Validity checking system, validity checking method, information processing card, checking device, and authentication apparatus

OBJECTIVEA user is prevented from inadvertently inputting authentication information to an unauthorized authentication system. In this manner, authentication information leakage is certainly avoided.SOLUTIONA validity checking system includes an information processing card, an authentication system that performs mutual authentication with the information processing card, and a checking device. The information processing card includes a validity authenticating means that authenticates the validity of the authentication system, and an impersonation preventing means that carries out an impersonation preventing process on the result of the authentication performed by the validity authenticating means. The checking device includes a verifying means that verifies the authentication result subjected to the impersonation preventing process and is output from the information processing card, and a verification result output means that outputs the result of the verification performed by the verifying means to a user in a perceptible manner. The verifying means may not be provided in the checking device, and an independent verification device may be provided.

TECHNICAL FIELD

The present invention relates to a validity checking system, a validity checking method, an information processing card, a checking device, and an authentication device. For example, the present invention is to be applied to a validity checking system, a validity checking method, an IC card, a checking device, and an authentication device that prevent leakage of the authentication information about a user due to impersonation in an authentication system using an IC card, and realize a safe computer system. This patent application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2006-254365, filed on Sep. 20, 2006, and the entire contents of which are incorporated herein by reference.

BACKGROUND ART

In an authentication system for a computer system that uses an IC (integrated circuit) card, it is necessary to perform identity authentication to confirm that the user is the authorized holder of the IC card, so as to prevent unauthorized use of the IC card through a theft or the like, as disclosed in Patent Document 1. Normally, a password called PIN (personal identification number) is used in such identity authentication.

In this authentication system, mutual authentication is performed between the IC card and the authentication system terminal, so as to prove that the IC card is not an unauthorized card issued by counterfeiting or alteration, and the authentication system terminal is not an unauthorized terminal.

This technique is known as internal authentication for authenticating the validity of the IC card when seen from the side of the authentication system terminal, and is also known as external authentication for authenticating the validity of the authentication system terminal when seen from the side of the IC card.

The authentication system terminal is then put into a password input waiting state. The user inputs the password to the authentication system terminal, and the input password is compared with a password stored beforehand in the IC card, so as to perform the identity authentication.

In the above procedures, however, the authentication system terminal that requires a password has not been proved to be valid for the user.

More specifically, in a case where an unauthorized terminal is modified so as to look as if rightfully authenticated, the user cannot determine that the terminal is an unauthorized terminal. Therefore, the user is always exposed to the danger of wrongful use or theft of the password through an impersonating authentication system terminal.

To solve the above problem, Patent Document 1 discloses a device that prevents password leakage. The device has a means that reads secret information available only to a subject user from an IC card, after authenticating the validity of an authentication system terminal. The unit presents the secret information to the user, and then requests the user to input the password.Patent Document 1: Japanese Patent Application Laid-Open No. 7-141480

DISCLOSURE OF THE INVENTION

Problems to be Solved by the Invention

By the technique disclosed in Patent Document 1, however, there is a possibility that a third party with intentions takes a look at the contents of the secret information available only to the user, when the secret information is displayed on the terminal in a conventional password leakage prevention device.

There still remains the problem of the risk that the password of the user is wrongfully used, if the stolen secret information is used to a forged impersonating authentication system terminal or the like.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a validity checking system, a validity checking method, an information processing card, a checking device, and an authentication device that enable the holder of the information processing card such as an IC card to check the result of authentication so as to determine whether authentication of the validity of the authentication system has been performed properly with the information processing card, and prevent the user from inadvertently inputting authentication information to a forged authentication system terminal, so as to certainly avoid authentication information leakage.

Means to Solve the Problems

A validity checking system according to the present invention includes an information processing card that has an information processing function, and an authentication system that performs mutual authentication with the information processing card. In this validity checking system, the information processing card includes:

a validity authenticating means that authenticates the validity of the authentication system; and

an impersonation preventing means that carries out an impersonation preventing process on the result of the authentication performed by the validity authenticating means, and

the validity checking system further includes

a checking device that includes a verifying means that receives the authentication result that is subjected to the impersonation preventing process and is output from the information processing card, and verifies the authentication result, and a verification result output means that outputs the result of the verification performed by the verifying means to a user in a perceptible manner.

