Authentication system, authentication method, and entrance/exit management system

A system including first and second IC cards and a host device adopts a communication mode in which the host device communicates with the first IC card only, and the first IC card communicates with the second IC card. The host device acquires inherent information encrypted by the first and second IC cards via the first IC card, decrypts the inherent information encrypted by the first and second IC cards, and collates the decrypted information with the inherent information to thereby authenticate the first and second IC cards.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2005-108908, filed Apr. 5, 2005, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an authentication system, an authentication method, and an entrance/exit management system in which authentication is performed using, for example, a plurality of IC cards.

2. Description of the Related Art

In recent years, to realize sophisticated security, it has been proposed that authentication be performed using a plurality of IC cards (e.g., contact-less IC cards) in an authentication system, an authentication method, or an entrance/exit management system. For example, as an entrance/exit management system in which the entrance/exit is permitted on conditions that the authentications of the plurality of IC cards are successful, there is a system in which person's entrance/exit is managed by performing processing to authenticate the plurality of IC cards. For example, in Jpn. Pat. Appln. KOKAI Publication No. 2003-150553, an authentication system is proposed in which a plurality of IC cards and a terminal device perform authentication processing to thereby make possible the sophisticated security in a computer network.

However, in the technology described in Jpn. Pat. Appln. KOKAI Publication No. 2003-150553, the terminal device has to communicate with each of the plurality of IC cards for each authentication processing. In the technology described in Jpn. Pat. Appln. KOKAI Publication No. 2003-150553, the terminal device has to manage various information for performing the authentication processing on all the IC cards.

BRIEF SUMMARY OF THE INVENTION

In an aspect of the present invention, an object is to provide an authentication system, an authentication method, and an entrance/exit management system in which an efficient operation is performed.

In a first aspect of the present invention, there is provided an authentication system comprising: a first electronic device; a second electronic device; and a host device, the first electronic device including: a first memory which stores first key information; a first encryption processing section which encrypts inherent information transmitted from the host device by use of the first key information stored in the first memory; a first transmitting section which transmits to the second electronic device the inherent information encrypted with the first key information by the first encryption processing section; and a transfer section which transfers to the host device information transmitted from the second electronic device and obtained by encrypting the inherent information encrypted with the first key information further by the second electronic device, the second electronic device including: a second memory which stores second key information; a second encryption processing section which encrypts the inherent information transmitted from the first electronic device and encrypted with the first key information by use of the second key information stored in the second memory; and a second transmitting section which transmits to the first electronic device the information encrypted with the second key information by the second encryption processing section, the host device including: a storage section which stores key information for decryption in association with the first electronic device; a third transmitting section which transmits the inherent information to the first electronic device; a decryption processing section which decrypts information transferred from the first electronic device and obtained by encrypting the inherent information by the first and second electronic devices by use of the decryption key information stored in association with the first electronic device in the storage section; and an authentication processing section which authenticates the first and second electronic devices based on the information decrypted by the decryption processing section and the inherent information.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1schematically shows a constitution example of an entrance/exit management system.

The entrance/exit management system shown inFIG. 1includes: a first IC card (portable electronic device)11; a second IC card (portable electronic device)12; a door13; a host device14and the like. The entrance/exit management system manages entrance/exit with respect to a facility such as a room or an area. Here, the entrance/exit management system permits entrance or exit of a specific person on conditions that authentications of a plurality of IC cards are successful in order to realize sophisticated security.

It is assumed that a user who utilizes the facility managed by the entrance/exit management system possesses the first IC card11. The first IC card11is constituted of a contact-less IC card. The first IC card11functions as a first authentication medium.

It is assumed that a user who utilizes the facility managed by the entrance/exit management system possesses the second IC card12. It is to be noted that the second IC card12may be possessed by a user who is different from the user of the first IC card11. The second IC card12functions as a second authentication medium.

The door13is disposed in a doorway or the like of the facility managed by the entrance/exit management system. The door13functions as a gate for the entrance/exit. The door13is controlled to open and close by the host device14. The door13may be provided with a lock mechanism which is controlled to unlock and lock by the host device14.

