JPH1028255A - Data-reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict the re-constitution of soft data on the user side. SOLUTION: This device is provided with a fetching means for fetching encoded data constituted of plural blocks by block units, extracting means 4 for extracting key information included in the (i)-th block, holding means 5 for holding the extracted key information until the (i+j)-th block is fetched, and decoding means 3 for decoding the data of the (i+j)-th block by using the key information held in the holding means 5. Therefor, the data for the (i+j)-th block cannot be decoded without obtaining the key information of the (i)-th block. Assuming even through the data of the (i)-th block are unnecessary for a user, the skip reading is impossible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data reproducing apparatus used for reproducing various software data such as a video source and an application program, and more particularly, to restrict the reconstruction of soft data on the user side. The present invention relates to a novel data reproducing apparatus as described above.

[0002]

BACKGROUND ART Multi-channel digital broadcasting using digital modulation technology has entered a practical stage. For example, some companies in the United States have prepared programs for as many as 150 channels using digital satellites. In the multi-channel broadcasting era, there is a high possibility that multiple programs you want to watch will line up in the same time zone. Will be transformed.

[0003] By the way, commercials inserted into a program are usually unrelated to the contents of the program, and since the program is forcibly displayed by interrupting the program, it cannot be said that the commercial is only annoying to the viewer. There is no such thing, but it is extremely important for broadcasters in sales policy. For example, if a commercial falls (an accident that a predetermined commercial could not be played at a predetermined time) occurs, it may develop into an important matter that may affect the relationship with the sponsor.

[0004] When watching a television broadcast in real time, a broadcaster may appropriately manage a program schedule so that a commercial break does not occur. However, when the recording / playback style as described above is generalized, it is undeniable that a broadcaster or a sponsor who extracts (or deletes or skips) only commercials in some way during playback may perform undesired data operations. .

[0005] Against this background, the inventors of the present application can eliminate one of the factors that hinder the sound development of the broadcasting business in the multi-channel broadcasting era by preventing commercials in a program from being deleted or skipped. Focus on
As technical means for that purpose, the present invention described below has been devised. In the above description, a television broadcast is given as a close example, but the present invention is not limited to this.
It may be a video source such as a still image or a moving image, an application program for games or business use, or a data file extracted from a database. In short, any data may be used as long as the data has additional information intentionally inserted by the data provider (including the creator, the owner, and the individual or corporation having the sales right). As the additional information, for example, copyright display information of the application program, constraint information such as license agreement, and adult content information on the Internet (a page indicating that minors are prohibited from accessing) can be shown. All of them are information intentionally inserted by the provider, and are information that is difficult to read by the user (unexpected).

[0006]

2. Description of the Related Art When recording digital satellite broadcasting or storing data obtained through a communication network such as the Internet on a personal computer, generally,
The former uses a magnetic tape, and the latter uses a hard disk or a magneto-optical disk. All storage media are identical in that data to be input in time series is sequentially written while shifting the storage position by one bit or plural bits.

[0007] Reading is performed in the order of writing, the reverse order, and "partial reading" (hereinafter, "partial reading").
Is also possible. Partial reading is performed very accurately, especially in the case of a hard disk or a magneto-optical disk, without a 1-bit error. The reason is that the write position is recorded in a management area on the medium (for example, a file allocation table area of a hard disk; commonly called FAT), and when reading, the head is positioned while referring to the recorded information. Because. In the case of magnetic tapes (excluding digital video tapes) used in VCRs, although high precision such as hard disks and magneto-optical disks cannot be obtained, for example, by using an editing device, In addition, partial reading can be performed with an accuracy that cannot be visually recognized.

[0008]

As described above, in the conventional recording (or storage) / playback device, partial reading can be easily performed. For example, the user can delete or skip unnecessary information. There is no particular difficulty. Or
There is no particular difficulty in changing the order intended by the information provider or cutting out a part of the provided information for secondary use.

