value such as an address of a bad region different for each memory used. Calculated by the combination of these two features, it is characterized in that the complete copy is physically impossible unless the bad memory areas of the original memory and the memory used for copying.

In addition, the present invention for achieving the above object, in the digital content playback method, when the digital content storage medium is inserted, reading the specific value recorded in the memory to calculate the encryption characteristic value used as a specific value ; And restoring original content data to the encryption characteristic value while sequentially reading data of the memory except the bad area, wherein the encryption characteristic value is calculated by a combination of specific values recorded in the memory to be used. In this case, a complete copy is physically impossible unless the bad memory areas of the original memory and the memory used for copying are identical.

In order to achieve the above object, the present invention provides a digital rights protection (DRM) device having a processor, which checks a bad pattern for each unit area of a memory device constituting a digital content storage medium, and determines a bad pattern extraction area. Function; Writing a code value of the determined bad pattern extraction area into a table selection code field of a card ID; And an area corresponding to the area code recorded in the table selection code field, and providing a computer-readable recording medium having recorded thereon a program for realizing a function of configuring a bad pattern DRM table based on the bad pattern table. .

The present invention also provides a digital rights protection (DRM) device having a processor, the function of extracting physical characteristics of a digital content storage medium; And a computer readable recording medium having recorded thereon a program for realizing a function of generating an encryption key using the extracted physical content of the digital content storage medium.

On the other hand, the present invention, the digital content recording device having a processor, the function of inspecting the bad pattern for each unit area of the memory element constituting the digital content storage medium, and determines the bad pattern extraction area; Writing a code value of the determined bad pattern extraction area into a table selection code field of a card ID; Inspecting an area corresponding to an area code recorded in the table selection code field and constructing a bad pattern digital copyright protection (DRM) table based on the bad pattern table; And a computer-readable recording medium having recorded thereon a program for realizing a function of recording digital content on a storage medium by using the bad pattern DRM table as an encryption key.

The present invention also provides a digital content recording apparatus having a processor, the function of extracting physical characteristics of a digital content storage medium; Generating an encryption key using physical characteristics of the extracted digital content storage medium; And a computer readable recording medium having recorded thereon a program for realizing a function of recording digital content on the digital content storage medium using the generated encryption key.

On the other hand, the present invention, when inserting the digital content storage medium in the digital content playback device equipped with a processor, by checking the area corresponding to the area code recorded in the table selection code field of the card ID, and based on the bad pattern table Configuring a pattern digital copyright protection (DRM) table; Checking whether patterns having an actual bad pattern address in the bad pattern DRM table are actual bad patterns; And a computer readable recording medium having recorded thereon a program for realizing a function of reproducing digital content by using the bad pattern DRM table as a decryption key according to the inspection result.

The present invention also provides a digital content reproducing apparatus having a processor, the function of extracting physical characteristics of a digital content storage medium; Generating a decryption key using physical characteristics of the extracted digital content storage medium; And a computer readable recording medium having recorded thereon a program for realizing a function of reproducing digital content using the generated decryption key.

As described above, the present invention utilizes physical characteristics such as bad patterns (bad blocks, bad pages, bad bits, etc.) of digital content media composed of NAND flash memory as encryption factors. There is an effect that can provide another unique DRM encryption table (bad pattern DRM table). That is, if there are 100 digital content storage media, all 100 are encrypted by different bad pattern DRM tables (DRM encryption tables).

In addition, the present invention does not use a table previously recorded in a specific area of the digital content storage medium, but obtains a bad pattern DRM table by acquiring a bad pattern, which is a physical characteristic of the storage medium, in the process of media authentication. Because the content is encrypted, the logical copy meaning of the storage medium is lost. This may be verified in the real bad pattern inspection step of the media authenticator, which will be described in more detail below.

Also, the present invention obtains a bad pattern, which is a physical characteristic of a storage medium, in a digital content media authentication process, generates a bad pattern DRM table, and stores the bad pattern based on the generated bad pattern DRM table. The physical copy meaning of the media is lost.

In addition, the present invention, since the copy of the digital content recorded on the digital content storage medium to which the DRM is applied for the above reason is virtually impossible and loses meaning, compared to a storage medium such as a CD or DVD in which the illegal piracy is prevalent. It is possible to fully protect the copyright of digital content, which can provide the rightful compensation to the copyright holders, thereby promoting the development of digital content creation and related technologies.

The above objects, features, and advantages will become more apparent from the detailed description given hereinafter with reference to the accompanying drawings, and accordingly, those skilled in the art to which the present invention pertains may share the technical idea of the present invention. It will be easy to implement. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

According to an exemplary embodiment of the present invention, for convenience of description, the NAND flash memory may be stored in a read only storage medium, not a public file system such as FAT (File Allocation Table) 16 or FAT32. A suitable specialized file system will be described as an example. However, it should be noted that the present invention is not limited thereto.

The configuration of the following file system is also characterized by being encrypted by a bad pattern DRM table (DRM encryption table) of a corresponding storage medium which is already determined when recording digital content. That is, in the structure of the file system, all areas except the minimum area for identifying the bad pattern DRM table (DRM encryption table) of the storage medium are encrypted with the corresponding DRM to block general access.

In general, the physical block 0 of the flash memory (hereinafter referred to as 'zero block') guarantees that the manufacturer is not a bad block. Therefore, in the zero block, format related information of a storage medium, a media ID (card ID), and the like are stored.

Hereinafter, a block having bad bits (that is, a bad block) by bad bit information will be described as an example. However, it should be noted that the present invention is equally applicable to a page having bad bits (that is, bad page) by bad bit information. Therefore, the bad block DRM table may be used as the DRM encryption table for the bad block, and the bad page DRM table may be used as the DRM encryption table for the bad page. Such a bad block DRM table and a bad page DRM encryption table are collectively referred to as a 'bad pattern DRM table (DRM encryption table)'.

The configuration of the zero block of the flash memory will now be described with reference to FIG. 1.

In the Master Boot Recorder (MBR) of page number 0 of the zero block, information related to the configuration of the flash memory and the file system is recorded.

