JP2003224558A - Content managing method and system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To generate the key data of previous versions on a terminal equipment side by obtaining the key data of the latest version and to decipher the ciphered contents of all the versions. <P>SOLUTION: In a key generation part 11, the key data are repeatedly ciphered from original seed key data for the number of times corresponding to the version of the contents with the seed key data as the data to be ciphered and the key data of the respective versions are obtained. In a ciphering part 13, the contents of the respective versions are ciphered by the obtained key data of the respective versions. Then, in the key generation part 21, the key data of the previous versions respectively are repeatedly deciphered from the key data of the latest version for the number of times required for the respective versions by a predetermined decipher function, and the contents are deciphered by the key in a deciphering part 23. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD OF THE INVENTION The present invention needs to restrict illegal copying such as video, image, audio, music, text, figure, program and other electronic data with copyright.
The present invention relates to a so-called content management method and system.

[0002]

2. Description of the Related Art Generally, in the case of a content which is copyrighted and whose illegal copy must be restricted, it is widely practiced to encrypt the content with respective key data. Further, a configuration in which necessary key data is obtained online from the center for decryption and the content is decrypted using the key data obtained from the center is also disclosed in, for example, Japanese Patent Laid-Open No. 9-34841. It is known in the art.

[0003]

However, the one disclosed in Japanese Patent Laid-Open No. 9-34841 transmits order information of a content desired to be purchased from the terminal device to the center and is generated based on the order information from the center. It only acquires the necessary key data, unlocks the content you want to purchase using this key data, and makes the contents available, and if there are multiple contents you want to use, It was necessary to transmit each order information for each content and obtain the necessary key data. Therefore, there is a problem that the order itself is troublesome, it takes a lot of time to obtain the key data, and the center side needs to manage a plurality of keys, which makes the system complicated.

The present invention solves the above-mentioned conventional problems. If the latest version of key data is obtained even if the content version is different, the key data of a version earlier than the key data is obtained. Easy to generate,
The present invention provides an excellent content management method and system that does not require the key data corresponding to each version to be obtained from the center.

[0005]

According to the content management method of the present invention, the content is encrypted by using the key data, and the encrypted content cannot be decrypted to the original state without using the key data. In this content management method, the key data is obtained by repeatedly encrypting the seed key data from the seed key data as the encrypted data for the number of times corresponding to the version of the content.

With this configuration, regardless of the version of the content, the key data of the previous version can be easily generated by simply obtaining the key data of the latest version, and the key data of the previous version can be obtained from the center. It has an effect that it is not necessary to obtain each one.

The content management system of the present invention is a content management system including a center device and a terminal device, and the center device receives the requested version of the key data based on the request from the terminal device. And a key data generation unit for generating each key data of a required version before the requested version based on the key data transmitted from the center device. And a decryption unit that decrypts the encrypted content of each version based on each key data generated in (4).

With this configuration, the latest version of the key data can be obtained from the center device, the key data of each version can be generated on the side of the terminal device, and the key data of each version can be obtained from the center device. It has the effect that it is not necessary.

Further, in the content management system of the present invention, the key data generation means repeatedly decrypts the latest version of the key data obtained from the center device by a predetermined decryption function a required number of times to obtain the required version of the key data. It is configured to generate.

With this configuration, it is possible to accurately generate the required key data by the key data generating means, and it is possible to accurately combine and use the required version of the contents.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below.

FIG. 1 is a schematic block diagram showing a configuration of a content management system according to an embodiment of the present invention, and FIG. 2 shows a method of generating key data at a center and a terminal in the same embodiment. It is a conceptual diagram.

As shown in FIG. 1, the content management system in this embodiment is composed of a center device 10 and a terminal device 20. And the center device 10
And the terminal device 20, by the operation from the terminal device 20,
It is configured to be able to communicate with each other via the Internet, electronic mail, a wired or wireless communication line, or any other communication network 30.

