JP2003008562A - Information processing apparatus and method, program, and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information processing apparatus that prevents unauthorized use of data. SOLUTION: A key storage part 51 of data stores decoding keys by the number of contracted users that are encrypted by a public key of the contracted users. When the user uses data of a non-public part 62, the user uses the private key to decrypt the encrypted decryption key in the key storage part 51 corresponding to the user and uses the decrypted decryption key to decrypt the encrypted data of the non-public part 62. Personal information is written in a label and the label is imbedded to the decrypted data as a watermark. The label imbedded in the data as the watermark is used to locate the source of the data when the data are illegally used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information processing apparatus and method, a program, and a recording medium, and in particular, an information processing apparatus and method, program suitable for use when data is distributed among a plurality of users, And a recording medium.

[0002]

2. Description of the Related Art It has become commonplace for digital data to be distributed over networks such as the Internet or as package media. The distribution of digital data is often encrypted and transmitted / received so that only predetermined users can view it due to the copyright and the like. Also, the digital data is
Since it is possible to create a duplicate product (copy product) whose quality does not deteriorate, copy restrictions are often applied.

[0003]

If there is a restriction on copying, for example, if copying is restricted even once, recording is not possible and the user's convenience is improved. There was a problem that it was damaged. In addition, when the restriction that copying from the second generation onwards is prohibited, copying up to the second generation cannot be prevented, and the copy is virtually free, so there is a problem that unauthorized use cannot be prevented. It was

When distributing digital data via the Internet or the like, it is necessary to store the digital data on the server side, but in case of many accesses or the server goes down, the same data is stored. It is necessary to store multiple data. Such a problem has a problem that the burden on the server side is increased.

The present invention has been made in view of such a situation, and an object thereof is to prevent unauthorized use by providing a portion for holding a plurality of keys and treating the portion as a part of data.

[0006]

A first information processing apparatus according to the present invention includes a management unit that manages encrypted data and a first key used for decrypting the data, and another device. Receiving means for receiving the second key, encrypting means for encrypting the first key with the second key received by the receiving means, first key encrypted by the encrypting means, and managing means And transmitting means for transmitting the data managed by the device to another device.

The receiving means also receives information about the user of the second key, and the encrypting means uses the second key.
The information about the user is also encrypted, and the transmitting means uses the second
The information about the user encrypted by the key of can be transmitted.

It is possible to further include a storage means for storing at least one of the second key and the user information received by the receiving means.

The managing means also manages unencrypted data for recognizing the contents indicated by the encrypted data, and is not encrypted at the time before the receiving means receives the second key. It is possible to further include providing means for providing the data to another device.

A first information processing method according to the present invention includes a management step of managing encrypted data and a first key used for decrypting the data, and a second key from another device. A reception control step of controlling reception, an encryption step of encrypting the first key with the second key of which reception is controlled in the processing of the reception control step, and a first encryption step of encryption in the processing of the encryption step. And a transmission control step of controlling transmission of the data managed by the processing of the management step to another device.

The first program of the present invention manages the encrypted data and the first key used for decrypting the data, and receives the second key from another device. A reception control step for controlling, an encryption step for encrypting the first key with the second key whose reception is controlled by the processing of the reception control step, and a first key encrypted by the processing of the encryption step And a transmission control step of controlling transmission of data managed by the processing of the management step to another device.

A first recording medium of the present invention is characterized by recording the program.

According to another aspect of the present invention, there is provided a second information processing apparatus, wherein the transmitting means transmits the user's first key to another apparatus and the second key encrypted by the first key transmitted by the transmitting means.
Associated with the encrypted data, the receiving key for receiving the data encrypted by the second key, and the second key encrypted by the first key received by the receiving unit. The embedding means for embedding as data and the first embedding as data accompanying the data by the embedding means
And a decryption means for decrypting the data by using the decrypted second key.

The sending means also sends information about the user, the receiving means also receives information about the user encrypted by the first key, and the embedding means includes information about the user and data accompanying the data. And the decoding means also decodes information about the user, which is incorporated as data accompanying the data, and the information about the user decoded by the decoding means is watermarked in the data decoded by the decoding means. It is possible to further include a mixing means for mixing as.