Bad block marking information is recorded in page numbers 1 to 5 of the zero block, and a card ID corresponding to a media ID is stored in page number 9 of the zero block. This Card ID is used to identify specific information of the digital content storage medium (memory card) configured as flash memory as shown in FIG. 2 (eg, Card Version, DRM Table Selection Code, Area Code, Manufacturer, etc.). Code, copyright ID (Writer ID), and card serial number information).

In particular, in the DRM Table Select Code field of the Card ID (page number 9 of zero block), a bad pattern (bad block, bad page, bad bit, etc.), which is a physical characteristic of a storage medium, is used. In implementing one DRM (Digital Right Management), an area (bad block, bad page, bad bit, etc.) in which a bad pattern (bad block, bad page, bad bit, etc.) to be used as a DRM encryption table (bad block DRM table) exists exists Area Code information of the area or the area including the largest number of bad blocks is recorded.

In this case, the bad pattern extraction region of the storage medium configured as the flash memory may be an entire block of the flash memory, but may be a specific region only. In addition, the size of the DRM encryption table (bad block DRM table) using the extracted bad pattern may also be configured in various ways such as 128 bytes, 256 bytes, 512 bytes.

For convenience of description, in this embodiment, the size of the DRM encryption table is set to 256 bytes, and the bad pattern extraction area for configuring the DRM encryption table is based on a specific area instead of the entire flash memory area. Will be explained. However, it should be noted that the present invention is not limited thereto.

In the above description, the term 'specific area' means that the entire block of the flash memory may be divided and processed in units of 2048 blocks. That is, as shown in FIG. 3, the bad pattern extraction area for configuring the DRM encryption table (bad block DRM table) is set in areas of 2048 blocks in all blocks of the flash memory, and among them, the area is set to a specific reference. A suitable area is determined as a bad pattern extraction area for constructing a DRM encryption table (bad block DRM table).

Here, the specific criterion is a criterion for determining whether the area is suitable for forming a 256-byte DRM encryption table (bad block DRM table). For example, if there is an area including a bad block having a threshold value (eg, 128) or more, the area is determined as the bad pattern extraction area. However, if there is no area including more than 128 bad blocks, the area containing the largest number of bad blocks among the plurality of areas (areas set in units of 2048 blocks) is the DRM encryption table. It becomes a bad pattern extraction area for (bad block DRM table) construction.

The bad pattern extraction area is determined based on a bad block table generated while formatting a memory card when a digital content storage medium (memory card) is produced, and the area code of the corresponding area is determined. Code value is recorded in the DRM Table Select Code field of the Card ID shown in FIG. 2.

4 is a flowchart illustrating an example of a method for configuring a bad block DRM table for digital copyright protection according to an embodiment of the present invention, and is recorded in the DRM Table Select Code field of a card ID. The procedure of configuring a bad block DRM table (DRM encryption table) by inspecting an area corresponding to an area code is shown.

As described above, referring to the configuration procedure of the bad block DRM table (DRM encryption table), an area is set in a block multiply unit (for example, a 2048 block multiply unit) in the entire block of flash memory, and the bad block table among these areas is selected. Based on this, a bad pattern extraction area corresponding to a specific criterion (eg, an area having a bad block more than a threshold value (eg, 128) or a lot of bad blocks) is determined, and a code of the corresponding area is determined. ) Value is recorded in the DRM table selection code field of the Card ID.

Thereafter, the bad pattern extraction area (that is, the area corresponding to the area code) is examined (401), and the bad block DRM table (DRM encryption table) is configured as shown in FIG. 5 or 7. You can do it (402-406). 5 is a 256-byte bad block DRM table (DRM encryption table) generated based on the bad block table of region 1 (blocks 0 to 2047) having more than 128 bad blocks, and FIG. It is a 256-byte bad block DRM table (DRM encryption table) generated by attaching padding data to the bad block table (see FIG. 6) of area 2 (blocks 2048 to 4095) each having fewer than two bad blocks.

Specifically, if the area to be inspected (the area corresponding to the area code) has more than 128 sufficient bad blocks so that a 256-byte bad block DRM table (DRM encryption table) can be formed (402), 128 A 256-byte bad block DRM table (DRM) consisting of 128 real bad block addresses based on the bad block table of an area having more than 256 (256 byte) bad blocks (e.g., block 0 to block 2047, area 1). Encryption table) (refer to FIG. 5) (403).

FIG. 5 shows a 256-byte bad block DRM table (DRM encryption table) based on the bad block table of area 1 (blocks 0 to 2047) having more than 128 bad blocks. In other words, there are 128 (256 bytes) or more real bad blocks in the area 1, and a 256-byte bad block DRM table (DRM encryption table) is formed using only the bad block address. In this case, padding as shown in FIG. 7 is not required.

On the other hand, if the corresponding region (the region to be inspected (the region corresponding to the region code)) does not contain enough bad blocks to constitute a 256-byte bad block DRM table (DRM encryption table) (402), Padding is performed in an appropriate manner (404, 405) to create a 256-byte bad block DRM table (DRM encryption table) (see Fig. 7) (406). In this case, the bad block DRM table (DRM encryption table) is composed of 18 (36 bytes) actual bad block addresses and 110 (220 bytes) padding data.

Here, there may be various methods of padding, but in this embodiment, a bad block DRM table (DRM) is utilized by using a card serial number filed (16 bytes) of a card ID. Encryption table). For example, using a padding value generated by sequentially ORing an existing real bad block table value and a card serial number value to each other using 256 bytes as shown in FIG. 7. Configure the bad block DRM table (DRM encryption table). That is, in the 'bad block table of area 2 having 128 or less bad blocks' in FIG. 6, the exclusive bad block table value and the card serial number value are sequentially ORed together to have 128 or less bad blocks. Padding data (i.e., bad block table values and card serials) in the bad block table in area 2 (blocks 2048 to 4095) (i.e., the bad block table with 18 (36 bytes) actual bad block addresses in FIG. 6). A 256-byte bad block DRM table (DRM encryption table) (see FIG. 7) to which the number value is sequentially generated is generated by exclusive OR. In this case, the bad block DRM table (DRM encryption table) is composed of an actual bad block address of 36 bytes and padding data ( 0x09, 0x10, 0x0B, 0x17, ... ) of 220 bytes.

