JP2003283486A - Content reproduction device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a content reproduction device for enabling a user to reproduce contents in a prescribed order and a content reproduction system using a communication system. <P>SOLUTION: In the content reproduction device having encrypted contents 13 created by encrypting a plurality of contents 38a-c to be reproduced in the prescribed order and a means for obtaining the contents 38a-c from the encrypted contents by using license keys 26a-c, the encrypted contents 13 are created by repeating a processing that the content 38c of the last reproduction order is encrypted so that it can be released by the license key 26c, after that, certain contents 38a, 38b and encrypted contents created by encrypting all the contents 38b, 38c of later reproduction orders than the contents 38a, 38b are added together and encrypted so that they can be released by the license keys 38a, 38b until the content 38a to be reproduced first is encrypted. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention utilizes a content reproducing apparatus and a communication system used under the condition that a content such as encrypted video information and document information and a license key for decrypting the encryption are distributed. Content reproduction system.

[0002]

2. Description of the Related Art In recent years, contents of video information such as movies and document information such as novels have been stored in recording media such as CD-ROMs and DVDs for distribution. Recently, these contents are also distributed on the Internet. When the content purchaser pays for the content at the store or on the Internet, the content seller collects the price for the content from the purchaser.
In some cases, the seller of the content collects the price of the content by encrypting the content and distributing the content free of charge, and by allowing the user of the content to purchase a license key for decrypting the content.

When the content is a movie, it is specified in each part, when it is a novel, manga, or game, it is a chapter, and when it is a test question, it is a question and an answer. The content may be divided so that the order of occurrence occurs, and each content after division may be sold. When encrypted and distributed, each content is encrypted and distributed for each content or packaged. The user purchases a license key peculiar to each content from the seller in order to decipher each content, deciphers the encryption using the license key, and then reproduces each content.

[0004]

From the above-mentioned content seller, it is preferable that the user reproduces each content in the reproduction order. However, when the user can freely select and purchase the license key, the user purchases only the license key for some content, for example, the license key for the content of the final chapter of the novel or the test solution, and There is a risk that you will be satisfied with the content only and will not purchase license keys for the rest of the content. In particular, if the last content contains a lot of information about the remaining content, playing the last content may result in the same situation as if the remaining content was also played.

In order for the user to keep the reproduction order of the contents, it is considered that the seller sells each license key to the user in the reproduction order of the contents at appropriate time intervals. However, this imposes a time burden on the user who wants to quickly reproduce all the contents. In order to limit the purchase of a license key and purchase a license key for a certain content, it is conceivable that the user is presented with a license key for a content that is earlier than the content. However, this may make the purchase of license keys troublesome and reduce the number of users.

The present invention solves the above-mentioned problems, and provides a content reproduction apparatus capable of causing a user to reproduce contents in a predetermined order, and a content reproduction system using a communication system.

[0007]

The content reproducing apparatus of the present invention comprises a plurality of contents (3) to be reproduced in a predetermined order.
8a-c) encrypted content created by encryption (13)
And a means for obtaining the decrypted content (38a-c) from the encrypted content (13) using the license key (26a-c), the encrypted content (13) First, the content in the last playback order
(38c) is encrypted with the license key (26c) so that it can be released,
After that, a content (38a) (38b) and the content (38a)
All contents (38b) (3) whose playback order is later than (a) (38b)
8c) is encrypted together with the encrypted content created by encryption, and the content (38a) that is played first is encrypted by the process of releasably encrypting with the license key (26a) (26b). It is characterized in that the license keys (26a-c) created by repeating the above process and used for the above encryption are different from each other.

A content reproduction system of the present invention comprises the above content reproduction apparatus (1) and the content reproduction apparatus (1).
And a key sales server (2) connected via a communication network (4) to the key sales server (2), which includes a license key (38a-c). The license key (38a-c) in response to a request from the content reproduction device (1)
Send to (1).

The content encryption method of the present invention is a content encryption method for encrypting a plurality of contents (38a-c) to be reproduced in a predetermined order. Encrypted with a license key (26c) so that it can be released, and after that, with certain contents (38a) (38b),
All the contents (38a) and (38b) in the playback order later than the contents (38b) (38c) are encrypted and created together with the encrypted contents, and released with the license keys (26a) (26b) It is created by repeatedly performing the encryption process that is possible until the first played content (38a) is encrypted, and the license key (26a-
Characteristic c) is different.