A second information processing method of the present invention uses a transmission control step for controlling transmission of a user's first key to another device, and a first key whose transmission is controlled by the processing of the transmission control step. An encrypted second key, a reception control step for controlling the reception of data encrypted by the second key, and a first reception control step by the processing of the reception control step.
The second key encrypted by the key of is embedded as data attached to the encrypted data, and the first key embedded as data attached to the data by the processing of the embedded step is encrypted by the first key. And a decrypting step of decrypting the second key and decrypting the data using the decrypted second key.

The second program of the present invention encrypts the transmission control step for controlling the transmission of the user's first key to another device, and the first key whose transmission is controlled by the processing of the transmission control step. The second key encrypted, the reception control step for controlling the reception of the data encrypted by the second key, and the second key encrypted by the first key whose reception is controlled by the processing of the reception control step. An embedding step of embedding the key of as a data attached to the encrypted data,
A decryption step of decrypting a second key encrypted by the first key incorporated as data accompanying the data in the process of the incorporating step, and decrypting the data using the decrypted second key. To run.

A second recording medium of the present invention is characterized by recording the program.

A first information processing apparatus and method of the present invention,
And in the program, encrypted data,
The first key used to decrypt the data is managed,
The first key is encrypted by a second key from another device,
The encrypted first key and the managed data are transmitted to another device.

A second information processing apparatus and method of the present invention,
Also, in the program, the user's first key is transmitted to another device, and the second key encrypted by the first key and the data encrypted by the second key are received. , The second key encrypted by the received first key is incorporated as data attached to the encrypted data, and the second key encrypted by the first key incorporated as data attached to the data The second key is decrypted and the decrypted second key is used to decrypt the data.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the configuration of an embodiment of an information processing system to which the present invention is applied. The servers 1-1 to 1-M are connected to each other by a network 3 typified by the Internet so as to exchange data with personal computers (hereinafter abbreviated as PC) 2-1 to 2-N. There is.

In the following description, the servers 1-1 to 1
-If M does not need to be individually distinguished, simply server 1
Write. The PCs 2-1 to 2-N are also described in the same manner.

FIG. 2 is a diagram showing an internal configuration example of the server 1. CPU (Central Processing Unit) 1 of server 1
1 executes various processes according to a program stored in a ROM (Read Only Memory) 12. RAM
The (Random Access Memory) 13 appropriately stores data and programs necessary for the CPU 11 to execute various processes. The input / output interface 15 is
An input unit 16 including a keyboard and a mouse is connected, and a signal input to the input unit 16 is output to the CPU 11. Further, the input / output interface 15 is also connected to an output unit 17 including a display and a speaker.

Further, the input / output interface 15 includes
A storage unit 18 including a hard disk and a communication unit 19 for exchanging data with the PC 2 via the network 3 are also connected. The drive 20 includes a magnetic disk 31, an optical disk 32, a magneto-optical disk 33,
It is used when reading data from or writing data to a recording medium such as the semiconductor memory 34.

Since the PC 2 basically has the same internal structure, its explanation is omitted.

Next, data exchanged between the server 1 and the PC 2 in the system shown in FIG. 1 will be described. FIG. 3 is a diagram showing a structure of data to be exchanged.
The data includes a key holding unit 51 and a data unit 52. The data section 52 includes a public section 61 and a non-public section 62.

The public part 61 of the data part 52 is the private part 6
Data having an advertising meaning, which informs the contents of the second data, is recorded. For example, the private section 62
If the data of is the data of the specified software,
The data of the public section 61 is the trial version of the software, and when the data of the non-public section 62 is the music data, the data of the public section 61 is the data of the intro part. Further, when the data of the non-public part 62 is data of a movie or the like, the data of the public part 61 is data of a trailer or the like.

As described above, the data of the publishing unit 61 is
Since it is meant to advertise the data of the non-disclosure section 62, it is not necessarily required to be included in the data section 52, and may be included as necessary.

The data in the public part 61 is not encrypted, but the data in the private part 62 is encrypted, and the encryption is decrypted by using the decryption key held in the key holding part 51. To be done. The key holding unit 51 can hold a plurality of 1 to n keys. Key holding unit 51
Each of the plurality of keys held in is composed of a decryption key and a label.