FIG. 6 is a bad block table created based on 128 bad blocks (for example, 18 (36 bytes) actual bad blocks) in area 2 (blocks 2048 to 4095). That is, when only 18 (36 bytes) bad blocks exist in the region 2 from 0x0812 to 0x0CFE, the bad block table is illustrated.

In order to create a 256-byte bad block DRM table (DRM encryption table) based on the bad block table including 18 (36 bytes) real bad block addresses of FIG. 6, padding should be performed. If the card serial number is "0x01020304050607080900010203040506", the padding value obtained through the XOR operation of the card serial number sequentially in the bad block table values is '0x09'. , '0x10', '0x0B', '0x17', ...

Therefore, padding data (i.e., a bad block table value and a card serial number value are sequentially generated by performing an XOR operation on a bad block table (see FIG. 6) including 18 real bad block addresses. Attached) to form a 256-byte bad block DRM table (DRM encryption table) as shown in FIG.

The bad block DRM table (DRM encryption table) formed by the above method is a probability uniquely unique factor that is determined according to the physical characteristics (bad pattern) that the storage medium (memory card composed of memory elements) may have.

8 is a flowchart illustrating an example of a method for recording digital content according to an embodiment of the present invention, and shows a procedure of producing a digital content storage medium.

First, the flash memory (e.g., NAND flash memory) of the digital content storage medium (memory card composed of memory elements) is low-formatted (801), and bit-by-bit bad pages (pages with bad bits) are written by 0xAA55 writing. In step 802, the bad block (block to which the bad bit belongs) is checked and the page or block having the bad bit is marked as a bad page or bad block (802). That is, a block having bad bits is marked as a bad block by bad bit information found at initialization (formatting), and a page having bad bits is marked as bad page by bad bit information found at initialization.

Thereafter, the bad block is recorded in the bad block table (803). In this case, the bad block table may include the entire flash memory block for each area divided by 2048 block multiples.

Next, after determining the area that satisfies a specific condition (reference) by referring to the recorded bad block table after low-formatting the flash memory, the area code value of the corresponding area is determined by the card ID. The data is recorded in the DRM Table Select Code field of (Page Number 9 of Zero Block) (804). For example, an area is set by dividing an entire block of flash memory into 2048 block units, and a bad pattern extraction for configuring a DRM encryption table (bad block DRM table) is performed. After determining the area, the area code value of the determined area is recorded in the DRM table selection code field of the card ID.

Here, the specific condition (reference) is a criterion for determining whether or not it is an area suitable for forming a 256-byte DRM encryption table (bad block DRM table). For example, an area including a bad block having a threshold value (for example, 128 or more) or an area including the largest number of bad blocks may be determined as the bad pattern extraction area. At this time, the determination of the bad pattern extraction area first checks whether there is an area including a bad block having a threshold value (for example, 128 or more). By determining the area including the largest number of bad blocks as the bad pattern extraction area, the area decision can be prioritized.

The area code value of the corresponding area determined as the bad pattern extraction area is recorded in the DRM Table Select Code field of the Card ID shown in FIG. 2 (804).

Thereafter, if the area to be inspected (the area corresponding to the area code) has more than 128 sufficient bad blocks (805), 128 (256) to form a 256-byte bad block DRM table (DRM encryption table). A 256-byte bad block DRM table (DRM encryption table) (refer to FIG. 5) consisting of 128 real bad block addresses is created based on the bad block table of the area having a bad block of bytes or more (806). For example, since there are 128 (256 bytes) or more real bad blocks in area 1 (blocks 0 to 2047), even if the address of a real bad block is 256 bytes, the bad block DRM table (DRM) Encryption table).

On the other hand, if the region (the region to be inspected (the region corresponding to the region code)) does not contain enough bad blocks to constitute a 256-byte bad block DRM table (DRM encryption table), padding (805). 2) A 256-byte bad block DRM table (DRM encryption table) (see Fig. 7) is created (807). That is, a 256-byte bad block DRM as shown in FIG. 7 using a padding value generated by sequentially performing an exclusive OR operation on a real bad block table value and a card serial number value. Configure a table (DRM encryption table).

For example, in the 'bad block table of area 2 having 128 or less bad blocks' in FIG. 6, an exclusive logical OR operation is performed on the real bad block table value and the card serial number value sequentially, thereby obtaining area 2 (block 2048 to block 4095). Padding data (i.e., the bad block table value and the card serial number value (e.g., a bad block table with 18 (36 bytes) of real bad block addresses in FIG. 6)). 36 bytes of Real Block by generating a 256-byte bad block DRM table (DRM encryption table) (see FIG. 7) attached to the value [0x01020304050607080900010203040506]). A bad block DRM table (DRM encryption table) consisting of a bad block address and 220 bytes of padding data ( 0x09, 0x10, 0x0B, 0x17, ... ) is constructed.

Subsequently, after deleting the bad block table that has been extracted and written to the zero block while formatting the flash memory in low format (808), the created bad block DRM table (DRM encryption table) is used as an encryption key to store a memory device (eg, NAND flash memory). In operation 809, the digital content is recorded on the digital content storage medium.

9 is a flowchart illustrating an example of an authentication process for reproducing digital content according to an embodiment of the present invention, and illustrates a procedure of reproducing a digital content storage medium.

First, when a digital content storage device composed of a memory element (for example, a NAND flash memory) is inserted into a digital content providing device (media playback device) (901), the digital content providing device (media playback device) generates a card ID (zero block). Page number 9) of the information is read and the authentication process is started (902). At this time, in the DRM table select code field of the card ID, an area in which bad patterns (bad blocks, bad pages, bad bits, etc.) to be used as a DRM decoding table (bad block DRM table) exist. Since Area Code information is recorded (an area having a bad block or above a threshold value or an area including the largest number of bad blocks), the card ID information is judged at the time of media playback.

Accordingly, an area corresponding to the DRM table select code of the card ID is examined (903) to configure a bad block DRM table (DRM decryption table) (904).

For example, if the area corresponding to the area code recorded in the DRM table selection code has more than 128 sufficient bad blocks, 128 actual (based on the bad block table of the area having 128 (256 bytes) or more bad blocks are provided. Real) A 256-byte bad block DRM table (DRM decoding table) composed of a bad block address is configured.