A validity checking system according to the present invention includes an information processing card that has an information processing function, and an authentication system that performs mutual authentication with the information processing card. In this validity checking system, the information processing card includes:

a validity authenticating means that authenticates the validity of the authentication system; and

an impersonation preventing means that performs an impersonation preventing process on the result of the authentication performed by the validity authenticating means, and

the validity checking system further includes:

a verification device that includes the verifying means that receives the authentication result that is subjected to the impersonation preventing process and is output from the information processing card, and verifies the authentication result; and

a checking device that includes a verification result output means that outputs the result of the verification received from the verification device to a user in a perceptible manner.

A validity checking method according to the present invention is used in a validity checking system that includes an information processing card, an authentication system that performs mutual authentication with the information processing card, and a checking device that receives information output from the information processing card.

This validity checking method includes:

a validity authenticating step that is carried out by the information processing card to authenticate the validity of the authentication system;

an impersonation preventing step that is carried out by the information processing card to carry out an impersonation preventing process on the result of the authentication performed in the validity authenticating step;

an authentication result outputting step that is carried out by the information processing card to output the authentication result subjected to the impersonation preventing process to outside;

a verifying step that is carried out by the checking device to receive the authentication result that is subjected to the impersonation preventing process and is output from the information processing card, and verify the authentication result; and

a verification result outputting step that is carried out by the checking device to output the result of the verification performed in the verifying step to a user in a perceptible manner.

A validity checking method according to the present invention is used in a validity checking system that includes an information processing card, an authentication system that performs mutual authentication with the information processing card, a verification device that receives information output from the information processing card, and a checking device that receives a verification result output from the verification device.

This validity checking method includes:

a validity authenticating step that is carried out by the information processing card to authenticate the validity of the authentication system;

an impersonation preventing step that is carried out by the information processing card to carry out an impersonation preventing process on the result of the authentication performed in the validity authenticating step;

an authentication result outputting step that is carried out by the information processing card to output the authentication result subjected to the impersonation preventing process to the verification device;

a verifying step that is carried out by the verification device to verify the authentication result subjected to the impersonation preventing process;

a first verification result outputting step that is carried out by the verification device to send the verification result to the checking device; and

a second verification result outputting step that is carried out by the checking device to output the verification result to a user in a perceptible manner.

Effects of the Invention

In accordance with the present invention, an IC card authenticates the validity of an IC card authentication system, and subjects the authentication result to an impersonation preventing process. The processed authentication result is transmitted to a checking device outside the IC card. The checking device or a verification device verifies the authentication result subjected to the impersonation preventing process, and outputs the verification result to the user of the IC card in a perceptible manner. In this manner, the user can be prevented from inadvertently inputting the authentication information to a forged authentication system. Thus, the present invention can provide a validity checking system, a validity checking method, an information processing card, a checking device, and an authentication device that can certainly prevent authentication information leakage.

EXPLANATION OF REFERENCE SYMBOLS

BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment

Structure of Authorization System

FIG. 1is a schematic view showing the structure of an authentication system using an IC card as a first embodiment of the present invention. The authentication system using an IC card shown inFIG. 1includes an IC card10, an authentication system terminal20, a portable checking device30, and a communication line40that connects the authentication system terminal20and the portable checking device30. The IC card10serves as an information processing card that has an information processing function.

The communication line40is a telephone line, the Internet, a radiowave connection (wireless communication), or the like.

When receiving various services with an IC card, a user inserts the IC card10to the authentication system terminal20, and inputs a password (equivalent to authentication information) through a keypad of the authentication system terminal20.

The authentication system terminal20uses the input password to perform user identity authentication. After succeeding in the user identity authentication, the authentication system terminal20provides services to the user.

FIG. 2is a block diagram showing the structure of the IC card10serving as the information processing card. The IC card10shown inFIG. 2includes a CPU (Central Processing Unit)11, a RAM (Random Access Memory)12, a ROM (Read Only Memory)13, an EEPROM (Electrically Erasable and Programmable Read-Only Memory)14, an interface unit15, and a contact terminal16.

The CPU11operates in accordance with a program, and controls the processing of the IC card10. The RAM12is a readable and writable volatile memory that stores programs and data. The ROM13is a read-only nonvolatile memory, and stores an authentication program17.

The CPU11reads the authentication program17into the RAM12. The CPU11executes the authentication program17read into the RAM12, so as to realize the function to authenticate the validity of the authentication system terminal20to which the IC card10is connected. Accordingly, the authentication program17and the CPU constitute the validity authenticating means.