The center device 10 is installed in a center or the like that controls the copyright management service of contents, and based on a request from the terminal device 20, generates key data that matches the request and sends it to the terminal device 20. It is a device.

That is, in the center device 10, a key generation unit 11 for generating each key data for encrypting the content, and the key data generated by the key generation unit 11 are requested by the terminal device 20. A communication unit 12 for transmitting to the terminal device 20 is provided accordingly.

In the present embodiment, the plaintext content stored in the center device 10 and further stored in the plaintext content storage unit 14 (original content not encrypted)
An encryption unit 13 is provided for encrypting the with the key data generated by the key generation unit 11. Therefore, the center device 1
0 also serves as a device that encrypts the content of each version with the key data corresponding to each version.

On the other hand, the terminal device 20 includes a center device 1
0 based on the key data obtained from the center device 10 via the communication unit 22 that communicates with
The key generation unit 21 that generates key data necessary for decrypting the encrypted content of each version stored in the encrypted content storage unit 26, and the key data generated by this key generation unit 21 And a decryption unit 23 for decrypting the encrypted content of each version stored in the encrypted content storage unit 26, and each version stored in the encrypted content storage unit 26 prior to decryption. Version check unit 2 for checking each version of the encrypted content of
4 and an output unit 27 that outputs the plaintext content 25 decrypted by the decryption unit 23.

Next, the operation of this embodiment will be described in more detail with reference to FIG.

First, the case of encrypting plaintext contents, that is, non-encrypted video, image, audio, music, text, figure, program and other contents will be described.

When encrypting the plaintext content, the encryption data may be encrypted by the encryption unit 13 using the key data generated by the key generation unit 11 of the center device 10. In this case, the key generation unit 11 Key data is generated as follows.
That is, the original seed key data (S201) is encrypted as the data to be encrypted with the encryption function (S202) described in FEAL (NTT, registered November 14, 1994), which is registered in ISO standard 9979, Generate the first version of the key data. Then, the generated first version key data is further encrypted as the data to be encrypted by the same predetermined encryption function (S202) to generate the second version key data. Similarly, the generated key data is encrypted as the data to be encrypted with the same predetermined encryption function (S202), and the third, fourth and fifth key data of newer versions (upper version) are obtained. To generate. Then, the content of each version is encrypted using the obtained key data of each version.

In this way, the key data Key (n) of version n can be obtained by repeating the encryption by the predetermined encryption function (S202) n times, and the contents of version n can be obtained by this version. It will be encrypted by the key data Key (n) of n.

The encrypted content includes the version number, FD (flexible disk), and CD-R.
OM (compact disc read-only memory),
It is recorded on any recording medium such as HD (hard disk), memory card, punch card, magnetic tape, etc. and provided to the user, or directly provided to the user via the Internet, e-mail, or other communication line, and the user's memory is stored. It is stored on the medium.

Next, the operation of decrypting the content thus encrypted and outputting it as plaintext content will be described.

In order to decrypt the encrypted content, it is necessary to obtain the key data suitable for the content. In the present embodiment, as described above, the key data K of the version n depends on the version of the content.
Since ey (n) is obtained by repeating encryption by a predetermined encryption function (S202) n times,
By obtaining the necessary latest key data Key (N) of version N, the key data Key (n) of each previous version n is individually generated by the key generation unit 21.

That is, when obtaining the necessary key data from the center device 10 using the terminal device 20, first,
The version check unit 24 checks the version of the encrypted content 26, and extracts the latest version N number. And the key data K of this version N
In order to obtain ey (N), the center device 10 is requested to obtain the latest key data Key (N) via the communication unit 22.

The center apparatus 10, which has been requested to obtain the latest key data Key (N), uses the key generation unit 11 to generate the latest key data Key (N) as described above (S2).
03), and transmits this to the terminal device 20 via the communication unit 12.

