Method and system for electronic authentification

An electronic authentication method for identifying a user who is going to use a recording medium into which the information for making use of any kind of computerized service has been stored, comprising a step to carry out authentication by comparing the authentication information input by the user who is going to use the recording medium into which the information for making use of any kind of computerized service has been stored with the authentication information recorded on the recording medium and a step to carry out authentication by comparing the authentication information input by the user or the authentication information recorded on the recording medium with the registered authentication information existing in the hub of the networking to provide the service.

BACKGROUND OF THE INVENTION

The prevent invention relates to an electronic authentication system for identifying a user who is going to use a recording medium in which information for making use of any kind of computerized service has been stored. More particularly, the invention relates to technology effective for application to an electronic authentication system for identifying a person who is going to use an IC card as the valid possessor of the IC card on which information has been stored for making use of any kind of computerized service. The invention is applicable, to e.g., a digital money system, a computerized certificate card of residence issued by a local government, or a home security system assuring lock/unlock conditions under centralized supervision.

Nowadays, systems have been devised to provide a certain kind of computerized service, such as, for example, a digital money system, a computerized certificate card of residence issued by a local government, or a home security system assuring lock/unlock conditions under centralized supervision, by storing the information for such service on a card-shaped recording medium and implementing the service, based on the information recorded on the card when the service is requested. When any of these systems provides service in this way through a card on which information for making use of the service has been stored, authentication is necessary to establish that the person who is going to use the card is a valid user of the card. For example, a system that allows a person to pay for purchased goods using a credit card generally uses an authentication method in which the system is given the code number of the person who is using the card for payment when identifying the card user.

Japanese Patent Prepublication No. Hei 10-149103 describes an authentication method and an authentication system in which it is possible to detect a counterfeit IC card offline from the central computer; i.e., there is no need for online communication between an electronic commerce and settlement terminal and the central computer for user authentication.

Japanese Patent Prepublication No. Hei 11-282998 describes a method of identifying a user of a communication system, which method is applied to communication systems comprising user cards, communication terminals and communication servers. According to this method, in the user authentication protocol to be completed when connecting a communication terminal to a communication server, the user operation is simple and data transmission and reception between the terminal and the server for user authentication are required only once.

Because the above-mentioned previous systems using cards carry out user authentication based on the code number of a specific user, a problem is encountered in that there is a possibility of cheating in settling an account using a stolen card, a counterfeit card, or the necessary code number acquired by dishonest means. In the present situation, there are no generally practicable methods which represent an alternative to the method of the present invention. In the future, electronic settlement and similar procedures using cards are expected to be prevalent, and so it will be important in carrying out such procedures to identify a person who is using the card.

SUMMARY OF THE INVENTION

The present invention has the object of providing a technology that solves the above problem and makes it possible to prevent cheating in the use of a recording medium on which information for making use of any kind of computerized service has been stored and to carry out authentication applicable to various computerized settlement systems and procedures at any place or any authentication level required.

In an electronic authentication system for identifying a user who is going to use a recording medium on which information for making use of any kind of computerized service has been stored, the present invention implements authentication of the user by using authentication information presented by the user, the authentication information recorded on the recording medium, and the registered authentication information existing in the hub of the network to provide the service.

In acccordance with the present invention, a user who wants to use a certain computerized service must, in advance, register authentication information for identifying the user with the central equipment in the hub of the network which is to provide the service. The central equipment records the authentication information on a recording medium and issues the recording medium to the user. Thus, the user gets his or her own recording medium in advance.

For example, a picture of the user's face, the image of a seal, or a signature is read by an image recognizing device, a seal reader, or a signature reader and is digitized. The central equipment of the electronic authentication system registers the digitized authentication information into a personal authentication information table for centralized management, stores the information on an IC card, and issues the card to the user.

When the user is going to use the service, the user inputs the user's authentication information and the authentication information recorded on the recording medium that the user has with him or her. Authentication is carried out by comparing the authentication information input by the user and the authentication information recorded on the recording medium.

