JP2006025279A - Electronic card, electronic card program, and storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To not only facilitate management and preservation of key information but also enable a user to safely exchange information, by utilizing an XML electronic envelope format to generate one file including key information and additional information. <P>SOLUTION: In an electronic card system 100, an electronic card comprises a card information part including information relating to the user and an encryption information part including information required for encrypting object data to be transmitted to the user. Object data can be encrypted on the basis of information included in encryption information parts of electronic cards by exchanging the electronic cards between a plurality of users, and information is safely exchanged on a network where there is a high risk of alteration, spoofing, etc. Since card information parts of the electronic cards include information relating to the users, the users can easily recognize whose electronic cards they are, by confirming contents of the electronic cards when exchanging the electronic cards. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technique for managing key information using an XML electronic envelope format.

  In recent years, with the spread of personal computers and the Internet, the use of e-mail and the like has become widespread in business. In particular, it is no exaggeration to say that e-mail is now a communication means equivalent to telephone in business. However, on the other hand, unlike the telephone system, information is exposed to dangers such as leakage, falsification, and impersonation in the Internet system via a large number of open servers. Since e-mail is transmitted and received in plain text via the above open server, there is always a high risk of tampering and spoofing.

  Conventionally, a method of encrypting plaintext has been used to solve these problems. As a specific encryption method, a method of encryption using a public key encryption method, a method of encryption using a passphrase, and the like are known.

  However, in the conventional encryption method, the user understands each encryption method, recognizes which encryption method is used, and decrypts it without using appropriate decryption software. I could not. Therefore, the user's understanding of the encryption method has become important, and there has been a problem that it is difficult to use for elderly people who are resistant to the Internet system and the like. In addition, both the sender and the receiver of e-mail need to have user-specific key information used for predetermined encryption and decryption in addition to appropriate software. In the case of exchanging only the key information, it is difficult to grasp which key information is used for encryption by “who” and “what method”.

  The present invention has been made in view of the above points, and manages key information by creating one file including key information and business card information using an XML (eXtensible Markup Language) electronic envelope format. It is an object of the present invention to provide a system that facilitates storage and allows users to exchange information safely.

  In one aspect of the present invention, an electronic business card includes a business card information unit including information about a user and an encryption information unit including information necessary for encrypting target data to be transmitted to the user. . According to this, by exchanging an electronic business card among a plurality of users, the target data can be encrypted based on the information included in the encryption information part of the electronic business card, and information can be safely transmitted on the network. Can be exchanged. In addition, since the business card information section of the electronic business card contains information about the user, when exchanging the electronic business card, it is easy to grasp who the electronic business card is by checking the contents of the electronic business card can do.

  In one aspect of the electronic business card, the electronic business card further includes a signature unit including information related to the signature of the user, and the encryption information unit includes a public key and a public key certificate used for the encryption. The signature unit includes signature information that is information for the user to sign, and a signature entity that is an entity of an electronic signature performed on the business card information unit. According to this, it is possible to confirm whether or not the information included in the business card information part has been tampered with by verifying based on the signature information and the signature entity included in the signature part of the electronic business card. In addition, it is possible to confirm whether or not the public key has been tampered with by building and verifying the path to the certificate authority based on the public key certificate included in the encryption information part. Therefore, information can be exchanged safely on the network.

  In another aspect of the electronic business card, the encryption information part includes a passphrase used for the encryption. According to this, the user can easily encrypt predetermined target data using the passphrase included in the encryption information part of the electronic business card. Therefore, even an elderly person who has little knowledge of encryption or the like can easily encrypt target data using an electronic business card and exchange information safely over a network.

  In another aspect of the present invention, an electronic business card program executed on a computer includes a business card information unit including information about a user, and information necessary for encrypting target data to be transmitted to the user. The computer is caused to function as generation means for generating an electronic business card based on the encryption information part included.

  According to the terminal having the above electronic business card program, an electronic business card including a business card information part and an encrypted information part can be easily generated. Here, the term "terminal" refers to a PC, PDA (Personal Digital Assistants), mobile phone, etc. that is used by each user and can send and receive emails and data to / from terminals used by other users via the network. is there. Each user can exchange the electronic business card generated by the terminal with another user using a floppy disk or the like. Therefore, the target data can be encrypted based on the information included in the encryption information part of the electronic business card, and information can be exchanged safely on the network.

  In one aspect of the electronic business card program, an electronic business card acquisition means for acquiring an electronic business card of another user, an authentication level setting means for setting an authentication level for the electronic business card, and the authentication level set in association with the set authentication level The computer is caused to function as storage means for storing an electronic business card in a business card store.