As described above, the decryption key is stored in the secret section 62.
It is a key to decrypt the data encryption of. This decryption key is
Different decryption keys may be associated with different pieces of data in the secret section 62, and the data handled by the server 1 is
The same decryption key may be associated even with the data of different secret sections 62. The label is information that identifies the owner of the public key that encrypts the decryption key, and is, for example, a name or a credit card number. Further, the label may also include the ID and the number associated with the information.

The decryption key and the label are encrypted by the public key used by the public key encryption system of the encryption system, for example. The data of a plurality of keys in which the decryption key and the label are encrypted by the public key are held in the key holding unit 51.

The data is stored in the storage unit 18 of the server 1 (FIG. 2).
In this case, the data may be stored as one data with the data structure as shown in FIG. 3, and the key holding unit 51, the public unit 52, and the private unit 62 respectively have file names. Alternatively, they may be associated with each other by an ID or the like and stored separately. When they are stored separately, they are delivered in the data structure as shown in FIG. 3 when delivered via the network 3.

Next, transfer of data having the data structure shown in FIG. 3 will be described with reference to the flowchart of FIG. In step S1, the server 1 delivers the data having the data structure shown in FIG. Here, the server 1 is a server having the right to permit the use of data. The data distributed by this distribution is sent to the PC via the network 3 in step S11.
2 is received. The PC 2 stores the received data in a storage unit (not shown).

Of the data received in step S11, the data in the public section 61 is not encrypted, so that it is possible to browse without the need for a key, etc., and refer to the data in the public section 61. When the user decides to purchase the browsed data (content), the public key is transmitted to the server 1 in step S11.

Therefore, the user (PC2) needs to obtain the public key and the secret key for using the encryption method based on the public key encryption method in advance. Here, any public key cryptosystem may be used for encryption, and the present invention can be implemented using any cryptosystem other than the public key cryptosystem.

The data distributed in step S1 has a data structure as shown in FIG. 3, but the key holding unit 51 is in a state where no key is held yet. Since the key is not held in the key holding unit 51, the encryption of the data in the private unit 62 cannot be decrypted. As a result, the PC 2 side stores the received data in the storage unit (not shown) in the PC 2. Even if the data is stored in, the data cannot be used (decrypted), and it is possible to prevent unauthorized use.

When the public key data is transmitted from the PC 2 to the server 1 in step S12 and the public key data is received by the server 1 in step S2,
In step S3, the server 1 encrypts the decryption key. When the public key is transmitted from the PC 2, the purchaser's information, for example, the information such as the name and the credit card number, which is the data of the label described above, is also transmitted. The credit card number is transmitted because it is used for payment of data purchase cost (usage charge).

On the server 1 side, the public key and label data from the PC 2 are stored and managed. Personal information is described in the label, and by managing this label,
It is possible to manage a user (user) who is given the right to use data.

The decryption key is a key used to decrypt the encryption of the secret section 62, and the decryption key is encrypted by the received public key. The label described above is also encrypted with the public key and transmitted together. The decryption key encrypted by the public key is sent to the PC in step S4.
Sent to 2.

In step S13, the PC 2 receives the decryption key encrypted with the public key transmitted from the server 1, and receives the decryption key and the label received in step S1.
In step 4, processing for holding the data stored in the storage unit in the key holding unit 51 is performed. By holding the decryption key in the key holding unit 51, in step S15, the decryption key is used to decrypt the secret unit 62, and the data of the secret unit 62 can be used.

The processing of steps S1 to S4 and steps S11 to S14 will be further described with reference to FIG. The server 1 uses the key holding unit 5 in step S1.
The data in the state where the key is not held is distributed to 1, and the PC 2 receives the data. The PC 2 reproduces the data of the disclosure unit 61 out of the received data.

By the information (video, audio, etc.) provided by the reproduced data of the publicizing unit 61, the user can
When you decide to purchase, the input screen of the specified form will be displayed on your PC.
The data displayed on the display 2 (not shown) and input to the input screen is transmitted as label data. At this time, the public key data is also transmitted.

On the server 1 side, the decryption key and the label are encrypted using the received public key. The decryption key is held on the server 1 side. The encrypted decryption key and label are transmitted to the PC 2 and received. The received decryption key and label pair is incorporated (held) in the key holding unit 51.