However, if the area corresponding to the area code recorded in the DRM table selection code does not contain enough bad blocks to constitute a 256-byte bad block DRM table (DRM decryption table), then a padding operation is performed. A bad block DRM table (DRM decoding table) (see FIG. 7) of bytes is constructed. That is, the 256-byte bad block DRM as shown in FIG. 7 using a padding value generated by sequentially performing an exclusive OR operation on a real bad block table value and a card serial number value. A table (DRM decryption table) is constructed.

Thereafter, in the bad block DRM table (DRM decoding table) configured as described above, it is checked whether blocks corresponding to actual bad block table values, not padding values, are real bad blocks (905). For example, the actual bad block in the bad block DRM table (DRM decryption table) of FIG. 7 composed of 36 bytes of real bad block addresses and 220 bytes of padding data (0x09, 0x10, 0x0B, 0x17, ...). Check that the blocks with block address values are real bad blocks.

Looking at the process of checking whether it is a real bad block, for example, randomly selecting about 10 bad blocks from a real bad block table and checking whether it is a real bad block (906). In this case, the write protect pin is disabled and the 0xAA55 and 0x55AA are written to the corresponding page of the real bad block to determine whether it is an actual bad block (907).

As a result of the check 907, if it is confirmed that the actual bad block, an additional number of real bad blocks are additionally checked (for example, about 10) in the same manner (906). Similarly, for the additionally selected badblock, disable the write protect pin and write 0xAA55 and 0x55AA to the corresponding page of the real badblock to determine if it is a real badblock. Confirmation process (907).

If all of these additional real badblock checks have passed (i.e., if the media use authorization has passed), then the use of digital content media (Play or Read) is permitted (908).

Therefore, if the media use authentication passes, the digital content data is decrypted using the generated bad block DRM table (DRM decryption table) and transmitted to the user (909).

However, if the media use authentication fails, the user is notified of the authentication failure and a request for confirmation of the corresponding digital content storage medium (910).

In the above, the number of real bad blocks to be inspected in the process of confirming whether they are real bad blocks or digital content encryption using a generated bad block DRM table (DRM encryption / decryption table) In decryption, there may be various conditions for applying encryption and decryption to the entire digital content or only applying specific encryption and decryption to a specific area. However, in the present embodiment, the end of the real bad block table is different. An example of application based on a value corresponding to the last lower 4 bits of the bad block address will be described.

For example, if the badblock table is the same as in FIG. 6 (that is, the badblock table of FIG. 6 is a badblock table having 18 (36 bytes) of real badblock addresses), the last badblock address is '0xFE'. Since the lower 4 bits value is '0x0E (= decimal 14)', the conditions are determined based on 'decimal 14'.

That is, the real bad block check examines bad blocks corresponding to multiples of 14. If there are not more than five bad blocks to be examined, the first bad block is additionally included in the sequential inspection target to maintain at least five total bad blocks.

Similarly, when described based on the above conditions, encryption of digital content data is also performed on blocks whose block addresses correspond to multiples of fourteen. Decoding also proceeds with the same criteria and conditions.

The method of the present invention as described above can be applied to various fields in consideration of the overall performance and other conditions of the system to which the DRM is applied. For example, it may be applied to an asymmetric encryption system.

Referring to the application example, as described above, a bad pattern DRM table (DRM encryption table) is first generated using the bad pattern. After generating a seed key through a hash function that uses the bad baton DRM table (DRM encryption table) as a conversion factor, the public key (Public Key (RSA, ECC, etc.)) is generated. Key and Private Key can also be created and applied to PKI solutions that are used in many existing fields. This is because the bad pattern of each digital content storage medium is a causal factor for the generation of a private key, and the contents of the private key do not need to be recorded in any logical way. It can be said that the security of the asymmetric encryption system used is further enhanced. That is, the server can download content data encrypted with the public key from the client and decrypt the content data using the private key extracted from the digital content data.

As described above, if the physical characteristics (bad block, bad page, bad bit, etc.) of the memory device constituting the digital content storage medium (memory card) in which the respective digital contents are recorded are utilized as encryption keys, Each storage medium has a different bad block DRM table (DRM encryption table). This can overcome the weakness that the existing DRM using a logical algorithm or encryption table loses its value as a DRM as a specific algorithm or encryption table is released.

For example, digitally copying the memory elements constituting the digital content storage medium (for example, NAND flash memory) by digital copying in any way for the purpose of illegal copying, or by physical dumping, such as memory dumping. Even if the medium is copied, the copied digital content storage medium is not valid. Because, even if the physical content of the same digital content storage medium is duplicated, the bad patterns (bad blocks, bad pages, bad bits, etc.) that are physical characteristics of the memory elements (for example, NAND flash memory) constituting the storage medium are duplicated. Because it is not. In other words, even if the bad block or bad page marking is duplicated in the spare area of the flash memory block, this cannot be physically a bad block or bad page, and thus a duplicated digital content storage medium (up to bad patterns). (Not duplicated) will be determined to be an invalid storage medium because the authentication failed during the inspection of the real bad block of the digital content media authentication process during use (playback).

This is because the existing media such as CDs and DVDs are exposed to the illegal copying of general users, which is a medium of profit for digital contents copyright holders, and at the same time, their digital contents have become a medium for unlimited copying through such media. On the contrary, the present invention can sufficiently protect the copyright holder's digital content for the above reasons.

Meanwhile, another example of a method of preventing illegal copying by copying a whole flash memory may include an encryption / decryption method using different bad areas (blocks, pages, subpages, and locations) for each memory.

For example, it is possible to record the addresses of bad areas (blocks, pages, subpages, locations) of used memory in a header data area, which is an area for recording characteristics of a memory card (digital content storage medium), not a data storage space. Set and record the area, extract the encryption characteristic value (for example, the encryption characteristic value based on the bad block DRM table (DRM encryption table)) by combining the addresses of the bad region, and then encrypt the original content data with the encryption characteristic value. The content data is recorded in the normal area except the bad area of the memory.

When the memory card is inserted, the playback apparatus reads the addresses of the bad areas from the header data area, combines the addresses of the bad areas, and uses encryption feature values (for example, a bad block DRM table (DRM encryption table)). And encrypts the data in memory sequentially without the bad area, restoring the original content data. At this time, the encryption characteristic value is calculated using a combination of singular values such as addresses of different bad areas for each memory used, so that a complete copy is not physically possible unless the bad areas of the memory and the original memory used for copying all match.

