JP2002259634A - Information distributing method, information transmitter, information receiver, information transmitting program, information receiving program, recording medium storing information transmitting program and recording medium storing information receiving program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily provide information distribution while securing secrecy. SOLUTION: Decipher information is prepared and transmitted to a reader A and through the reader A to a reader B by enumerating the pair of a reading range identifier for identifying a reading range to permit reading of a voucher to respective readers A and B and a common key for enciphering this reading range and by enciphering the pair while using the public key of each of readers in an information distributing device 100 of a voucher issuer. In the information distributing device 100 of each of readers A and B, the decipher information received respectively is deciphered by using his/her own secret key and a common key for deciphering the reading range permitted to himself/herself is acquired. In the information distributing device 100 of the voucher issuer, the part designated by the reading range identifier is enciphered by the correspondent common key and transmitted to the reader A and through the reader A to the reader B. In the information distributing device 100 of each of readers A and B, the permitted reading range in the voucher received respectively is deciphered by the common key acquired beforehand.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information distribution method for distributing information while ensuring confidentiality, and an information transmission apparatus, an information reception apparatus, an information transmission program, an information reception program, and an information transmission used for the method. The present invention relates to a recording medium storing a program and a recording medium storing an information receiving program.

[0002]

2. Description of the Related Art Conventionally, as a method of distributing information while securing confidentiality via a network, for example, there are a plurality of companies performing electronic commerce, and a company A transmits a slip to a company B and a company C. In this case, the company A, which is the voucher issuer, sends a voucher describing only information that can be shown only to the company B and a voucher describing only information that can be viewed only to the company C. Prepare different slips,
The information was transmitted to companies B and C, which are viewers, respectively.

[0003]

However, such a method has the following problems.

(1) The slip issuer needs to prepare a different slip for each viewer.

[0005] (2) The slip issuer must directly send the slip to each viewer because a slip to be passed to a certain viewer may be peeped through another viewer. .

(3) In order to be able to directly transmit a slip to a viewer, it is necessary that the slip issuer and all viewers are directly connected via a network.

[0007] Further, even when a slip is encrypted using an encryption technique, it is necessary to prepare an encrypted slip for each viewer so that other viewers cannot decrypt the slip.

[0008] The present invention has been made in view of the above, and an object of the present invention is to provide an information distribution method capable of easily realizing information distribution while ensuring confidentiality.

Another object of the present invention is to provide an information transmitting apparatus, an information receiving apparatus, an information transmitting program, an information receiving program, a recording medium storing the information transmitting program, and a recording medium storing the information receiving apparatus used in the above information distribution method. Is to provide.

[0010]

According to a first aspect of the present invention, there is provided an information distribution method for transmitting information described by a structured document from a publisher to a viewer via a network. An information distribution method for distributing to another viewer, wherein a correspondence between a browsing range identifier for identifying a browsing range of information and a browsing person permitted to browse the browsing range by the information transmitting device of the issuer. A process of registering browsing definition information that indicates the browsing range, a process of enumerating a set of the browsing range identifier and a common key for encrypting and decrypting the browsing range, and creating encryption information, A process of listing a pair of a viewing range identifier and a common key for each viewer based on the encrypted information, and creating decryption information by encrypting each pair using a public key of each viewer; Decryption information A process of transmitting the information designated by the browsing range identifier to a corresponding common key based on the encrypted information, and a process of encrypting the information encrypted with the common key. Transmitting the decrypted information from the information transmitting device, and transmitting the decrypted information to its own secret key by the browser's information receiving device. A process of acquiring a browsing range identifier indicating a browsing range permitted to be browsed by the user and a common key, and decrypting the decrypted information received from the information transmitting device to the information receiving device of another browsing device. Transmitting the encrypted information, receiving the encrypted information from the information transmitting apparatus, and decrypting the part of the encrypted information specified by the previously acquired viewing range identifier with the common key. When, Transmitting the encrypted information received from the information transmitting device to the information receiving device of the another viewer, and performing the information receiving device of the viewer by the information receiving device of the another viewer. A process of receiving decryption information from the server, a process of decrypting the received decryption information using its own secret key, and a process of acquiring a browsing range identifier and a common key indicating a browsing range to which the user is permitted to browse. A process of receiving encrypted information from the information receiving device of the viewer, and a process of decrypting, with a common key, a portion specified by the previously acquired browsing range identifier in the encrypted information; Is performed.

According to the present invention, the information transmitting device of the information issuer encrypts the decryption information created based on the browsing definition information and the encryption information with the public key that each viewer discloses.
In the information receiving device of each viewer, by decrypting the encrypted decrypted information with its own private key, by acquiring a common key that can decrypt only the browsing range that is allowed to browse by itself, The information issuer does not need to prepare information on structured documents using the same browsing definition information, encryption information, and decryption information for each viewer.

[0012] In addition, since the information receiving device of each viewer can decode only the browsing range permitted by the user, the confidentiality of the information is ensured, and the information publisher can send the information directly to each viewer. I do not have to send it.

Thus, the information transmitting apparatus of the information issuer and the information receiving apparatuses of all viewers do not need to be directly connected via the network.

[0014] In the information distribution method, when the content of the browsing definition information, the encryption information, and the decryption information is changed and distributed a plurality of times, the information of the issuer is included in the processing. The transmitting device encrypts the portion designated by the viewing range identifier with the corresponding common key based on the encrypted information, and transmits the information encrypted with the common key to the information receiving device of the viewer. And the process of repeatedly executing only the above, the process of receiving the encrypted information from the information transmitting device by the information receiving device of the viewer, and the process of viewing the previously acquired The process of decrypting the part specified by the range identifier with the common key, and the process of transmitting the encrypted information received from the information transmitting device to the information receiving device of another viewer, only repeatedly executed, The process of receiving the encrypted information from the information receiving device of the viewer by the information receiving device of the different viewer, and specifying the browsing range identifier acquired earlier among the encrypted information. It is characterized in that only the process of decrypting the part with the common key and only the process are repeated.