The recording medium of the present invention is a recording medium storing an encrypted content (13) created by encrypting a plurality of contents (38a-c) to be reproduced in a predetermined order. In (13), first, the content (38c) in the last reproduction order is releasably encrypted with the license key (26c), and thereafter, the content (38a) (38b) and the content (38a) (38b) Along with the encrypted content created by encrypting all the contents (38b) (38c) whose playback order is later than, the process of releasably encrypting with the license key (26a) (26b), First played content (38
It is characterized in that the license key (26a-c) used for the encryption is different by being created by repeating the process a) until it is encrypted.

[0011]

[Operation and effect] Since the encrypted content (13) is created as described above, the encrypted content (13) can be decrypted only by a specific license ski (26a). As a result of descrambling the encrypted content (13), the content (38a) that should be reproduced first among the plurality of contents (38a-c) can be reproduced. On the other hand,
The rest of the content remains encrypted. The encrypted content related to the remaining content can be decrypted only by a specific license ski (26b) different from the above. In addition, as a result of decryption of this encrypted content, the content that should be reproduced second from the beginning (38b)
Can be regenerated. And the rest of the content remains encrypted. Thus, according to the invention,
A plurality of contents to be played in order can be encrypted so as to be played to the user in order.

Further, in the present invention, each license key (26a-c) is different, and a certain license key (26a-c) and the content (38a-
c) and correspond. Therefore, according to the present invention, the seller can cause the user to reproduce the plurality of contents in the order desired by the seller, and the license key peculiar to the contents can be reproduced when the contents are reproduced.
By selling (26a-c) to the user, the consideration for each content can be collected. Further, according to the present invention, the seller sells the license key to the user at a time interval in order to allow the user to reproduce the content in a predetermined order, or restricts the user when purchasing the license key. All license keys (26-c) without the need to do troublesome work after distributing content, such as providing
Can be published to the user at the same time.

The content reproducing device (1) is connected to the key sale server (2) through the communication network (4),
The key sale server (2) transmits the license key (26a-c) to the content reproduction apparatus (1) in response to a request from the content reproduction apparatus (1), so that the user does not have to go to the store. The license keys (26a-c) can be purchased at any time. Further, since the license key (26a-c) has a small data amount, it is suitable for distribution via the communication network (4).

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic diagram of a content reproduction system according to the present invention. This system is a content playback device (1) used by a user to play back content.
And a key sale server (2) for selling a license key for decrypting content, and a content encryption device (3) for creating encrypted content. The content reproduction device (1) and the key sale server (2) are connected to the Internet (4). The key sale server (2) and the content encryption device (3) can communicate with each other via the LAN (5).

FIG. 2 is a schematic diagram of the main configuration of the terminal device (1). The content reproduction device (1) includes a CPU (6) and a memory.
(7), hard disk (8), network interface (9), recording medium drive device (10), display (1
1) and an input device (12). The encrypted content (hereinafter, encrypted content) A '(13) and the content reproduction program (14) are stored in a recording medium (16) such as a CD-ROM or a DVD and distributed to users. The user attaches the obtained recording medium (16) to the recording medium drive device (10). The content playback program (14)
The content obtained by decrypting the encrypted content A '(13) is displayed on the display (11), read by the recording medium drive device (10), and the CPU
It is executed by (6). The recording medium (16) also stores a WEB page display program (15).
By means of (15), the content reproduction device (1) can display a WEB page (HTML document) included in the key sale server (2) on the display (11) via the Internet (4). The content (13) may be downloaded via the Internet (4) and stored in the hard disk (8). The same applies to the content reproduction program (14) and the WEB page display program (15).

An operating system (not shown) is stored in the hard disk (8), and the content reproducing program (14) and the WEB page display program (15) cooperate with the operating system to execute the above-mentioned operation. Perform processing. Note that the key sale server (2) and the content encryption device (3) also have an operation system, and the programs, which will be described later, included therein also process in cooperation with the operation system.

FIG. 3 is a schematic view of the main configuration of the key sale server (2). The key sale server (2) is
1), a memory (22), a hard disk (23), a network interface (24) and the like. The hard disk (23) has a WEB page (25) for selling keys, a license key (26a-c) to be sold to users, and a license key.
It is provided with a key sales program (27) for performing various processes in the sale of (26a-c) and a database (28) for recording various user information.

The WEB page (25) is a content reproducing device.
It is transmitted to (1) and displayed on the display (11) of the device (1). The user selects the license key (26a-c) to be purchased using the WEB page (25) and notifies the key selling server (2) of the type of license key (26a-c) to be purchased. W
The EB page (25) is a page for the user to input information such as name, address and credit card number.
A page showing a list of license keys (26a-c) to be purchased, a purchase amount, and a purchase decision button may be provided.