  According to the terminal having the above electronic business card program, the authentication level can be arbitrarily set for the electronic business cards of other users. Here, the authentication level is set according to how much a user trusts a certificate or the like included in the electronic business card of another user. For example, when the user knows that the predetermined electronic business card is completely reliable as the authentication level, the user sets “no need to construct a path to the certificate authority based on the certificate included in the electronic business card” can do. By setting such an authentication level, it is not necessary to perform path construction verification, and the processing time can be greatly shortened.

  In another aspect of the business card program, the electronic business card further includes a signature unit including information related to the signature of the user, and the electronic business card program is configured to use the business card information based on information included in the signature unit. The computer is further caused to function as business card information falsification determining means for determining the presence / absence of falsification, and the storage means stores the electronic business card in a business card store based on the determination result by the business card information falsification determining means. According to this, a terminal having an electronic business card program can detect falsification of business card information based on information included in a signature part of another user's electronic business card. Therefore, for example, when falsification is detected, it can be set not to store the electronic business card. Therefore, even if it is an exchange of information on a network where there is a high risk of falsification because it passes through a large number of open servers, it is possible to detect falsification of information contained in the business card information part by signature. Damage caused by impersonation can be avoided.

  In another aspect of the business card program, the encryption information section includes a public key and a public key certificate used for the encryption, and the electronic business card program is based on the public key certificate. The computer is further caused to function as public key falsification determination means for determining whether or not a key has been falsified, and the storage means stores the electronic business card in a business card store based on a determination result by the public key falsification determination means. According to this, the terminal having the electronic business card program can detect the falsification of the public key based on the public key certificate included in the encryption information part of the electronic business card of another user. Therefore, for example, when falsification is detected, it can be set not to store the electronic business card. Therefore, even when information is exchanged on a network where there is a high risk of falsification, it is possible to detect in advance falsification of a public key that is important as encrypted information using a public key certificate.

  In another aspect of the business card program, an electronic business card extracting means for extracting an electronic business card corresponding to a destination user from the business card store, and for encrypting target data from the encrypted information part of the extracted electronic business card Encryption information extracting means for extracting necessary encryption information, encryption means for encrypting the target data based on the extracted encryption information, signature giving means for giving a signature to the encrypted target data, encryption The computer is caused to function as a creating unit that creates an electronic envelope having information about the target data and the assigned signature as one file, and a sending unit that transmits the created electronic envelope to the destination user.

  According to the terminal having the above electronic business card program, the target data to be transmitted is encrypted based on the encryption information included in the encryption information part of the electronic business card corresponding to the transmission destination user. Specifically, the extraction of the electronic business card is performed by searching information related to the user in the business card information section stored in the business card store based on the name of the destination user. In addition, the user can give a signature in order to prevent falsification of the encrypted target data as necessary. Then, the terminal encloses the information related to the encrypted target data and the signature in an electronic envelope in an XML format that can collect a plurality of pieces of information into one file. According to this, the user can easily encrypt the target data based on the electronic card of the transmission destination user without being aware of the encryption method. In addition, since a signature for preventing falsification can be transmitted to the transmission destination user together with the target data in one electronic envelope format, it is possible to exchange safely on the network.

  In another aspect of the electronic business card program, receiving means for receiving data from a sender user, electronic envelope determining means for determining whether or not the data is an electronic envelope, and the electronic envelope determining means are electronic envelopes When it is determined that there is an extraction means for extracting an electronic business card and authentication level corresponding to the sender user from the business card store, verification for verifying the electronic envelope based on the extracted electronic business card and authentication level The computer is caused to function as a means and a display means for displaying a verification result by the verification means.

  The terminal having the electronic business card program extracts the electronic business card and authentication level of the transmission source user from the business card store when the data received from another terminal is an electronic envelope. And based on the said electronic business card and an authentication level, the said electronic envelope is verified and a verification result is displayed. That is, the terminal checks whether there is no danger in browsing information contained in the electronic envelope received from another terminal based on the electronic business card stored in advance in the business card store. Therefore, information can be exchanged safely even on a network where there is a high risk of falsification or impersonation.

  In still another aspect of the electronic business card program, the computer further functions as a certificate determination unit that determines whether or not a public key certificate is included in the encryption information part of the electronic business card extracted by the extraction unit. The verification unit determines that the certificate determination unit includes a public key certificate, and if the authentication level extracted by the extraction unit is high, constructs the path of the public key certificate. And verify.

  The terminal having the electronic business card program performs verification based on the authentication level set for the electronic business card when the electronic key card of the transmission source user includes a public key certificate. Specifically, when the authentication level is high, verification is performed after a path to the certificate authority is constructed based on the public key certificate. On the other hand, if the authentication level is low, the public key certificate is fully trusted without building a path. In this way, by verifying the public key certificate based on the authentication level set in advance by the user, for example, when the electronic business card is directly exchanged and the information contained in the electronic business card can be fully trusted, By setting the authentication level low and omitting the verification time for path construction, the processing time can be greatly shortened.

  According to still another aspect of the present invention, a computer-readable storage medium is provided for encrypting target data to be transmitted to a user, and a business card information unit including information about the user. A program for operating as a generating means for generating an electronic business card based on an encrypted information part including necessary information is stored.

  By executing the program stored in the storage medium on the computer, the same aspect as executing the above-described electronic business card program on the computer can be realized.

  According to the present invention, the XML electronic envelope format is used to create one file including key information and business card information, thereby facilitating the management and storage of key information and allowing the user to safely store information. It is possible to exchange.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

[Electronic business card system]
First, the electronic business card system according to the present embodiment will be described. FIG. 1 shows a schematic configuration of the electronic business card system. The electronic business card system 100 makes it easy to manage and store key information for encrypting target data by using an XML electronic business card (hereinafter referred to as “electronic business card”) unique to each user. It is a system that can exchange information safely. Here, the details of the electronic business card will be described later, but the business card information and the encrypted information are contained in an XML-format electronic envelope (hereinafter referred to as “electronic envelope format”) that can collect a plurality of information in one file. Is enclosed.

  As shown in FIG. 1, in an electronic business card system 100, a terminal A and a terminal B used by a user are connected via a network 2 so that they can communicate with each other. One preferred example of network 2 is the Internet. Here, the terminals A and B are a personal computer, a PDA, a mobile phone, etc. that are used by each user and can send and receive mails and data to and from terminals used by other users via the network 2. . Although the details will be described later, the user stores the electronic business card of another user in a terminal having the electronic business card program, and uses the information included in the electronic business card as a target of transmission / reception via the network 2. By encrypting the target data, it is possible to exchange information safely.

  Although only terminals A and B are shown in FIG. 1, the present invention is not limited to this, and a plurality of terminals used by a plurality of users are connected via the network 2 so that they can communicate with each other. It is assumed that

  Here, the outline of the registration of electronic business cards and the transmission / reception method of the target data by this system will be described. Specifically, a case will be described in which user A and user B exchange electronic business cards and then user A sends target data encrypted to user B attached to an email. The user A and the user B meeting for the first time first exchange the floppy disks storing the respective electronic business cards. In this example, the electronic business card is exchanged by putting it in a floppy disk. Which method is used is arbitrary. Specifically, in a method using a two-dimensional code, electronic business card data can be printed as a two-dimensional barcode on a business card on a paper medium. According to this, when exchanging a normal business card, the data of an electronic business card can be exchanged easily and simultaneously.

  User A uses terminal A having an electronic business card program to verify information contained in user B's electronic business card and confirm the contents. If there is no particular problem in the verification check operation, the electronic business card of user B is stored in the business card store of terminal A. At this time, the user A sets an authentication level in association with the electronic business card of the user B. Similarly, the user B uses the terminal B having the electronic business card program to store the electronic business card of the user A in the business card store and sets the authentication level. In this way, the process of storing an electronic business card of another user in the business card store and setting the authentication level is called “registration process”.

  After the registration process, the user A extracts the electronic business card of the transmission destination user B of the predetermined target data from the business card store. Then, the electronic business card program encrypts the target data with the encryption information included in the extracted electronic business card. Furthermore, the user A gives a signature to the encrypted target data as necessary. Then, the electronic business card program creates an XML electronic envelope (hereinafter referred to as an “electronic envelope”) having the encrypted target data and information about the signature as one file, and uses the electronic envelope attached to an email. To party B. In this way, the process of transmitting the target data encrypted using the electronic card of another user is called “transmission process”.

  User B who has received the mail with the electronic envelope attached extracts the electronic business card and authentication level of sender user A from the business card store. Then, the electronic business card program verifies whether or not the information of the electronic envelope has been falsified based on the encryption information and the authentication level included in the extracted encryption information portion of the electronic business card. Then, the user B decrypts the encrypted target data included in the electronic envelope according to the verification result, and browses it on the terminal B. The process of decrypting and browsing the encrypted target data after verifying an electronic envelope received from another user based on the electronic card of the transmission source user is referred to as a “reception process”.

[Encryption method]
Next, an encryption method for securely exchanging target data on the network 2 will be described in detail. There are roughly two encryption methods: “encryption using a public key encryption method” and “encryption using a passphrase”.

  First, “encryption using public key cryptography” will be described in detail. In this method, a private key / public key pair is used for encryption. Specifically, when transmitting the target file, the electronic business card program of the transmission source encrypts and transmits the target file using the public key of the transmission destination user that can be obtained by anyone. This encrypted target file can only be correctly decrypted with the private key of the destination user. Therefore, the transmission destination user who has received the encrypted target file decrypts and browses the target file encrypted with the private key that he / she only has. Such “encryption using public key cryptography” is used in, for example, PGP (Pretty Good Privacy; registered trademark), S / MIME (Multipurpose Internet Mail Extensions), and the like. In S / MIME, the authenticity of a public key is also realized using a PKI (Public Key Infrastructure) mechanism. In “encryption using a public key cryptosystem”, a file in which a third party organization puts together a public key and data for which the owner is guaranteed is called a public key certificate. Public key certificates are used for encryption. For example, FIG. 2 shows a data structure of an X.509 format public key certificate that is currently generally used. The public key certificate stores information as shown in FIG. 2 in a binary format.

  Next, “encryption using a passphrase” will be described in detail. In this method, an arbitrary passphrase determined in advance between the transmission source user and the transmission destination user is used. Specifically, when transmitting the target file, the electronic business card program of the transmission source encrypts the file using a passphrase and transmits it. The transmission source user who has received the encrypted target data decrypts and browses the file in which the passphrase is input.

  In the case of “encryption using public key cryptosystem”, the encryption information used for encryption and decryption is binary data in which the contents as shown in FIG. 2 are described, and “passphrase is used. In the case of “encryption”, the encryption information used for encryption is an enumeration of character strings. Therefore, conventionally, even if only encrypted information used for encryption and decryption is exchanged between users, the exchange of the target data with "who" based on the binary data and the list of character strings at the time of exchange I couldn't figure out if it was the encryption information needed for Further, even if a public key certificate is included, it is difficult to determine who the encrypted information is from the public key certificate. However, as in the present invention, an electronic business card is created as a single file including encrypted information and business card information by using an electronic envelope format, so that “who” is based on information about the user included as the business card information. It is possible to easily grasp whether the encrypted information is "." That is, personal authentication can be performed by exchanging as an electronic business card.

[Electronic business card]
Next, the electronic business card will be described in detail with reference to FIGS. FIG. 3 is a diagram schematically showing the data structure of an electronic business card. FIG. 4 is a schema example of an electronic business card.

  First, with reference to FIG. 3A and FIG. 4A, an electronic business card when performing encryption using a public key cryptosystem will be described. As shown in FIG. 3A, the electronic business card includes a business card information part, an encrypted information part, and a signature part. Furthermore, the encryption information part is composed of a public key, and the signature part is composed of signature information and a signature entity.

  In the business card information section, user information such as name and address described in a normal business card or electronic business card vCard (registered trademark) format is stored in a predetermined XML schema. Specifically, as shown in FIG. 4A, the name, company name, address, etc. of the business card information section are stored in the XML schema. It should be noted that binary data such as images can also be encoded and stored in the business card information section. Further, in order to use the flexibility of XML, an extension area tag is defined in advance, and each user or application can freely define a tag within this tag to provide extensibility.

  In the encryption information part, a public key to be used when encrypting the target data in the future is stored in a predetermined XML schema. Specifically, as shown in FIG. 4A, the public key of the encrypted information part is stored in the XML schema. The XML schema can be designed so that various keys can be stored depending on the security level by using the flexibility of XML. In addition, a public key certificate that certifies the public key can be stored together.

  In the signature part, the signature information and the signature entity are stored in the XML schema. The signature information includes information for signing, and the signature entity includes an electronic signature entity performed on the business card information part. Therefore, by verifying the signature entity and the business card information part, it is possible to confirm whether the business card information part has been tampered with. Specifically, as shown in FIG. 4A, the signature information and the signature entity of the signature part are stored in the XML schema. The XML signature specification includes, for example, XML-Signature Syntax and Processing recommended by W3C (World Wide Web Consortium), and these XML signatures can be arbitrarily used. The signature part is given only when the signature can be given in the electronic business card. The element to be signed may be the entire business card information part due to the characteristics of the XML signature, or partial application such as only the name and address is possible.

  Next, with reference to FIG. 3B and FIG. 4B, an electronic business card when encryption using a passphrase is performed will be described. As shown in FIG. 3B, the electronic business card includes a business card information part and an encrypted information part. Furthermore, the encryption information part is composed of a passphrase. In the encryption using the passphrase, since the signature cannot be given to the passphrase, there is no signature part.

  In the business card information section, the user information is stored in a predetermined XML schema in the same manner as the encryption using the public key cryptosystem described above. Specifically, as shown in FIG. 4B, the name, company name, address, etc. of the business card information section are stored in the XML schema.

  In the encryption information part, a pass phrase to be used when encrypting the target data in the future is stored in a predetermined XML schema. Specifically, as shown in FIG. 4B, the passphrase of the encryption information part is stored in the XML schema.

[Electronic business card program]
Next, the electronic business card program will be described in detail with reference to FIGS. FIG. 5 is a block diagram of a general-purpose application, an XML generation program, and an electronic business card program that constitute the present invention. FIG. 6 is a diagram schematically showing the data structure of a business card store that constitutes an electronic business card program.

  As shown in FIG. 5, the present invention includes a general-purpose application, an XML generation program, and an electronic business card program. The XML generation program and the electronic business card program are appropriately called and executed by a general-purpose application such as a DLL (Dynamic Linking Library). In other words, the general-purpose application calls and executes an XML generation program and an electronic business card program as necessary.

  The general-purpose application includes a registration application that includes an operation unit 21 and an authentication level setting unit 22, and a data generation application that includes a data generation unit 23 and a communication unit 24. In addition, the electronic business card program includes a capturing unit 31, a business card store 32, an authentication determination unit 33, an encrypted information extraction unit 34, and a business card generation unit 35.

  The capturing unit 31 analyzes the electronic business cards of other users acquired by various methods, and stores them in a business card store 32 that collectively manages the electronic business cards like a business card holder. In addition, when receiving the encrypted target data from the other user, the capturing unit 31 performs path verification to the certificate authority each time based on the public key certificate included in the electronic business card, or path verification The information on whether or not to trust the public key certificate completely is set as an authentication level, and is stored together with the business card store 32. Specifically, the authentication level “high” refers to path verification to the certificate authority based on the public key certificate included in the electronic business card every time the encrypted target data is received from another user. On the other hand, the authentication level “low” means that when the encrypted target data is received from another user, the public key certificate included in the electronic business card is completely trusted and the path verification is not performed. . Registration processing such as analysis and storage of an electronic business card and setting of an authentication level is performed when the operation unit 21 and the authentication level setting unit 22 of the registration application call the electronic business card program capturing unit 31.

  The authentication determination unit 33 accesses the business card store 32 when data with a signature is transmitted from another user, and verifies the signature based on the corresponding electronic business card. Further, the authentication determination unit 33 constructs a path to the certificate authority and performs verification when the corresponding electronic business card includes a public key certificate and the authentication level “high” is set. Specifically, the authentication level “high” is a setting that it is necessary to inherit the trust from the root certificate authority trusted by the user B. Accordingly, the authentication judgment unit 33 of the electronic business card program traces the issuer of the public key in order from the certificate included in the encryption information of the electronic business card of the user A, and the certificate of the root certificate authority set by the user in advance. It is assumed that the path construction is successful if the signature of each certificate can be verified with the public key of the issuer.

  As shown in FIG. 6, the business card store 32 collectively manages the electronic business cards of other users taken in by the take-in unit 31 and the authentication level information set by itself. The electronic business card is composed of a business card information part, an encrypted information part, and a signature part, and each information is stored. As described above, the authentication level is set depending on how much the user trusts the public key certificate included in the electronic card of another user. Therefore, as shown, no authentication level is set in the case of encryption using a passphrase that does not include a public key certificate. By setting such an authentication level, a user exchanges an electronic business card directly with the other user, and when it is known that the user can trust, the user sets that the public key certificate is completely trusted. As a result, it is not necessary to construct a path to the certificate authority, and the processing time can be greatly shortened. It is assumed that the business card store 32 also stores his / her electronic business card.

  The encryption information extraction unit 34 extracts the encryption information necessary for creating the encrypted target data from the business card store 32 and passes it to the data generation unit 23 of the data generation application. In the case of “encryption using a public key cryptosystem”, the encryption information is a public key. On the other hand, in the case of “encryption using a passphrase”, the encryption information is a passphrase.

  The business card generation unit 35 generates a user's electronic business card based on business card information and encrypted information such as a user's name and address input in advance. Specifically, in the case of “encryption using public key cryptography”, an electronic business card including business card information, public key, public key certificate, signature information, and signature entity is generated as shown in FIG. Is done. Note that the user can arbitrarily set whether or not to include the public key certificate, signature information, and signature entity. On the other hand, in the case of “encryption using a passphrase”, an electronic business card including business card information and a passphrase as shown in FIG. 3B is generated.

  The data generation unit 23 calls the encryption information acquired from the encryption information extraction unit 34 and the XML generation program 25 to encrypt the target data to be transmitted to other users. That is, encryption target data is generated. The generated data to be encrypted is stored in the local terminal or transmitted to the other user as it is using the communication unit 24.

  The XML generation program 25 is a program that can generate XML in an electronic envelope format. Specifically, the XML generation program 25 converts the electronic business card generated by the business card generation unit 35 into XML in an electronic envelope format. Further, based on the data to be encrypted generated by the data generation unit 23, XML in an electronic envelope format is generated.

[registration process]
Next, a registration process executed by the electronic business card system 100 will be described with reference to FIG. FIG. 7 is a flowchart of the registration process. It is assumed that user A and user B meeting for the first time exchange a normal business card, and at the same time, replace each electronic business card created in advance on a floppy disk. In this embodiment, a process in which user A uses terminal A to register user B's electronic business card will be described. Further, it is assumed that the electronic business cards of user A and user B are both generated based on “encryption using public key cryptography”.

  The user A takes in the electronic business card of the user B acquired using the terminal A and displays it on the screen (step S1). The electronic business card program possessed by the terminal A determines whether or not the public key certificate is included in the encryption information part of the electronic business card (step S2). If the public key certificate is included (step S2; Yes), the electronic business card program builds a path to the certificate authority based on the public key certificate and verifies whether the public key included in the electronic business card has been tampered with. (Step S3). And a verification result is displayed on a screen and it progresses to Step S4. If the public key certificate is not included (step S2; No), the process proceeds to step S4.

  The electronic business card program determines whether or not information related to the signature is included in the signature part of the electronic business card (step S4). If information related to the signature is included (step S4; Yes), the presence / absence of falsification of the business card information included in the business card information section is verified based on the signature entity included in the signature section (step S5). And a verification result is displayed on a screen and it progresses to Step S6. In addition, when the information regarding the signature is not included (step S4; No), the process proceeds to step S5.

  User A reconfirms the contents of the electronic business card based on the verification results displayed on the screen in steps S3 and S5 (step S6). If it is determined that there is no particular problem (step S7; No), the electronic business card of the user B is stored in the business card store 32 as shown in FIG. 6 (step S8). Furthermore, when the public key certificate is included in the electronic business card, does user A completely trust user B's public key certificate only (authentication level “low”)? If the path can be constructed, whether to trust (authentication level “high”) or the like is set by own judgment (step S9). In addition, even if the user A does not include the public key certificate or signature in the electronic business card or the path construction is not normally performed based on the public key certificate included in the electronic business card, Since it is an electronic business card exchanged directly with the user B, the authentication level can be set to “low” when it is considered reliable.

  The electronic business card program stores the authentication level set by the user A in the business card store 32 in association with the electronic business card of the user B. This completes the registration process. If it is determined in step S7 that there is a problem, the electronic business card program ends the registration process without storing the electronic business card of user B in the business card store 32.

[Transmission / reception processing]
Next, a transmission / reception process executed by the electronic business card system 100 will be described with reference to FIG. FIG. 8 is a flowchart of transmission / reception processing. It is assumed that user A and user B have exchanged electronic business cards and completed registration processing, and that an application for decrypting encrypted target data is installed in each terminal. To do. Further, in the present embodiment, it is assumed that the user A encrypts predetermined target data and transmits the encrypted target data to the user B by attaching it to an email.

  User A extracts the electronic business card of user B from the business card store 32 (step S11). Specifically, the electronic business card program searches the business card information stored in the business card store 32 based on the name of the user B and the like, and extracts a matching electronic business card. And an electronic business card program acquires the encryption information for encrypting the object data transmitted to the user B from the extracted electronic business card (step S12). Further, the electronic business card program encrypts the target data to be transmitted to the user B with the acquired encryption information (step S13). User A also gives his / her signature if necessary to prevent tampering (step S14). The electronic program creates an electronic envelope having the encrypted target data and signature information as one file (step S15), and attaches the electronic envelope to a mail and transmits it to the terminal B used by the user B ( Step S16).

  The electronic business card program of terminal B that has received the predetermined data from terminal A first performs a confirmation process (step S17). Here, the confirmation process will be described in detail with reference to FIG. FIG. 9 is a flowchart of the confirmation process performed in the transmission / reception process.

  According to FIG. 9, the electronic business card program determines whether the format of the predetermined data (step S21) acquired from the terminal A is an electronic envelope (step S22). When it is determined that the format of the predetermined data is not an electronic envelope (step S22; No), the electronic business card program ends the confirmation process. On the other hand, when it is determined that the format of the predetermined data is an electronic envelope (step S22; Yes), the electronic business card program determines whether or not the electronic business card of the user A who is the transmission source is registered. 32 is inquired (step S23). If the electronic business card of the user A is not registered in the business card store 32, the electronic envelope acquired from the terminal A cannot be verified (step S24). Is finished (step S27).

  On the other hand, when the electronic business card of the user A is registered in the business card store 32 (step S23; Yes), the authentication level set in association with the electronic business card is determined (step S25). If the set authentication level is “low”, even if the public key certificate of the user A's electronic business card is included, the public key certificate is fully trusted without performing path construction, and the step Proceed to S27. On the other hand, if the set authentication level is “high” and the public key certificate is included in the user A's electronic business card, a path is constructed again to confirm whether or not falsification has occurred (step S26). Proceed to Specifically, when the set authentication level is “high”, it is necessary to inherit the trust from the root certificate authority trusted by the user B. Then, the electronic business card program completes the confirmation process by displaying the verification result (step S27), and returns to the transmission / reception process shown in FIG.

  When the user B browses the result of the verification performed by the confirmation process and determines that there is no problem (step S18; Yes), the electronic business card program decrypts the target data included in the electronic envelope received from the terminal A. Display, and the transmission / reception processing is completed (step S19). On the other hand, when the user B determines that there is a problem (step S18; No), the electronic business card program ends the transmission / reception process without decrypting the target data included in the electronic envelope.

  As described above, in the present invention, an electronic business card is created by enclosing encryption information (public key, passphrase, etc.) and additional information (business card information) in an XML-format electronic envelope. In other words, the electronic business card is a single file, but includes both business card information and encrypted information. Therefore, management and storage of encrypted information can be facilitated by exchanging electronic business cards among a plurality of users. In addition, encrypted users can exchange encrypted business cards more easily than conventional PGP and S / MIME based on the encrypted information included in the electronic business cards, and information can be safely transmitted over the network 2. Can be exchanged.

  Furthermore, in the present invention, in the case of “encryption using a public key cryptosystem”, it is possible to prevent a third party from falsifying the business card information by including information related to the signature in the electronic business card. In addition, since a user can arbitrarily set an authentication level for another user's electronic business card, if the other user is known to be reliable, the certificate authority can be based on the public key certificate. It is not necessary to construct a path up to this time, and the processing time can be greatly shortened.

  In this embodiment, the authentication level is set to either “high” or “low”. However, the present invention is not limited to this, and “pass construction is performed once a month. Any level can be set, such as “Build and verify certificate”.

  Like this electronic business card system, the XML electronic envelope format is used to create a single file containing key information and additional information, thereby facilitating management and storage of the key information and allowing the user to safely Can be exchanged.

It is a figure which shows schematic structure of the electronic business card system in this invention. It is a figure which shows typically the data structure of a public key certificate. It is a figure which shows typically the data structure of an electronic business card. It is an example of a schema of an electronic business card. It is a block diagram of a general purpose application, an XML generation program, and an electronic business card program. It is a figure which shows typically the data structure of a business card store. It is a flowchart of the registration process in this invention. It is a flowchart of the transmission / reception process in this invention. It is a flowchart of the confirmation process in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 ... Network 21 ... Operation part 22 ... Authentication level setting part 23 ... Data generation part 24 ... Communication part 25 ... XML production | generation program 31 ... Capture part 32 ... Business card store 33 ... Authentication determination part 34 ... Encrypted information extraction part 35 ... Business card Generator 100 ... Electronic business card system

Claims (17)