The host device14controls the entrance/exit with respect to the facility managed by the entrance/exit management system. The host device14has a function of controlling the opening/closing of the door13, a function of communicating with the first IC card11and the second IC card12, and a function of processing various information.

Next, a constitution example of the host device14will be described.

As shown inFIG. 1, the host device14includes an IC card reader and writer15, a host computer16, a door control section17and the like.

The IC card reader and writer15has a function of radio-communicating with the IC cards for use as the first IC card11and the second IC card12. The IC card reader and writer15receives data from the IC card, and transmits data to the IC card by the radio communication with the IC cards.

The host computer16functions as a control section of the host device14. The host computer16processes various types of information based on a preset processing program or the like. For example, the host computer16radio-communicates with the IC card (the first IC card11or the second IC card12) via the IC card reader and writer15to thereby authenticate the IC card (or the person who possesses the IC card. The host computer16controls the opening/closing of the door13by the door control section17based on an authentication result of the authentication processing of the IC card.

The door control section17controls the opening/closing of the door13. The door control section17opens/closes the door13based on a control signal from the host computer16.

Next, there will be described constitution examples of the first IC card11and the second IC card12.

FIG. 2is a block diagram showing the constitution examples of the first IC card11and the second IC card12.

As shown inFIG. 2, each of the first and second IC cards11,12includes: a transmission/reception antenna section21; a power supply section22; a modulation/demodulation circuit section23; a control section24; a memory section25; and the like. The power supply section22, the modulation/demodulation circuit section23, the control section24, and the memory section25are constituted of a integrally formed module Ca. The module Ca is electrically connected to the transmission/reception antenna section21, and they are buried in a housing C which forms each of the first and second IC cards11,12.

The transmission/reception antenna section21transmits and receives radio waves with respect to the reader and writer15and another IC card. For example, the transmission/reception antenna section21is constituted of a loop antenna or the like buried in the housing.

The power supply section22supplies a power to each component of the IC card11or12. The IC card11or12constituted as shown inFIG. 2is a contact-less IC card without any battery. Therefore, in the constitution shown inFIG. 2, the power supply section22converts the radio wave received by the transmission/reception antenna section21into the power to thereby generate the power to be supplied to each component.

The modulation/demodulation circuit section23modulates and demodulates an electric signal. The modulation/demodulation circuit section23converts (demodulates) an electric signal as the radio wave received by the transmission/reception antenna section21into digital data, or converts (modulates) the digital data for transmission into the electric signal to be transmitted as the radio wave. For example, the modulation/demodulation circuit section23demodulates into the digital data the electric signal as the radio wave received by the transmission/reception antenna section21, and the section outputs the demodulated digital data to the control section24. The modulation/demodulation circuit section23modulates the digital data for transmission from the control section24into the electric signal to be transmitted as the radio wave, and the section outputs the modulated electric signal to the transmission/reception antenna section21.

The control section24controls the whole IC card. The control section24controls an operation of each component, or processes various information. The control section24performs, for example, analysis of data, control of input/output of data and the like.

The memory section25is constituted of a volatile memory (random access memory: RAM), a non-rewritable nonvolatile memory (read only memory: ROM), a rewritable nonvolatile memory (EEPROM, flash ROM or the like) and the like. The RAM functions as, for example, a working memory for temporarily storing various data. The ROM functions as a program memory in which, for example, a pre-stored control program, control data, a processing program or the like is stored. Various types of data or processing program is stored in the rewritable nonvolatile memory.

For example, in the rewritable nonvolatile memory, there are stored ID information, key information and the like for use in the present entrance/exit management system. The ID information is identification information for specifying each IC card in the entrance/exit management system. The ID information is information which is inherent in each IC card. The key information is for use in encryption processing in authentication processing in entrance/exit management. The key information is set with respect to each IC card. It is to be noted that in the following description, the key information stored in the memory section25of the first IC card11is referred to as first key information, and the key information stored in the memory section25of the second IC card12is referred to as second key information.