Key sales program (27) is on the WEB page
(25) and license key (26a-c) content playback device
Perform the transmission process to (1). The database (28) records the user information input by the user on the first page, the type and price of the license key (26a-c) purchased by the user, and the like.

FIG. 4 is a schematic diagram of the main configuration of the content encryption device (3). The content encryption device (3) is C
PU (31), memory (32), network interface
(33), first hard disk (34), second hard disk (3
5) and a recording medium writing device (36).

The first hard disk (34) has a CPU (31)
An encryption program (37) executed by the above, three contents A to C (38a-c) to be encrypted, and three license keys (26a-c) are stored. These license keys (26a-c) are different license keys, and they are already set before the content is encrypted. The content encryption device (3) uses these contents A
~ C (38a-c) and the license key (26a-c) are used to create the encrypted content A '(13). The created encrypted content A '(13) is stored in the second hard disk (35) and then written in the recording medium (16) by the recording medium writing device (36). The second hard disk (35) also stores a content reproduction program (14) and a WEB page display program (15) stored in the recording medium (16) in addition to the encrypted content A '(13). The recording medium (16) stores the content (13) and these programs (14) and (15),
It is distributed to users. Copying from the second hard disk (35) to the recording medium (16) is performed on many recording media (16). The content encryption device (3) can generate the encrypted content A '(13) (before or during the creation).
The license key (26a-c) is transmitted to the key sale server (2), and the transmitted license key (26a-c) is stored in the hard disk (23) as shown in FIG.

FIG. 5 is a flowchart of the processing performed by the content encryption device (3) by the encryption program (37) to create the encrypted content A '(13). For example, the content is a detective novel, and the content A (38a)
Is the detective story case, Content B (38b) is the investigation,
Content C (38c) contains the solution. Therefore, when these contents are reproduced in the order of A (38a), B (38b), and C (38c), they are reproduced according to the flow of the story of the novel. Based on this order, the content encryption device (3) performs content encryption as follows.

First, the content C (38c), which is the last to be reproduced, is encrypted so as to be decrypted with the license key γ (26c) (S40). As a result, encrypted encrypted content C ′ is created. In addition, content C (3
It is expressed that C ′ = F ₁ (C, γ) that the encrypted content C ′ is created by performing the decipherable encryption operation F ₁ on the 8c) with the license key γ (26c). .

Next, the content B (38b) reproduced before the content C (38c) and the encrypted content C'are matched (S41). And in the data created by this,
Encryption operation that can be decrypted with license key β (26b) F ₂
Then, the encrypted content B ′ is created (S42). That is, B ′ = F ₂ (B + C ′, β).

Next, the content A (38a) reproduced before the content B (38b) and the encrypted content B'are matched (S43). And in the data created by this,
Encryption operation that can be decrypted with license key α (26a) F ₃
To create encrypted content A '(13) (S4
Four). That is, A ′ = F ₃ (A + B ′, α). Since the content A (38a) is the content to be reproduced first, the encrypted content A '(13) is finally stored in the second hard disk (35), and the content encryption processing ends (S45). In this embodiment, the number of contents is 3
However, even if the number of contents is larger than this, the contents are encrypted in the same manner as described above.

The processing performed by the content reproduction system according to the present invention in order to reproduce the content will be described. The user inserts the recording medium (16) into the recording medium drive device (1) provided in the content reproducing device (1) as shown in FIG.
Attach it to 0). Display a list of files stored in the recording medium (16) by processing of the operating system
When it is displayed on (11) and the content reproduction program (14) or the encrypted content A '(13) is selected, the content reproduction program (14) is started. Then the display (11)
A content player screen (50) as shown in FIG. 6 is displayed. FIG. 6 is a schematic diagram showing a state of the content reproduction apparatus (1) during the content reproduction processing. On the content player screen (50), a content display screen (51) on which content is displayed, various buttons (52) for instructing content reproduction operation, and an access button for instructing access to the key sales server (2). (53) and a button (54) indicating "Yes" and "No" for designating whether or not a license key is purchased are displayed.