With reference to FIG. 6, a process performed when the decryption key and the label are held in the key holding unit 51 and the data stored in the storage unit of the PC 2 is used (step S15).
Processing) will be described. The data stored in the storage unit is first separated into the key holding unit 51 and the data unit 52. The data part 52 of the separated data is further separated into a public part 61 and a private part 62. The data of the publicized part 61 of the separated data part 52 is ready to be used as it is, and is therefore reproduced as necessary.

In order to use the data of the secret section 62, a decryption key is necessary. The decryption key is held in the key holding unit 51 separated from the data unit 52. Key holding unit 51
Since the decryption key held in is encrypted with the public key, it can be decrypted with the private key of the user who purchased this data. When the decryption key is decrypted, the label is also decrypted together. The decrypted decryption key is used for decryption by the secret section 62.

The decrypted label is incorporated into the decrypted secret data 62 as a watermark. As described above, by incorporating the decrypted data of the private section 62, that is, the label in which the personal information is written into the usable data as a watermark, the data of the private section 62 is illegally used. In some cases, the source of the data can be examined by reading the embedded watermark label.

In this way, the source of the data can be checked even if the data is illegally used. The watermark is a technique of embedding in data so that a user who uses the data cannot recognize that the data contains a label. In the present invention, what kind of method is used? May be used.

The data of the public section 61 is the same as the non-public section 6
In the case where it constitutes a part of the data of No. 2, the process of incorporating the data of the disclosure unit 61 is performed after the non-disclosure unit 62 is decrypted, and the data of the disclosure unit 61 is incorporated into the data. The label is incorporated as a watermark. Further, in the case where the public section 61 does not constitute a part of the data of the private section 62, since it is not necessary after the purchase, the data stored on the PC 2 side is the public section 6
1 may be deleted.

As described above, when the data of the secret section 62 is used, the private key of the individual is used to perform the decryption process of the encryption applied to the decryption key. The key holding unit 51 can hold a plurality of decryption keys encrypted with different public keys. Only the private key corresponding to those public keys can break the encryption.

When a plurality of users use one piece of data on one PC 2, each user has a private key. Therefore, the decryption key encrypted with the private key corresponding to the private key for each user is It is necessary to hold the key holding unit 51. To store a plurality of decryption keys in the key holding unit 51, the server 1
On the side, the processing of steps S2 to S4 of the flowchart shown in FIG. 4 is performed, and on the PC2 side, steps S12 to S4 are performed.
It is necessary to repeat the processing of 14 for each of the keys to be held in the key holding unit 51. Repeating these processes a plurality of times means that the charging process is performed every time the processes are repeated, so that the usage fee can be collected without fail.

When it is desired to hold a plurality of decryption keys in the key holding unit 51 in order to use one PC 2 for a plurality of users as described above, step S1
In the process of 2, the plurality of public keys may be transmitted, and the information of the plurality of labels may be transmitted together.

When attention is paid to one user A, since the user A has only one public key and one private key, even if data is copied to a plurality of computers, the data is used for each computer. It is possible to

That is, by applying the present invention,
Since identification is performed not for each machine but for each user (personal authentication), when one data is used in one computer, only the user who contracts and holds the decryption key in the key holding unit 51, The data cannot be used and the computer can be used, but other users who do not have a contract cannot use the data.

Further, even if the data itself is illegally copied, the decryption key held in the key holding unit 51 cannot be read out. As a result, copying can be done but it cannot be used. . However, a user who contracts and holds the decryption key in the key holding unit 51 is
Even if it is copied to another computer a plurality of times, the copied data can be used for each computer.

If the secret key is, for example, a fingerprint, a voiceprint, an iris, or the like that is used as a key, then the above-described processing for personal authentication is surely performed (more reliable). It is possible to perform certain authentication).

In the above description of the embodiment, the server 1 is the data distribution source and the PC 2 is the reception side. However, instead of the PC 2, the server 1 other than the data distribution source is the reception side. The server 1 can be used as a distribution source. Such a case will be described below. The server 1-1 is a distribution source having the right to give a permission to use data, the server 1-2 is a data receiving side and a distribution source having no right to give a permission to use the data, and the PC 2 is a receiving side. The operation will be described with reference to the flowchart of FIG.