Next, there will be described a constitution example of the IC card reader and writer15disposed in the host device14.

FIG. 3is a block diagram showing a constitution example of the IC card reader and writer15.

As shown inFIG. 3, the reader and writer15is constituted of: a transmission/reception antenna section31; a modulation/demodulation circuit section32; a control section33; an interface34and the like.

The transmission/reception antenna section31is constituted of an antenna for transmitting and receiving the radio waves. The transmission/reception antenna section31transmits the radio wave for communicating with the IC card, and receives the radio wave transmitted from the IC card. The modulation/demodulation circuit section32modulates and demodulates the electric signals. The modulation/demodulation circuit section32converts (demodulates) into the digital data the electric signal as the radio wave received by the transmission/reception antenna section31, and converts (modulates) the digital data for transmission into the electric signal to be transmitted as the radio wave. For example, the modulation/demodulation circuit section32demodulates into the digital data the electric signal as the radio wave received by the transmission/reception antenna section31, and outputs the demodulated digital data to the control section33. The modulation/demodulation circuit section23modulates the digital data for transmission from the control section33into the electric signal to be transmitted as the radio wave, and outputs the modulated electric signal to the transmission/reception antenna section31.

The control section33controls the whole IC card reader and writer15. The control section33controls the operation of each component, or processes various information. The control section33performs, for example, analysis of data, control of transmission/reception of data and the like. The interface34is an interface to be connected to the host computer16. The control section33performs data communication with the host computer16via the interface34.

Next, there will be described a constitution example of the IC card reader and writer15disposed in the host device14.

FIG. 4is a block diagram showing a constitution example of the host computer16.

As shown inFIG. 4, the host computer16includes: a control section41; a RAM42; a ROM43; a nonvolatile memory44; a hard disk drive (HDD)45; a random number generating section46; a first interface47; and a second interface48.

The control section41controls the whole host computer16. The control section41is constituted of, for example, a CPU, an internal memory and the like. The control section41performs various processing based on the program stored in the ROM43, the nonvolatile memory44, or the HDD45.

The RAM42is a volatile memory in which data is temporarily stored. The ROM43is a memory in which a control program, control data or the like is stored beforehand. The nonvolatile memory44is constituted of a rewritable nonvolatile memory such as an EEPROM. For example, system information or the like is stored in the nonvolatile memory44. For example, a processing program, various types of data or the like is stored in the HDD45. The HDD45includes a database (DB)45a.

In the database45a, there is stored information on a person which is permitted to enter or leave the facility as information for performing the entrance/exit management. In the present entrance/exit management system, there are stored at least ID information of the IC card possessed by each person and decryption key information associated with the ID information as the information on the person who is permitted to enter or leave the facility in the database45a. In the present entrance/exit management system, it is presumed that the entrance/exit is permitted in a case where the authentications of a plurality of IC cards are successful. Therefore, the decryption key information associated with each ID information stored in the database45acorresponds to key information set to the IC card containing the ID information, and key information set to another IC card provided simultaneously with the IC card containing the ID information.

The random number generating section46generates a random number for use as inherent information in the authentication processing. It is to be noted that the random number generating section46may be realized in a case where the control section41executes the processing program stored in the ROM43, the nonvolatile memory44, or the HDD45.

The first interface47is an interface to be connected to the IC card reader and writer15. The control section41performs data communication with the IC card reader and writer15via the first interface47. The second interface48is an interface to be connected to the door control section17. The second interface48outputs to the door control section17a control signal for opening or closing the door, the control signal being transmitted from the control section41.

Next, there will be described a processing example of entrance/exit management in the present entrance/exit management system.

FIGS. 5 and 6are flowcharts showing a processing example of the entrance/exit management in the entrance/exit management system. Here, in the entrance/exit management system, conditions for operating the door13are that authentications of the host device14and a plurality of IC cards (the first IC card11and the second IC card12) are successful.