According to the present invention, processing such as registration of browsing definition information, creation of encryption information, creation of decryption information, encryption and transmission in the information transmitting apparatus, and reception and decryption of decryption information in the information receiving apparatus are performed. The processing is executed only once at the beginning, thereby speeding up the processing.

In this information distribution method, an information distribution device is constituted by the information transmission device of the issuer and the information reception device of the viewer, and the information distribution device is composed of the issuer, the viewer, and the different browsing device. It is characterized by being used for each person.

According to a second aspect of the present invention, there is provided an information transmitting apparatus for transmitting information described in a structured document from a publisher to another viewer via a network via a viewer. An information transmitting device, wherein: a browsing definition information registration unit for registering browsing definition information indicating a corresponding relationship between a browsing range identifier for identifying a browsing range of information and a viewer permitted to browse the browsing range; Encryption information creating means for creating encryption information by enumerating a set of an identifier and a common key for encryption / decryption of the viewing range, based on the viewing definition information and the encryption information, A decryption information creating unit that enumerates a pair of a browse range identifier and a common key for each of the browsers and encrypts the decryption information using a public key of each of the browsers, and decrypts the decryption information of the browser. information Decryption information transmitting means for transmitting to the communication apparatus, based on the encryption information, encryption means for encrypting with a corresponding common key portion viewing range identifier specifies,
Information transmitting means for transmitting the information encrypted by the encrypting means to the information receiving device of the viewer.

According to a third aspect of the present invention, there is provided an information receiving apparatus for transmitting information described by a structured document from a publisher to another viewer via a network via a viewer. An information receiving device, comprising: a decryption information receiving means for receiving decryption information transmitted by the information transmitting device of the second invention; and a decryption device that decrypts the received decryption information using its own secret key. Acquiring means for acquiring a browsing range identifier indicating a browsing range permitted for browsing and a common key, and decryption information transmitting means for transmitting the decryption information received by the decryption information receiving means to the information receiving device of another viewer And information receiving means for receiving the encrypted information transmitted by the information transmitting apparatus of the second aspect of the present invention, and a portion of the encrypted information designated by the previously acquired browsing range identifier. Decoding means for decoding in, and having a information transmitting means for transmitting to said another viewer information receiving apparatus the encrypted information received by the information receiving means.

According to a fourth aspect of the present invention, there is provided an information receiving apparatus according to the first aspect, wherein the information described by the structured document is distributed from the publisher to another viewer via the network via the viewer. Information receiving device for receiving the decrypted information transmitted by the information receiving device of the third aspect of the present invention, and decrypting the received decrypted information using its own secret key, Acquiring means for acquiring a browsing range identifier indicating a browsing range to which the user is permitted to browse and a common key; and information receiving means for receiving encrypted information transmitted by the information receiving apparatus of the third invention. And decrypting means for decrypting, with a common key, a portion designated by the previously acquired browsing range identifier in the encrypted information.

A fifth information transmission program according to the present invention is an information transmission program for distributing information described by a structured document from a publisher to another viewer via a network via a viewer. Processing for registering browsing definition information indicating a browsing range identifier for identifying a browsing range of information and a browsing permitting a browsing person permitted to browse the browsing range for the computer system of the issuer;
A process of enumerating a set of the browsing range identifier and a common key for encrypting and decrypting the browsing range to create encryption information; and performing browsing based on the browsing definition information and the encryption information. A process of listing decryption information and a set of a common key for each user, creating decryption information by encrypting each using the public key of each browser, and transmitting the decryption information to the browser. Executing a process of encrypting a portion specified by a viewing range identifier with a corresponding common key based on the encrypted information, and a process of transmitting information encrypted with the common key to the viewer. It is characterized by the following.

[0021] The information transmission program, when changing the content of information common to the browsing definition information, the encryption information, and the decryption information and distributing the information a plurality of times, transmits the encrypted information to the encrypted information. A process of encrypting a portion specified by the browsing range identifier with a corresponding common key based on the
Only the process of transmitting the information encrypted with the common key to the viewer is repeatedly performed.

A sixth information receiving program according to the present invention is an information receiving program for distributing information described by a structured document from a publisher to another viewer via a network via a viewer. The processing of receiving the decrypted information transmitted by the information transmitting program of the fifth aspect of the present invention with respect to the computer system of the viewer, and decrypting the received decrypted information using its own secret key. A process of acquiring a browsing range identifier indicating a browsing range to which the user is permitted to browse and a common key; a process of transmitting the received decrypted information to another browsing person; A process of receiving the transmitted encrypted information, a process of decrypting a portion of the encrypted information specified by the previously acquired browsing range identifier with a common key, Characterized in that to execute a process of transmitting the encrypted information to another viewer, the.

[0023] The information receiving program, when changing the content of the information common to the browsing definition information, the encryption information, and the decryption information and distributing the information a plurality of times, executes the information transmission program in the processing. A process of receiving the transmitted encrypted information, a process of decrypting a portion of the encrypted information specified by the previously acquired browsing range identifier with a common key, and a process of receiving the encrypted information. Is transmitted to another viewer, and only the process is repeatedly executed.

A seventh information receiving program according to the present invention is an information receiving program for distributing information described by a structured document from a publisher to another viewer via a network via a viewer. Receiving the decrypted information transmitted by the information receiving program of the sixth invention to the computer system of another viewer, and decrypting the received decrypted information using its own secret key; Thereby, a process of acquiring a browsing range identifier indicating a browsing range to which the user is permitted to browse and a common key, a process of receiving encrypted information transmitted by the information receiving program of the sixth invention, and And decrypting, with a common key, a portion specified by the previously acquired browsing range identifier in the encrypted information.