Therefore, according to the simplest way,
After deleting or changing the order of all unnecessary information while looking at the screen, it can be reconstructed into data preferable for the user by overwriting, or after cutting out the desired information, New data can be easily created. However, for example, when the deleted information or order has an important meaning for the data provider, or when the data is used secondarily, the provider cannot overlook such an action, but the data is not reconstructed. Because there is no way to know this, there is a problem that no measures can be taken in practice.

An object of the present invention is to provide a useful technical means capable of restricting the reconstruction of soft data on the user side.

[0011]

The technical items necessary to achieve the above object are as follows. That is,
A fetching unit that fetches encoded data composed of a plurality of blocks in block units, an extracting unit that extracts key information included in the i-th block, and holds the extracted key information until the fetching of the (i + j) -th block. I + using the holding means and the key information held in the holding means.
decoding means for decoding the data of the j-th block;
Should be provided.

Alternatively, a storage medium provided with the following technical items may be used. That is, encoded data composed of a plurality of blocks is stored, and i
A storage medium having a data structure in which key information for decrypting the + j-th block is hidden may be used. According to these, if the key information of the i-th block is not obtained, the data of the (i + j) -th block cannot be decrypted, so that the data of the i-th block is unnecessary for the user. It is also indispensable to achieve the above-mentioned object that reading is impossible, i-th and i + j-th are not interchangeable, or i-th or i + j-th extraction is also impossible. Is obtained.

[0013] Alternatively, capturing means for sequentially capturing encoded data consisting of a plurality of blocks in block units, extracting means for extracting key information included in each of the captured blocks, and key information of each extracted block. A calculating means for generating combined key information of blocks in the next fetching order collectively, a holding means for holding the compounded key information until the block of the next fetching order is fetched, and a compound held in the holding means And decoding means for decoding data of a block corresponding to the block in the next fetch order using the encryption key information.

According to this, a unique operation is obtained in which the blocks in the next fetching order cannot be combined unless all the key information included in each block is prepared. Further, the above-mentioned object is achieved by using, on the data generation side, a capture unit for sequentially capturing arbitrary data in block units, a key information generation unit for generating key information corresponding to each block, and an output of the key information generation unit. Coding means for coding the data of each block, holding means for holding the coded block at least until the next block is coded, and coding the block fetched from the holding means at the time of fetching. And an adding means for adding key information used for the conversion.

The key information of the current block to be encoded (the (i + j) th block as viewed from the data reproducing apparatus side) is
This is because it becomes at least the sub-data of the previous block (the i-th block) that has been encoded. Alternatively, when the block to be encoded at the time of extraction is other than the first block, the key information generating means may use key information reflecting key information one block before the current block as key information of the block to be encoded.

Since the encoding key information of each block has relevance, for example, “...
The key information of each block is integrated ... ".

[0017]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are views showing an embodiment of the data reproducing apparatus according to the present invention. In FIG. 1, four parts (reference numerals 1 to 4) indicated by solid-line rectangular frames schematically show technical matters indispensable for the present embodiment. It may consist of a circuit or unit, or it may consist of a combination of several parts, circuits or units.
In the following description, an example of a configuration that is considered to be preferable is shown, but the presentation example is to prove that the present invention can be sufficiently implemented, and within the intended range of the present invention. It goes without saying that other configurations other than the modified configuration or the presented example are also included.

In FIG. 1, reference numeral 1 denotes a CD-ROM as a “storage medium” described in the gist of the invention. This CD-
The physical structure, recording principle, and reproduction principle of the ROM 1 are well-known and will not be described in detail, but a feature of the present embodiment lies in the structure of recorded data. FIG. 2 is a schematic diagram of the data structure. In FIG. 2, D represents a complete data group (for example, BO in the case of a data file).
F to EOF). The illustrated data group D is composed of a plurality of blocks. Here, for convenience, the data group D is composed of n blocks B _{1 to} B _n . As will be clear from the following description, the value of n must be at least “2” or more. If it is less than "2", the purpose of the present invention is not achieved.