Specifically, client-end equipment of the electronic authentication system includes peripheral devices, such as the above-mentioned image recognizing device, seal reader, and signature reader, and an IC card reader. These devices scan the user's face, a seal, and a signature, if appropriate, and input the resulting images to the equipment. At the same time, the IC card reader reads the authentication information from the IC card, such as the image of a face, the image of a seal, and a signature. The equipment compares the face image, seal, and signature input by the user with the corresponding authentication information read from the IC card, such as face image data, seal image data, and signature data and checks for a match between them.

According to a preset condition, further authentication is carried out by comparing the authentication information input by the user or the authentication information recorded on the recording medium with the registered authentication information existing at the central equipment. According to the result of this authentication, the electronic authentication system judges whether the user who is going to use the recording medium is a valid registered user for the service.

Because the electronic authentication system of the present invention executes user authentication by using authentication information input by the user who is going to use the recording medium, the authentication recorded on the recording medium, and the authentication information registered at the central equipment, as described above, the system can prevent cheating in the use of the recording medium on which information for making use of any kind of computerized service has been stored. Furthermore, the system can carry out authentication applicable to various computerized settlement systems and procedures at any place or any authentication level required.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As a preferred embodiment of the invention, an electronic authentication system for identifying a user who is going to use an IC card will be explained.

FIG. 1is a schematic diagram outlining the electronic authentication system of the present embodiment. As shown inFIG. 1, the electronic authentication system of the present embodiment essentially comprises a central electronic authentication equipment101, a client-end electronic authentication equipment102, and an IC card103.

The central electronic authentication equipment101stores authentication information in its authentication information table, handles the issue of IC card103, and performs user authentication processing. The client-end electronic authentication equipment102handles user authentication at the client terminal. The IC card103is a recording medium on which information for making use of any kind of computerized service is stored.

FIG. 2is a block diagram showing a schematic structure of the central electronic authentication equipment101in the present embodiment. As shown inFIG. 2, the central electronic authentication equipment101comprises a CPU201, storage202, magnetic disk storage203, a keyboard204, a display device205, a CD-ROM drive206, an IC card read/write device207, an image recognizing device208, a seal reader209, a signature reader210, and an authentication information table211.

The CPU201controls all operations of the central electronic authentication equipment101. The storage202is a main storage into which various types of processing programs and data are loaded when required for controlling the operations of the central electronic authentication equipment101.

The magnetic disk storage203is a storage for storing varioius types of processing programs and data. The keyboard204is used for various input operations required for the registration of authentication information, the issue of an IC card103, and authentication processing.

The display device205displays various kinds of information for the registration of authentication information, the issue of an IC card103, and authentication processing. The CD-ROM drive206reads the contents of a CD-ROM on which various types of processing programs have been recorded.

The IC card read/write device207stores authentication information on the IC card103. The image recognizing device208is an interface for inputting, as image information, a picture of the face of the user who wants to recceive an IC card103on which information for making use of any kind of computerized service has been stored.

The seal reader209reads the image of a seal presented by the user as image information. The signature reader210reads the signature written by the user as image information. The authentication information table211is a table for storing the authentication information for identifying a user who wants to use any kind of computerized service.

In addition, the central electronic authentication equipment101includes an authentication information registration handling section220, an IC card issue handling section221, an authentication request acceptance handling section222, a secondary authentication handling section223, a historical record handling section224, and a historical authentication handling section225.

The authentication information registration handling section220registers the user supplied authentication information for identifying the user in the authentication information table211. The IC card issue handling section221records the authentication information registered in the authentication information table211on the IC card103and issues the card to the user.

The authentication request acceptance handling section222receives the authentication information input by the user who is going to use the IC card103or the authentication information recorded on the IC card103, accepts an authentication request from the client-end electronic authentication equipment102, and in reply to the request, sends the result of authentication executed by the central electronic authentication equipment101to the client-end electronic authentication equipment102.