[0025] The information receiving program according to the present invention, when changing the contents of the information common to the browsing definition information, the encryption information, and the decryption information and distributing the information a plurality of times, includes Only the process of receiving the transmitted encrypted information and the process of decrypting the part of the encrypted information specified by the previously acquired viewing range identifier with the common key are repeatedly executed. Features.

According to the fifth, sixth and seventh aspects of the present invention, an information transmitting program for executing the present information transmitting method or an information receiving program for executing the present information receiving method is provided via a network or the like. By installing it in a computer system, the computer system can function as an information transmitting device or an information receiving device that executes the present method.

According to an eighth aspect of the present invention, there is provided a computer-readable recording medium storing the information transmission program according to the fifth aspect of the present invention.

A ninth aspect of the present invention is a computer readable recording medium storing the information receiving program of the sixth aspect of the present invention.

A tenth aspect of the present invention is a computer-readable recording medium storing the information receiving program of the seventh aspect of the present invention.

In the eighth, ninth and tenth aspects of the present invention,
Insert a recording medium storing an information transmission program for executing the present information transmission method or a recording medium storing an information reception program for executing the present information reception method into a predetermined slot of a computer system and install the same. This allows the computer system to function as an information transmitting device or an information receiving device that executes the present method.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present information distribution method focuses on the concept of a copy-type slip in order to ensure the confidentiality of information exchanged between companies in electronic commerce (hereinafter referred to as a "slip"). is there. A copy-type slip can be created so that information including a plurality of slips is made different by a single entry, and the disclosure range of information is regulated by passing each slip to a different viewer.

In this information distribution method, the issuer of the slip is
By defining in advance the part that allows individual viewers to view one slip, even if the slip is transmitted in a bucket brigade manner between multiple viewers when the slip is transmitted, the part defined for each viewer It is intended to be viewed only.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing the overall configuration of a system to which the information distribution method according to one embodiment is applied. The system shown in the figure is an information distribution device 100 for realizing information distribution.
, A site 200 for forming an information distribution channel, and a business application 4 that enables creation and browsing of information
00 is located in each company, and each site 200
Is a configuration connected via the network 300.

FIG. 2 is a functional block diagram showing the configuration of the information distribution apparatus 100. The information distribution device 100 includes a receiving unit 1 that receives information from the information distribution device 100 at another site.
01 and a decryption unit 102 for decrypting the encrypted information
A storage unit 103 for storing information, an encryption unit 104 for encrypting information, a transmission unit 105 for transmitting information to the information distribution apparatus 100 of another site, and control information used for encryption and decryption. The control information dictionary 106 to be registered and each unit 10
And a control unit 107 that controls the operations of 1 to 105.

The information distribution device 100 includes an information transmitting device and an information receiving device. The information transmission device has an encryption unit 104, a transmission unit 105, and the like as main units, and the information reception device has a decryption unit 102, a reception unit 101, and the like as main units.

The information distribution apparatus 100 is configured by a computer system, and the processing of each of the units 101 to 105 is executed by a computer program (information transmission program, information reception program). Of course, the information distribution device may be configured by dedicated hardware.

The computer program may be installed on the information distribution apparatus 100 by downloading it via the network 300,
The recording medium storing the computer program may be installed in the information distribution device 100 by inserting the recording medium into a predetermined slot of the information distribution device 100. Here, the recording medium refers to various recording media capable of recording a program, such as a magnetic disk, an optical disk, a magneto-optical disk, and a semiconductor memory.

In this information distribution method, two types of encryption methods, a common key encryption method and a public key encryption method, are used as information encryption methods.

The common key encryption method is an encryption method in which an encryption key used for encrypting information and a decryption key used for decrypting the encrypted information are the same. The encryption key and the decryption key are hereinafter referred to as a “common key”. This common key encryption method is used for encrypting and decrypting the slip itself.

The public key cryptosystem is a cryptosystem in which an encryption key and a decryption key are different. Each company has its own encryption and decryption keys. The encryption key is called "public key" because it is open to the public and can be easily known by others. On the other hand, the decryption key is called a “secret key” because it is kept secret outside the company and cannot be known by others. If any person encrypts information using the "public key" of a certain company, the encrypted information can only be decrypted with the "secret key", and only the company that has the "secret key" Can be decoded. This public key cryptosystem is used to encrypt and decrypt the "common key".

The control information dictionary 10 of each information distribution device 100
6 is a public key of a public key cryptosystem,
It consists of a secret key of public encryption, browsing definition information, encryption information, and decryption information.

The public key of the public encryption system is a public key obtained from a site to which information is transmitted. Used for encrypting information to be transmitted.

The secret key of the public key cryptosystem is a unique secret key of the own site, and is used for decrypting information encrypted by the public key disclosed to another site.

The browsing definition information is information, which is defined by the voucher issuer, indicating which part of the voucher can be viewed by whom. Here, the slip is described using a structured document. A structured document is a document in which elements such as titles, chapters, paragraphs, and words in the document have a hierarchical structure, unlike ordinary flat documents, and each element can be uniquely identified using an identifier. It is like that. The slip represented by the structured document is composed of information such as date, product name, and price in the slip, and each element can be uniquely specified using an identifier.

The encryption information is information used for encrypting a slip. As shown in FIG. 3, the slip includes the target audience, such as “the range that only the viewer A can view”, “the range that only the viewer B can view”, and the “range that the viewer A and the viewer B can view”. Range according to the difference. Each of the divided ranges is referred to as a “viewing range”. Each “viewing range” is made up of each element of the structured document, and can be uniquely specified from the slip using the “viewing range identifier” as an identifier. The encryption information is information used when individually encrypting the “viewing range” in the voucher. The “viewing range identifier” indicating the “viewing range”, and the encryption and decryption of the “viewing range” are performed. Is a list that enumerates a pair with a “common key” to be used. The encryption information is automatically created using the browsing definition information.