As another example, the bad area (block, page, subpage, location) of the used memory is marked as a bad area at a defined location of a corresponding free area, and the encryption characteristic value (for example, bad) is combined by combining addresses of the bad area. After extracting the encryption feature value based on the block DRM table (DRM encryption table), the original content data is encrypted using the encryption feature value, and the content data is recorded in the normal area except the bad area of the memory.

When the memory card is inserted, the playback apparatus checks the memory, reads the addresses of the bad areas, and combines the addresses of the bad areas to combine the encryption characteristic values (for example, the bad block DRM table (DRM encryption table)). And encrypts the data in memory sequentially without the bad area, restoring the original content data. At this time, by calculating the encryption characteristic value with a combination of singular values, such as the address of a different bad area for each memory used, a complete copy is not physically possible unless the bad memory areas of the main memory and the memory used for copying coincide.

In another example, a bad area (block, page, subpage, location) of a used memory is marked as a bad area at a defined location of a corresponding free area, and a specific value (for example, a serial number, etc.) recorded in the memory is marked. After extracting the encryption feature values (e.g., the encryption feature values based on the bad block DRM table (DRM encryption table)), the original content data is encrypted using these encryption feature values, and the contents are stored in the normal area except the bad area of memory. Record the data.

Thereafter, when the memory card is inserted, the playback apparatus checks the memory and reads the specific value recorded in the memory, and uses the encryption characteristic value (for example, the encryption characteristic value based on the bad block DRM table (DRM encryption table)). ), And sequentially read the data in the memory excluding the bad area, and restore the original content data with this encryption characteristic value. At this time, by calculating the encryption characteristic value using a combination of specific values recorded in the memory used, a complete copy is not physically possible unless the bad areas of the memory used for copying and the original memory all match.

In the above, in order to copy the memory card of which the intellectual property is guaranteed, the bad area of the memory is read, and the normal area of the memory card to be copied is identically marked as the bad area, thereby creating the same encryption characteristic value to prevent duplication. To do this, the playback apparatus checks whether or not the bad area is physically created or simply marked for duplication by inserting / reading data into the bad area when the memory card is inserted. Memory card 'recorded digital content data is not played back. In this way, the authenticity of the bad area can be discriminated to distinguish illegal copy memory cards.

10 is a block diagram illustrating an example of an apparatus for constructing a bad pattern DRM table for digital copyright protection according to an embodiment of the present invention. For convenience of description, the operation of the apparatus for generating the bad block DRM table (DRM encryption table) will be described.

The bad pattern detection unit 101 sets an area in a block (/ bad page) multiple unit (for example, a 2048 block multiple unit) from an entire block of flash memory (/ bad page), and in each area, a bad block (/ bad page). Is detected.

The actual bad pattern inspection unit 102 determines a bad pattern extraction region corresponding to a specific criterion (eg, an area having a bad block (/ bad page) above a threshold or an area having many bad blocks (/ bad page)). Then, the area code value of the corresponding area is recorded in the DRM table selection code field of the card ID. At this time, the area code value recorded in the DRM table selection code field of the card ID is, for example, an area code value of the bad pattern extraction area that satisfies a specific condition, among the areas set by dividing the entire flash memory block by 2048 blocks. to be. In this case, the specific condition is, for example, a criterion for determining whether or not a bad block (/ bad page) DRM table (DRM encryption table) is a suitable area (Area). An area including the / bad page or an area including the largest number of bad blocks (/ bad page) may be determined as the bad pattern extraction area.

The bad pattern table creating unit 103 records the address of the bad block (/ bad page) of the area corresponding to the area code recorded in the DRM table selection code field of the card ID in the bad block (/ bad page) table.

The bad pattern DRM table operation unit 104 checks an area corresponding to the area code recorded in the DRM table selection code field of the card ID. That is, it is checked whether the area corresponding to the area code has enough bad blocks (/ bad pages) to form a bad block (/ bad page) DRM table (DRM encryption table).

The bad pattern DRM table generating unit 105 determines a bad block (/ bad page) based on the bad pattern table (bad block table / bad page table) of the area corresponding to the area code recorded in the DRM table selection code field of the card ID. Configure a DRM table (DRM encryption table).

For example, if the area corresponding to the area code has enough bad blocks of 128 or more, 128 or more (256 bytes) bad blocks can be configured to form a 256-byte bad block DRM table (DRM encryption table). Based on the bad block table of the region (for example, block 0 to block 2047 region 1), a 256-byte bad block DRM table (DRM encryption table) composed of 128 real bad block addresses (see FIG. 5). Write.

In addition, if the area corresponding to the area code does not include enough bad blocks to form a 256-byte bad block DRM table (DRM encryption table), a padding operation is performed to perform a 256-byte bad block DRM table. (DRM Encryption Table) [See Fig. 7]. For example, the bad block DRM table (DRM encryption table) of FIG. 7 is composed of 18 (36 bytes) actual bad block addresses and 110 (220 bytes) padding data. In this case, as an example of a padding method, a padding value generated by sequentially performing an exclusive logical sum (XOR) operation of a real bad block table value and a card serial number value is used. As shown in FIG. 7, a 256-byte bad block DRM table (DRM encryption table) may be configured.

11 is a block diagram showing an example of a digital content recording apparatus according to an embodiment of the present invention.

The bad pattern inspection and marking unit 111 low-formats the flash memory (for example, NAND flash memory) of the storage medium (memory card composed of memory elements), and writes a bit page (bad bit) to 0xAA55 writing. Page) or the bad block (block to which the bad bit belongs) and the page or block with the bad bit is marked as a bad page or bad block.

The pad pattern area selection unit 112 determines the area that satisfies a specific condition (reference) by referring to the bad block (/ bad page) table recorded after the row memory is formatted in a row, and the media information recording unit 113. ) Records the Area Code value of the corresponding area in the DRM Table Select Code field of the Card ID (page number 9 of the zero block).