First, the host device14transmits a response request to the IC card by the IC card reader and writer15(step S1). The IC card reader and writer15transmits, as the response request, a radio wave obtained by modulating a signal requiring the identification information (ID information).

It is assumed that the first IC card11is brought in an area (communication area) reached by the radio wave transmitted from the reader and writer15of the host device14in this state. Then, the radio wave transmitted from the reader and writer15of the host device14is received by the transmission/reception antenna section21of the first IC card11. On receiving the radio wave from the transmission/reception antenna section21, the power supply section22of the first IC card11generates a power in response to the electric signal supplied from the transmission/reception antenna section21. The generated power is supplied to each component of the first IC card11. Accordingly, the first IC card11is started to be ready for performing various processing.

In the first IC card11brought into an operative state, the radio wave received by the transmission/reception antenna section21is demodulated by the modulation/demodulation circuit section23, and the demodulated data is supplied to the control section24. Here, the ID information request transmitted from the IC card reader and writer15of the host device14is demodulated into digital data, and the data is supplied to the control section24(step S2).

On receiving the ID information request, the control section24of the first IC card11reads the ID information of the first IC card11stored (registered) beforehand in the memory section25. When the ID information is read from the memory section25, the control section24allows the modulation/demodulation circuit section23to modulate the digital data as the read ID information. This modulated signal (ID information) is transmitted as the radio wave by the transmission/reception antenna section21(step S3).

The radio wave indicating the ID information transmitted from the first IC card11is received by the IC card reader and writer15of the host device14(step S4). In the IC card reader and writer15, the radio wave indicating the ID information transmitted from the first IC card is received by the transmission/reception antenna section31.

The radio wave received by the transmission/reception antenna section31is demodulated by the modulation/demodulation circuit section32, and the demodulated data (data indicating the ID information) is supplied to the control section33. The control section33provided with the ID information from the first IC card11outputs the ID information received from the first IC card11to the host computer16via the interface34. In the host computer16, the ID information from the IC card reader and writer15, which has been received from the first IC card11, is input via the first interface47, and once held in the RAM42.

On receiving the ID information from the first IC card11, the host device14judges whether or not the received ID information is ID information registered beforehand in the database45a(step S5). In this case, the control section41of the host computer16collates the ID information received from the first IC card11with that registered in the database45a.

In a case where it is judged that there exists, in the database45a, ID information which agrees with the received ID information as a result of the collation (step S5, YES), the control section41of the host computer16judges that the first IC card11is an IC card registered beforehand in the database45a.

Moreover, in a case where it is judged that the ID information which agrees with the received ID information as a result of the collation does not exist in the database45a(step S5, NO), the control section41of the host computer16judges that the first IC card11is not the IC card registered beforehand in the database45a. In this case, the control section41of the host computer16ends the processing while the door13remains closed (step S6).

Furthermore, the host device14which has ended the processing of the received ID information returns to the step S1, and transmits the response request. It is to be noted that in a case where it is judged that there does not exist the ID information which agrees with the received ID information in the database45a, the host device14may inform that the authentication has failed by a display section, a speaker or the like (not shown).

Moreover, in a case where it is judged that the received ID information is registered in the database45a(step S5, YES), the control section41of the host computer16generates the random number as the inherent information by the random number generating section46(step S7).

The random number as this inherent information is data for the host device14and the respective IC cards (the first IC card11and the second IC card12) to perform the authentication processing by the key information. That is, in the authentication processing, each IC card encrypts the random number as the inherent information by the key information, and the host device decrypts the random number as the inherent information encrypted with the key information by each IC card.

When the random number generating section46generates the random number as the inherent information, the control section41of the host computer16stores the generated random number in the RAM42(step S8). Moreover, the control section41transmits the random number as the inherent information to the first IC card11(step S9).

In this case, the control section41transmits, to the first IC card11, the data including the inherent information as, for example, a request (authentication request) command for encryption with respect to the first IC card11. That is, the control section41supplies the data including the inherent information to the IC card reader and writer15via the first interface47. After the data including the random number as the inherent information is supplied from the host computer16, the control section33of the IC card reader and writer15modulates the data by the modulation/demodulation circuit section32, and transmits the data as a radio wave from the transmission/reception antenna section31to the first IC card11.

When the random number as the inherent information is transmitted from the host device14to the first IC card11, the first IC card11receives the random number as the inherent information transmitted from the host device14(step S10).

In this case, in the first IC card11, the transmission/reception antenna section21receives the radio wave transmitted from the host device14, and the modulation/demodulation circuit section23demodulates the radio wave. The data demodulated by the modulation/demodulation circuit section23is supplied to the control section24. For example, the data demodulated by the modulation/demodulation circuit section23is an encryption request command including the random number as the inherent information.

The data including the random number as the inherent information is supplied to the control section24of the first IC card11, and the control section encrypts the random number as the inherent information included in the data received from the host device14by use of the first key information stored beforehand in the memory section25(step S11).

The first key information is used by the host device14in authenticating the first IC card11, and the key information is inherent in the first IC card11.

On encrypting the inherent information by the first key information, the control section24of the first IC card11transmits, to the second IC card12, the inherent information encrypted with the first key information (step S12).

In this case, the control section24of the first IC card11supplies, to the modulation/demodulation circuit section23, the data including the inherent information encrypted with the first key information as, for example, an encryption request (authentication request) command with respect to the second IC card. Accordingly, the modulation/demodulation circuit section23of the first IC card11modulates the data, and the transmission/reception antenna section21transmits the data as a radio wave.

When the first IC card11transmits the inherent information encrypted with the first key information, the second IC card12receives the inherent information encrypted with the first key information from the first IC card11(step S13).

In this case, in the second IC card12, the transmission/reception antenna section21receives the radio wave transmitted from the first IC card11, and the modulation/demodulation circuit section23demodulates the radio wave. There is supplied to the control section24the data including the inherent information encrypted with the first key information and demodulated by the modulation/demodulation circuit section23. For example, the data demodulated by the modulation/demodulation circuit section23is the encryption request command including the inherent information encrypted by the first IC card11using the first key information.

The data including the inherent information encrypted with the first key information is supplied to the control section24of the second IC card12, and the control section further encrypts the inherent information encrypted with the first key information and included in the data received from the first IC card11by use of second key information stored beforehand in the memory section25(step S14).

According to this processing, the inherent information encrypted with the first key information is further encrypted with the second key information. It is to be noted that the second key information is for use by the host device14in authenticating the second IC card12, and the key information is inherent in the second IC card12.

When the inherent information encrypted with the first key information is further encrypted with the second key information, the control section24of the second IC card12transmits, to the first IC card11, information (inherent information encrypted with the first and second key information) obtained by further encrypting the inherent information encrypted with the first key information by use of the second key information (step S15).

In this case, the control section24of the second IC card12allows the modulation/demodulation circuit section23to modulate the data including the inherent information encrypted with the first and second key information as, for example, a response to the encryption request command transmitted from the first IC card11in the step S12. The data is transmitted as a radio wave by the transmission/reception antenna section21.

When the inherent information encrypted with the first and second key information is transmitted from the second IC card12, the first IC card11receives data including the inherent information encrypted with the first and second key information from the second IC card12(step S16).

In this case, in the first IC card11, the transmission/reception antenna section21receives the radio wave transmitted from the second IC card12, and the modulation/demodulation circuit section23demodulates the radio wave. The data demodulated by the modulation/demodulation circuit section23is supplied to the control section24. Here, the data demodulated by the modulation/demodulation circuit section23is, for example, a response from the second IC card with respect to the encryption request command transmitted in the step S12.

On receiving the inherent information encrypted with the first and second key information from the second IC card12, the first IC card11transmits, to the host device14, the inherent information encrypted with the first and second key information and transmitted from the second IC card12(step S17).

In this case, the control section24of the first IC card11allows the modulation/demodulation circuit section23to modulate the data including the inherent information encrypted with the first and second key information and transmitted from the second IC card12as, for example, a response to the encryption request command transmitted from the host device14in the step S9. The transmission/reception antenna section21transmits the data as the radio wave.

When the first IC card11transmits the data including the inherent information encrypted with the first and second key information, the host device14receives, from the first IC card11, the inherent information encrypted with the first and second key information (step S18).

In this case, in the host device14, the transmission/reception antenna section31of the IC card reader and writer15receives the radio wave transmitted from the first IC card11, and the modulation/demodulation circuit section32demodulates the radio wave. The data demodulated by the modulation/demodulation circuit section32includes the inherent information encrypted with the first and second key information. For example, here, the data demodulated by the modulation/demodulation circuit section32is a resistance from the first IC card to the encryption request command transmitted in the step S9.

Moreover, the data demodulated by the modulation/demodulation circuit section32of the IC card reader and writer15is supplied to the control section41of the host computer16via the interface34of the IC card reader and writer15and the first interface47of the host computer16. In the host computer16, information (inherent information encrypted with the first and second key information) received from the first IC card11is stored in the RAM42or the like.

When the information (inherent information encrypted with the first and second key information) received from the first IC card11is stored in the RAM42, the control section41of the host computer16decrypts the information from the first IC card11by use of the key information for decryption (step S19).

It is assumed that the key information for decryption is stored in the database45aor the like in association with the ID information of each IC card. Therefore, the control section41of the host computer16decrypts the information (inherent information encrypted with the first and second key information and transmitted from the first IC card11) received in the step S18by use of the decryption key information corresponding to the ID information (ID information of the first IC card11) received in the step S4.

It is to be noted that the key information for decryption may be, for example, the first key information stored in the first IC card11and the second key information stored in the second IC card12. In this case, the first and second key information are stored as the decryption key information corresponding to the ID information of the first IC card11in the database45a.

When the information received from the first IC card11is decrypted, the control section41of the host computer16collates the demodulated information with the inherent information (inherent information stored in the RAM42in the step S8) as source information of encryption, generated in the step S7, to thereby judge whether or not a predetermined relation is established between the information (step S20). For example, when the first key information stored in the first IC card and the second key information stored in the second IC card are registered as the decryption key information corresponding to the ID information of the first IC card11in the database45a, the control section41judges whether or not the decrypted information agrees with the inherent information generated in the step S7.

In a case where it is judged that a predetermined relation is established between the decrypted information and the inherent information generated in the step S7as a result of judgment in the step S20(e.g., in a case where the decrypted information agrees with the inherent information) (step S20, YES), the control section41judges that the information received from the first IC card11is right information. This means that the first IC card11and the second IC card12which have encrypted the inherent information generated in the step S7are judged to be right IC cards. In other words, in a case where the predetermined relation is established between the decrypted information and the inherent information generated in the step S7as a result of judgment in the step S20(step S20, YES), the control section41judges that the authentications of the host device14as well as the first IC card11, and the host device14as well as the second IC card12are successful.

In a case where it is judged that the authentications of the first and second IC cards11,12are successful in this manner, the control section41of the host computer16permits the entrance/exit of the person who possesses the first and second IC cards11,12. In this case, the control section41of the host computer16transmits to the door control section17a control signal for opening the door13. On receiving this control signal, the door control section17opens the door13(step S21). Accordingly, in the present entrance/exit management system, there is obtained a state in which the entrance/exit of the person who possesses the first and second IC cards11,12is possible.

Moreover, in a case where any predetermined relation is not established between the decrypted information and the inherent information generated in the step S7as a result of the judgment (step S20, NO), the control section41of the host computer16judges that the entrance/exit of the person who possesses the first and second IC cards11,12is not permitted. In this case, the control section41of the host computer16allows the door13to remain closed (step S6). In this case, the control section41of the host computer16ends the processing, and returns to a state of the step S1to transmit an application request.

As described above, the entrance/exit management system adopts a communication mode in which the host device14communicates with the only first IC card11and the first IC card11communicates with the second IC card12. The host device14acquires the inherent information encrypted by the first IC card11and the second IC card12via the first IC card11, and the device decrypts the inherent information encrypted by the first IC card11and the second IC card12to thereby authenticate the first IC card11and the second IC card12.

Consequently, it is possible to reduce times of communications between the host device14and the IC cards11,12as authentication objects. As a result, high security can be realized. Moreover, it is possible to realize an increase of an efficiency or a speed of the authentication processing with respect to a plurality of IC cards. Furthermore, in the host device14, it is not necessary to manage the information for the authentication processing with respect to all the IC cards11,12, and the device may hold information necessary for the authentication processing in association with the first IC card. As a result, the host device14can efficiently manage the information, and the information management is facilitated.

Moreover, as a modification of the above embodiment, the present invention is applicable to processing to authenticate three or more IC cards (mediums for authentication). In a case where three or more IC cards11,12b,12c, . . . ,12nare authenticated, in principle, in the same manner as in the above embodiment, the respective IC cards successively encrypt inherent information such as a random number generated by the host device14, and the cards may be finally authenticated based on information obtained by the host device in decrypting the information encrypted by all of the IC cards. It is to be noted that in this case, in the database45a, the decryption key information corresponding to the key information (second, third, . . . , N-th key information) for use in encryption processing in the respective IC cards12b,12c, . . . ,12nare associated with the ID information of the first IC card11, and stored.

Furthermore, as modes for realizing the authentications of three or more IC cards, for example, there are considered: a method (first method) in which a plurality of IC cards successively performs processing in a tandem manner (in series) with respect to a specific IC card that communicates with the host device14; and a method (second method) in which a plurality of IC cards successively performs processing in a tandem manner (in parallel) with respect to a specific IC card that communicates with the host device14.

First, the first method will be described as a realizing mode in a case where the host device authenticates three or more IC cards.

FIG. 8is an explanatory view showing a processing example based on the first method.

In this first method, as shown inFIG. 8, a plurality of IC cards12b,12c, . . . ,12nother than the first IC card11perform encryption processing and transmit and receive the encrypted information in a chain manner (in series), respectively. That is, the IC card which directly communicates with the host device14is the first IC card11only in the same manner as in the above processing example. The plurality of IC cards12b,12c, . . . ,12nother than the first IC card11successively transmit the encrypted information to the next IC card. Furthermore, the last IC card12ntransmits to the first IC card11the information successively encrypted by all of the IC cards. The first IC card11transfers to the host device the information encrypted by all of the IC cards.

It is to be noted that in this case, the last IC card12nneeds to judge whether or not the IC card itself is the last. Here, for example, the respective IC cards12b,12c, . . . ,12nmay judge whether or not there exists another IC card that does not perform the encryption processing. The information for identifying the IC card requiring the encryption processing may be transmitted from the first IC card11to the IC card12bor12n.

This example will be described in association with the above-described operation example. Processing similar to that of the steps S1to S21is performed except that all the IC cards12b,12c, . . . ,12nother than the first IC card11execute the processing similar to that of the steps S13to S15. That is, each IC card encrypts the information received from another IC card to transmit the information to the next IC card.

As a typical example, it is assumed that the IC cards12band12cexist in addition to the first IC card11. In this case, the IC card12breceives the inherent information encrypted by the first IC card11in the same manner as in the step S13. On receiving the inherent information encrypted by the first IC card11in the step S13, the IC card12bencrypts the information received by the step S13in the same manner as in the step S14. This encrypted information is transmitted from the IC card12bto the next IC card12cas the processing of the step S15.

Furthermore, the IC card12creceives the information encrypted by the IC card12bas processing similar to that of the step S13. On receiving the information encrypted by the IC card12b, the IC card12cencrypts the information received from the IC card12bin the same manner as in the step S14. The encrypted information is the information encrypted by all of the IC cards. Therefore, the IC card12ctransmits the encrypted information to the first IC card11. When this information is transmitted to the first IC card11, processing similar to that of the steps S16to S21is performed.

According to such first method, entrance/exit management can be realized based on the authentications of three or more IC cards.

Next, the second method will be described as a realizing mode in a case where the host device authenticates three or more IC cards.

FIG. 9is an explanatory view showing a processing example based on the second method.

In this second method, as shown inFIG. 9, a plurality of IC cards12b,12c, . . . ,12nother than the first IC card11perform encryption processing and transmit and receive the encrypted information in an independent manner (in series with the first IC card), respectively. That is, the IC card which directly communicates with the host device14is the first IC card11only in the same manner as in the above processing example. The plurality of IC cards12b,12c, . . . ,12nother than the first IC card11do not directly transmit or receive data with one another, and they transmit and receive data with respect to the first IC card11, respectively. Therefore, the first IC card11successively receives the encrypted information from the respective IC cards12b,12c, . . . ,12(n−1), and transmits the received encrypted information to the next IC cards12c, . . . ,12n. Furthermore, on receiving the encrypted information from the last IC card12n, the first IC card11transfers to the host device the information successively encrypted by all of the IC cards.

It is to be noted that in this case, the first IC card11needs to identify the last IC card12n. Here, for example, the first IC card11may retain beforehand information for identifying another IC card requiring the encryption processing. The information for identifying the IC card requiring the encryption processing may be received from the host device14together with the inherent information.

This example will be described in association with the above-described operation example. In the second method, processing similar to that of the steps S13to S16may be executed between the first IC card11and all of the IC cards12b,12c, . . . ,12n. Processing other than this processing can be realized by processing similar to that of the steps S1to S21. That is, every time the first IC card11receives the encrypted information from each IC card, the first IC card transmits the received encrypted information to the next IC card.

For example, it is assumed that the IC cards12band12cexist in addition to the first IC card11. In this case, the first IC card11receives the information encrypted by the IC card12bin the same processing as that of the steps S1to S16. Then, the first IC card11judges that the next IC card12cexists, and transmits the information encrypted by the IC card12bto the IC card12c. On the other hand, the IC card12cencrypts the information received from the first IC card11, and transmits the encrypted information to the first IC card11in the same manner as in the steps S13to S15.

On receiving the information encrypted by the IC card12c, the first IC card11judges that the IC card12cis the last IC card. According to this judgment, the first IC card11transfers the information encrypted by the IC card12cto the host device14. Accordingly, processing similar to that of the steps S17to S21is performed.

According to such second method, the entrance/exit management can be realized based on the authentications of three or more IC cards. It is to be noted that in the second method, the first IC card11may execute processing similar to that of the steps S13to S16together with the plurality of IC cards12b,12c, . . . ,12nin an arbitrary order.

It is to be noted that the first, second, and third electronic devices are not limited to the above-described contact-less IC cards (radio cards), and the present invention is similarly applicable to, for example, even a case where portable terminal devices are used such as a contact-less IC card, cellular phone, and PDA.

As described above, the present entrance/exit management system adopts the communication mode in which the host device14communicates with the only specific first IC card11among the plurality of IC cards11,12b,12c, . . . ,12n, and the other IC cards12b,12c, . . . ,12ncommunicate with the first IC card11or with one another. The host device14acquires the inherent information successively encrypted by all of the IC cards11,12b,12c, . . . ,12nvia the first IC card11, and the device decrypts the inherent information successively encrypted by all of the IC cards to thereby authenticate all of the IC cards11,12b,12c, . . . ,12n.

In consequence, it is possible to reduce times of communications between the plurality of IC cards11,12b,12c, . . . ,12nas the authentication objects and the host device14. As a result, high security can be realized. Moreover, it is possible to improve an efficiency or increase a speed in the authentication processing with respect to the plurality of IC cards. Furthermore, the host device14does not have to manage information for the authentication processing with respect to all of the IC cards11,12b,12c, . . . ,12n, and the device may associate the information required for the authentication processing with the first IC card11, and retain the information. As a result, the host device14can efficiently manage the information, and the information management is facilitated.