The decryption information designates, for the slip encrypted with the “common key”, a portion that is permitted to be viewed by each viewer, and a “common key” for decrypting the portion.
Is the information used to pass the A list in which a set of a “viewing range identifier” indicating a “viewing range” that can be viewed by a certain viewer and a “common key” used for encrypting the viewing range is referred to as “individual decryption information”. The “individual decryption information” corresponding to each viewer is encrypted using the “public key” of the viewer, resulting in the “encrypted individual decryption information”.
It is. Further, a list listing “encrypted individual decryption information” for all viewers is “decryption information”. This “decryption information” includes browsing definition information, encryption information,
It is automatically created using the "public key" of each viewer.

The decryption unit 102 of the slip transmission destination decrypts the decrypted information using its own “private key”, so that the browse range permitted to browse and the “common” for decrypting the browse range are decrypted. Key ". Then, the "viewing range" where viewing of the encrypted slip is permitted
Can be decrypted using the “common key”.

Next, a processing procedure in the present embodiment will be described with reference to FIGS. As shown in the flowchart of FIG. 4, the processing procedure is divided into three stages: a procedure key setting procedure, decryption information creation and distribution procedure, and a slip creation and distribution. If you want to process the same slip multiple times, perform the procedure from step to step only once,
Thereafter, only the procedure is repeated for each slip.

This procedure shows a case where the slip is distributed among the slip issuer, the viewer A and the viewer B. The voucher creates the voucher, grants permission to view it,
The person who can transmit the slip to the viewer A. The viewer A is a person who can receive a slip from a slip issuer and transmit the slip to the viewer B. The viewer B is a person who can receive the slip from the viewer A.

FIG. 5 is a sequence chart showing a key setting process according to a procedure. The procedure at the site of the slip issuer is procedure A, the procedure at the site of viewer A is procedure B, and the procedure at the site of viewer B is procedure C.

Procedure A-1 Setting of Public Key of Viewer: The slip issuer obtains the “public key” of the public key cryptosystem of the viewer A and the viewer B from each viewer. The control information dictionary 106 of the slip issuer's own site receives and registers the “public key” of each viewer.

Procedure B-1 Setting of Private Key of Own Site:
The viewer A sets the “secret key” of the public key cryptosystem of the own site. Viewer A's own site control information dictionary 106
Receives and registers this "secret key".

Procedure C-1 Setting of Private Key of Own Site:
The viewer B sets the “secret key” of the public key cryptosystem of the own site. Control information dictionary 106 of viewer B's own site
Receives and registers this "secret key".

FIG. 6 is a sequence chart showing the process of creating and distributing decryption information according to the procedure.

First, the following processing is performed at the site of the slip issuer.

Procedure A-1 Setting of browsing definition information: The slip issuer creates a base slip and defines the correspondence between the "viewing range" and the viewers who can view the "viewing range". . Then, the browsing definition information is created by listing the correspondence. Control information dictionary 10 of own site
In step 6, the browsing definition information is registered.

Procedure A-2 Creation of common key in common key cryptosystem: The control unit 107 reads out “browsing definition information” registered in the control information dictionary 106, and reads each “browsing definition information” described in “browsing definition information”. For the “range”, a “common key” of a common key cryptosystem for encrypting and decrypting the “viewing range” is created.

Procedure A-3 Creation of Encrypted Information: The control unit 107 sets the “viewing range” described in the “viewing definition information”.
Of the “encryption information” by enumerating a set of “viewing range identifier” indicating “a” and “common key” created in step A-2.
Create The control information dictionary 106 registers the “encrypted information”.

Procedure A-4 Creation of Decryption Information: Control Unit 1
07 is a description of the “viewing range identifier” indicating the “viewing range” that is permitted to each individual viewer described in the “viewing definition information”, and the “common key” created in step A-2. "Individual decoding information" is created by listing the pairs. Then, the “individual decryption information” for all the viewers is listed together, and each “individual decryption information” is encrypted using the “public key” of the public key encryption method of each individual viewer, thereby obtaining “ "Decryption information" is created. The control information dictionary 106 registers the “decoding information”.

Procedure A-5 Transmission of Decryption Information: Transmitter 1
In step 05, the “decryption information” created in the previous procedure is transmitted to the viewer A.

Subsequently, the following processing is performed on the site of the viewer A.

Procedure B-1 Receiving Decryption Information: Viewer A
Receives the “decryption information” transmitted from the slip issuer in step A-5. The control information dictionary 106 registers this decryption information.

Procedure B-2 Decryption of Decryption Information: Viewer A
The control unit 107 of the site of the control information dictionary 10
The “decryption information” registered in 6 is decrypted using the “private key” of its own site's public key encryption method registered in the control information dictionary 106 with respect to its own “encrypted individual decryption information”. Thereby, "individual decryption information" described for the own site is obtained. That is, it is possible to obtain the “viewing range” permitted to be viewed by the slip issuer and the “common key” for decrypting the “viewing range”. The control information dictionary 106 registers the “individual decryption information”.

Procedure B-3 Transmission of Decoded Information: Transmitter 1
In step 05, the “decryption information” received in step B-1 is transmitted to the viewer B.

Subsequently, the following processing is performed on the site of the viewer B.

Procedure C-1 Reception of Decryption Information: Viewer B
Receives the “decryption information” transmitted from the viewer A in step B-3. Control information dictionary 1
06 registers this decryption information.

Procedure C-2 Decryption of Decryption Information: Viewer B
The control unit 107 of the site performs the same processing as the procedure B-2.