As an example, an area is set by dividing the entire block of flash memory by 2048 block units, and a bad block (/ bad page) DRM table (DRM encryption table) is configured among the areas suitable for a specific condition (reference). After determining as the bad pattern extraction area for, the area code value of the determined area is recorded in the DRM table selection code field of the card ID. In this case, the specific condition (reference) is a criterion for determining whether or not the area is suitable for forming a bad block (/ bad page) DRM table (DRM encryption table). For example, an area including a threshold (eg, 128) or more bad blocks (/ bad pages) or an area containing the largest number of bad blocks (/ bad pages) is bad. The pattern extraction region may be determined. At this time, the determination of the bad pattern extraction area first checks whether there is an area including a bad block (/ bad page) having a threshold value (for example, 128 or more), and if the area does not exist, a plurality of areas (2048 blocks). An area including the largest number of bad blocks (/ bad page) among areas set in units of multiples is determined as a bad pattern extraction area. The area code value of the corresponding area determined as the bad pattern extraction area is recorded in the DRM Table Select Code field of the Card ID shown in FIG. 2.

The bad pattern DRM table generating unit 114 generates a bad block (/ bad page) based on the bad pattern table (bad block table / bad page table) of the area corresponding to the area code recorded in the DRM table selection code field of the card ID. Configure a DRM table (DRM encryption table). For example, if the area corresponding to the area code has more than 128 sufficient bad blocks, the bad block table of the area having more than 128 (256 bytes) bad blocks (for example, block 0 to block 2047 area 1) is used. Based on this, create a 256-byte bad block DRM table (DRM encryption table) [see Fig. 5] consisting of 128 real bad block addresses, and the area corresponding to the area code is a 256-byte bad block DRM table (DRM). If there are not enough bad blocks to constitute an encryption table), padding is performed to create a 256-byte bad block DRM table (DRM encryption table) (see Fig. 7).

The content encryption recording unit 115 utilizes the bad pattern DRM table (DRM encryption table) generated by the bad pattern DRM table generating unit 114 as an encryption key and stores the digital content storage medium composed of memory elements (eg, NAND flash memory). Record digital content.

12 is a block diagram showing an example of a digital content reproduction apparatus according to an embodiment of the present invention.

When the media information collecting unit 121 inserts a digital content storage device composed of a memory element (for example, a NAND flash memory) into a digital content providing device (media playback device), the media information collecting unit 121 stores information on a card ID (page number 9 of zero block). Read At this time, in the DRM table selection code field of the card ID, an area where a bad pattern (bad block, bad page, bad bit, etc.) to be used as a bad pattern DRM table (DRM decoding table) is present (bad block (/ bad of threshold value or more) Area Code information of the area having the page) or the area containing the largest number of bad blocks (/ bad page) is recorded, so that the card ID information is collected during media playback.

The bad pattern DRM table generating unit 122 uses a bad block based on a bad pattern table (bad block table / bad page table) in an area corresponding to a DRM table selection code of a card ID. (/ Bad page) Configures a DRM table (DRM decryption table). For example, if the area corresponding to the area code recorded in the DRM table selection code has more than 128 sufficient bad blocks, 128 actual blocks are based on the bad block table of the area having more than 128 (256 bytes) bad blocks. (Real) constitute a 256-byte bad block DRM table (DRM decoding table) [see FIG. 5] composed of a bad block address, and the area corresponding to the area code recorded in the DRM table selection code is a 256-byte bad block DRM. If there are not enough bad blocks to constitute a table (DRM decryption table), padding is performed to form a 256-byte bad block DRM table (DRM decryption table) (see FIG. 7). That is, the 256-byte bad block DRM as shown in FIG. 7 using a padding value generated by sequentially performing an exclusive OR operation on a real bad block table value and a card serial number value. A table (DRM decryption table) is constructed.

In the media authenticator 123, the actual bad block (/ bad page) table is not a padding value in the bad block (/ bad page) DRM table (DRM decryption table) generated by the bad pattern DRM table generator 122. Check if the blocks (/ pages) corresponding to the (Table) value are real bad blocks (/ bad pages). For example, the actual bad block in the bad block DRM table (DRM decryption table) of FIG. 7 composed of a 36-byte real bad block address and 220 bytes of padding data ( 0x09, 0x10, 0x0B, 0x17, ... ). Check that the blocks with block address values are real bad blocks.

Here, to check whether it is a real bad block (/ bad page), for example, randomly select about 10 bad blocks (/ bad page) from the real bad block (/ bad page) table. To check if it is a real bad block (/ bad page). At this time, disable the WP (Write Protect) pin and write 0xAA55 and 0x55AA to the corresponding page of the real bad block (/ bad page) to write the actual bad block (/ bad page). Check At this time, if it is confirmed that the actual bad block (/ bad page), in the same way by additionally checking the appropriate number of real bad blocks (/ bad page), and additionally, Disable the WP (Write Protect) pin for the selected bad block (/ bad page) and write 0xAA55 and 0x55AA to the corresponding page of the real bad block (/ bad page). Check if it is an actual bad block (/ bad page).

The content decryption and playback unit 124 permits the use of digital content media (Play or Read) based on the authentication result of the media authentication unit 123. That is, if the media use authentication is passed, the generated bad block (/ bad page) DRM table (DRM decryption table) is utilized to decrypt the digital content data to the user and deliver it to the user, or if the media use authentication fails, the authentication fails. Notify the user of the request for confirmation of the corresponding digital content storage medium.

13 is a block diagram showing an example of a key generation device of an asymmetric encryption system to which the present invention is applied.

The bad pattern detection unit 131 sets an area in a block (/ bad page) multiple unit (for example, 2048 block multiple unit) from an entire block of flash memory (/ bad page), and in each area, a bad block (/ bad page) Is detected.

The bad pattern DRM table generating unit 132 determines a bad block based on a bad pattern table (bad block table / bad page table) in an area corresponding to a DRM table select code of a card ID. (/ Bad page) Configures a DRM table (DRM encryption table). For example, if the area corresponding to the area code recorded in the DRM table selection code has more than 128 sufficient bad blocks, 128 actual blocks are based on the bad block table of the area having more than 128 (256 bytes) bad blocks. (Real) Configure a 256-byte bad block DRM table (DRM encryption table) [see FIG. 5] composed of a bad block address, and the area corresponding to the area code recorded in the DRM table selection code is a 256-byte bad block DRM table. If there are not enough bad blocks to constitute (DRM encryption table), padding is performed to form a 256-byte bad block DRM table (DRM encryption table) (see Fig. 7). That is, the 256-byte bad block DRM as shown in FIG. 7 using a padding value generated by sequentially performing an exclusive OR operation on a real bad block table value and a card serial number value. Configure a table (DRM encryption table).