In other words, a terminal authenticating function is realized by the CPU11executing the authentication program17.

The EEPROM14is a readable and writable nonvolatile memory that stores mostly data, such as a semiconductor memory or a flash memory. The EEPROM14stores a card secret key141, a card public key142, a card public key certificate143for the card public key142, and a certification authority public key144.

The card public key certificate143is a certificate for the card public key142signed in a predetermined format by a certification authority, for example. The card public key certificate143is decrypted by the certification authority public key144, and the card public key142is extracted.

As will be described later, the authentication system terminal20and the portable checking device30also store some of or all of a secret key, a public key, and a public key certificate. With the use of those keys and certificate, encrypted communications are performed between the IC card10and the authentication system terminal20, and the IC card10and the portable checking device30.

The EEPROM14stores the card holder authentication information145of the holder of the IC card10, such as the personal identification number and the password.

In addition to that, the EEPROM14stores notified party address information146. As will be described later, the portable checking device30is notified of terminal authentication results with the use of the notified party address information146in this embodiment.

Here, the notified party address information may be the identification number of the portable checking device30of the ID card holder, or an e-mail address of the IC card holder, for example.

The interface unit15is an interface unit for connecting with the authentication system terminal20. The contact terminal16is brought into contact with the contact terminal of the authentication system terminal20, so that the IC card10is connected to the authentication system terminal20.

Accordingly, the interface unit15controls data communications between the IC card10and the authentication system terminal20through serial input and output and the likes, so that communications can be made between the IC card10and the authentication system terminal20. The IC card10receives a power supply from the authentication system terminal20via the contact terminal16.

Although the IC card10shownFIG. 2is a contact-type IC card, it may be a non-contact type IC card that has an antenna coil and makes wireless communications with the authentication system terminal20. Alternatively, the IC card10may be a hybrid type IC card that has the features of both a contact type and a non-contact type, or may be of a two-way access type that can share one memory between two interface units.

FIG. 3is a block diagram showing the structure of the authentication system terminal20. The authentication system terminal20shown inFIG. 3includes a CPU21, a RAM22, a ROM23, an EEPROM24, an IC card interface unit25, a communication interface unit26, a keypad27, and a display28.

The CPU21controls the entire authentication system terminal20. The CPU21reads a program from the ROM23into the RAM22, and executes the program, so as to realize the later described authenticating function.

The RAM22is a volatile memory that stores data and programs. The ROM23is a nonvolatile memory that stores programs to be executed by the CPU21.

The EEPROM24stores a terminal secret key241, a terminal public key242, a terminal public key certificate243, and a certification authority public key244.

The terminal public key certificate243is a certificate for the terminal public key242signed in a predetermined format by a certification authority, for example. This terminal public key certificate243is decrypted with the certification authority public key244, so that the terminal public key242can be extracted.

Accordingly, in this authentication system, encrypted communications are made between the authentication system terminal20and the IC card10with the use of those keys and certificate and the likes.

In this embodiment, the certification authority public key242stored in the authentication system terminal20has the same contents as the certification authority public key144stored in the IC card10. Also, instead of the ROM23and the EEPROM24, a storage medium such as a hard disk can be used.

The IC card interface unit25is an interface that performs communications between the authentication system terminal20and the IC card10inserted to the card insertion slot.

The communication interface unit26is an interface unit that connects the authentication system terminal20to the communication line40. The communication interface unit26may be a modem connected to a telephone line, or a network interface unit connected to a LAN, for example. As will be described later, encrypted communications between the IC card10and the portable checking device30are performed through the communication interface unit26of the authentication system terminal20.

The keypad27is an input unit through which information is input to the authentication system terminal20. The user of the IC card10uses the keypad27to input the personal identification number.

The display28is a display unit that displays an operation instruction, a processing status, and the likes. More specifically, when the CPU21executes the authentication program, the result of the authentication performed on the connected IC card, a message for prompting an input of the personal identification number for user authentication, and the likes can be displayed on the display28.

FIG. 4is a block diagram showing the structure of the portable checking device30. Like a regular portable telephone handset, the portable checking device30shown inFIG. 4includes an antenna31and a radio unit32that perform wireless communications with a base station, a control unit33such as a CPU that operates in accordance with a program, a memory34, a display unit35formed with a liquid crystal display or the like, an operating unit36formed with a keyboard or the like, a speaker37, and a vibrator38.