The secondary authentication handling section223executes authentication by comparing the authentication information input by the user who is going to use the IC card103or the authentication information recorded on the IC card103with the authentication information registered in the central electronic authentication equipment101.

The historical record handling section224records an authentication acceptance number generated upon the acceptance of an authentication request from the client-end electronic authentication equipment102, an authentication request number generated upon the issue of an authentication request from the client-end electronic authentication equipment102, or the value of an authentication counter to count a properly completed authentication on the central electronic authentication equipment101.

The historical authentication handling section225executes authentication by comparing the authentication acceptance number, authentication request number, or authentication counter value recorded on the IC card103with the authentication acceptance number, authentication request number, or authentication counter value recorded in the central electronic authentication equipment101.

Programs to control the operation of the authentication information registration handling section220, the IC card issue handling section221, the authentication request acceptance handling section222, the secondary authentication handling section223, the historical record handling section224, and the historical authentication handling section225in the central electronic authentication equipment101are stored on a recording medium, such as a CD-ROM. After being stored on a magnetic disk, these programs shall be loaded into the main storage and run. A recording medium alternative to the CD-ROM may be used to record the programs.

FIG. 3is a block diagram showing a schematic structure of the client-end electronic authentication equipment102in the present embodiment. As shown inFIG. 3, the client-end electronic authentication equipment102comprises, a CPU301, storage302, magnetic disk storage303, a keyboard304, a display device305, a CD-ROM drive306, an IC card read/write device307, an image recognizing device308, a seal reader309, a signature reader310, and an authentication level table311.

The CPU301controls all operations of the client-end electronic authentication equipment102. The storage302is a main storage into which various types of processing programs and data are loaded when required for controlling the operations of the client-end electronic authentication equipment102.

The magnetic disk storage303is a storage for storing various types of processing programs and data. The keyboard304is used for various input operations required for authentication processing. The display device305displays various kinds of information for authentication processing.

The CD-ROM drive306reads the contents of a CD-ROM on which types of processing programs have been recorded. The IC card read/write device307reads/writes authentication information from/into the IC card103.

The image recognizing device308is an interface for inputting a picture of the face of the user, who is going to use the IC card103, in the form of image information. The seal reader309reads the image of a seal, presented by the user, in the form of image information.

The signature reader310reads the signature written by the user as image information. The authentication level table311stores the information that indicates what level of authentication processing is to be executed by the client-end electronic authentication equipment102and the central electronic authentication equipment101.

In addition, the client-end electronic authentication equipment102includes a primary authentication handling section320, an authentication request handling section321, an authentication result output handling section322, a historical record handling section323, and a service implementing section324.

The primary authentication handling section320executes authentication by comparing the authentication information input by the user who is going to use the IC card103with the authentication information recorded on the IC card103. The authentication request handling section321sends the authentication information input by the user who is going to use the IC card103or the authentication information recorded on the IC card103to the central electronic authentication equipment101, thus issuing an authentication request thereto, and receives the result of authentication executed by the central electronic authentication equipment101.

The authentication result output handling section322judges whether the central electronic authentication equipment101has identified the user from the authentication information input by the user or the authentication information recorded on the IC card103, according to the result of authentication received from the central electronic authentication equipment101, and outputs the result of authentication.

The historical record handling section323records an authentication acceptance number which is generated upon the acceptance of an authentication request, an authentication request number which is generated upon the issue of an authentication request, or the value of an authentication counter to count a properly completed authentication on the IC card103. In conjunction with the IC card103, the service implementing section324executes a processing for making use of any kind of computerized service; e.g., a digital money system, a computerized certificate card of residence issued by a local government, or a home security system assuring lock/unlock conditions under centralized supervision.

Programs to control the operation of the primary authentication handling section320, the authentication request handling section321, the authentication result output handling section322, the historical record handling section323, and the service implementing section324of the client-end electronic authentication equipment102are recorded on a recording medium, such as a CD-ROM. After being stored on a magnetic disk, these programs shall be loaded into the main storage and run. A recording medium alternative to the CD-ROM may be used to record the programs.