In the media authentication unit 133, the actual bad block (/ bad page) table is not padding value in the bad block (/ bad page) DRM table (DRM encryption table) generated by the bad pattern DRM table generation unit 132. Check if the blocks (/ pages) corresponding to the (Table) value are real bad blocks (/ bad pages). For example, the actual bad block in the bad block DRM table (DRM encryption table) of FIG. 7 composed of 36 bytes of real bad block addresses and 220 bytes of padding data ( 0x09, 0x10, 0x0B, 0x17, ... ). Check that the blocks with block address values are real bad blocks.

Here, in order to check whether it is a real bad block (/ bad page), for example, a random bad block (/ bad page) of about 10 randomly is selected from a real bad block (/ bad page) table. Select to check if it is a real bad block (/ bad page). At this time, disable the WP (Write Protect) pin and write 0xAA55 and 0x55AA to the corresponding page of the real bad block (/ bad page) to write the actual bad block (/ bad page). Check if it is. At this time, if it is confirmed that the actual bad block (/ bad page), in the same way by additionally checking the appropriate number of real bad blocks (/ bad page), and additionally, Disable the WP (Write Protect) pin for the selected bad block (/ bad page) and write 0xAA55 and 0x55AA to the corresponding page of the real bad block (/ bad page). Check if it is an actual bad block (/ bad page).

The seed key generation unit 134 generates a seed key through a hash function using a bad baton DRM table (DRM encryption table) as a conversion factor.

The asymmetric encryption key generator 135 generates the seed key generated by the seed key generator 134 as a public key and a private key through a PKI algorithm (RSA, ECC, etc.).

The public key may be used to encrypt digital content data, and the private key may be used to decrypt digital content data.

On the other hand, the method of the present invention as described above can be written in a computer program. And code and code segments constituting the program can be easily inferred by computer programmers in the art. In addition, the created program is stored in a computer-readable recording medium (ASIC, CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, information storage medium such as OTP (One Time Programable)), Read and executed to implement the method of the present invention. The recording medium may include any type of computer readable recording medium.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

The present invention can be used for digital copyright protection (DRM) technology using a bad pattern, digital content recording / reproducing technology using the same, and digital content storage medium technology thereof.

1 is an exemplary configuration diagram of a digital content storage medium used in the present invention;

2 is an explanatory diagram showing an example of the card ID of FIG. 1;

3 is an explanatory diagram showing an example of a bad pattern extraction area when a whole block of digital content storage medium is divided into 2048 blocks according to an embodiment of the present invention;

4 is a flowchart illustrating an example of a method for configuring a bad block DRM table for digital copyright protection according to an embodiment of the present invention;

5 is an explanatory diagram illustrating an example of a 256-byte bad block DRM table generated in a bad block table of area 1 having more than 128 bad blocks according to an embodiment of the present invention;

FIG. 6 is an explanatory diagram showing an example of a bad block table of area 2 having up to 128 bad blocks used in the present invention; FIG.

FIG. 7 is an explanatory diagram showing another example of a 256-byte bad block DRM table generated by attaching padding data to a bad block table of region 2 having 128 or less bad blocks according to an embodiment of the present invention; FIG. ,

8 is a flowchart showing an example of a digital content recording method according to an embodiment of the present invention;

9 is a flowchart illustrating an example of an authentication process for playing digital content according to an embodiment of the present invention;

10 is a block diagram illustrating an example of an apparatus for constructing a bad pattern DRM table for digital copyright protection according to an embodiment of the present invention;

11 is a block diagram showing an example of a digital content recording apparatus according to an embodiment of the present invention;

12 is a block diagram showing an example of a digital content reproduction apparatus according to an embodiment of the present invention;

13 is a block diagram showing an example of a key generation device of an asymmetric encryption system to which the present invention is applied.

* Explanation of symbols on the main parts of the drawing

101: bad pattern detection unit 102: actual bad pattern inspection unit

103: bad pattern table creation unit 104: bad pattern DRM table operation unit

105: bad pattern DRM table generation unit 111: bad pattern inspection and marking unit

112: bad pattern area selection unit 113: media information recording unit

114: bad pattern DRM table generation unit 115: content encryption recording unit

121: Media information collecting unit 122: Bad pattern DRM table generation unit

123: media authentication unit 124: content decryption and playback unit

131: bad pattern detection unit 132: bad pattern DRM table generation unit

133: media authentication unit 134: seed key generation unit

135: asymmetric encryption key generation unit 136: public key sharing unit

137: private key utilization unit

Claims (41)