The terminal unit 20 receives the latest key data Key (N) from the center unit 10 by the communication unit 22 (S204) and outputs it to the key generation unit 21. Key generator 2
1 is decrypted by the decryption function (S205) described in FEAL (NTT, registered November 14, 1994), which is registered in ISO standard 9979, in which the latest received key data Key (N) is predetermined as the data to be decrypted. Key data Key (N-1) of the previous version N-1 is generated.

The generated key data Key (N-1) of the previous version N-1 is input again to the decryption function (S205) as the decrypted data, if necessary, and is input to the previous version of the version N-1. N-2 key data Key (N-2) is generated. The key data Key thus decrypted
Is decoded by the decoding function (S205) several times,
Generate the required version of key material.

Therefore, now, the content of version n is included in the encrypted content 26,
If it is desired to generate the key data necessary for decrypting the content 26, the received latest version N of the key data Key (N) is repeatedly decrypted by N-n times (S205).
Key data Ke of version n required by decrypting with
It is possible to generate y (n) (S20).
6).

When the key generation unit 21 generates the required version n of the key data Key (n) in this manner, the key data Key (n) is supplied to the decryption unit 23, where the generated key data Key (n). ) Is used to decrypt each required version n of encrypted content. Then, the decrypted plaintext content 25 is supplied to the output unit 27, where it is output in each form.

That is, when the content is video, image, audio, music, etc., the electronic data thereof is decoded and output using a display or speaker, and in the case of a computer program, that program is It is output to the platform to be executed, and in the case of sentences, figures, etc., it is output to a display device or the like that operates with an application program suitable for the data format. The output form may be arbitrarily selected by the user.

As described above, according to the present embodiment, the content is encrypted with different key data according to the version of the content, and each key data can be decrypted by the predetermined decryption function. Because
By simply obtaining the latest version of the key data from the center device, it is possible to generate the key data of each previous version on the terminal device side and decrypt the encrypted content of each version, There is an advantage that it is not necessary to obtain the key data of each version from the center device one by one, and the center device does not need to manage the keys of a plurality of versions.

Therefore, according to the present embodiment, it is particularly effective when the versions of contents are updated one after another. For example, as in a communication car navigation device, necessary map data, traffic regulation data, etc. are obtained from the center device when necessary, in large numbers within a certain range, and partially stored in the terminal device. It is very effective when you want to use it again when necessary.

This will be described in more detail below.

Recently, in the communication navigation system,
When you send your current location and destination to the center, the center sends route information from your current location to your destination, as well as map data and traffic regulation data that are necessary to advance that route. It has become known to display on and to guide you to your destination.

By the way, in the case of this type, in order to transmit the map data from the present location to the destination and the traffic regulation data, the map data and the traffic regulation for each area divided into a square of 200 m on a side or 400 m A large number of pieces of data and the like are transmitted in combination from the present location to the destination, and the number of individual delimited map data and traffic regulation data may be very large.

Therefore, it is considered to obtain only the map data and the traffic regulation data that are necessary ahead of the destination for a certain period of time or a certain distance, but even in this case, each A lot of separated map data and traffic regulation data will be obtained.

Since it is desirable that these map data, traffic regulation data, etc., can be used again once they are obtained, they can be stored in a terminal device or a storage medium on the terminal side. However, map data, traffic regulation data, etc. are updated daily with the latest information,
Alternatively, the version is being updated from time to time, and thus the map data and traffic regulation data stored in this manner will include various versions of map data and traffic regulation data.

On the other hand, the map data and the traffic control data thus obtained are often charged, and the map data and the traffic control data stored in the storage medium of the terminal side cannot be easily used by others. Need to be regulated. Therefore, it is conceivable to use key data suitable for the version for these map data and traffic regulation data, and to encrypt these map data and traffic regulation data with the key data.

In such a case, as described above, the number of individually separated map data and traffic regulation data will be very large, and those versions will also be individually separated. When data and traffic regulation data etc. are obtained, there will be multiple different versions, and when decoding these map data and traffic regulation data, etc.
The key data that matches the version is required, and the management of the key data becomes very troublesome.