FIG. 4is a block diagram showing a schematic structure of the IC card103in the present embodiment. As shown inFIG. 4, the IC card103comprises a CPU401, a RAM402, an EEPROM403, a ROM404, a power supply405, a send/receive section406, an authentication information table407, and information for service408.

The CPU401controls all operations of the IC card103. The RAM402is a storage into which various types of processing programs and data are loaded when required for controlling the operations of the IC card103. The EEPROM403is a storage for storing the authentication information table407.

The ROM404is a storage for storing various types of processing programs and data, such as an operating system for controlling all operations of the IC card103. The power supply405operates to supply all parts of the IC card103with the electric power required for operation.

The send/receive section406is provided for inputting and outputting data from/to the central electronic authentication equipment101and the client-end electronic authentication equipment102. The authentication information table407stores the authentication information for identifying the user who wants to use any kind of computerized service. The information for service408is information for making use of any kind of computerized service; e.g., a digital money system, a computerized certificate card of residence issued by a local government, or a home security system assuring lock/unlock conditions under centralized supervision.

In addition, the IC card103includes an authentication information storing section410, an authentication information reference handling section411, and a service implementing section412.

The authentication information storing section410stores authentication information sent from the central electronic authentication equipment101and the client-end electronic authentication equipment102into the authentication information table407. The authentication information reference handling section411reads the authentication information from the authentication information table407and sends it to the client-end electronic authentication equipment102.

In conjunction with the client-end electronic authentication equipment102, the service implementing section412executes processing for making use of any kind of computerized service, such as, for example, a digital money system, a computerized certificate card of residence issued by a local government, or a home security system assuring lock/unlock conditions under centralized supervision, by using the information for service408.

Programs to control the operation of the authentication information storing section410, the authentication information reference handling section411, and the service implementing section412of the IC card103are recorded on a recording medium, such as a ROM and shall be run when necessary. A recording medium alternative to the ROM may be used to record the programs.

In the present embodiment, the client-end electronic authentication equipment102to provide the user with any kind of computerized service sets an authentication processing level suitable for the service of implementation in the authentication level table311; the service is, for example, a digital money system, a computerized certificate card of residence issued by a local government, or a home security system assuring lock/unlock conditions under centralized supervision.

FIG. 5is a diagram schematizing the authentication level table311in the present embodiment. As shown inFIG. 5, the authentication level table311comprises four data items: what is subjected to authentication by image501, authentication level502, acceptable range of image recognition (from)503, and acceptable range of image recognition (to)504.

What is subjected to authentication by image501is data to indicate what image information is subjected to authentication by an image. Authentication level502is data to indicate what level of authentication processing is to be executed by the client-end electronic authentication equipment102and the central electronic authentication equipment101.

Acceptable range of image recognition (from)503is the minimum extent to which the two images match up when judged to be matching by comparison. Acceptable range of image recognition (to)504is the maximum extent to which the two images match up when judged to be matching by comparison.

In the authentication level table311in the present embodiment, the above data items are set, depending on how high the security is required to be for the computerized service of implementation; e.g., a digital money system, a computerized certificate card of residence issued by a local government, or a home security system assuring lock/unlock condition under centralized supervision.

For example, if authentication by an image is required, as the data item of what is subjected to authentication by image501, data such as “user's face,” “image of a seal,” or “signature” is set to specify a type of image information. If authentication by an image is not necessary, data to specify “authentication by ID” is set. “Authentication by ID” indicates authentication by a user ID number and a password and authentication processing on the basis of an authentication acceptance number, an authentication request number, or an authentication counter value.

For the authentication level502, data to designate “authentication level A,” “authentication level B,” or “authentication level C” is set. “Authentication level A” means that the client-end electronic authentication equipment102executes primary authentication and the central electronic authentication equipment101executes secondary authentication for all authentication information. By thus executing authentication processing by both the client-end electronic authentication equipment102and the central electronic authentication equipment101, protection against imitating the IC card103is provided and more reliable and firm authentication processing can be executed.