FIG. 7 is a flowchart showing the processing of the present content reproduction system after the display of the content player screen (50). By using the input device (12), the user can access the access button (53) or "Ye".
When the button (54) marked "s" is pressed, the WEB page display program (15) runs, the content reproduction device (1) accesses the key sale server (2), and the WEB page (25)
Is requested to be transmitted (S60). The key sale server (2) transmits the WEB page (25) to the content reproduction apparatus (1) (S61),
The transmitted WEB page (25) is displayed on the display (11) as shown in FIG. On the WEB page (25), contents A to C (38a-c) from encrypted contents A '(13)
The license key (26a-c) is displayed for each license key (26a-c) that the user wants to purchase.
Can be selected. The user may purchase any license key from the three license keys α (26a), β (26b), and γ (26c). You may purchase all license keys at once. The user specifies the license key (26a-c) to be purchased on the WEB page (25), and sends a purchase notification to the key selling server (2) (S63). Key sale server (2)
Transmits the license key (26a-c) designated by the user to the content reproduction device (1) (S64). Content playback device
(1) stores the received license key (26a-c) in the hard disk (8).

Based on the content reproduction program (14), the content reproduction apparatus (1) automatically receives the encrypted content A'on receipt of the license keys (26a-c) stored in the hard disk (8). Perform the process to cancel the encryption in (13). The subsequent processing differs depending on whether the purchased license key is α (26a) or whether the purchased license key includes α (26a) (S65).

FIG. 8 shows that the content reproducing apparatus (1) is similar to that shown in FIG.
It is a conceptual diagram which shows the process for obtaining content AC (38a-c) from the encrypted content A '(13) encrypted as shown in FIG. FIG. 8A shows the encrypted content A ′ (13), the circle P3 shows the encryption by the encryption operation F ₃ , and the inside of the circle P3 is encrypted by the encryption operation F ₃ . The data area is shown. Similarly, the circle P2 indicates the encryption by the encryption operation F ₂ , the circle P1 indicates the encryption by the encryption operation F ₁ , and the inside of the circle P2 indicates the encryption operation F 2.
_The data area encrypted by ₂ is shown, and the inside of the circle P1 shows the data area encrypted by the encryption operation F ₁ . The data area enclosed by the circles P3 and P2 shows the data area of the encrypted content A (38a), and the data area enclosed by the circles P2 and P1 shows the encrypted content B.
The data area of (38b) is shown, and the inside of the circle P1 shows the data area of the encrypted content C (38c).

Even if the encrypted content A '(13) as described above is decrypted by using the license key β (26b), the circle P on which these license keys act
The data area in 2 is located inside the circle P3 and is impossible because it has been encrypted by the encryption operation F ₃ . To decrypt the encrypted content in the circle P2, first, to decrypt by encryption operation F ₃ is a condition. Similarly, it is impossible to decrypt the encrypted content A ′ (13) using the license key γ (26b). Therefore, for the encrypted content A ′ (13), the decryption operation G ₃ using the license key α (26a) is performed.
You can only do it. As a result, the content A (38
a) and the encrypted content B'will be obtained. The operation and the result are expressed as A + B ′ = G ₃ (A ′, α).

FIG. 8 (b) shows the result of performing the descrambling operation G ₃ using the license key α (26a) on the encrypted content A ′ (13). The data area indicated by a square indicates that the encryption has been released. Among the contents A to C (38a-c), the content A (38a) having the first reproduction order is deencrypted and can be reproduced. The rest of the content (38b, c) is still encrypted and unplayable. The data area in the circle P2 in which the encryption by the encryption operation F ₃ is released is the encrypted content B ′. Even if the encrypted content B ′ is decrypted by using the license key γ (26b), the data area in the circle P1 is located inside the circle P2, and the encryption operation F _{2 is performed.} It is impossible because it is Therefore, for encrypted content B ',
Only the descrambling operation G ₂ using the license key β (26b) can be performed. As a result, the content B (38b) and the encrypted content C'are obtained. That is, B + C '
= G ₂ (B ′, β).

FIG. 8 (c) shows the result of performing the descrambling operation G ₂ using the license key β (26b) on the encrypted content B ′. The encryption of the content B (38b) to be reproduced next to the content A (38a) is released, and the content B (38b) can be reproduced. The content C (38c) whose reproduction order is the last is still encrypted, and the encrypted content C ′ exists. The encrypted content C ′ can be decrypted by performing the decryption operation G ₁ using the license key γ (26c). That is, C = G
It becomes ₁ (C ', γ).

FIG. 8D shows the result of performing the descrambling operation G ₁ using the license key γ (26c) on the encrypted content C ′. The content C (38c) to be reproduced next to the content B (38B) has been decrypted so that it can be reproduced. In this way, if the contents A to C (38a-c) are encrypted as shown in FIG. 5, the encryption of each content is sequentially released in accordance with the reproduction order desired by the seller, and the user can reproduce the reproduction order. According to the content A ~
C (38a-c) will be reproduced.