According to the present embodiment, different key data is used for encryption depending on the version, and the key data can be decrypted by a predetermined decryption function. By encrypting map data, traffic regulation data, etc. with different key data according to each version and decrypting the key data with a predetermined decryption function, only the latest key data can be sent from the center device. All you have to do is generate key data for all previous versions on the terminal side,
It will be possible to easily decrypt and use the map data and traffic regulation data of all versions before that. Therefore, according to the present embodiment, it is not necessary to manage the key data on the side of the center and the terminal side, and the communication time with the center device can be greatly shortened.

The navigation device has a lot of data and information such as road information and traffic stagnation information in addition to map data and traffic regulation data. Therefore,
When there are many types of data and information in this way, the seed key data, encryption function, decryption function, etc. are made different according to the type of each data and information,
If the version is different among them, it is desirable to repeat encryption and decryption as many times as each version.

In the present embodiment, the key generation unit 21 of the terminal device 20 is described as having a decryption function for decryption in advance, but the decryption function is obtained from the center device together with the key data of the latest content. It may be done.

Further, in this embodiment, the decryption function is used only for decryption, and is configured so that it cannot be encrypted even if it is used in reverse. That is, the generated key data is only the key data of the version before the version of the obtained key data, and the key data of the new version after that is not generated. As a result, if you want to use a new version of the content, you must obtain the key data for the new content version and later versions from the center device. Effectively works to prevent the accompanying illegal copying.

[0045]

As described above, according to the present invention, the key data for decrypting the content can be easily generated on the terminal device side, and even if a large amount of key data is required, There is an advantage that it is not necessary to manage the key data, and communication with the center device can be easily performed in a short time.

[Brief description of drawings]

FIG. 1 is a block diagram showing an outline of a content management system according to an embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating a key data generation method used in the content management system according to the embodiment of the present invention.

[Explanation of symbols]

10 Center device 11 Key generator 12 Communications Department 13 Cryptographic Department 14 Plaintext content storage 20 terminal devices 21 Key generator 22 Communication unit 23 Decryptor 24 Version check section 25 Plaintext content storage 26 Encrypted content storage 27 Output section 30 communication network

Claims (7)

[Claims] 1. A content management method for encrypting a content using key data, wherein the encrypted content cannot be decrypted to the original state without using the key data. A content management method configured to obtain the seed key data from the seed key data as encrypted data by repeatedly encrypting the seed key data a number of times corresponding to the version of the content. 2. A content management system including a center device and a terminal device, wherein the center device transmits the requested version of key data to the terminal device based on a request from the terminal device. And a key data generation unit for generating each key data of a required version before the requested version based on the key data transmitted from the center device. And a decryption unit that decrypts the encrypted content of each version based on each of the key data generated in. 3. The key data generation means is configured to repeatedly decrypt the latest version of the key data obtained from the center device a required number of times with a predetermined decryption function to generate the required version of the key data. The content management system according to claim 2, which is characterized in that. 4. A content management device for managing content having a plurality of versions, wherein an encryption unit for encrypting the content with different encryption keys for each version and a single seed key data for the encryption key. A content management device, comprising: an encryption key generation unit that generates by encrypting at least once with a predetermined encryption function. 5. The content management device according to claim 4, wherein the encryption key generation unit is configured to associate the number of times of encryption of the generated encryption key with the version information of the content. . 6. A terminal device for decrypting contents having a plurality of versions, wherein the decryption unit decrypts the contents with different decryption keys for each version, and the decryption key is a single key data in a predetermined decryption. A terminal device, comprising: a decryption key generation unit that generates a decryption key by decrypting it at least once. 7. The decryption key generation unit is configured to associate the number of times the generated decryption key is decrypted with the version information of the content.
The terminal device described.