FIG. 7 is a sequence chart showing the process of creating and distributing a slip according to the procedure.

First, the following processing is performed at the site of the slip issuer.

Procedure A-1 Creation of a slip: The slip issuer creates a slip to be transmitted. Own site storage unit 103
Accumulates this slip.

Procedure A-2 Encryption of slip: Encryption section 1
04 reads out “encryption information” registered in the control information dictionary 106 and the slip stored in the storage unit 103, and reads “viewing range identifier” listed in “encryption information” and “common”. Creates an "encrypted slip" by encrypting the element indicated by the "viewing range identifier" of the slip with a "common key" for all "viewing ranges" in the slip using the pair with the "key" I do.

Procedure A-3 Transmission of encrypted slip:
The transmission unit 105 transmits the “encrypted slip” created in the previous procedure to the viewer A.

Subsequently, the following process is performed on the site of the viewer A.

Procedure B-1 Receiving encrypted slip:
The receiving unit 101 of the site of the viewer A receives the “encrypted slip” transmitted from the slip issuer in step A-3.

Procedure B-2 Decryption of Encrypted Slip:
The decryption unit 102 reads out “individual decryption information” registered in the control information dictionary 106, and uses a set of “viewing range identifier” and “common key” listed in “individual decryption information”, The “decrypted slip” is created by decrypting the viewing range in the slip indicated by the “viewing range identifier” with the “common key”. The “decrypted slip” is one in which only the range permitted by the viewer A is readable. Storage unit 1
03 stores the “decrypted slip”.

Procedure B-3 Use of decrypted slip:
The viewer A browses the “decrypted slip” stored in the storage unit 103 using the business application 400.

Procedure B-4 Transmission of encrypted slip:
The transmitting unit 105 transmits the “encrypted slip” received in step B-1 to the viewer B.

Subsequently, the following process is performed on the site of the viewer B.

Procedure C-1 Receiving the encrypted slip:
The receiving unit 101 of the site of the viewer B receives the “encrypted slip” transmitted from the viewer A in step B-4.

Procedure C-2 Decryption of Encrypted Slip:
The decryption unit 102 of the site of the viewer B performs the same process as the procedure B-2.

Procedure C-3 Use of decrypted slip:
The viewer B browses the “decrypted slip” stored in the storage unit 103 using the business application 400.

[Embodiment] An embodiment of the present invention will be described below.
In this embodiment, XML is used as the structured document, XPath is used as the “viewing range identifier”, DES is used as the common key encryption method, and RSA is used as the public key encryption method.

In this embodiment, as shown in FIG.
It is assumed that when transmitting a structured document slip from the company to Braun and Carlos, there are only communication routes from Albert to Braun and from Braun to Carlos.

Here, Albert is a planning company, Braun is a computer manufacturing company, and Carlos is a sales company. Al
Bert wants to allow Braun to view only the information necessary for manufacturing, such as product composition and manufacturing costs, but not other information. On the other hand, there is a request to allow Carlos to view only the information necessary for sales, such as the product configuration and selling price, but not to view other information.

Next, as to the processing procedure in this embodiment, three steps of setting a step key, creating and distributing step decryption information, and creating and distributing a step slip will be described in order.

Step A Setting of Key Step A: Albert's process: Albert obtains the "public key" of Braun and Calros. The control information dictionary 106 of the own site registers these “public keys”.
FIG. 9 shows an example of the registered “public key”.

Step B: Processing of Braun: Braun sets the "secret key" of the public key cryptosystem of its own site. The control information dictionary 106 of the own site stores the “secret key”
Register FIG. 10 shows an example of the registered “secret key” of Braun.

Step C: Processing by Carlos: Calros sets the "secret key" of the public key cryptosystem of its own site. The control information dictionary 106 of the own site stores the “secret key”
Register FIG. 11 shows an example of the registered “secret key” of Calros.

Step Creation and Distribution of Decryption Information Step A Processing of Albert Company Step A-1 Setting of browsing definition information: Albert Corporation
A slip as shown in FIG. 12 is created, and a viewing range shown in FIG. 13 is defined for this slip. FIG. 13 shows three types of “viewing range identifiers”: “/ product / composition / item”, “/ product / production cost”, and “/ product / sales price”. Albert defines the correspondence between the viewing range shown in FIG. 14 and the viewers permitted to view.

The correspondence shown in the figure is that "/ product / composition / item" is permitted to be viewed by both Braun and Calros, and "/ product / production cost" is permitted to be viewed only by Braun. , "/ Product / sales price" for Calr
Only the os company is permitted to browse.

Albert based on this correspondence, FIG.
Then, “view definition information” shown in FIG. 5 is created. Control information dictionary 1
06 registers this “browsing definition information”.

Step A-2 Creation of Common Key in Common Key Cryptography: The control unit 107 of Albert Company encrypts each “viewing range” described in the “viewing definition information” registered in the previous step. Create a “common key” using the DES.

FIG. 16 shows an example of a set of a viewing range identifier and a corresponding “common key”. The common key in the figure is "
/ Commodity / composition / item ”is“ 83 69 838B ”,“ /
The “product / production cost” is “76 8C 5E 83”, and the “/ product / sales price” is “83 7081 5B”.

Step A-3 Creation of Encrypted Information: Al
The control unit 107 of the bert company makes the “encryption information” by associating the “common key” created in the previous step with the “viewing range identifier” of the “browsing definition information” registered in step A-1. create. "Encryption information" created
FIG. 17 shows an example.

Step A-4 Creation of Decryption Information: Albe
The control unit 107 of the rt company enumerates the "common key" and the "viewing range identifier" created in step A-2 based on the "viewing definition information" for each company, thereby obtaining the individual decryption information shown in FIG. Is created, and the individual decryption information is encrypted using the “public key” by the RSA for each company to create the “decryption information” shown in FIG.