Inspecting a bad pattern for each unit area of a memory device constituting a digital content storage medium, and determining a bad pattern extraction area; Inspecting the bad pattern extraction region to construct a bad pattern DRM table based on a bad pattern table; And encrypting the digital content using the bad pattern DRM table as an encryption key. The method of claim 1, The bad pattern table is generated when a memory format of the digital content storage medium is formatted, and digital content encryption method, characterized in that composed of the address value of the bad pattern for each unit area which is a physical characteristic that the memory device can have. The method of claim 2, The bad pattern DRM table is digital content encryption method, characterized in that consisting of only the bad pattern table. The method of claim 2, The bad pattern DRM table is configured by using a card serial number field of a card ID, and digitally configured to pad the values generated by sequentially performing an exclusive OR operation on the value of the bad pattern table and the card serial number value. Content encryption method. The method of claim 1, The bad pattern is a digital content encryption method, characterized in that any one of the bad block, bad page, or bad bit information. The method of claim 1, The bad pattern extracting region may be any one of an entire memory block, an area including 128 or more bad blocks, or an area including a maximum number of bad patterns. The method of claim 1, And a unit area of the memory device is an area set in units of 2048 block multiples. delete The method of claim 1, And the size of the bad pattern DRM table is 256 bytes. The method of claim 1, And the memory device is a NAND flash memory. delete delete Inspecting a bad pattern for each unit area of a memory device constituting a digital content storage medium, and determining a bad pattern extraction area; Inspecting the bad pattern extraction region to construct a bad pattern DRM table based on a bad pattern table; And recording the digital content on a storage medium using the bad pattern DRM table as a bad pattern encryption key. The method of claim 13, The bad pattern table is generated during a memory format of the digital content storage medium, and the digital content recording method comprises an address value of a bad pattern for each unit area, which is a physical property of a memory device. The method of claim 14, And the bad pattern DRM table comprises only the bad pattern table. The method of claim 14, The bad pattern DRM table is configured by using a card serial number field of a card ID, and digitally configured to pad the values generated by sequentially performing an exclusive OR operation on the value of the bad pattern table and the card serial number value. How to record content. The method of claim 13, And the bad pattern is any one of a bad block, a bad page, and bad bit information. The method of claim 13, And the bad pattern extraction area is one of an entire memory block, an area including 128 or more bad blocks, or an area including a maximum number of bad patterns. delete Examine the bad pattern of the used memory, determine the bad pattern extraction area in the header data area, which is an area for recording the characteristics of the memory card (digital content storage medium) and not the data storage space, and record the area code of the extraction area. Making; Extracting an encryption characteristic value by combining addresses of the bad pattern corresponding to the area code; And And encrypting the original content data using the encryption characteristic value and recording the content data in a normal area excluding the bad area of the memory. Inspecting a bad pattern of the used memory and marking the bad pattern at a defined position of a free area corresponding thereto; Determining a bad pattern extraction region; Inspecting the bad pattern extraction region and extracting an encryption characteristic value by combining addresses of the region marked with the bad pattern; And And encrypting the original content data using the encryption characteristic value and recording the content data in a normal area excluding the bad area of the memory. delete delete delete A bad pattern DRM table is constructed based on a bad pattern table obtained by examining a bad pattern extraction area determined by examining a bad pattern for each unit area of a memory device constituting a digital content storage medium. A digital content reproduction method of playing content, When the digital content storage medium is inserted, inspecting the determined bad pattern extraction region to construct a bad pattern DRM table based on a bad pattern table; Checking whether patterns having actual bad pattern address values in the bad pattern DRM table are actual bad patterns; And And reproducing digital content by using the bad pattern DRM table as a decryption key according to the inspection result. The method of claim 25, The bad pattern table is generated when a format of the memory of the digital content storage medium, the digital content playback method characterized in that composed of the address value of the bad pattern for each unit area, which is a physical property that the memory device can have. The method of claim 26, The bad pattern DRM table comprises only the bad pattern table. The method of claim 26, The bad pattern DRM table is configured by using a card serial number field of a card ID, and digitally configured to pad the values generated by sequentially performing an exclusive OR operation on the value of the bad pattern table and the card serial number value. How to play content. The method of claim 25, And the bad pattern is one of a bad block, a bad page, and bad bit information. The method of claim 25, The process of checking whether the patterns having actual bad pattern address values in the bad pattern DRM table are actual bad patterns, Disabling the write protect pin and writing 0xAA55 and 0x55AA on the corresponding page of the real bad pattern to check whether it is a real bad pattern . delete Examine the bad pattern of the used memory, determine the bad pattern extraction area in the header data area, which is an area for recording the characteristics of the memory card (digital content storage medium) rather than the data storage space, and record the area code by recording the area code. A method of reproducing content data encrypted by combining addresses of a bad pattern corresponding to a code, and then encrypted by the encryption property value and reproducing content data recorded in a normal area except a bad area of a memory. When the digital content storage medium is inserted, reading the addresses of the bad area from the header data area and combining the addresses of the bad area to calculate an encryption characteristic value used for content data encryption; And Restoring the original content data to the encryption characteristic value while sequentially reading the content data of the memory except the bad area, The encryption characteristic value is calculated by a combination of singular values, such as addresses of different bad areas, for each memory used, so that complete duplication is not physically possible unless the bad areas of the original memory and the memory used for copying are all identical. Digital content playback method. Examining the bad pattern of the used memory, marking that the bad pattern in the defined position of the free area corresponding to it, determine the bad pattern extraction area, examine the bad pattern extraction area, the area of the area marked with the bad pattern A method of reproducing content data encrypted by combining an address and then encrypted with the encryption property value and recorded in the normal area excluding the bad area of the memory, the method comprising: When the digital content storage medium is inserted, checking the memory to read addresses of the bad area, and combining the addresses of the bad area to calculate an encryption characteristic value used to encrypt the content data; And Restoring original content data to the encryption characteristic value while sequentially reading data of a memory except a bad area, The encryption characteristic value is calculated by a combination of singular values, such as addresses of different bad areas, for each memory used, so that complete duplication is not physically possible unless the bad areas of the original memory and the memory used for copying are all identical. Digital content playback method. delete 34. The method of claim 32 or 33, When the digital content storage medium is inserted, whether or not the bad area is physically created or simply marked for duplication is confirmed by writing / reading data in the bad area. In a digital rights protection (DRM) device with a processor, Checking a bad pattern for each unit area of a memory device constituting a digital content storage medium, and determining a bad pattern extraction area; Inspecting the bad pattern extraction region and configuring a bad pattern DRM table based on a bad pattern table; And A computer-readable recording medium having recorded thereon a program for realizing a function of encrypting digital content using the bad pattern DRM table as an encryption key. delete In a digital content recording device having a processor, Checking a bad pattern for each unit area of a memory device constituting a digital content storage medium, and determining a bad pattern extraction area; Inspecting the bad pattern extraction region and configuring a bad pattern DRM table based on a bad pattern table; And And encrypting the digital content using the bad pattern DRM table as an encryption key and recording the data on a storage medium. delete In a digital content playback device having a processor, A bad pattern DRM table is constructed based on a bad pattern table obtained by examining a bad pattern extraction area determined by examining a bad pattern for each unit area of a memory device constituting a digital content storage medium. A function of inspecting the bad pattern extraction area and constructing a bad pattern digital copyright protection (DRM) table based on a bad pattern table when inserting a digital content storage medium in which content is recorded; Checking whether patterns having an actual bad pattern address in the bad pattern DRM table are actual bad patterns; And And reproducing digital contents by using the bad pattern DRM table as a decryption key according to the inspection result. delete

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