A business card information section containing information about the user,
An electronic business card, comprising: an encryption information unit including information necessary for encrypting target data to be transmitted to the user. The electronic business card further comprises a signature part including information on the user's signature,
The encryption information part includes a public key and a public key certificate used for the encryption,
The signature part includes signature information which is information for the user to sign, and a signature entity which is an entity of an electronic signature performed on the business card information part. The listed electronic business card.   The electronic business card according to claim 1, wherein the encryption information unit includes a passphrase used for the encryption. A program executed on a computer,
Based on a business card information unit including information about the user and an encryption information unit including information necessary for encrypting target data to be transmitted to the user, the computer is used as a generation unit that generates an electronic business card. Electronic business card program characterized by functioning. Electronic business card acquisition means for acquiring electronic cards of other users,
Authentication level setting means for setting an authentication level for the electronic business card;
5. The electronic business card program according to claim 4, wherein the computer is caused to function as a storage unit that stores the electronic business card in a business card store in association with the set authentication level. The electronic business card further comprises a signature part including information on the user's signature,
The electronic business card program
Based on the information included in the signature part, further causing the computer to function as business card information falsification determining means for determining whether the business card information has been falsified,
6. The electronic business card program according to claim 5, wherein the storage unit stores the electronic business card in a business card store based on a determination result by the business card information falsification determination unit. The encryption information part includes a public key and a public key certificate used for the encryption,
The electronic business card program
Based on the public key certificate, further causing the computer to function as public key falsification determination means for determining whether or not the public key has been falsified,
The electronic business card program according to claim 5 or 6, wherein the storage unit stores the electronic business card in a business card store based on a determination result by the public key falsification determination unit. An electronic business card extracting means for extracting an electronic business card corresponding to a destination user from the business card store;
Encrypted information extracting means for extracting encrypted information necessary for encrypting target data from the encrypted information part of the extracted electronic business card;
An encryption means for encrypting the target data based on the extracted encryption information;
A signature adding means for adding a signature to the encrypted target data;
Creating means for creating an electronic envelope having the encrypted target data and the attached signature information as one file;
The electronic business card program according to any one of claims 4 to 7, wherein the computer is caused to function as transmission means for transmitting the created electronic envelope to the transmission destination user. Receiving means for receiving data from the sender user;
Electronic envelope determination means for determining whether or not the data is an electronic envelope;
An extraction means for extracting an electronic business card and an authentication level corresponding to the transmission source user from the business card store when the electronic envelope determination means determines that the electronic envelope is an electronic envelope;
Verification means for verifying the electronic envelope based on the extracted electronic business card and authentication level;
The electronic business card program according to any one of claims 5 to 8, wherein the computer is caused to function as display means for displaying a verification result by the verification means. Causing the computer to further function as certificate determination means for determining whether or not a public key certificate is included in the encryption information part of the electronic business card extracted by the extraction means;
The verification unit determines that the certificate determination unit includes a public key certificate, and constructs a path of the public key certificate when the authentication level extracted by the extraction unit is high. 10. The electronic business card program according to claim 9, wherein verification is performed. A computer-readable storage medium, wherein the computer is
In order to operate as a generating means for generating an electronic business card based on a business card information part including information on the user and an encrypted information part including information necessary for encrypting target data to be transmitted to the user A storage medium that stores the program. The computer,
Electronic business card acquisition means for acquiring electronic cards of other users;
Authentication level setting means for setting an authentication level for the electronic business card;
The storage medium according to claim 11, further storing a program for further operating as storage means for storing the electronic business card in a business card store in association with the set authentication level. The electronic business card further comprises a signature part including information on the user's signature,
The computer,
A program for further operating as business card information falsification determining means for determining whether or not the business card information is falsified based on information included in the signature part,
The storage medium according to claim 12, wherein the storage unit stores the electronic business card in a business card store based on a determination result by the business card information falsification determination unit. The encryption information part includes a public key and a public key certificate used for the encryption,
The computer,
Based on the public key certificate, a program for further operating as public key falsification determination means for determining whether or not the public key has been falsified is stored,
The storage medium according to claim 12 or 13, wherein the storage unit stores the electronic business card in a business card store based on a determination result by the public key falsification determination unit. The computer,
An electronic business card extracting means for extracting an electronic business card corresponding to a destination user from the business card store;
Encrypted information extraction means for extracting encryption information necessary for encrypting target data from the encrypted information part of the extracted electronic business card;
Encryption means for encrypting the target data based on the extracted encryption information;
A signature providing means for giving a signature to the encrypted target data;
Creating means for creating an electronic envelope in which the information related to the encrypted target data and the attached signature is made into one file;
The storage medium according to any one of claims 11 to 14, wherein a program for further operating as a transmission unit that transmits the created electronic envelope to the transmission destination user is stored. The computer,
Receiving means for receiving data from the sender user;
Electronic envelope determination means for determining whether the data is an electronic envelope;
An extraction means for extracting an electronic business card and an authentication level corresponding to the sender user from the business card store when the electronic envelope determination means determines that the electronic envelope is an electronic envelope;
Verification means for verifying the electronic envelope based on the extracted electronic business card and authentication level;
The storage medium according to any one of claims 12 to 15, wherein a program for further operating as a display unit that displays a verification result by the verification unit is stored. The computer,
A program for further operating as a certificate determination unit for determining whether or not a public key certificate is included in the encryption information part of the electronic business card extracted by the extraction unit;
The verification unit determines that the certificate determination unit includes a public key certificate, and constructs a path of the public key certificate when the authentication level extracted by the extraction unit is high. The storage medium according to claim 16, wherein verification is performed.

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