“Authentication level B” means that after the client-end electronic authentication equipment102executes primary authentication, the central electronic authentication equipment101executes secondary authentication as in “authentication level A”, except that the central electronic authentication equipment101does not execute authentication using image information during the secondary authentication. Instead, the central electronic authentication equipment101executes authentication based on only numerical information (such as user ID, password, authentication acceptance number, authentication request number, or authentication counter value). “Authentication level C” means that the client-end electronic authentication equipment102completes the authentication procedure.

If “authentication by ID,” which means that authentication by an image is not executed, is set for what is subjected to authentication by image501, the authentication level502is set at “authentication level A” with the acceptable range of image recognition (from)503and acceptable range of image recognition (to)504being “0%.”

In the present embodiment, on the other hand, a user who wants to use a certain computerized service must initially input the authentication information for identifying the user to the system and register with the central electronic authentication equipment101where the authentication information is registered in the authentication information table211. The authentication information is then recorded on the IC card103that is in turn issued to the user. In this way, the user must get his or her own IC card103in advance.

FIG. 6is a diagram schematizing the authentication information table211in the present embodiment. As shown inFIG. 6, the authentication information table211comprises data items: user ID601, user password602, personal authentication information603, authentication information on the equipment that issued the card604, image information605to607, authentication acceptance number608, authentication request number609, and authentication counter601.

User ID601is an identifier to identify the user who registered his or her authentication information with the central electronic authentication equipment101. User password602is the set password of the user. Personal authentication information603is a hash value specific to each user, set to identify the user.

Authentication information on the equipment that issued the card604is a hash value to identify the central electronic authentication equipment101that issued the IC card103on which the registered authentication information has been stored. Image information605to607are image data of a user's face, image of a seal, and a signature that have been registered as authentication information.

Authentication acceptance number608is the authentication number (random number) set the last time the central electronic authentication equipment101accepted an authentication request from the client-end electronic authentication equipment102. Authentication request number609is the authentication number (random number) set the last time the client-end electronic authentication equipment102issued an authentication request to the central electronic authentication equipment101. Authentication counter610is data to count successfully completed authentication of the user who is going to use the IC card103as the valid possessor of the IC card103.

When registering a user who wants to use a certain computerized service in the present embodiment, first, the authentication information registration handling section220of the central electronic authentication equipment101writes user ID601of the user and user password602input by the user into the appropriate setting fields of the authentication information table211.

Next, the authentication information registration handling section220generates a hash value that is specific to the user for identifying the user and writes the hash value into the setting field of personal authentication information603, and then sets a hash value for identifying the central electronic authentication equipment101and writes it into the setting field of authentication information on the equipment that issued the card604.

Then, using the image recognizing device208, seal reader209, or signature reader210, the authentication information registration handling section220reads the picture of the user's face, a print of the seal presented by the user, or the signature written by the user, which is specified as that which is subjected to authentication by an image to acquire the image information. After embedding the personal authentication information603as a digital watermark into the image in order to detect imitation of the image if a counterfeit should be used, the authentication information registration handling section220stores the image into the appropriate one of the fields of image information605to607. Besides, the authentication information registration handling section220initializes the values of authentication acceptance number608, authentication request number609and authentication counter610to “0.”

Next, the IC card issue handling section221of the central electronic authentication equipment101records the authentication information thus registered in the authentication information table211into the authentication information table407of the IC card103and issues the IC card103to the user.

FIG. 7is a diagram schematizing the authentication information table407in the present embodiment. As shown inFIG. 7, the authentication information table407comprises data items: user ID701, user password702, personal authentication information703, authentication information on the equipment that issued the card704, image information705to707, authentication acceptance number708, authentication request number709, and authentication counter710, and counter of authentication completed without referring to central equipment711.

User ID701is an identifier to identify the valid user of the IC card103. User password702is the set password of the user. Personal authentication information703is a hash value specific to each user, set to identify the user.

Authentication information on the equipment that issued the card704is a hash value to identify the central electronic authentication equipment101that issued the IC card103. Image information705to707are image data of user's face, an image of the seal, and a signature of the valid user of the IC card103, respectively.

Authentication acceptance number708is the authentication number (random number) set the last time the central electronic authentication equipment101accepted an authentication request from the client-end electronic authentication equipment102. Authentication request number709is the authentication number (random number) set the last time the client-end electronic authentication equipment102issued an authentication request to the central electronic authentication equipment101.

Authentication counter710is data to count successfully completed authentication of the user who is going to use the IC card103as the valid possessor of the IC card103. Counter of authentication completed without referring to central equipment711is data to count successfully completed authentication of the user who is going to use the IC card103as the valid possessor of the IC card103, completed without issuing an authentication request to the central electronic authentication equipment101.

The IC card issue handling section221of the central electronic authentication equipment101in the present embodiment sends to the IC card103the foregoing authentication information registered in the authentication information table211to which the data item of counter of authentication completed without referring to central equipment711has been added, and instructs the IC card103to store that information. The authentication information storing section410of the IC card103receives the authentication information sent from the central electronic authentication equipment101and stores it into the authentication information table407.

FIG. 8is a flowchart illustrating the procedure for authentication processing to be executed by the client-end equipment in the present embodiment. A user who is seeks to obtain a certain computerized service sets the IC card103that the user has with him or her on the IC card read/write device307of the client-end electronic authentication equipment102. The user commands the client-end equipment102to start authentication processing via the keyboard304, then the primary authentication handling section320begins to operate.

In step801, the primary authentication handling section320of the client-end electronic authentication equipment102accepts the password input by the user who is going to use the IC card103. In step802, the primary authentication handling section320instructs the IC card103of the user via the IC card read/write device307to send the contents of the authentication information table407. The authentication information reference handling section411of the IC card103reads the authentication information from the authentication information table407and sends it to the client-end electronic authentication equipment102.

In step803, the primary authentication handling section320judges whether the password input by the user matches the user password702existing in the authentication information table407of the IC card103. If both match up, the processing proceeds to step804. If both do not match, the authentication processing terminates with the display of a message of unsuccessful authentication in step821.

In step804, the primary authentication handling section320reads the appropriate one of image information705to707from the authentication information table407of the IC card103and extracts the digital authentication information, namely, the embedded digital watermark from the appropriate image among the image information705to707.

In step805, the primary authentication handling section320judges whether the digital authentication information extracted from among the image information705to707matches the personal authentication information703existing in the authentication information table407of the IC card103. If both match up, the processing proceeds to step806. If both do not match, the authentication processing terminates with the display of a message of unsuccessful authentication in step821.

In step806, the primary authentication handling section320reads the authentication level table311stored into the magnetic disk storage303of the client-end electronic authentication equipment102.

In step807, the primary authentication handling section320judges whether there is what is subjected to authentication by image by referring to the data item of what is subjected to authentication by image501in the authentication level table311. If image information to be subjected to authentication by image is set for the above data item, the processing proceeds to step808. If none of image information to be subjected to authentication by image is set, the processing proceeds to step810.

In step808, by using the image recognizing device308, seal reader309, or signature reader310of the client-end electronic authentication equipment, the primary authentication handling section320reads the image of the user's face, a print of the seal presented by the user, or the signature written by the user which is indicated by what is subjected to authentication by image501to acquire the required image information. Then, the primary authentication handling section320compares the acquired image with the image data existing in the appropriate field among image information705to707stored in the authentication information table407of the IC card103.

In step809, the primary authentication handling section320judges whether the extent to which the acquired image of the user's face, the print of the seal, or signature matches the corresponding image information existing in the authentication information table407falls within the range specified by the acceptable range of image recognition (from)503and acceptable range of image recognition (to)504. If the above comparison falls within the specified range, the processing proceeds to step810. If the above comparisono falls outside the specified range, the authentication processing terminates with the display of a message of unsuccessful authentication in step821.

In step810, the primary authentication handling section320finds what is the authentication level502: “authentication level A,” “authentication level B,” or “authentication level C.” If the authentication level502is “authentication level A” or “authentication level B,” the processing proceeds to step811.

In step811, a random number is generated as an authentication request number that is unique to an authentication request that the client-end electronic authentication equipment102is now going to issue to the central electronic authentication equipment101. In step812, the authentication request handling section321sends the thus generated current authentication request number and the contents of the authentication level502and the authentication information table407to the central electronic authentication equipment101, thus issuing the authentication request thereto.

In step813, the authentication request handling section321receives the result of authentication from the central electronic authentication equipment101. In step814, the authentication result output handling section322judges whether the central electronic authentication equipment101has identified the user by referring to the contents of the authentication information table407, according to the result of authentication received. If authentication is successful, according to the contents of the authentication information table407, the processing proceeds to step815. If authentication is unsuccessful, the authentication processing terminates with the display of a message of unsuccessful authentication in step821.

In step815, the historical record handling section323sends to the IC card103the current authentication acceptance number that has now been generated by the central electronic authentication equipment101, the current authentication request number generated under step811upon the issue of the authentication request, and the authentication counter value incremented by the central electronic authentication equipment101, and the value of the counter of authentication completed without referring to central equipment711which has been initialized to “0” and instructs the IC card103to store them. The authentication information storing section410of the IC card103stores the authentication acceptance number, authentication request number, authentication counter value, and the value of the counter of authentication completed without referring to central equipment711received from the client-end electronic authentication equipment102into the authentication information table407.

As the result of step810, if the authentication level502in the authentication level table311is “authentication level C,” the processing proceeds to step820. In step820, the historical record handling section323increments the authentication counter710and the counter of authentication completed without referring to central equipment711by one, sends the values of these counters to the IC card103, and instructs the IC card103to store them. The authentication information storing section410of the IC card103stores the authentication counter value and the value of the counter of authentication completed without referring to central equipment711received from the client-end electronic authentication equipment102into the authentication information table407.

In step816, the authentication result output handling section322displays a message indicating that the user who is going to use the IC card103has been identified as the valid possessor of the IC card103. In step817, the service implementing section324, in conjunction with the service implementing section412of the IC card103, executes the processing for making use of a certain computerized service; e.g., a digital money system, a computerized certificate card of residence issued by a local government, or a home security system assuring lock/unlock conditions under centralized supervision.

FIG. 9is a flowchart explaining the procedure for authentication processing to be executed by the central equipment in the present embodiment. In step901, the authentication request acceptance handling section222of the central electronic authentication equipment101receives an authentication request sent from the client-end electronic authentication equipment102and accepts the authentication request.

In step902, the secondary authentication handling section223reads the record associated with the user ID701received from the client-end electronic authentication equipment102out of the authentication information table211from the magnetic disk storage203.

In step903, the secondary authentication handling section223judges whether the user password702received from the client-end electronic authentication equipment102matches the user password602existing in the authentication information table211of the central electronic authentication equipment101. If both match up, the processing proceeds to step904. If both do not match, the indication “unsuccessful” is set as the result of authentication and the processing proceeds to step916.

In step904, the secondary authentication handling section223judges whether the personal authentication information, namely, the embedded digital watermark in the appropriate image among the image information705to707received from the client-end electronic authentication equipment102matches the personal authentication information603existing in the authentication information table211of the central electronic authentication equipment101. If both match up, the processing proceeds to step905. If both do not match, the indication “unsuccessful” is set as the result of authentication and the processing proceeds to step916.

In step905, the historical authentication handling section225judges whether the authentication acceptance number708received from the client-end electronic authentication equipment102matches the authentication acceptance number608existing in the authentication information table211of the central electronic authentication equipment101. If both match up, the processing proceeds to step906. If both do not match, the indication “unsuccessful” is set as the result of authentication and the processing proceeds to step916.