Step S performed in the server 1-1
The processing of 31 to S34 is the same as the processing of steps S1 to S4 performed in the server 1 of the flowchart of FIG. In addition, the processes of steps S41 to S44 performed by the server 1-2 are steps S11 to S1 performed by the PC 2 of the flowchart of FIG.
This is the same as the processing of 4.

If the server 1-2 does not directly use the data (if there is no decryption), the steps S41 to S44 can be omitted. That is, the server 1-2 is the server 1-
1, the data itself is supplied and the distribution is performed in step S45, but the server 1-2 does not use the data (the user of the server 1-2 can view the data supplied from the server 1-1, If it is not used), it is not necessary to perform the process related to the contract with the server 1-1 in steps S41 to S44, and the process can be omitted.

That is, the processing performed by the server 1-1 and the server 1-2 is the same as the processing performed by the server 1 and the PC 2 in the flowchart of FIG.
This is because the server 1-1 is the data distributor and the server 1-2 is the data receiving side, and the relationship is the same as the relationship between the server 1 and the PC 2 in FIG.

Here, the server 1-1 is, for example, a server operated by a company that distributes music contents, and charges the download of the contents by the user, and the server 1-2, For example, it is assumed that the server is a server of a company that operates a home page on which music hit charts are posted.

The server 1-2 operates a home page that publishes a music hit chart, and a button associated with the data downloaded from the server 1-1 is provided on the hit chart. The button is, for example, a preview button or a download button. By providing such a button on the homepage,
The server 1-2 delivers the data downloaded from the server 1-1 in step S45.

The data distributed in step S45 has a data structure as shown in FIG. 3. In this case, the decryption key encrypted by the public key of the server 1-2 is the key holding unit. This is the data stored in 51.

When the user of the PC 2 browses the home page operated by the server 1-2 and operates the button associated with the data downloaded from the server 1-1, which is provided on the home page, the above-mentioned operation is performed. As described above, the data in which the key holding unit 51 holds the decryption key encrypted with the public key of the server 1-2 is downloaded and stored in the PC 2 in step S51. PC
The user of No. 2 is different from the user of Server 1-2,
The private key is different, and the decryption key encrypted with the public key of the server 1-2 held in the key holding unit 51 cannot be decrypted, resulting in unauthorized use of data and server 1-
It is possible to prevent the leakage of information related to the second privacy.

After that, when the user decides to purchase the downloaded data, in step S52,
Information serving as a public key and a label is transmitted to the server 1-1. The processes of steps S35 to S37 performed by the server 1-1 are the same as the processes of steps S2 to S4 performed by the server 1 in the flowchart of FIG. Also, step S52 performed in the PC2.
The processing of steps S55 to S55 is the same as the processing of steps S12 to S15 performed by the PC 2 in the flowchart of FIG.

That is, the processing performed by the server 1-1 and the PC 2 is the same as the processing performed by the server 1 and the PC 2 in the flowchart of FIG. As described above, the process related to the key, that is, the process of transmitting the public key in the PC 2 and the process of encrypting the decryption key in the server 1-1 is always performed by the server 1-which is the original distributor of the data. 1, in other words, the server 1-1 that has the right to give permission to use the data does not, and the server 1-2 that is the secondary distribution source does not.

By doing so, it becomes possible to grasp all users who use the data in the server 1-1 having the right to the data. Therefore, it is possible to reliably perform the charging process.

As described above, the server 1-2 other than the server 1-1, which is the distributor having the right to use the data.
To enable the distribution of data,
In addition, the processing related to the decryption key for making the data available (billing processing) is performed by the server 1-1, so that even if the server 1-1 does not hold a plurality of the same data, The other servers 1-2 are in a state of holding the same data, and substantially the same data are in a state of being held by a plurality of servers 1.

This makes it possible to efficiently use the capacity of the storage unit 18 (FIG. 2) of the server 1-1,
On the user side, data can be obtained from a plurality of servers 1, and as a result, it is possible to improve the efficiency of data advertising. If the advertising efficiency is improved, it can be expected that the charge for using the data will increase.

In the above-mentioned embodiment, it is explained that data is transmitted and received via the network 3, but
Data may be exchanged using a network other than the network 3. For example, data may be distributed via a broadcasting network, a CD (Compact Disk) or a DVD (Digital Versatile).
Data may be distributed by recording the data on a recording medium such as a disk and distributing the data. in this way,
When one data is distributed (distributed) by different methods, the same decryption key may be used for the same data, or the same data may be decrypted differently by different distribution methods. You may make it use a key.