Step A-5 Transmission of decryption information: Albe
The transmission unit 105 of the company rt transmits the “decryption information” created in the previous step to the company Braun.

Step B: Processing by Braun Step B-1 Reception of Decryption Information: The receiving unit 101 of Braun receives “decryption information” from Albert.

Step B-2 Decryption of Decryption Information: Brau
The decryption unit 102 of the n company decrypts the part of the “decryption information” encrypted with the “public key” of the company using the “secret key” of the own site RSA registered in the control information dictionary 106 in advance. . As a result, "individual decryption information" shown in FIG. 20, that is, a "viewing range identifier" indicating a "viewing range" permitted to be viewed by Braun and a "common key" for decrypting the viewing range are obtained. The control information dictionary 106 registers the “individual decryption information”.

Step B-3 Transmission of Decoded Information: The transmitting unit 105 converts the “decoded information” received from Albert into Calr.
Send to os.

Step C: Processing by Carlos: The receiving section 101 of Calros receives the "decoded information" from Braun, and the decoding section 102 performs the same processing as in step B-2. FIG. 21 shows “Individual decryption information” of Calros.

Step Creation and Distribution of a Voucher Step A Process of Albert Company Step A-1 Creation of a Voucher: Albert uses the business application 400 to create the voucher shown in FIG.

Step A-2 Slip Encrypt: Albert
Based on the “encryption information” registered in the control information dictionary 106, the encryption unit 104 of the company encrypts the “viewing range” of the slip in FIG. 12 with the corresponding common key. FIG. 22 shows the encrypted slip.

Step A-3 Transmission of the slip: The transmitting section 105 of Albert Co. sends this “encrypted slip” to the Braun.
Send to company.

Step B: Processing by Braun Step B-1 Receiving the encrypted slip: The receiving section 101 of Braun receives the “encrypted slip” transmitted from Albert.

Step B-2 Decryption of Encrypted Voucher: The decryption unit 102 of Braun Inc. obtains all “viewing range identifiers” relating to the browsing of the company obtained in step B-2.
Then, the part of the “encrypted slip” designated by the “viewing range identifier” is decrypted with the “common key” using the pair of The storage unit 103 stores the decrypted slip. FIG.
3 shows a slip partially decrypted by Braun. The “viewing range” permitted only by Calros cannot be decrypted because Braun has not obtained the “common key” for decrypting the “viewing range”.

Step B-3 Use of Decrypted Voucher: Braun browses the voucher stored in the storage unit 103 using the business application 400 and performs necessary business.

Step B-4 Transmission of encrypted slip: The transmission section 105 of Braun sends the “encrypted slip” received from Albert to Calros.

Step C: Processing by Carlos: The receiving section 101 of Calros receives the "encrypted slip" from Braun, and the decrypting section 102 performs the same processing as in step B-2. FIG. 24 shows a slip partially decrypted by Calros.

Therefore, according to the present embodiment, in the information distribution device 100 of the slip issuer, the decryption information created based on the browsing definition information and the encryption information is encrypted with the public key published by each viewer. Information distribution device 100 for each viewer
By decrypting the encrypted decryption information with its own private key, a common key capable of decrypting only the browsing range permitted to browse by itself can be obtained. It is not necessary to prepare a slip that shares the definition information, the encryption information, and the decryption information for each viewer, so that confidentiality can be ensured and information can be easily distributed between companies.

Further, since the information distribution device of each viewer can decrypt only the browsing range permitted by the user, the slip issuer does not need to directly transmit the slip to each viewer, thereby keeping the information secret. It is possible to easily distribute information between companies while ensuring the security.

As a result, it is not necessary for the information distribution device of the slip issuer and the information distribution device of all viewers to be directly connected by a network. It can be done easily.

[Second Embodiment] FIG. 25 is a sequence chart showing another process of creating and distributing a slip.
7 is different from the sequence chart of FIG. 7 in the processing at the site to which the viewer A belongs. In addition, the same processes as those in the sequence chart of FIG. 7 are assigned the same procedure numbers, and the processes at the site to which the publisher belongs and the site to which the viewer B belongs are not described here.

Following the processing at the site to which the issuer belongs in the procedure A, the following processing is performed at the site of the viewer A.

Procedure B'-1 Receiving the encrypted slip: The receiving unit 101 of the site of the viewer A performs the procedure A-3.
To receive the "encrypted slip" sent from the slip issuer.

Procedure B'-2 Decryption of Encrypted Slip: Decryption section 102 reads out "individual decryption information" registered in control information dictionary 106, and reads "individual decryption information".
By using the pair of “viewing range identifier” and “common key” listed in “1. Is created. The “decrypted slip” is one in which only the range permitted by the viewer A is readable. The storage unit 103 stores the “decrypted slip”.

Procedure B'-3 Use of decrypted slip: Viewer A browses the "decrypted slip" stored in storage section 103 using business application 400, and corrects the content. This modification can be made to a portion permitted only to the viewer A and also to a portion commonly permitted to both the viewer A and the viewer B. Storage unit 10
No. 3 stores this "corrected slip".

Procedure B'-4: Encrypting Modified Slip: Encrypting section 104 of site of viewer A stores "individual decryption information" registered in control information dictionary 106 and accumulation section 103. The "corrected slip" is read, and using the set of "viewing range identifier" and "common key" listed in "individual decryption information", for all sets,
A new “encrypted slip” is created by encrypting the element indicated by the “viewing range identifier” with the “common key”.

Procedure B′-5 Transmission of Encrypted Voucher: The transmitting unit 105 transmits the new “encrypted voucher” created in the previous procedure to the viewer B.

Therefore, according to the present embodiment, the viewer A modifies the contents of the slip received from the issuer and views the destination in accordance with the view definition of the issuer. The user B can view the corrected slip.