In step906, the historical authentication handling section225judges whether the value of the counter of authentication completed without referring to central equipment711received from the client-end electronic authentication equipment102is “0.” If the value of the counter of authentication completed without referring to central equipment711is “0,” the processing proceeds to step907. If the value is not “0,” the processing proceeds to step908.

In step907, the historical authentication handling section225judges whether the value of the authentication counter710received from the client-end electronic authentication equipment102matches the value of the authentication counter610existing in the authentication information table211of the central electronic authentication equipment101. If both match up, the processing proceeds to step909. If both do not match, the indication “unsuccessful” is set as the result of authentication and the processing proceeds to step916.

In step908, the historical authentication handling section225judges whether the value resulting from subtracting the value of the counter of authentication completed without referring to central equipment711from the value of the authentication counter710received from the client-end electronic authentication equipment102matches the value of the authentication counter610existing in the authentication information table211of the central electronic authentication equipment101. If both match up, the processing proceeds to step909. If both do not match, the indication “unsuccessful” is set as the result of authentication and the processing proceeds to step916.

In step909, the historical authentication handling section225judges whether the last-time authentication request number709received from the client-end electronic authentication equipment102matches the authentication request number609existing in the authentication information table211of the central electronic authentication equipment101. If both match up, the processing proceeds to step910. If both do not match, the indication “unsuccessful” is set as the result of authentication and the processing proceeds to step916.

In step910, the secondary authentication handling section223judges whether the personal authentication information703and the authentication information on the equipment that issued the card704received from the client-end electronic authentication equipment102matches the personal authentication information603and the authentication information on the equipment that issued the card604existing in the authentication information table211of the central electronic authentication equipment101. If both match up, the processing proceeds to step911. If both do not match, the indication “unsuccessful” is set as the result of authentication and the processing proceeds to step916.

In step911, the secondary authentication handling section223finds what is the authentication level502received from the client-end electronic authentication equipment102. If the authentication level is “authentication level A,” the processing proceeds to step912. If the authentication level is “authentication level B,” the processing proceeds to step914.

In step912, the secondary authentication handling section223compares the appropriate image among image information705to707received from the client-end electronic authentication equipment102with the corresponding image among image information605to607existing in the authentication information table211of the central electronic authentication equipment101.

In step913, the secondary authentication handling section223judges whether the appropriate image among image information705to707received from the client-end electronic authentication equipment102matches the corresponding image among image information605to607existing in the authentication information table211of the central electronic authentication equipment101. If both match up, the processing proceeds to step914. If both do not match, the indication “unsuccessful” is set as the result of authentication and the processing proceeds to step916.

In the present embodiment, authentication by an image is performed by comparing the appropriate image among image information705to707in the authentication information table407of the IC card103with the corresponding image among image information605to607in the authentication information table211of the central electronic authentication equipment101. Alternatively, authentication by an image may be performed by comparing the image information input by the user through the client-end electronic authentication equipment102with the corresponding image among image information605to607in the authentication information table211of the central electronic authentication equipment101.

In step914, a random number is generated as an authentication acceptance number that is unique to the authentication request that the central electronic authentication equipment101has now accepted. In step915, the historical record handling section224sets the thus generated current authentication acceptance number and the current authentication request number generated by the client-end electronic authentication equipment102for authentication acceptance number608and authentication request number609in the authentication information table211. The historical record handling section224increments by one the value of the authentication counter received from the client-end electronic authentication equipment102and sets the incremented value for authentication counter610in the authentication information table211. Furthermore, the thus generated current authentication acceptance number, the newly set authentication counter610, and the data indicating successful authentication are set as the result of authentication and the processing proceeds to step916.

In step916, the authentication request acceptance handling section222sends the result of authentication as set through the foregoing processing to the client-end electronic authentication equipment102.

Although the invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form may be changed in the details of construction and the combination and arrangement of parts without departing from the spirit and the scope of the invention as hereinafter claimed.