When data is distributed using such a recording medium, the recording medium is a ROM (Read Only Memory).
When the type is y), the user's PC 2 that has acquired the recording medium cannot newly install the key in the key holding unit 51 (it cannot be written in the recording medium).
By providing and managing the key holding unit 51 on the C2 side, the above-described processing can be performed.

The present invention can also be applied to a case where the viewing right of a broadcast is given. For example, if you make a contract to give the viewing right of the broadcast every month,
The broadcasting station changes the decryption key every month. A viewer who wishes to view makes a contract by transmitting the public key to the broadcasting station side. At that time, the viewing fee for the broadcast is also paid. As a result, the viewer side can watch the program of the desired broadcast only during the contract period.

On the broadcasting station side, it is only necessary to broadcast the program with the keys for the contracted viewers held in the key holding unit 51, so special processing such as transmission to each contracted viewer is required. Does not have to be done.

On the broadcast station side, the keys for the subscribed viewers may be held in the key holding unit 51, but may not be held. If you keep the key for the viewer,
If the number of subscribers increases, the amount of key data alone will be enormous and various failures may occur. In consideration of such a case, it may not be held.

When the data is not held in such a manner, the broadcasting station side transmits only the encrypted data. Of course, the non-encryption unit may be included. On the viewer side, if the key is obtained and stored in advance by some method, the received encrypted data can be decrypted.

Of course, the present invention can be applied to a case where a right to view a predetermined program is given in addition to a case where the right to view is given for a certain period.

As described above, when the data is decrypted on the PC 2 side and made available, a label as personal information is incorporated as a watermark in the data to give permission to use the data, for example. When the server 1-1 having the right recognizes the fact that the data is distributed by the server 1 or the like which has not given the permission of the use right, the label incorporated in the distributed data is checked. This makes it possible to identify an individual who is illegally using the data. If the individual can be identified, it is possible to prevent the expansion of unauthorized use of data.

The series of processes described above can be executed by hardware, but can also be executed by software. When a series of processes is executed by software, it is possible to execute various functions by installing a computer in which the programs that make up the software are built into dedicated hardware, or by installing various programs. The recording medium is installed in a general-purpose personal computer, for example.

The recording medium is a server 1 as shown in FIG.
A magnetic disk 1 (including a flexible disk) on which a program is recorded, which is distributed in order to provide the program to a user separately from the PC 2 and the PC 2, and an optical disk 32.
(CD-ROM (Compact Disk-Read Only Memory), DVD (Di
gital Versatile Disk)), magneto-optical disk 33
In addition to being configured by a package medium (including MD (Mini-Disc) (registered trademark)) or a semiconductor memory 34, a program stored in a computer and provided to a user is stored. The ROM 12 and the hard disk including the storage unit 18 are included.

In the present specification, the steps for describing the program provided by the medium are not limited to the processing performed in time series, but may be performed in parallel according to the order described. Alternatively, it also includes processes that are individually executed.

In this specification, the system means
It represents the entire apparatus composed of a plurality of devices.

[0080]

As described above, according to the first information processing apparatus and method, and the program of the present invention, the encrypted data and the first key used when decrypting the data are managed, and the like. Since the first key is encrypted with the second key from the device of the above, and the encrypted first key and the managed data are transmitted to the other device, it is possible for multiple users to Even in the case of sharing one data, it is possible to give each user the right to use the data.

A second information processing apparatus and method of the present invention,
According to the program, the user's first key is transmitted to another device, and the second key encrypted by the first key and the data encrypted by the second key are received. Then, the second key encrypted by the received first key is incorporated as data associated with the encrypted data, and the second key encrypted by the first key incorporated as data associated with the data is encrypted. Since the second key is decrypted and the decrypted second key is used to decrypt the data, even if one data is shared by a plurality of users, the data can be decrypted for each user. It becomes possible to give the right to use.

[Brief description of drawings]

FIG. 1 is a diagram showing the configuration of an embodiment of an information processing system to which the present invention has been applied.

FIG. 2 is a diagram illustrating an internal configuration example of a server 1.

FIG. 3 is a diagram illustrating a data structure.

FIG. 4 is a flowchart illustrating data transfer.

FIG. 5 is a diagram illustrating a method of processing a key.

FIG. 6 is a diagram illustrating a process performed when using data.

FIG. 7 is a flowchart illustrating data transfer.

[Explanation of symbols]

1 server, 2 PCs, 3 networks, 11
CPU, 12 RPM, 13 RAM, 14
Bus, 15 input / output interface, 16 input unit, 17 output unit, 18 storage unit, 19 communication unit, 20 drive, 51 key holding unit, 52 data unit, 61 public unit, 62 private unit

Claims (12)

[Claims] 1. A management unit that manages encrypted data and a first key used when decrypting the data, a receiving unit that receives a second key from another device, and the receiving unit. An encryption unit that encrypts the first key with the second key received by the first key; and the first key encrypted by the encryption unit and the data managed by the management unit. An information processing apparatus comprising: a transmitting unit that transmits to the other apparatus. 2. The receiving means also receives information about the user of the second key, the encrypting means also encrypts information about the user with the second key, and the transmitting means comprises: The information processing apparatus according to claim 1, wherein the information about the user encrypted by the second key is also transmitted. 3. The second signal received by the receiving means.
The information processing apparatus according to claim 2, further comprising a storage unit that stores at least one of the key and the information about the user. 4. The management unit also manages unencrypted data for recognizing the content indicated by the encrypted data, and at the time before the reception unit receives the second key, The information processing apparatus according to claim 1, further comprising a providing unit that provides the unencrypted data to the other device. 5. A management step of managing the encrypted data and a first key used when decrypting the data, and a reception control step of controlling reception of the second key from another device. An encryption step of encrypting the first key with the second key whose reception is controlled by the process of the reception control step; and the first key encrypted by the process of the encryption step. And a transmission control step of controlling transmission of the data managed in the processing of the management step to the other device. 6. A management step of managing encrypted data and a first key used when decrypting the data, and a reception control step of controlling reception of the second key from another device. An encryption step of encrypting the first key with the second key whose reception is controlled by the process of the reception control step; and the first key encrypted by the process of the encryption step. And a transmission control step of controlling transmission of the data managed by the processing of the management step to the other device. 7. A recording medium on which the program according to claim 6 is recorded. 8. A transmitting means for transmitting the user's first key to another device, a second key encrypted by the first key transmitted by the transmitting means, and the second key. A receiving means for receiving the data encrypted by the key and a second key encrypted by the first key received by the receiving means are incorporated as data accompanying the encrypted data. An embedding means, and decrypting the second key encrypted by the first key incorporated as data accompanying the data by the embedding means, and decrypting the data by using the decrypted second key. An information processing device, comprising: a decoding unit for decoding. 9. The transmitting means also transmits information regarding the user, the receiving means also receives information regarding the user encrypted by the first key, and the embedding means includes information regarding the user. Is also incorporated as data associated with the data, and the decryption unit also decrypts information about the user incorporated as data associated with the data, wherein the decryption is performed on the data decrypted by the decryption unit. 9. The information processing apparatus according to claim 8, further comprising a mixing unit that mixes the information about the user decrypted by the unit as a watermark. 10. A transmission control step of controlling transmission of a user's first key to another device, and a second encryption encrypted by the first key whose transmission is controlled in the processing of the transmission control step. A key, a reception control step for controlling reception of data encrypted by the second key, and a second key encrypted by the first key whose reception is controlled by the processing of the reception control step. Is embedded as data associated with the encrypted data, and the second key encrypted by the first key incorporated as data associated with the data in the process of the incorporating step And a decrypting step of decrypting the data using the decrypted second key. 11. A transmission control step for controlling transmission of a user's first key to another device, and a second encryption encrypted by the first key whose transmission is controlled in the processing of the transmission control step. A key, a reception control step for controlling reception of data encrypted by the second key, and a second key encrypted by the first key whose reception is controlled by the processing of the reception control step. Is embedded as data associated with the encrypted data, and the second key encrypted by the first key incorporated as data associated with the data in the process of the incorporating step And a decrypting step of decrypting the data by using the decrypted second key. 12. A recording medium on which the program according to claim 11 is recorded.