Patent Publication Number: US-2005138429-A1

Title: Data communication intermediation program and apparatus for promoting authentication processing in cooperation with purchaser portable terminal having personal identification information and communication function

Description:
TECHNICAL FIELD  
      The present invention relates generally to authentication processing and, more particularly, to a client computer provided with a data communication intermediation program mediating data communication for personal authentication and settlement authentication in Internet shopping and with a communication intermediation apparatus mediating the above data communication.  
     BACKGROUND ART  
      Currently, a series of actions is widely conducted as Internet shopping for purchasing items such as products or services from web sites of individuals, corporations or the like created on the Internet and executing payment-settlement procedures. In this specification, a service is considered as one of products which can be selected by purchasers, and items such as products or services are described as products for the sake of simplicity.  
      First, a purchaser browses products published on shop&#39;s web pages and selects a product to be purchased utilizing a web browser from a client computer such as a personal computer (hereinafter referred to as PC) connected to the Internet. When the product to be purchased is determined, the purchaser indicates purchase intention and enters into purchase procedures. In the purchase procedures, a personal authentication is executed for clarifying an identity of the purchaser and checking whether the purchaser really has the intention to conduct a transaction, and a settlement authentication is executed for checking whether a payment is performed by the purchaser or whether the purchaser has ability to pay. The personal authentication is executed based on personal information which is information for identifying the purchasing individual and the settlement authentication is executed based on settlement information, such as a credit card number, a bank account number or the like. In this specification, the personal information and the settlement information are collectively referred to as personal identification information, hereinafter. The shop ships the product if results of above personal authentication and settlement authentication are preferable, and the purchase procedures are terminated.  
      In this way, the personal identification information plays an important role in the Internet shopping.  
      However, in the case of the Internet shopping conducted by the client computer such as PC, the purchaser inputs the personal identification information on the client computer when the personal authentication and the settlement authentication are needed. Since, in the client computer such as PC, the input personal identification information is generally stored in a hard disk, an ill-intentioned third party directly reads the information in the hard disk, reads out the information by intruding into a terminal apparatus via network and peeping remaining histories when the authenticated person is away from the terminal apparatus, resulting in the personal identification information such as accounts, passwords, credit card numbers, addresses and telephone numbers to be easily leaked to the third party other than the purchaser. As a result, “spoofing” can happen, wherein the third party purchases products as if the third party becomes the authenticated person.  
      On the other hand, the purchaser may conduct the internet shopping with a purchaser portable terminal provided with a communication function, including a cell phone. In this case, since data such as the personal identification information are stored in memories inside the purchaser portable terminal instead of being stored in a removable separate apparatus such as a hard disk, the “spoofing” is not likely to happen due to leakage of the personal identification information, comparing to the client computer such as PC. However, a problem exists in regard to difficulty of obtaining sufficient information, because, since the screen size of the purchaser portable terminal is generally small, the purchaser has to switch or scroll the screens in order to select or compare products so that extra efforts are required; communication speed is often slow as compared to PC and the like; it takes lot of time to download data such as images; and the communication charge is expensive; and from other reasons.  
      Therefore, what is needed is to use a client computer which can display multiple images on one screen for browsing products by the purchaser for the personal authentication and settlement authentication processing, because client computer provides a display screen having the size large enough to give detailed description of the products and a fast communication function to give sufficient information for deciding the purchase, although the personal identification information should not be stored in the place where the data can be leaked to the third party, such as hard disks of the client computer for preventing the “spoofing”.  
     DISCLOSURE OF THE INVENTION  
      An object of the present invention is to provide an environment for the purchaser to select products using a client computer, such as PC, with a large screen and better operability and for enabling a personal identification information requested at the time of the personal authentication and the settlement authentication be obtained from a purchaser portable terminal with less risk of leakage of information to a third party, instead of a client computer, to prevent “spoofing”, while products are selected.  
      In order to achieve the above object, there is provided a communication intermediating program causing a client compute connectable to a server via a computer network to execute personal identification processing in cooperation with a portable terminal storing personal identification information therein, the personal identification processing having, in response to a personal identification information request signal from the server, transferring the personal identification information request signal to the portable terminal; and transferring to the server the personal identification information stored in the portable terminal, the personal identification information being sent to the client computer by the portable terminal in response to the personal identification information request signal.  