[0121]

As described above, the information distribution method, the information transmitting device, the information receiving device, the information transmitting program, the information receiving program, the recording medium storing the information transmitting program, and the information receiving program according to the present invention are stored. According to the recording medium, the information issuer does not need to prepare information of a structured document in which the browsing definition information, the encryption information, and the decryption information are common for each of the viewers. Information can be distributed.

Further, since the information receiving device of each viewer can decrypt only the browsing range permitted by itself, the confidentiality of the information is ensured, and the information publisher can send the information directly to each viewer. There is no need to send the information, and information can be easily distributed while securing confidentiality.

As a result, it is not necessary for the information transmitting device of the information issuer and the information receiving devices of all the viewers to be directly connected to each other via a network, so that confidentiality can be ensured and information can be easily distributed. Can be.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an overall configuration of a system to which an information distribution method according to an embodiment is applied.

FIG. 2 is a functional block diagram illustrating a configuration of an information distribution device.

FIG. 3 is a diagram showing an example of a slip.

FIG. 4 is a flowchart showing a schematic processing procedure in the embodiment.

FIG. 5 is a sequence chart showing a key setting process.

FIG. 6 is a sequence chart showing a process of creating and distributing decryption information.

FIG. 7 is a sequence chart showing a process of creating and distributing a slip.

FIG. 8 is a diagram showing a flow of a slip distributed between companies.

FIG. 9 is a diagram showing an example of public keys of Braun and Calros.

FIG. 10 is a diagram illustrating an example of a Braun private key.

FIG. 11 is a diagram showing an example of a private key of Calros.

FIG. 12 is a diagram showing an example of a slip using a structured document.

FIG. 13 is a diagram showing an example of a viewing range in a slip.

FIG. 14 is a diagram illustrating an example of a correspondence relationship between a browsing range and a browsing person permitted to browse.

FIG. 15 is a diagram illustrating an example of browsing definition information.

FIG. 16 is a diagram illustrating an example of a correspondence relationship between a viewing range identifier and a common key.

FIG. 17 is a diagram illustrating an example of “encryption information”.

FIG. 18 is a diagram illustrating an example of a list in which “individual decryption information” is collected for all companies.

FIG. 19 is a diagram illustrating an example of “decryption information”.

FIG. 20 is a diagram illustrating an example of “individual decryption information” of Braun.

FIG. 21 is a diagram showing an example of “individual decryption information” of Calros.

FIG. 22 is a diagram showing an example of a slip encrypted with a common key corresponding to a “viewing range”.

FIG. 23 is a diagram showing an example of a slip partially decrypted by Braun.

FIG. 24 is a diagram showing an example of a slip partially decrypted by Calros.

FIG. 25 is a sequence chart showing another process of creating and distributing a slip.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 information distribution device 101 reception unit 102 decryption unit 103 storage unit 104 encryption unit 105 transmission unit 106 control information dictionary 107 control unit 200 site 300 network 400 business application

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04L 9/00 601E (72) Inventor Nobuyuki Kobayashi 2-3-1 Otemachi, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Telephone Co., Ltd. F term (reference) 5J104 AA16 EA01 EA06 EA19 NA02 PA10

Claims (15)