The characteristic point of the data structure shown in FIG.
And each block B_i(I is 1, 2,... N)
Like) encoded main data M_iAnd sub data K_iComposed of
Second, the sub data K_iAfter j blocks
Main data K_{i + j}Is the decryption key. An example
For example, j = 1, n = 10, and the time axis of each block
Input order is B₁, B_Two………, B_n(Ie B first
₁Enters, then B_TwoIs entered, and finally B_n
In the order of input), the first block B₁Vice
Data K₁Is the 1 + jth, that is, the second block
B_TwoMain data M_TwoBecomes the decryption key information of
10-1st block B_n-1Sub data K of _n-1Is 1
0-1 + jth, that is, the tenth block B_nLord of
Data M_nIs the decryption key information. The tenth
Block B_nIs the last block of the data group D,
Since there is no decryption block,_n
May be omitted or filled with appropriate dummy data
No problem. Also, the first block B₁Is the data group D
And the corresponding sub-data (decryption key
Information) does not exist, the corresponding block B₁Main data of
M₁To raw data without encoding or a suitable dummy
Need to fill with data.

The CD-ROM 1 of the present embodiment recorded with such a characteristic data structure can read the data group D by a normal CD-ROM drive, but has the configuration shown in FIG. If not added, data cannot be reproduced (decoded). In FIG. 1, 2 is a CD-R
OM drive device (hereinafter abbreviated as “drive device”). The drive device 2 includes at least a CD-ROM
1 has a function of extracting the data group D recorded in 1 in block units and in the recording order, and a function of outputting the extracted block _Bi to the decoding circuit 3 and the extraction circuit 4. Therefore, the drive device 2 of the present embodiment includes the CD-ROM 1
Since the data group D (encoded data composed of a plurality of blocks; see FIG. 2) recorded in the block is taken in block units, the data group D corresponds to the “capturing unit” described in the gist of the invention.

Next, the decoding circuit 3 is intended to decode the main data M _i of the input block B _i, decryption key information used for decoding is one that is removed from the memory circuit 5. The memory circuit 5 is used for storing the output of the extracting circuit 4, the extraction circuit 4 sub data K from the input block B _{i
This is} to separate and extract _i . These decoding circuits 3,
The extraction circuit 4 and the storage circuit 5 correspond to the “decoding unit”, the “extraction unit”, and the “holding unit” described in the gist of the invention, respectively. Incidentally, 6 is any apparatus for reproducing main data M _i completing decoding (e.g., video display).

In such a configuration, the operation will be described using, for example, the data group D in FIG. 2. First, the first block B ₁ extracted from the drive device 2 is composed of the decoding circuit 3 and the extraction circuit 4. After the sub data K ₁ of the block B ₁ is separated and extracted by the extraction circuit 4, the sub data K ₁ is stored in the storage circuit 5. Next, when the second block B ₂ is taken out, this block B ₂ is inputted to the decoding circuit 3 and the extraction circuit 5 in the same manner as described above, but the storage circuit 5 already has the sub-block of the _first block B ₁ . Data K ₁
Since There is already stored, the decoding circuit 3, and decrypts the main data M ₁ of the second block B ₁ using a sub data K ₁ of the first block B _1. At this time, the extraction circuit 4 outputs the sub data K _{2 of the second} block B _2.
The are separated and extracted, the contents of the memory circuit 5 will be rewritten by the sub data K _2. Thereafter, these decoding, separation extraction and storage update are repeated for each block, and when the last block _Bn is reached (for example, when EOF is detected), the processing is terminated.

As described above, in this embodiment, since the main data M _{i + 1} of the (i + 1) -th block is decoded using the sub-data K _i of the i-th block, for example, the block B _{1 in} FIG. If skipped, the second block B
Because can not decode ₂ of the main data M _2, it can prohibit skipping the first block B _1, or can prohibit the first block swapping of B ₁ and second block B _2, or, 1 th cut can prohibit for secondary use of the block B ₁ and the second block B _2, unique effect that is obtained.

In the above example, the main data M _{i + 1} of the (i + 1) -th block is decoded using the sub-data K _i of the i-th block, ie, the adjacent block (j =
Although the sub-data and the main data of 1) are combined, the present invention is not limited to this. For example, sub data and main data of adjacent blocks (j = 2) may be combined with each other, or sub data and main data of adjacent blocks may be combined with a plurality of blocks interposed.

In the configuration example of FIG. 1, when the i-th block B _i is skipped, the main data M _{i + j} of the (i + j) -th block B _{i + j} cannot be decoded. If the blocks B _i and B _{i + j} are not necessary for the user, the user does not have any disadvantage and the intended effect cannot be obtained. FIG. 3 is an improved example of FIG. 1 in which such a case is assumed. The difference from FIG. 1 is that an arithmetic circuit (arithmetic means) 10 for integrating the output of the memory circuit 5 and a second memory circuit (holding means) 11 for storing the integrated value are provided. Is used as the decoding key information of the decoding circuit 3. When the output of the arithmetic circuit 10 is used, the arithmetic circuit 10 also has a function as a holding unit.

According to this, since the main data of each block is decoded based on the integrated value of the sub data of each block, if even one block is skipped, the decoding of the subsequent blocks is not performed. It becomes impossible and the inconvenience described above does not occur. Note that the arithmetic circuit 10 may perform a function other than “integration”. The point is that it is only necessary to generate data reflecting the contents of the sub-data of all the blocks taken in sequentially. For example, an arithmetic method such as a logical sum, a logical product, or an exclusive logical sum may be used. Alternatively, these calculation methods may be combined.

By the way, in particular, moving images such as video sources
In the image, reverse reproduction is often performed.
The configuration 3 has a disadvantage that reverse reproduction cannot be performed. Figure
Reference numeral 4 is an improved example which eliminates such inconvenience. Figure 4
Thus, 20 can store the sub data of all the blocks.
Stack memory with a capacity of about
The address of memory 20 is managed by "first in first out method"
The point that is being done is the point. That is, first-in, first-out
In the first method, the sub data K of the first block₁Big in
Given the address, the sub data K of the second block_Two
Is given the next largest address, ...
Lock secondary data K_nGiven a small address
From the stack memory 20, K sorted in reverse order
_n……… K_Two, K₁Is read. What
Note that, in the configuration shown in FIG.
The capacity of the backup memory 20 to the minimum (for one sub-data)
I just need.

Alternatively, reverse reproduction can be performed as shown in FIG. That is, a storage circuit 30 having a capacity capable of storing sub-data of all blocks, and an address management circuit 31 for managing addresses of the storage circuit 30
And the storage circuit 3 is controlled by the address management circuit 31.
The address designation at the time of writing the sub-data to 0 and the reproduction in the normal order may be performed in ascending order, and the address specification in the reverse reproduction may be performed in the descending order (the ascending order and the descending order may be reversed). Further, it is preferable to add a function of designating an arbitrary address to the address management circuit 31, since random reproduction can be performed.

As shown in FIG. 6, when the block whose decoding has been completed is written back to the drive device 2,
Finally, raw data can be generated on a storage medium (of course, overwritable) of the drive device 2. The use of raw data allows reverse playback and random playback to be performed freely. This configuration can be applied to a case where a block whose decoding has been completed is reproduced in real time. This is because all blocks are reproduced at least once in perfect form, and this does not violate the intention of the data source provider.

In the above embodiment, the storage medium is a CD-R
Although OM was shown, it is not limited to this. For example, various devices such as a removable magnetic disk, a DVD (digital video disk), a rewritable optical disk, and a cartridge-type or card-type storage device can be appropriately used.
FIG. 7 is a diagram showing one embodiment of the data generation device according to the present invention. This data generation device is used in the production / editing site of various software data described at the beginning.

In FIG. 7, reference numeral 40 denotes a data storage device which stores arbitrary soft data before encoding (hereinafter, "raw data"). Note that, instead of the data storage device 40, a device that directly generates raw data may be used. The data storage device 40 (or a device that directly generates raw data)
It corresponds to the capturing means described in the gist of the invention, and has at least a function of extracting raw data in block units.

An encryption circuit 41 encrypts raw data extracted from the data storage device 40 in block units.
Is an encryption key generation circuit for generating key information necessary for encryption. Here, “encryption” is one usage form of encoding, and is generally understood to give data invisibility (confidentiality), but the present invention is not limited to such a narrow meaning. In short, it is only necessary that key information is required and the invisibility can be obtained as a result. If it meets this condition, for example, general methods such as data compression and format conversion can be used. Any encoding technique may be used. Therefore, the illustrated encryption circuit 41
Corresponds to the encoding means described in the gist of the invention, and the encryption key generation circuit 44 corresponds to the key information generation means described in the gist of the invention.

Reference numeral 42 denotes a holding circuit. The holding circuit 42
For example, the storage device is a storage device such as a memory or a register having a capacity of at least one block, holds the encrypted data generated by the encryption circuit 41, and overwrites and updates the held content with the next encrypted data. Things.
Therefore, the holding circuit 42 holds the i-th encrypted data up to the point of generation of the (i + j) -th (j = 1) encrypted data, and thus corresponds to the holding means described in the gist of the invention. Note that the capacity of the holding circuit 42 may be two blocks or more (j> 1). In this case, if the storage area is divided into j equal parts and used like a shift register, i +
When the j-th encrypted data is stored, the i-th encrypted data can be taken out.

Reference numeral 43 denotes a sub-data adding circuit as adding means described in the gist of the invention. The sub data addition circuit 43
The key data from the encryption key generation circuit 44 is added to the encrypted data extracted from the holding unit 42 and output. In such a configuration, the key information from the encryption key generation circuit 44 is provided to the encryption circuit 41 and also to the sub data addition circuit 43.
Now, the storage capacity of the holding circuit 42 is one block (j = 1).
Then, when the i-th block is taken out from the holding circuit 42, the encryption of the (i + j) -th block is performed in the encryption circuit 41, and the encryption key generation circuit 44 outputs the key of the (i + j) -th block. Information has been retrieved.

Therefore, in the sub data adding circuit 43,
The key information of the (i + j) -th block is added to the i-th block, and a data group D having the structure shown in FIG. 2 is generated and output. FIG. 8 is an improved configuration diagram of FIG.
The difference is that the key information from the encryption key generation circuit 44 is subjected to predetermined arithmetic processing, and is then provided to the encryption circuit 41. The arithmetic circuit 50 and the storage circuit 51 are components necessary for arithmetic processing. The arithmetic processing is, for example, processing for integrating the key information from the encryption key generation circuit 44 and the storage information in the storage circuit 51. The integration result is provided to the encryption circuit 41, and the storage circuit The storage contents of 51 are updated.

Now, the first block in the encryption circuit 41
When encrypting the (head block), the storage circuit 51
The stored contents are empty (zero reset state) and the encryption key
Key information (K) from the generation circuit 44₁ ) Is encrypted as is
Circuit 41 and stored in the storage circuit 51.
It is. Then start encrypting the second block
In the arithmetic circuit 50, the
Key information (key information of the second block; K_Two )
The storage information (K₁ ) And integration (K₁ + K _Two )
Is performed, and the result of the integration is given to the encryption circuit 41.
At the same time, the data is overwritten in the storage circuit 51. Then the third
When the encryption of the eye block starts, the arithmetic circuit 50
Is the key information from the encryption key generation circuit 44 (the third
Key information of block; K_Three ) And the storage information of the storage circuit 51.
Information (K₁ + K_Two ) And integration (K₁ + K_Two+ K_Three ) Done
And the result of the integration is given to the encryption circuit 41.
Is overwritten on the storage circuit 51. ... and ...
When the encryption of the last block is started, the arithmetic circuit 50
Is the key information from the encryption key generation circuit 44 (the last block).
Lock key information; K_n ) And information stored in the storage circuit 51
(K₁ + K_Two + K_Three + …… + K_n-1 ) And integration (K₁ +
K_Two + K_Three + …… + K_n-1 + K_n ) Is performed, and its accumulation
The result is provided to the encryption circuit 41 and the storage circuit
51 is overwritten.

Therefore, according to this improved example, the first block
If the encryption key information of the block other than the lock is (K₁ + K
_Two ), (K₁ + K_Two + K_Three ), ........., (K₁ + K
_Two + K _Three + …… + K_n-1 ), (K₁ + K_Two + K_Three + ……
+ K_n-1 + K_n ), And in each case the key one block before
-Including information, the playback side when even one block is missing
A unique effect is obtained that the decryption can be prohibited.
In this example, “integration” is performed.
Absent. For example, OR, AND, or exclusive OR
There may be. In short, it reflects the key information one block before
It is sufficient that the calculated result is obtained. The key one block before
-Information is the "operation result" one block before.
You.

[0038]

According to the present invention, since the reconstruction of the soft data on the user side can be regulated, the additional information intentionally inserted or deleted by the provider can be deleted or skipped, or
It is possible to provide a very useful technology for protecting intellectual property, which can effectively eliminate the change of the order intended by the provider or the extraction of information for secondary use.

[Brief description of the drawings]

FIG. 1 is a principle configuration diagram of an embodiment.

FIG. 2 is a schematic diagram of a data structure according to an embodiment;

FIG. 3 is an improved configuration diagram (part 1) of one embodiment.

FIG. 4 is an improved configuration diagram (part 2) of one embodiment.

FIG. 5 is an improved configuration diagram (part 3) of one embodiment.

FIG. 6 is an improved configuration diagram (part 4) of one embodiment.

FIG. 7 is a configuration diagram of another embodiment.

FIG. 8 is an improved configuration diagram of another embodiment.

[Explanation of symbols]

B _{1 to} B _n : block D: data group (encoded data) K _{1 to} K _n : sub data (key information) 1: CD-ROM (storage medium) 2: drive device (capturing means) 3: decoding circuit (Decoding means) 4: Extraction circuit (extraction means) 5: Storage circuit (holding means) 10: Operation circuit (operation means) 11: Second storage circuit (holding means) 40: Data storage device (capturing means) 41 : Encryption circuit (encoding means) 42: holding circuit (holding means) 43: sub-data addition circuit (addition means) 44: encryption key generation circuit (key information generation means)

Claims (5)

[Claims] An input means for inputting encoded data comprising a plurality of blocks in block units; an extraction means for extracting key information included in an i-th block; and an input means for inputting the extracted key information to an i + j-th block. A data reproducing apparatus comprising: a holding unit that holds the data up to the time of (1); and a decoding unit that decodes the data of the (i + j) -th block using the key information held by the holding unit. 2. A data structure in which encoded data comprising a plurality of blocks is stored and key information for decoding an (i + j) -th block is hidden inside an i-th block. Storage media. 3. A fetching means for sequentially taking encoded data consisting of a plurality of blocks in block units, an extracting means for extracting key information included in each fetched block, and a key information of each extracted block. A calculating means for generating combined key information of blocks in the next fetching order collectively, a holding means for holding the compounded key information until the block of the next fetching order is fetched, and a compound held in the holding means Decoding means for decoding data of a block corresponding to the block in the next fetch order using the encryption key information;
A data reproducing device comprising: 4. An input means for sequentially taking in arbitrary data in block units, a key information generating means for generating key information corresponding to each block, and a code for each block using the output of the key information generating means. Encoding means for encoding, a retaining means for retaining the encoded block at least until the encoding of the next block, and a key used for encoding at the time of the extraction at the block extracted from the retaining means. A data generating device comprising: an adding unit that adds information. 5. The method according to claim 1, wherein the key information generating means is configured to, when the block to be encoded at the time of the extraction is other than the first block, generate key information reflecting the key information one block before,
5. The data generation device according to claim 4, wherein the key information is used as the key information of the encoding target block.