The control unit33includes a voice communication function unit331and a mail transmitting and receiving function unit332that perform control operations for achieving the respective functions of a portable telephone handset.

In addition to the above components, the portable checking device30further includes a card public key39in which the public key data of the IC card10is stored. The card public key39is included as a component for realizing this embodiment.

The card public key39may be stored in the memory34, as shown inFIG. 4. As will be described later, encrypted communications are made between the portable checking device30and the IC card10with the use of the card public key39in this embodiment. Therefore, the place where the card public key39should be stored is not particularly limited.

In this embodiment, the contents of the card public key39stored in the portable checking device30are the same as the contents of the card public key142stored in the IC card10.

As described above, in this embodiment, before receiving services with the use of the IC card10, the user inserts the IC card10to the authentication system terminal20. Following the message displayed on the display28of the authentication system terminal20, the user inputs the personal identification number through the keypad27.

The authentication system terminal20then communicates with the IC card10, and performs authentication of the user based on the data held by the IC card10or the input personal identification number or the like. After the user is authenticated, services with the use of the IC card10are provided to the user in this embodiment.

(Procedures for Performing Authentication in Authentication System)

Referring now to the flowcharts shown inFIGS. 5 through 7, the authentication procedures with the use of the IC card10in the authentication system shown inFIG. 1are described.

FIG. 5is a flowchart showing the authentication procedures to be performed after the IC card10is inserted to the authentication system terminal20until the service providing operation is performed.

When the IC card10is inserted to the authentication system terminal20by a user in this authentication system, the IC card10and the authentication system terminal20authenticate the validity of each other (S5001). This authentication procedure (the procedures for performing mutual authentication) will be described later in detail, with reference toFIG. 6.

In this authentication system, the mutual authentication between the IC card10and the authentication system terminal20is performed first (seeFIG. 6), and the IC card10performs processing in accordance with the results of the mutual authentication.

When the validity of the authentication system terminal20is authenticated by the IC card10, the IC card10generates the data formed with the terminal authentication result (hereinafter referred to as the data M) (S5002).

The IC card10encrypts the data M with the use of the card secret key141, and generates encrypted data (hereinafter referred to as the encrypted data C) (S5003).

This encrypting operation is performed by the CPU11and the card secret key141with the use of a program stored in the ROM13. The program, the CPU11, and the card secret key141form the impersonation preventing means.

The IC card10adds the notification address information146stored in the EEPROM14to the encrypted data C, and transmits the encrypted data C having the notified party address information146to the authentication system terminal20(S5004).

The authentication system terminal20then transmits the received encrypted data C to the notified party address designated by the communication interface unit26, so that the encrypted data C is transmitted to the portable checking device30via the communication line40(S5005).

The portable checking device30decrypts the received encrypted data C with the use of the card public key39stored in the memory34, so as to recover the data M (S5006).

Since the data M can be recovered from the encrypted data C, the validity of the authentication system terminal20is authenticated. Accordingly, the portable checking device30indicates that the validity has been authenticated on the display unit35of the portable checking device30(S5007).

The CPU of the control unit33, the program for activating the CPU (recorded in the control unit), and the card public key39form a verifying means. The display unit35serves as a verification result output means.

More specifically, the portable checking device30displays “The validity of the authentication system terminal20has been authenticated” on the display unit35.

The user then confirms the validity of the authentication system terminal20with the restored data M. After that, the user inputs the authentication information such as the personal identification number or the password to the authentication system terminal20through the keypad27(S5008).

When the authentication information is input by the user, the authentication system terminal20adds the input authentication information to an identity authentication request, and transmits the authentication information to the IC card10(S5009). The transmission is performed through the communication interface unit26that serves as the authentication information output means.

The IC card10compares the received authentication information with the card holder authentication information145stored in the EEPROM14, and then authenticates the validity of the user (the identity authentication) (S5010).

The CPU11, the ROM card holder authentication information145, the program that is stored in the ROM13and activates the CPU11, and the interface unit15constitute the identity authentication output means.

The result of the identity authentication performed on the user by the IC card10is returned to the authentication system terminal20, and various services are provided to the user with the IC card10in accordance with the result (S5011). Here, the CPU21is activated in accordance with the program recorded on the ROM23, and the services are provided based on the information stored in the EEPROM24or the RAM22. The program recorded on the ROM23, the CPU21, the EEPROM24, and the RAM22constitute the service provision starting means.

As described above, the results of the mutual authentication between the IC card10and the authentication system terminal20are encrypted in the IC card10, and are decrypted to the data M in the portable checking device30. In this manner, the contents of the mutual authentication results aren't leaked to a third party, and the user can confirm the validity of the authentication system terminal20before inputting the authentication information.

Next, the mechanism for performing mutual validity authentication between the IC card10and the authentication system terminal20(the above mentioned mutual authentication) is described.

FIG. 6is a flowchart showing the procedures for performing mutual authentication between the IC card10and the authentication system terminal20.

First, the authentication system terminal20performs internal authentication of the IC card10. In doing so, the authentication system terminal20generates a random number (a random number A), and stores the random number A into the RAM22in the authentication system terminal20(S6001).

The authentication system terminal20then transmits the generated random number A to the IC card10(S6002).

Receiving the random number A, the IC card10generates a new random number B, and stores the random number A and the random number B into the RAM12in the IC card10(S6003).

Using the card secret key141, the IC card10generates the signature for the data formed with the random number A (hereinafter referred to as the card signature SA) (S6004).

The signature for the data A is generated by performing hashing operation on the data A formed with the random number A and encrypting the obtained hash value with the card secret key141of the IC card10.

The IC card10adds the card public key certificate143that is a certificate issued by a certification authority for the card public key142to the IC card10, to the random number B and the card signature SA. The IC card10then transmits the random number B and the card signature SA to the authentication system terminal20(S6005).

Here, the card public key certificate143is a certificate CA. The card public key142that is the public key to the IC card10is a card public key PA.

The authentication system terminal20extracts the card public key PA to the IC card10from the received certificate CA (S6006), and performs verification of the card signature SA (S6007).

The verification of the card signature SA is carried out by performing hashing operation on the data A formed with the random number A stored in the RAM22in the authentication system terminal20and determining whether the obtained hash value is the same as the value obtained by decrypting the card signature SA of the IC card10with the card public key PA to the IC card10.

The authentication system terminal20authenticates the validity of the IC card10through the verification of the card signature SA.

Next, authentication of the authentication system terminal20by the IC card10is carried out.

Using the terminal secret key241stored in the EEPROM24, the authentication system terminal20generates the signature for the data formed with the random number B (hereinafter referred to the terminal signature SB) (S6008).

The authentication system terminal20adds the terminal public key certificate243that is the certificate for the terminal public key242to the authentication system terminal20, to the terminal signature SB. The authentication system terminal20then transmits the terminal signature SB to the IC card10(S6009).

Here, the terminal public key242to the authentication system terminal20is a terminal public key PB, and the terminal public key certificate243is a certificate CB.

The IC card10extracts the terminal public key PB to the authentication system terminal20from the received certificate CB (S6010), and carries out verification of the terminal signature SB (S6011).

Like the verification of the card signature SA, the verification of the terminal signature SB is carried out by performing hashing operation on the data formed with the random number B stored in the RAM12in the IC card10and determining whether the obtained hash value is the same as the value obtained by decrypting the terminal signature SB with the terminal public key PB.

In this manner, the IC card10performs authentication of the validity of the authentication system terminal20through the verification of the terminal signature SB.

The procedures for performing mutual authentication between the IC card10and the authentication system terminal20in accordance with this embodiment have been described, but authentication may be carried out with a common key, instead of the above described public keys. In such a case, the IC card10and the authentication system terminal20use a common secret key, and perform encrypting and decrypting on data.

As described above, in this authentication system, before the user inputs the personal identification number, the results of validity authentication performed by the IC card10and the authentication system terminal20are transmitted to the portable checking device30that is always carried by the user.

Accordingly, in a case where the portable checking device30does not receive the result of validity authentication of the authentication system terminal20(the result of mutual authentication or the data M), the user determines that the authentication system terminal20is not trustworthy, and refrains from inputting the personal identification number that is the authentication information.

Alternatively, in a case where decrypting the encrypted data C reveals that the decrypted data is data whose validity is not authenticated (data other than the data M) even though the portable checking device30receives the authentication result of the authentication system terminal20, the portable checking device30can indicate the invalidity of the authentication system terminal20.

Referring now to the flowchart showing inFIG. 7, the procedures to be carried out until the portable checking device30indicates the invalidity are described.

When the user inserts the IC card10to the authentication system terminal20, mutual validity authentication is started between the IC card10and the authentication system terminal20(S7001).

In this authentication system, mutual authentication is performed between the IC card10and the authentication system terminal20, and services are provided in accordance with the result of the mutual authentication. Accordingly, in a case where the IC card10does not authenticate the validity of the authentication system terminal20, the IC card10generates the data formed with the authentication result indicating the invalidity (hereinafter referred to as the data N) (S7002).

The IC card10encrypts the data N with the use of the card secret key141, and generates encrypted data (hereinafter referred to as the encrypted data D) (S7003).

The IC card10adds the notification address information146stored in the EEPROM14to the encrypted data D, and sends the encrypted data D having the notified party address information146the authentication system terminal20(S7004).

The authentication system terminal20transmits the received encrypted data D to the notified party address designated through the communication interface unit26, so that the encrypted data D is transmitted to the portable checking device30via the communication line40(S7005).

The portable checking device30decrypts the received encrypted data D with the use of the card public key39stored in the memory34, so as to recover the data N (S7006).

The data N from the encrypted data D indicates that the validity of the authentication system terminal20is not authenticated and the authentication system terminal20is invalid. The portable checking device30then causes the display unit35to display the message indicating that the authentication system terminal20is invalid (S7007).

More specifically, the portable checking device30displays the message, “the validity of the authentication system terminal20has not been authenticated”, on the display unit35.

Accordingly, based on the recovered data, if the mutually authenticated data M is recovered, the portable checking device30displays the validity of the authentication system terminal20and if the mutually unauthenticated data N is recovered, the portable checking device30displays the invalidity of the authentication system terminal20.

In this manner, the user can be protected from the danger of inputting the personal identification number, which is the authentication information about the user, to the authentication system terminal20that aims to wrongfully obtain the personal identification number as the authentication information.

Since the existing IC card10and the existing authentication system terminal20can be used as they are in this embodiment, the above described effects can be achieved without any cost to change the existing system resource.

After the IC card10and the authentication system terminal20of this embodiment authenticate the validity of each other (the above described mutual authentication), it is possible to generate and encrypt data that includes the results of the mutual authentication between the authentication system terminal20and the IC card10, and the time of the mutual authentication.

In such a case, since the encrypted data includes the time of the mutual authentication, the user can check the time of the mutual authentication with the portable checking device30. Accordingly, it is possible to prevent generation of fake authentication result data indicating the validity of the authentication system terminal20.

Further, an expiration date may be set in the time of the mutual authentication, and the IC card10may receive authentication information and perform identity authentication only before the expiration date.

In this embodiment, the authentication information including a password, a personal identification number, or the like is input. However, the card holder authentication information145stored in the IC card10of this embodiment may be biometrics information such as a fingerprint, a voiceprint, a face, a retina pattern, or an iris code.

In such a case, the keypad27of the authentication system terminal20is an input device such as a sensor that reads fingerprints, a microphone that picks up voices, or a camera. The IC card10checks the data that is input through such an input device, so as to perform more reliable identity authentication.

In this embodiment, the portable checking device30may use a speaker or a vibrator as the means of showing the user the validity authentication result of the authentication system terminal20, other than the display.

Also, the portable checking device30decrypts the encrypted data C, and identity authentication is performed by the IC card10in this embodiment. However, the present invention is not limited to that, and the data M formed with a mutual authentication result may be encrypted after the IC card10performs authentication of the validity of the authentication system terminal20(the above described mutual authentication). The data M may be then transmitted to the designated portable checking device30, and the encrypted data C may be decrypted by the portable checking device30. Also, the card holder authentication information145stored in the IC card10may be transferred to the authentication system terminal20, and identity authentication may be performed by the authentication system terminal20, instead of the IC card10.

In this case, a complicated biometrics information checking operation that cannot be performed or takes a long period of time with the limited hardware resource of the IC card10can be performed by the authentication system terminal20whose validity has been authenticated.

Further, even if the time of contact between the authentication system terminal20and the IC card10such as a non-contact IC card is very short, user validity information can be performed by the authentication system terminal20whose validity has been mutually authenticated after a communication between the IC card10and the authentication system terminal20is ended.

Also, the IC card10stores the notification address information146about the portable checking device30in this embodiment. However, the present invention is not limited to that, and it is possible to set a reliable verification device placed on a communication line, instead of the portable checking device30, as a notification destination.

FIG. 8shows a structure having this verification device added thereto. InFIG. 8, the same components as those described so far are denoted by the same reference numerals as those used so far. The authentication system using an IC card shown inFIG. 8includes an IC card10, an authentication system terminal20, a portable checking device30, a communication line40, and a verification device50that is connected to the IC card10and the portable checking device30through the communication line40, and can communicate with the IC card10and the portable checking device30.

In this case, the verification device50may operate to transmit the encrypted data C to the portable checking device30linked to the IC card10. More specifically, the reliable verification device50verifies and decrypts the encrypted data C, and can transmit the restored data M to the portable checking device30.

With this arrangement, the portable checking device30does not need to store the card public key39, and the above described effects can be achieved by the user simply registering the address of the portable checking device30with the reliable verification device50.

Also, in a case where an e-mail address of the portable checking device30of the IC card holder or an e-mail address of the holder of the IC card10is registered with the notification address information146in this embodiment, the encrypted data C generated by the IC card10is transmitted to the holder of the IC card10when the IC card10is being wrongfully used by a third party. Accordingly, the holder of the IC card10can be promptly notified of the unauthorized use of the IC card10.

In the first embodiment, the IC card10performs identity authentication with the use of the authentication information obtained through the authentication system terminal20and the card holder authentication information145registered in the IC card10, and then provides various services. However, the present invention is not limited to that arrangement, and the IC card10may be of a non-contact type, and such a non-contact IC card may be provided in a portable terminal.

In this case, the connection terminal16of the IC card10and the IC card interface unit25of the authentication system terminal20further include a wireless communication function that can perform non-contact communications. With the non-contact IC card being provided in a portable terminal, it is possible to form a non-contact IC card equipped terminal that includes the non-contact IC card.

With this arrangement, the non-contact IC card equipped terminal can display the result of authentication of the IC card on the non-contact IC card equipped terminal.

Second Embodiment

Next, a second embodiment of the present invention is described, with reference to the accompanying drawings.

FIG. 9is a schematic view of the structure of an authentication system that uses an IC card in accordance with the second embodiment. The authentication system that uses an IC card shown inFIG. 9includes an IC card10a, an authentication system terminal20a, and a portable checking device30a.

To receive various services through the IC card10a, a user inserts the IC card10ato the authentication system terminal20a. After the IC card10ais returned from the authentication system terminal20a, the user inserts the IC card10ato the portable checking device30a. Following the information displayed on the portable checking device30a, the user inputs a password (or the authentication information) through the keypad of the authentication system terminal20a.

Using the input password, the authentication system terminal20aperforms identity authentication on the user. After succeeding in the identity authentication, the authentication system terminal20aprovides the user with various services through the IC card10a.

FIG. 10is a block diagram showing the structure of the IC card10a. Instead of the notification address information146, terminal authentication result information147that is an element for realizing the second embodiment is stored in the EEPROM14, which differs from the structure shown inFIG. 2.

FIG. 11is a block diagram showing the structure of the portable checking device30a. As shown inFIG. 11, in addition to the CPU51, the RAM52, and the ROM53, the portable checking device30aincludes an IC card interface unit54and a display55that are elements for realizing the second embodiment.

As described above, in the second embodiment, before receiving services, the user inserts the IC card10ato the authentication system terminal20a, and the validity of the authentication system terminal20ais authenticated. In accordance with the mutual authentication result, the authentication result is stored in the terminal authentication result information147in the IC card10a, and the card holder authentication information145of the IC card10ais transferred to the authentication system terminal20a.

After the IC card10ais returned from the authentication system terminal20ato the user, the user inserts the IC card10ato the portable checking device30a, and the terminal authentication result information147of the IC card10ais read into the portable checking device30athrough the IC card interface unit54. If the user confirms the result of the validity authentication of the authentication system terminal20adisplayed on the display55of the portable checking device30a, the user inputs the personal identification number through the keypad27of the authentication system terminal20a.

In this manner, the authentication system terminal20aperforms identity authentication of the user, with the use of the card holder authentication information145received beforehand from the IC card10aand the input personal identification number.

After the user is authenticated in the above manner, the authentication system in accordance with the second embodiment provides the user with various services through the IC card10a.

The exemplary embodiments of the present invention are described above, but the present invention can be embodied in various forms without departing from the spirit and the main characteristic defined by the claims of the present application. For this reason, the embodiments should be considered to be illustrative and not restrictive. The scope of the invention is indicated by the appended claims rather than by the description and the abstract. All variations and modifications within the range of equivalency of the claims are therefore intended to be embraced in the present invention.