      According to the above invention, products are browsed and selected utilizing a client computer, such as PC, with better operability which large screen provides clear and detailed information; the personal authentication and the settlement authentication is executed with the personal identification information stored in the purchaser portable terminal which has less possibility of leakage of the personal identification information to the third party than a terminal apparatus such as PC; and, therefore, the “spoofing” can be prevented. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  shows a configuration example of an embodiment of the present invention;  
       FIG. 2  shows an example of a credibility check of electronically signed data;  
       FIG. 3  is a flowchart of a first embodiment;  
       FIGS. 4 and 5  are flowcharts of a second embodiment; and  
      FIGS.  6  to  9  are flowcharts of a third embodiment. 
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION  
      Embodiments of the present invention will now be described with reference to the drawings. It is however to be noted that the technical field of the present invention is not limited to those embodiments but covers the invention as defined in the appended claims and equivalents thereof.  
       FIG. 1  shows a configuration example of an embodiment of the present invention.  
      A shop server  110  is a server providing a web page  111  of a shop. A client computer  120  is installed with a web browser  121  for browsing the web page and a communication intermediation program  122  of the present invention, and further provided with a communication module  123 . The web browser  121  and the communication intermediation program  122  are implemented on the same operating system and the communication intermediation program  122  can be activated from the web browser  121 .  
      The shop server  110  and the client computer  120  are connected via Internet  140 .  
      A purchaser portable terminal  130  is provided with a communication module  131  which can communicate data with the communication module  123  in the client computer  120  and an IC card  132  containing personal identification information  133 . As an example of the communication module  123  and the communication module  131 , Bluetooth or IEEE 802.11 wireless module is preferred.  
      The IC card  132  is a chip card with built-in IC chip and has a calculation function, a memory larger than a magnetic card and a high security function. The security function includes an encryption function for preventing eavesdropping of data by encrypting and decrypting data transactions with outside of the card with the calculation function and a function for preventing forges, falsifications, interpolations and the like, such that circuitry of the chip itself is destroyed when attempting to disassemble and analyze the IC card due to tamper-resistance (i.e., a property for resisting physical attacks from the outside and making analysis difficult). In this way, the personal identification information  133  is less likely to leak to the third party than PC, because of protecting not only the personal identification information  133  itself in the IC card  132 , but also the transaction of the personal identification information  133  between the IC card  132  and an external apparatus.  
      The personal identification information  133  stores a CA electronically-signed purchaser portable terminal electronic certificate and a purchaser portable terminal private key as the personal information, and credit card information needed for credit card settlement as the settlement information. Also, for example, the personal identification information  133  may store an address, a name, an age, a telephone number and a blood type as the personal information, and a bank account number and the like as the settlement information.  
      The CA electronically-signed purchaser portable terminal electronic certificate is an electronic certificate issued to the purchaser portable terminal by CA (Certification Authority), with a CA electronic signature added. The purchaser portable terminal electronic certificate includes a purchaser portable terminal public key, and CA assures that the purchaser portable terminal public key certainly is a possession of the purchaser portable terminal itself.  
      The electronic signature utilizes a public key infrastructure, and is generated by converting base data to a message digest following a certain algorithm (hush function) and by encrypting the message digest with the private key of the signer, and is utilized as a pair with the base data.  FIG. 2  shows how to be able to check the credibility of the electronically signed data via network.  
       FIG. 2  shows an example of a credibility check of electronically signed data. This example is the case that the CA electronically-signed purchaser portable terminal electronic certificate is received. The receiver side  220  compares a message digest  225  obtained by decrypting a CA electronic signature  222  with a CA public key  230  with a message digest  224  obtained by converting a purchaser portable terminal electronic certificate  221  with a hush function  223 . If the results are the same, it is known that data is not interpolated in the middle of transmission and that the CA electronic signature  222  certainly has been added to the purchaser portable terminal electronic certificate  221 . Since existence of the CA is credible, credibility is established for the received purchaser portable terminal electronic certificate  221 . The base data is not limited to the electronic certificate and the signer is not limited to CA, and in those cases, the purchaser portable terminal electronic certificate, the CA electronic signature and CA public key may be read differently as corresponding data, an electronic signature of a corresponding signer and a public key of a corresponding signer, respectively. Since the credibility check of an electronically signed document is often performed in the specification, the check procedure is hereinafter referred to as an “electronic signature check”.  
       FIG. 3  is a flowchart of a first embodiment. The first embodiment is an example wherein, in the Internet shopping including the personal authentication executed by means of the purchaser portable terminal electronic certificate and the settlement authentication executed by means of the credit card information, a communication intermediation program transfers a personal information request from the shop server to the purchaser portable terminal, transfers the CA electronically-signed purchaser portable terminal electronic certificate returned from the purchaser portable terminal to the shop server, transfers a settlement information request from the shop server to the purchaser portable terminal and transfers the credit card information returned from the purchaser portable terminal to the shop server for executing authentication processing respectively.  
      On the assumption of the embodiment, the shop server has already obtained a CA electronic key  301 . Also, the IC card in the purchaser portable terminal  130  has already stored the CA electronically-signed purchaser portable terminal electronic certificate  302  and the credit card information  303  as the personal identification information.  
      First, the purchaser accesses to the shop server  110  via the Internet, browses seller&#39;s web page  111  stored in the shop server  110  and selects products, using a web browser  121  of the client computer  120  with a large screen which facilitates obtaining information and with good operability (S 1 ). When deciding a product to be purchased, the purchaser sends order information and purchase intention to the shop server (S 2 ). For example, step S 2  is achieved by clicking a button provided on the web page for moving to a purchase procedure when the product is selected in advance, and by the click the purchaser is judged to have purchase intention for the product selected by then. The order information includes information about the product to be purchased and the number of the product.  
      The shop server  110  notifies the client computer  120  of beginning of the purchase procedure (S 3 ). In step S 3 , for example, a page is transmitted with special embedded HTML tags indicating the beginning of the purchase. In response to the notification of the beginning of the purchase procedure, the communication intermediation program is activated and starts transfer (S 4 ). In step S 4 , for example, the communication intermediation program  122  may be activated when the web browser  121  detects the special HTML tags indicating the beginning of the purchase. Then, the shop server  110  sends a personal information request to the client computer  120  in order to execute a personal authentication (S 5 ). The communication intermediation program  122  transfers the personal information request to the purchaser portable terminal  130  via a communication module  123  (S 6 ). Responding to the personal information request, the purchaser portable terminal  130  returns the CA electronically-signed purchaser portable terminal electronic certificate  302  from the IC card  132  storing the personal identification information  133 , and the CA electronically-signed purchaser portable terminal electronic certificate  302  are sent to the client computer  120  via a communication module  131  (S 7 ). The communication intermediation program  122  transfers the CA electronically-signed purchaser portable terminal electronic certificate to the shop server  110  without storing the CA electronically-signed purchaser portable terminal electronic certificate  302  into a hard disk of the client computer (S 8 ) The shop server  110  uses a CA public key  301  to perform an electronic signature check of the CA electronically-signed purchaser portable terminal electronic certificate  302  (S 9 ). A procedure of the electronic signature check is given in  FIG. 2 . The personal authentication is terminated when credibility of the purchaser portable terminal electronic certificate is established in step S 9 .  
      When the personal authentication succeeds in step S 9 , then, the shop server  110  requests the settlement information to the client computer  120  (S 10 ). The communication intermediation program  122  transfers the settlement information request to the purchaser portable terminal  130  (S 11 ). Responding to the settlement information request, the IC card  132  in the purchaser portable terminal  130  returns credit card information  303 , and the credit card information  303  are sent to the client computer  120  via the communication module  131  (S 12 ). The communication intermediation program  122  transfers the credit card information to the shop server without storing the credit card information  303  into a hard disk of the client computer (S 13 ). The shop server conducts a credit examination based on the credit card information  303  and terminates the settlement authentication (S 14 ). Subsequently, although not shown, the first embodiment is terminated through a sipping transaction of the product due to the settlement authentication result.  
      The returned credit card information  303  of step S 12  is desired to be encrypted in order not to be intercepted by the third party other than the shop server. For example, if the purchaser portable terminal  130  has obtained a shop server public key, the information maybe encrypted by means of the shop server public key. Although the embodiment is an example that the personal authentication and the settlement authentication are executed separately, the personal authentication and the settlement authentication may be executed at the same time. In this case, in step S 7 , the IC card  132  in the purchaser portable terminal  130  may return the CA electronically-signed purchaser portable terminal electronic certificate  302  and the credit card information  303  simultaneously.  
      According to the embodiment, while using the client computer with a large screen for selecting the product, the personal authentication and the settlement authentication can be completed using the personal identification information which is stored in the IC card in the purchaser portable terminal and is less likely to be leaked to the third party. Therefore, the Internet shopping can be conducted without leaving the personal identification information on the hard disk of the client computer and, at the same time, the spoofing can be prevented which is due to an environment for readout of the personal identification information from the hard disk in spite of facilitating the internet shopping.  
       FIGS. 4 and 5  are flowcharts of a second embodiment. In  FIG. 4 , lower ends of flows  407 ,  408 ,  409  respectively for the portable terminal  130 , the client computer  120  and the shop server  110  continue to upper ends of corresponding flows of  FIG. 5 , and therefore, the description is conducted by combining the two figures together. The second embodiment is an example wherein, in the Internet shopping including the personal authentication executed by means of the purchaser portable terminal electronic certificate and the settlement authentication executed by means of the credit card information, the communication intermediation program transfers the personal information request from the shop server to the purchaser portable terminal, transfers the CA-signed purchaser signature returned from the purchaser portable terminal to the shop server, transfers the settlement information request from the shop server to the purchaser portable terminal and transfers to the shop server the settlement information, encrypted based on common key cryptography and returned from the purchaser portable terminal for executing authentication processing respectively.  
      On the assumption of the embodiment, the IC card in the purchaser portable terminal  130  has already obtained the CA electronically-signed purchaser portable terminal electronic certificate  302  and the credit card information  303  as the personal identification information, and the shop server  110  has already obtained a CA electronically-signed shop server electronic certificate  401 . The purchaser portable terminal and the shop server have already obtained the CA public key  301 .  
      In  FIG. 4 , first, the purchaser accesses to the shop server  110  via the Internet, browses seller&#39;s web page  111  stored in the shop server  110  and selects products, using a web browser  121  of the client computer  120  with a large screen which facilitates obtaining information and with good operability (S 1 ). When deciding a product to be purchased, the purchaser sends order information  402  and purchase intention to the shop server (S 2 ) For example, step S 2  is achieved by clicking a button provided on the web page for moving to a purchase procedure and by the click the purchaser is judged to have purchase intention for the product selected by then. The order information  402  is information about the product to be purchased and the number of the product.  
      The shop server  110  notifies the client computer  120  of beginning of the purchase procedure (S 3 ). In step S 3 , for example, a page is transmitted with special embedded HTML tags indicating the beginning of the purchase. In response to the notification of the beginning of the purchase procedure, the communication intermediation program is activated and starts transfer (S 4 ). In step S 4 , for example, the communication intermediation program  122  may be activated when the web browser  121  detects the special HTML tags indicating the beginning of the purchase.  
      The shop server  110  sends the personal information request and the CA electronically-signed shop server electronic certificate  401  to the client computer  120  (S 15 ). The communication intermediation program  122  transfers the personal information request and the CA electronically-signed shop server electronic certificate  401  to the purchaser portable terminal  130  (S 16 ). The IC card  132  in the purchaser portable terminal  130  uses the CA public key  301  to perform an electronic signature check of the CA electronically-signed shop server electronic certificate  401  (S 17 ). The shop server authentication is terminated when credibility of the shop server electronic certificate is established in step S 17 .  
      After the shop server authentication of step S 17 , in response to the personal information request, the IC card  132  in the purchaser portable terminal  130  returns the CA electronically-signed purchaser portable terminal electronic certificate  302 , and the CA electronically-signed purchaser portable terminal electronic certificate is sent to the client computer  120  (S 18 ). The communication intermediation program  122  transfers the CA electronically-signed purchaser portable terminal electronic certificate to the shop-server  110  without storing the CA electronically-signed purchaser portable terminal electronic certificate  302  into the hard disk of the client computer  120  (S 19 ). The shop server  110  performs an electronic signature check of the CA electronically-signed purchaser portable terminal electronic certificate  302  (S 20 ) The personal authentication is terminated when credibility of the purchaser portable terminal electronic certificate is established in step S 20 . Since the credibility of the purchaser portable terminal electronic certificate is established in step S 20 , a purchaser portable terminal public key  403  is stored, which is included in the purchaser portable terminal electronic certificate, for later use.  
      Then the shop server  110  generates a session key which is equivalent to a common key for encrypting subsequent communication with the common key cryptography (S 21 ). The shop server  110  encrypts the session key  404  and the order information  402  using the purchaser portable terminal public key  403  and sends an encrypted session key  405  and encrypted order information  406  to the client computer (S 22 ). By encryption using the purchaser portable terminal public key  403 , the session key  404  and the order information  402  can not be read out unless one has a purchaser portable terminal private key, that is effectively, can only be decrypted by the purchaser portable terminal. The communication intermediation program  122  transfers the encrypted session key  405  and the encrypted order information  406  to the purchaser portable terminal (S 23 ). The IC card in the purchaser portable terminal  130  decrypts the encrypted session key  405  and the encrypted order information  406  using the purchaser portable terminal private key to pick up the session key  404  and the order information (S 24 ).  
      Reference is hereinafter made to  FIG. 5 . Subsequently, The IC card  132  in the purchaser portable terminal  130  returns the order information  402  with a no-transfer flag in order to make the purchaser confirm the purchasing product on the client computer, and the order information is sent to the client computer  120  via the communication module  131  (S 25 ). The no-transfer flag is used when it is not desirable for the intermediate program to transfer data. For example, the no-transfer flag is achieved by sending a page embedded with special HTML tags indicating the no-transfer flag. The communication intermediate program  122  detects the no-transfer flag, makes the web browser  121  display the order information  402  for making the purchaser conduct a final confirmation of the order information and, when receiving the result of the final confirmation, sends a settlement information request to the purchaser portable terminal unless the purchase is cancelled (S 26 ).  
      In response to the settlement information request, the IC card  132  in the purchaser portable terminal  130  returns encrypted credit card information  501  which is credit card information  303  encrypted by the session key  404  and the encrypted credit card information  501  is sent to the client computer (S 27 ). The communication intermediate program  122  transfers the encrypted credit card information to the shop server  110  without storing the encrypted credit card information  501  into the hard disk of the client computer  120  (S 28 ). In the shop server  110 , the encrypted credit card information is decrypted and the credit card information  303  is picked up (S 29 ). Then, the settlement authentication is completed with the credit examination of the credit card (S 30 ). Subsequently, although not shown, the second embodiment is terminated through a sipping transaction of the product due to the settlement authentication result.  
      According to the embodiment, while using the client computer with a large screen for selecting the product, the personal authentication and the settlement authentication can be completed using the personal identification information which is stored in the IC card in the purchaser portable terminal and is less likely to be leaked to the third party. Encryption of the communication between the shop server and the purchaser portable terminal is done. No the personal identification information is left on the hard disk of the client computer. Therefore, while maintaining an environment for facilitating the internet shopping, not only the spoofing can be prevented which is caused by readout of the personal identification information from the hard disk of the client computer, but also the spoofing can be prevented which is caused by eavesdropping of the communication among the purchaser portable terminal, the client computer and the shop server.  
       FIGS. 6, 7 ,  8  and  9  are flowcharts of a third embodiment. As is the case with the relationship between  FIGS. 4 and 5 , lower ends of flows of  FIG. 6 , lower ends of flows of  FIG. 7  and lower ends of flows of  FIG. 8  continue to upper ends of flows of  FIG. 7 , upper end of flows of  FIG. 8  and upper end of flows of  FIG. 9 , respectively, and therefore, the description is conducted by combining the four figures together. The third embodiment is an example that the present invention is applied to a mechanism called SET (Secure Electronic Transaction), which is developed as a standard specification of existing credit card settlement. The third embodiment shows an example that, in the Internet shopping, the personal authentication is executed by means of the purchaser portable terminal electronic certificate and the settlement authentication is executed by means of the credit card information. For executing authentication processing respectively the communication intermediation program transfers the personal information request from the shop server to the purchaser portable terminal, transfers the CA electronically-signed purchaser signature returned from the purchaser portable terminal to the shop server, transfers the settlement information request from the shop server to the purchaser portable terminal and transfers to the shop server the data including credit card information encrypted based on a card company server public key and returned from the purchaser portable terminal.  
      On the assumption of the embodiment, the purchaser portable terminal  130  can process a function of software called Wallet, which is generally executed by PC of the purchaser in SET. Also, the purchaser portable terminal  130  has already obtained the CA electronically-signed purchaser portable terminal electronic certificate  302 ; the shop server  110  has already obtained a CA electronically-signed shop server electronic certificate  401 ; and the card company server  150  has already obtained a CA electronically-signed card company server electronic certificate  601 . Further, the purchaser portable terminal  130 , the shop server  110  and the card company server  150  have already obtained the CA public key  301 .  
      The card company server sends CA electronically-signed card company server electronic certificate  401  to the shop server in advance (S 31 ).  
      In  FIG. 6 , first, the purchaser accesses to the shop server  110  via the Internet, browses seller&#39;s web page  111  stored in the shop server  110  and selects products, using a web browser  121  of the client computer  120  with a large screen which facilitates obtaining information and with good operability (S 1 ). When deciding a product to be purchased, the purchaser sends order information  402  and purchase intention to the shop server (S 2 ). For example, step S 2  is achieved by clicking a button provided on the web page for moving to a purchase procedure and by the click the purchaser is judged to have purchase intention for the product selected by then. The order information  402  is information about the product to be purchased and the number of the product.  
      The shop server  110  notifies the client computer  120  of beginning of the purchase procedure (S 3 ). In step S 3 , for example, a page is transmitted with special embedded HTML tags indicating the beginning of the purchase. In response to the notification of the beginning of the purchase procedure, the communication intermediation program is activated and starts transfer (S 4 ).  
      The shop server  110  sends to the client computer  120  the CA electronically-signed card company server electronic certificate  601 , the CA electronically-signed shop server electronic certificate  401  and the order information  402  (S 32 ). The communication intermediation program  122  transfers to the purchaser portable terminal  130  the CA electronically-signed card company server electronic certificate  601 , the CA electronically-signed shop server electronic certificate  401  and the order information  402  (S 33 ).  
      The IC card  132  in the purchaser portable terminal  130  uses the CA public key  301  to perform the electronic signature check of the CA electronically-signed shop server electronic certificate  401  and executes a shop server authentication (S 34 ) If the authentication succeeds, a shop server public key  602  is stored, which is included in the shop server electronic certificate. Subsequently, Using the CA public key, the electronic signature check is performed also for the CA electronically-signed card company server electronic certificate  601  to execute a card company server authentication (S 35 ). If the authentication succeeds, a card company server public key  603  is stored, which is included in the card company server electronic certificate. Then, the IC card  132  in the purchaser portable terminal  130  generates a purchaser portable terminal electronic signature using the order information  402  as base data to form purchaser portable terminal electronically-signed order information  604  (S 36 ). The purchaser portable terminal electronic signature ensures that the order has been issued by the purchaser and, therefore, the purchaser can not explain away.  
      Reference is hereinafter made to  FIG. 7 . Also, the IC card  132  in the purchaser portable terminal  130  summarizes the credit card information  303  and a message digest generated from the order information  402  as the settlement information and generates encrypted settlement information  701  by encrypting with the card company public key  603  (S 37 ). Consequently, the credit card information can only be decrypted by a private key of the credit card company and will not be underlooked by the shop. In this way, the CA electronically-signed purchaser portable terminal electronic certificate  302 , the purchaser portable terminal electronically-signed order information  604  and the encrypted settlement information  701  are sent to the client computer  120  (S 38 ). The communication intermediate program  122  transfers to the shop server the CA electronically-signed purchaser portable terminal electronic certificate  302 , the purchaser portable terminal electronically-signed order information  604  and the encrypted settlement information  701  encrypted with the credit card company server public key (S 39 ). The shop server  110  performs the electronic signature check of the CA electronically-signed purchaser portable terminal electronic certificate  302  and executes the personal authentication (S 40 ) If the authentication succeeds, the purchaser portable terminal public key  403  is stored. Then, the electronic signature check is performed for the purchaser portable terminal electronically-signed order information  604  (S 41 ). If results of comparison are the same, the order information is credible and the shop can find out the name, the number and the like of a product to be offered to the purchaser. As proof of the agreement of the order between the purchaser and the shop, the shop server generates a shop server electronic signature using a message digest generated from the order information  402  as base data and generates a shop server electronically-signed message digest  702  (S 42 ). Then, the shop server  110  sends to the card company server  150  the CA electronically-signed purchaser portable terminal electronic certificate  302 , the CA electronically-signed shop server electronic certificate  401 , the shop server electronically-signed message digest  702  and the settlement information  701  encrypted with the card company server public key  603  (S 43 ). By sending the message digest, rather than the order information, details of the order will not be transmitted to the card company, and the card company will only know total amount and the fact that the agreement has been reached between the purchaser and the shop for the order.  
      The card company server  150  performs the electronic signature check of the CA electronically-signed shop server electronic certificate  401  and executes a shop server authentication (S 44 ). If the authentication succeeds, the shop server public key  602  is stored, which is included in the shop server electronic certificate.  
       FIG. 8  is used from here. Subsequently, the card company server  150  performs the electronic signature check of the CA electronically-signed purchaser portable terminal electronic certificate  302  and executes a personal authentication (S 45 ). If the authentication succeeds, the purchaser portable terminal public key  403  is stored, which is included in the purchaser portable terminal electronic certificate. Then, the encrypted settlement information  701  is decrypted using the card company server private key (S 46 ). The credit information is picked up from the settlement information and a settlement authentication is executed by performing the credit examination (S 47 ). Further, the electronic signature check is performed for the shop server electronically-signed message digest  702  to confirm that the agreement has been reached between the purchaser and the shop for the order (S 48 ). Although the card company server  150  can not comprehend the direct order information  402 , the card company server  150  can confirm that the seller has checked the details of the order information  402  from the purchaser in step S 42 . Then, a sent message digest  702  is compared to a message digest which has been generated from the order information  402  and which is obtained when the settlement information  304  is decrypted (S 49 ). The comparison is performed in order to confirm whether the settlement amount is based on the order information  402 . If results of the comparison are the same, it is confirmed that the amount charged by the shop certainly is based on the order information  402  of the purchaser. In order to notify the shop of a result of the examination, a card company server electronically-signed examination result  801  is generated (S 50 ) The card company server  150  send to the shop server the card company server electronically-signed examination result  801  and the settlement information  701  encrypted with the card company server public key  603  (S 51 ).  
       FIG. 9  is used from here. The shop server  110  performs the electronic signature check of the card company server electronically-signed examination result  801  and completes the settlement authentication with the examination result (S 52 ). In order to notify the purchaser, a shop server electronic signature is generated using the examination result as base data, and a shop server electronically-signed examination result  901  is generated (S 53 ). The shop server electronically-signed examination result  901  and the settlement information  701  encrypted with the card company server public key  603  are sent to the client computer  120 .  
      The communication intermediation program  122  transfers the shop server electronically-signed examination result  901  and the encrypted settlement information  701  to the purchaser portable terminal  130  (S 55 ).  
      The IC card  132  in the purchaser portable terminal  130  performs the electronic signature check of the shop server electronically-signed examination result  901 , and after the credibility is confirmed, the examination results is checked (S 56 ). At this point, the purchaser portable terminal notifies the client computer of completion of entire processing and, for example, the notification may be displayed by the browser. In this way, the third embodiment is terminated.  
      According to the embodiment, while using the client computer with a large screen for selecting the product, the personal authentication and the settlement authentication can be completed using the personal identification information which is stored in the IC card in the purchaser portable terminal and which is less likely to be leaked to the third party, and also directly utilizing the existing mechanism of SET. Therefore, while maintaining an environment for facilitating the internet shopping, not only the spoofing can be prevented which is caused by readout of the personal identification information from the hard disk of the client computer, but also the spoofing can be prevented which is caused by eavesdropping of the communication among the purchaser portable terminal, the client computer, the shop server and the card company server, and further, if equipment for SET have been installed, the equipment can be directly utilized, resulting in a benefit that the past equipment investment does not hove to be wasted.  
      Above described embodiments of the present invention are not limited to the authentication processing associated with the purchase transaction conducted by the shop server and can be applied to the authentication processing associated with other transactions.  
     Industrial Applicability  
      As described above, according to the present invention, in the Internet shopping, while using the client computer with a large screen for selecting the product, an environment can be provided for a personal authentication and a settlement authentication without storing personal identification information of the purchaser into a hard disk of the client computer which the possibility that data can be read out by a third party, so that the spoofing can be prevented. Further, by using an encryption function included in an IC card in a purchaser portable terminal, communication data can be protected between a server and the purchaser portable terminal, so that the spoofing can be prevented, which is due to eavesdropping of the personal identification information.