Referring again to FIG. 7, the content reproduction apparatus (1) performs the process of decrypting the encrypted content A ′ (13), but the purchased license key is α (26a), or If the purchased license key includes α (26a), the decryption operation G ₃ is performed using the license key (26a) (S67). As a result, the content A (38a) to be reproduced first and the encrypted content B'are obtained. These are stored in the hard disk (8) of the content reproduction apparatus (1), and the content A (38a) is reproduced based on the content reproduction program (14) and displayed on the content display screen (51).

If the purchased license key does not include α (26a), or if the purchased license key does not include α (26a), the content reproduction device (1) causes the encrypted content A '(13). Unable to cancel the encryption of (S6
8). Therefore, the user purchases the license key α (26a) using the WEB page (25) (S63).

In FIG. 7, the processing of the content reproduction system is completed by reproducing the content A (38a), but the user continues to reproduce the content B (38b) and further the content C (38c). Good. It will be apparent from the above description that the next reproducible content is the content B (38b) and the processing of the content reproduction system performed in the subsequent reproduction operation.

The above description of the embodiments is for explaining the present invention and should not be construed to limit the invention described in the claims or to limit the scope thereof. The configuration of each part of the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made within the technical scope described in the claims.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a content reproduction system according to the present invention.

FIG. 2 is a schematic diagram of a main configuration of a content reproduction device (1) according to the present invention.

FIG. 3 is a schematic diagram of a main configuration of a key sale server (2) according to the present invention.

FIG. 4 is a schematic diagram of a main configuration of a content encryption device (3) according to the present invention.

FIG. 5 is a flowchart showing a process of a content encryption device (3).

FIG. 6 is a content reproduction device during content reproduction processing.
It is a schematic diagram showing a situation of (1).

FIG. 7 is a flowchart showing processing of the content reproduction system.

FIG. 8 is a conceptual diagram showing a process in which a content reproduction device obtains content from encrypted content.

[Explanation of symbols]

(1) Content playback device (2) Key sales server (4) Communication network (13) Encrypted content (26a) (26b) (26c) License key (38a) (38b) (38c) Content

Claims (4)

[Claims] 1. An encrypted content (13) created by encrypting a plurality of contents (38a-c) to be reproduced in a predetermined order, and the encryption using a license key (26a-c). Content (38a-) decrypted from content (13)
In the content reproduction apparatus including means for obtaining (c), the encrypted content (13) is such that first the content (38c) in the last reproduction order is releasably encrypted with the license key (26c), and thereafter there is Content (38a) (38b) and the content (38a
All contents (38b) (3) whose playback order is later than (a) (38b)
8c) is encrypted together with the encrypted content created by encryption, and the content (38a) that is played first is encrypted by the process of releasably encrypting with the license key (26a) (26b). The content reproduction device is characterized in that the license keys (26a-c) used for the encryption are different by being created by repeating the above process. 2. The content reproduction device (1) according to claim 1.
And a key selling server (2) connected to the content reproducing device (1) through a communication network (4), wherein the key selling server (2) is a license key. (26a-c), the license key (26a-c) is provided to the content reproduction apparatus (1) in response to a request from the content reproduction apparatus (1).
Content playback system to send to. 3. A content encryption method for encrypting a plurality of contents (38a-c) to be reproduced in a predetermined order, wherein first, the content (38c) having the last reproduction order is released with a license key (26c). Encrypt as much as possible, and after that, the content (38a) (38b) and the content (38a)
All contents (38b) (3) whose playback order is later than (a) (38b)
8c) is encrypted together with the encrypted content created by encryption, and the content (38a) that is played first is encrypted by the process of releasably encrypting with the license key (26a) (26b). The content encryption method is characterized in that the license key (26a-c) used for the above encryption is different, which is created by repeatedly performing the above. 4. A recording medium storing encrypted content (13) created by encrypting a plurality of contents (38a-c) to be reproduced in a predetermined order, wherein the encrypted content (13) is First, the content (38c) having the last reproduction order is releasably encrypted with the license key (26c), and thereafter, the content (38a) (38b) and the content (38c) are deleted.
All contents (38b) (3) whose playback order is later than (a) (38b)
By repeating the process of releasably encrypting with the license key together with the encrypted content created by encrypting 8c) until the first played content (38a) is encrypted. A recording medium having different license keys (26a-c) created and used for the above encryption.