[Claims] 1. An information distribution method for distributing information described by a structured document from an issuer to another visitor via a network via a network, the information transmitting apparatus of the issuer. By registering a browsing range identifier identifying a browsing range of information and browsing definition information indicating a correspondence relationship with a viewer permitted to browse the browsing range, encrypting the browsing range identifier and the browsing range. A process of enumerating a set of a common key for decryption and creating encryption information; and forming a set of a viewing range identifier and a common key for each viewer based on the viewing definition information and the encryption information. Enumerating, respectively, a process of creating decryption information by encrypting using a public key of each viewer, a process of transmitting the decryption information to an information receiving device of the viewer, and a process based on the encryption information. , Performing a process of encrypting a portion designated by the viewing range identifier with a corresponding common key, and a process of transmitting information encrypted with the common key to the information receiving device of the viewer. A process of receiving decryption information from the information transmitting device by the information receiving device, and a browsing range identifier indicating a browsing range to which the user is permitted to browse by decrypting the received decryption information using its own secret key. A process of acquiring decrypted information received from the information transmitting device to the information receiving device of the other viewer; and a process of receiving encrypted information from the information transmitting device. A process of decrypting, with a common key, a portion designated by the previously acquired browsing range identifier in the encrypted information; and transmitting the encrypted information received from the information transmitting apparatus to the another browser. Emotion Transmitting the decrypted information from the information receiving device of the browsing device to the receiving device of the another browsing device; A process of obtaining a browsing range identifier and a common key indicating a browsing range to which the user is permitted to perform browsing, and a process of receiving encrypted information from the browsing information receiving device. Decrypting, with a common key, a portion specified by the previously acquired browsing range identifier in the encrypted information. 2. In the case where the content of the information that shares the browsing definition information, the encryption information, and the decryption information is changed and distributed a plurality of times, the information transmission device of the issuer in the processing includes: A process of encrypting a portion designated by a viewing range identifier with a corresponding common key based on the encrypted information, a process of transmitting information encrypted with the common key to an information receiving device of the viewer, Is repeated, and the information receiving device of the viewer receives the encrypted information from the information transmitting device, and the browsing range identifier acquired earlier is designated among the encrypted information. And decrypting the encrypted information received from the information transmitting apparatus to the information receiving apparatus of the other viewer. A process of receiving encrypted information from the viewer's information receiving device by the information receiving device of the user, and a portion of the encrypted information designated by the previously obtained browsing range identifier is designated by a common key. 2. The information distribution method according to claim 1, wherein the decryption process and the decryption process are repeatedly performed. 3. An information distribution device is configured by the information transmission device of the issuer and the information reception device of the viewer, and the information distribution device is provided to each of the issuer, the viewer, and the different viewer. 3. The information distribution method according to claim 1, wherein the information distribution method is used. 4. An information transmitting apparatus of an issuer for distributing information described in a structured document from an issuer via a network to another observer via an observer, the information being transmitted by the issuer. Browsing definition information registration means for registering browsing definition information indicating a correspondence between a browsing range identifier for identifying a range and a browsing person permitted to browse the browsing range; encryption / decryption of the browsing range identifier and the browsing range Encryption information creating means for creating encryption information by enumerating a set of common keys for encryption, a browsing range identifier and a common key for each viewer based on the browsing definition information and the encryption information. And decryption information creating means for creating decryption information by encrypting the decryption information using the public key of each viewer, and decryption information transmission for transmitting the decryption information to the information receiving device of the viewer. An encrypting means for encrypting a portion designated by a browsing range identifier with a corresponding common key based on the encrypted information; and an information receiving device of the viewer for encrypting the information encrypted by the encrypting means. An information transmitting device, comprising: an information transmitting unit configured to transmit information to an information transmitting device. 5. An information receiving apparatus for a reader when distributing information described by a structured document from a publisher to another viewer via a network via a network, A decryption information receiving means for receiving decryption information transmitted by the described information transmitting device, and a browsing range indicating a browsing range to which the user is permitted to browse by decrypting the received decryption information using his / her own secret key. An acquisition unit that acquires an identifier and a common key; a decryption information transmission unit that transmits decryption information received by the decryption information reception unit to the information reception device of the another viewer; Information receiving means for receiving the transmitted encrypted information; decryption means for decrypting, with a common key, a portion of the encrypted information designated by the previously acquired browsing range identifier; An information transmitting means for transmitting the encrypted information received by the information receiving means to the information receiving apparatus of the another viewer. 6. An information receiving apparatus for another viewer when distributing information described by a structured document from a publisher to another viewer via a network via a network, Item 5. A decryption information receiving means for receiving decryption information transmitted by the information receiving apparatus according to Item 5, and decrypting the received decryption information using its own secret key to indicate a browsing range to which the user is permitted to browse. Acquiring means for acquiring a viewing range identifier and a common key; information receiving means for receiving encrypted information transmitted by the information receiving apparatus according to claim 5; A decryption unit for decrypting a part specified by the acquired browsing range identifier with a common key. 7. An information transmission program for distributing information described in a structured document from a publisher to another viewer via a network via a network, wherein the program is transmitted to a computer system of the publisher. In contrast, a process of registering a browsing range identifier for identifying a browsing range of information and browsing definition information indicating a correspondence relationship with a viewer permitted to browse the browsing range, and encrypting the browsing range identifier and the browsing range. A process of enumerating a set of a common key for decryption and creating encryption information; and a set of a viewing range identifier and a common key for each viewer based on the viewing definition information and the encryption information. Based on the encryption information, a process of creating decryption information by encrypting using the public key of each viewer, a process of transmitting the decryption information to the viewer, A process of encrypting a portion designated by a viewing range identifier with a corresponding common key, and a process of transmitting information encrypted with the common key to the viewer. . 8. When the content of the information that shares the browsing definition information, the encryption information, and the decryption information is changed and distributed a plurality of times, browsing is performed based on the encryption information in the processing. 8. A process for encrypting a portion designated by a range identifier with a corresponding common key and a process for transmitting information encrypted with the common key to the viewer. Information transmission program described. 9. An information receiving program for distributing information described by a structured document from a publisher to another viewer via a network via a network, the information receiving program comprising: On the other hand, a process of receiving decryption information transmitted by the information transmission program according to claim 7 or 8, and decrypting the received decryption information using its own secret key, thereby enabling browsing permitted by the user. 9. A process for acquiring a browsing range identifier indicating a range and a common key, a process for transmitting received decrypted information to another viewer, and an encrypted information transmitted by the information transmission program according to claim 7 or 8. The process of receiving the encrypted information, the process of decrypting the part of the encrypted information specified by the previously acquired browsing range identifier with the common key, and the process of receiving the encrypted information Information receiving program characterized by executing a process of transmitting to the viewer, the. 10. The browsing definition information, the encryption information,
In the case where the content of the information sharing the decryption information is changed and distributed a plurality of times, among the processes, a process of receiving the encrypted information transmitted by the information transmission program; and In the information, the process of decrypting the portion specified by the previously acquired browsing range identifier with the common key, and the process of transmitting the received encrypted information to another viewer are repeatedly executed. The information receiving program according to claim 9, wherein: 11. An information receiving program for distributing information described by a structured document from an issuer to another viewer via a network via a network, the information receiving program comprising: The system receives the decrypted information transmitted by the information receiving program according to claim 9 or 10, and decrypts the received decrypted information using its own secret key, thereby permitting the user to browse the system. A process of acquiring a browsing range identifier indicating the browsing range and a common key, a process of receiving encrypted information transmitted by the information receiving program according to claim 9 or 10, and a process of receiving the encrypted information. An information receiving program for executing, by using the common key, a process of decrypting a part specified by the previously acquired browsing range identifier. 12. The browsing definition information, the encryption information,
In the case of changing the content of the information having the common decryption information and distributing the information a plurality of times, among the processes, a process of receiving the encrypted information transmitted by the information receiving program; and 12. A process of decrypting, with a common key, a portion specified by a previously acquired browsing range identifier in information, and only the following process is repeatedly performed.
Information receiving program described. 13. A computer-readable recording medium storing the information transmission program according to claim 7. Description: 14. A computer-readable recording medium storing the information receiving program according to claim 9 or 10. 15. A computer-readable recording medium storing the information receiving program according to claim 11. Description: