Information processing system, control device, and information processing method

Abstract

An information processing system (10) comprises an information terminal (20) and a control device (50). The control device (50) comprises: a storage unit (53) that stores a root certificate including a public key; a communication unit (51) that receives a server certificate from the information terminal (20); and a control unit (52) that uses the public key included in the root certificate to verify a signature included in the server certificate, and releases a device restriction on the condition that the verification of the signature was successful at the timing at which a release operation was received by the information terminal (20) or the control device (50).

Description

Information processing system, control device, and information processing method

[0001] The present invention relates to an information processing system, a control device, and an information processing method.

[0002] Conventionally, security systems for locking and unlocking doors of facilities have been known. Patent Document 1 discloses a security system that can safely remotely lock and unlock a house without requiring other devices such as a fingerprint authentication device. Patent Document 2 discloses an information processing system that performs authentication using a private key, a public key, a server certificate, etc., and locks and unlocks a delivery locker or a car.

[0003] JP 2014-159692 A JP 2018-74205 A

[0004] The present invention provides an information processing system and the like that can shorten the time from when a user performs an operation until the restriction on a device is released.

[0005] An information processing system according to one embodiment of the present invention is an information processing system used to release restrictions on equipment that restricts the operation of an item, and includes an information terminal and a control device, wherein the information terminal has a first memory unit that stores a first private key, a first public key corresponding to the first private key, and a server certificate, and a first communication unit that transmits the server certificate to the control device, and the server certificate includes the first public key and a signature for the first public key, and the control device has a second memory unit that stores a root certificate including a public key, a second communication unit that receives the server certificate from the information terminal, and a control unit that verifies the signature included in the server certificate using the public key included in the root certificate and releases the restriction on the equipment on the condition that the signature has been successfully verified at the time the release operation is accepted by the information terminal or the control device.

[0006] A control device according to one embodiment of the present invention is a control device that releases restrictions on equipment that restricts the operation of an item, and includes: a memory unit in which a root certificate including a public key is stored; a communication unit that receives the server certificate including a first public key and a signature for the first public key from an information terminal that has a first memory unit in which a first private key, a first public key corresponding to the first private key, and a server certificate is stored; and a control unit that verifies the signature included in the server certificate using the public key included in the root certificate and releases the restriction on the equipment, provided that the signature has been successfully verified at the time the release operation is accepted by the information terminal or the control device.

[0007] An information processing method according to one aspect of the present invention is an information processing method executed by an information processing system used to release restrictions on equipment that restricts the operation of an item, the information processing system comprising an information terminal and a control device, the information terminal comprising a first memory unit in which a first private key, a first public key corresponding to the first private key, and a server certificate are stored, and the control device comprising a second memory unit in which a root certificate including a public key is stored, the information processing method comprising the steps of: the information terminal transmitting the server certificate to the control device, the server certificate including the first public key and a signature for the first public key; the control device receiving the server certificate from the information terminal; the control device verifying the signature included in the server certificate using the public key included in the root certificate; and the control device releasing the restriction on the equipment, provided that the signature has been successfully verified at the time the release operation is accepted by the information terminal or the control device.

[0008] An information processing method according to one aspect of the present invention is an information processing method executed by a control device that releases restrictions on equipment that restricts the operation of an item, wherein the control device has a memory unit in which a root certificate including a public key is stored, and the information processing method includes the steps of receiving the server certificate including a first public key and a signature for the first public key from an information terminal that has a first memory unit in which a first private key, a first public key corresponding to the first private key, and a server certificate are stored, verifying the signature included in the server certificate using the public key included in the root certificate, and releasing the restriction on the equipment, provided that the signature has been successfully verified at the time the release operation is accepted by the information terminal or the control device.

[0009] A program according to one aspect of the present invention is a program for causing a computer to execute the information processing method.

[0010] An information processing system according to an aspect of the present invention can reduce the time it takes from when a user performs an operation until the restriction on a device is lifted.

[0011] FIG. 1 is an external view of an information processing system according to an embodiment. FIG. 2 is a block diagram showing the functional configuration of the information processing system according to an embodiment. FIG. 3 is a sequence diagram of an operation example for storing a server certificate in an information terminal according to an embodiment. FIG. 4 is a diagram showing an example of a format of a server certificate. FIG. 5 is a sequence diagram of an operation example 1 of the information processing system according to an embodiment. FIG. 6 is a sequence diagram of an operation example 2 of the information processing system according to an embodiment. FIG. 7 is a sequence diagram of an operation example 3 of the information processing system. FIG. 8 is a sequence diagram of an operation example 4 of the information processing system. FIG. 9 is a sequence diagram of an operation example 5 of the information processing system. FIG. 10 is an external view of an electrically assisted bicycle equipped with a control device and an electric lock. FIG. 11 is a sequence diagram of an operation example 6 of the information processing system. FIG. 12 is a sequence diagram of an operation example 7 of the information processing system. FIG. 13 is a sequence diagram of an operation example 8 of the information processing system. FIG. 14 is a sequence diagram of an operation example 9 of the information processing system. FIG. 15 is a sequence diagram of an operation example 10 of the information processing system. FIG. 16 is a sequence diagram of an operation example 11 of the information processing system. Fig. 17 is a sequence diagram of an operation example 12 of the information processing system. Fig. 18 is a sequence diagram of a modified example of the operation of the information processing system.

[0012] Hereinafter, the embodiments will be described in detail with reference to the drawings. Note that the embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component placement and connection forms, steps, and step order shown in the following embodiments are merely examples and are not intended to limit the present invention. Furthermore, among the components in the following embodiments, components not recited in independent claims will be described as optional components.

[0013] It should be noted that the drawings are schematic diagrams and are not necessarily strict illustrations. In addition, in the drawings, substantially the same components are denoted by the same reference numerals, and overlapping descriptions may be omitted or simplified.

[0014] (Embodiment) [Configuration] First, the configuration of an information processing system according to an embodiment will be described. Fig. 1 is an external view of the information processing system according to an embodiment. Fig. 2 is a block diagram showing the functional configuration of the information processing system according to an embodiment.

[0015] 1, an information processing system 10 according to an embodiment is a system for safely unlocking an electric lock 60 using an information terminal 20 and a management terminal 30. The information processing system 10 includes the information terminal 20, the management terminal 30, a control device 50, and an electric lock 60. The control device 50 and the electric lock 60 are installed as an electric lock system on a door 81 (or door frame) within a facility 80, for example. The facility 80 is, for example, an apartment building, but may also be a facility other than a residence, such as an office building.

[0016] The information terminal 20 is an information terminal used by users of the facility 80 to unlock the electric lock 60. Users of the facility 80 include not only visitors to the facility 80 (see FIG. 1 ; in other words, non-residents) but also residents residing in the facility 80. The information terminal 20 is, for example, a portable information terminal such as a smartphone or a tablet terminal. The information terminal 20 includes a communication unit 21, an information processing unit 22, a memory unit 23, an operation reception unit 24, a measurement unit 25, a transmission power measurement unit 26, a position measurement unit 27, and a display unit 28.

[0017] The communication unit 21 is a communication circuit that enables the information terminal 20 to communicate with each of the management terminal 30 and the control device 50. For example, the communication unit 21 performs wireless communication with the management terminal 30 via a wide area communication network such as the Internet, and performs wireless communication with the control device 50 via a local communication network.

[0018] The information processing unit 22 performs information processing for unlocking the electric lock 60. The information processing unit 22 is realized, for example, by a microcomputer, but may also be realized by a processor. The functions of the information processing unit 22 are realized, for example, by the microcomputer or processor constituting the information processing unit 22 executing a computer program stored in the storage unit 23.

[0019] The storage unit 23 is a storage device that stores information necessary for the information processing, the computer programs, etc. The storage unit 23 is realized by, for example, a semiconductor memory.

[0020] The operation reception unit 24 receives operations from the user. The operation reception unit 24 is realized by, for example, a touch panel, but may also be realized by hardware keys or the like.

[0021] The measurement unit 25 measures the received signal strength (RSSI: Received Signal Strength Indicator) of the wireless communication signal transmitted from the control device 50 to the information terminal 20. The measurement unit 25 is realized by, for example, a measurement circuit. The measurement unit 25 may be realized as a part of the communication unit 21.

[0022] The transmission power measurement unit 26 measures the transmission power (TxPower) of the wireless communication signal transmitted from the information terminal 20 to the control device 50. The transmission power measurement unit 26 is realized by, for example, a measurement circuit. The transmission power measurement unit 26 may be realized as part of the communication unit 21.

[0023] The position measurement unit 27 measures the current position (coordinates) of the information terminal 20. The position measurement unit 27 is realized by, for example, a Global Navigation Satellite System (GNSS) module such as a Global Positioning System (GPS) module.

[0024] The display unit 28 displays an image. The display unit 28 is realized by, for example, a liquid crystal panel, but may also be realized by an organic EL panel. If the operation reception unit 24 is realized by a touch panel and the touch panel is placed on the display unit 28, the touch panel and the image displayed on the display unit 28 constitute a GUI (Graphical User Interface).

[0025] The management terminal 30 is an information terminal used by a manager or the like of the facility 80. The manager or the like may be the owner of the facility 80 or an employee of the management company of the facility 80. The management terminal 30 is, for example, a portable information terminal such as a smartphone or a tablet terminal. The management terminal 30 includes a communication unit 31, an information processing unit 32, a memory unit 33, an operation reception unit 34, a measurement unit 35, a transmission power measurement unit 36, a position measurement unit 37, and a display unit 38.

[0026] The communication unit 31 is a communication circuit that enables the management terminal 30 to communicate with each of the information terminal 20 and the control device 50. The communication unit 31 performs wireless communication with the information terminal 20 via a wide area communication network such as the Internet, and performs wireless communication with the control device 50 via a local communication network, for example.

[0027] The information processing unit 32 performs information processing for granting the information terminal 20 the authority to unlock the electric lock 60, and information processing for unlocking the electric lock 60. The information processing for granting the information terminal 20 the authority to unlock the electric lock 60 is, for example, processing for issuing a server certificate to the information terminal 20 (described later). The information processing unit 32 is realized, for example, by a microcomputer, but may also be realized by a processor. The functions of the information processing unit 32 are realized, for example, by the microcomputer or processor constituting the information processing unit 32 executing a computer program stored in the storage unit 33.

[0028] The storage unit 33 is a storage device that stores information necessary for the information processing, the computer program, etc. The storage unit 33 is realized by, for example, a semiconductor memory.

[0029] The operation reception unit 34 receives operations from the administrator. The operation reception unit 34 is realized by, for example, a touch panel, but may also be realized by hardware keys or the like.

[0030] The measurement unit 35 measures the received signal strength of the wireless communication signal transmitted by the control device 50 to the management terminal 30. The measurement unit 35 is realized by, for example, a measurement circuit. The measurement unit 35 may also be realized as part of the communication unit 31.

[0031] The transmission power measurement unit 36 ​​measures the transmission power of the wireless communication signal transmitted from the management terminal 30 to the control device 50. The transmission power measurement unit 36 ​​is realized by, for example, a measurement circuit. The transmission power measurement unit 36 ​​may also be realized as part of the communication unit 31.

[0032] The position measurement unit 37 measures the current position (coordinates) of the management terminal 30. The position measurement unit 37 is realized by, for example, a GNSS module such as a GPS module.

[0033] The display unit 38 displays an image. The display unit 38 is realized by, for example, a liquid crystal panel, but may also be realized by an organic EL panel. If the operation reception unit 34 is realized by a touch panel and the touch panel is placed on the display unit 38, the touch panel and the image displayed on the display unit 38 constitute a GUI.

[0034] The control device 50 controls the locking and unlocking of the electric lock 60. The control device 50 is built into, for example, the door 81 or the door frame. The control device 50 includes a communication unit 51, a control unit 52, a memory unit 53, an operation reception unit 54, and a measurement unit 55.

[0035] The communication unit 51 is a communication circuit that enables the control device 50 to communicate with each of the information terminal 20 and the management terminal 30. The communication unit 51 performs wireless communication with the information terminal 20 and the management terminal 30, for example, via a local communication network.

[0036] The control unit 52 performs information processing to lock or unlock the electric lock 60. Specifically, the control unit 52 locks or unlocks the electric lock 60 by outputting a control signal to the electric lock 60. The control unit 52 is realized, for example, by a microcomputer, but may also be realized by a processor. The functions of the control unit 52 are realized, for example, by the microcomputer or processor constituting the control unit 52 executing a computer program stored in the storage unit 53.

[0037] The storage unit 53 is a storage device that stores information necessary for the information processing, the computer program, etc. The storage unit 53 is realized by, for example, a semiconductor memory.

[0038] The operation reception unit 54 receives operations from the user. The operation reception unit 54 is realized by, for example, hardware keys such as push buttons, but may also be realized by a touch panel.

[0039] The measurement unit 55 measures the received signal strength (RSSI: Received Signal Strength Indicator) of the wireless communication signal transmitted from the information terminal 20 to the control device 50. The measurement unit 55 is realized by, for example, a measurement circuit. The measurement unit 55 may be realized as a part of the communication unit 51.

[0040] The electric lock 60 locks or unlocks the door 81 based on a control signal output from the control unit 52. Specifically, the electric lock 60 has an electric motor and a transmission mechanism that transmits the driving force of the electric motor to the deadbolt. The driving force of the electric motor is transmitted to the deadbolt via the transmission mechanism, causing the deadbolt to move to a locked or unlocked position.

[0041] [Example of Operation for Storing a Server Certificate in an Information Terminal] First, an example of operation for storing a server certificate in the information terminal 20 will be described. Fig. 3 is a sequence diagram of an example of operation for storing a server certificate in the information terminal 20. In the following example of operation for storing a server certificate and in operation examples 1 to 12 described later, the information terminal 20 will be described as being used by a user of the facility 80, and the management terminal 30 will be described as being used by a manager or the like of the facility 80. The user may be a non-resident, such as a parcel delivery person or a person dispatched by a housekeeping service provider, but may also be a resident of the facility 80.

[0042] The server certificate serves as an unlocking permit for the electric lock 60. As shown in Fig. 3, a public key A and a corresponding private key A are stored in the storage unit 23 of the information terminal 20. The public key A and the private key A are generated, for example, when an application program (hereinafter simply referred to as an app) for using the information processing system 10 is installed in the information terminal 20, and are stored in the storage unit 23.

[0043] Furthermore, the storage unit 33 of the management terminal 30 stores a public key B and a corresponding private key B. The public key B and the private key B are stored in the storage unit 33, for example, when an app for using the information processing system 10 is installed in the management terminal 30.

[0044] First, the user performs a predetermined operation on the operation reception unit 24 of the information terminal 20 on which the above-mentioned application is running. The predetermined operation is an operation for installing a server certificate. The operation reception unit 24 receives the predetermined operation (S11).

[0045] When the operation reception unit 24 receives a predetermined operation, the information processing unit 22 generates a server certificate issuance request and causes the communication unit 21 to transmit the generated issuance request to the management terminal 30. The issuance request includes the public key A. That is, the communication unit 21 transmits the public key A to the management terminal 30 (S12). The communication unit 21 transmits the public key A to the management terminal 30 by wireless communication via the wide area communication network.

[0046] The communication unit 31 of the management terminal 30 receives the issuance request including the public key A. If the administrator confirms the user's issuance request and allows the user to unlock the electric lock 60, the information processing unit 32 generates a signature for the received public key A and usage conditions using the private key B (S13). The information processing unit 32 also causes the communication unit 31 to transmit a server certificate including the public key A, usage conditions, and signature to the information terminal 20 (S14). The usage conditions are, for example, information indicating timing requirements (in other words, expiration dates) and are determined in advance, for example, by the administrator who uses the management terminal 30. The timing requirements, for example, specify the start and end points at which the server certificate is valid, but it is sufficient to specify at least the end point.

[0047] The format of the server certificate may be, for example, an X.509 certificate. Fig. 4 is a diagram showing an example of the format of a server certificate. The validity period of the certificate in Fig. 4 corresponds to the above-mentioned usage conditions (timing requirements), the subject public key information corresponds to public key A, and signatureValue corresponds to the signature. Usage conditions other than the expiration date may be stored in the extension area of ​​the format in Fig. 4.

[0048] The communication unit 21 of the information terminal 20 receives the server certificate. The information processing unit 22 stores the received server certificate in the storage unit 23 (S15).

[0049] [Operation Example 1] A description will be given of operation example 1 up to unlocking the electric lock 60 using the server certificate stored as described above. Fig. 5 is a sequence diagram of operation example 1 of the information processing system 10.

[0050] 5, a root certificate is stored in the storage unit 53 of the control device 50. The root certificate includes a public key B. The root certificate is generated, for example, by the information processing unit 32 of the management terminal 30, and is stored in the storage unit 53 by being transmitted to the control device 50 by the communication unit 31. The root certificate may be stored in the storage unit 53 by the manufacturing equipment when the control device 50 is manufactured.

[0051] The information processing unit 22 of the information terminal 20 starts (executes) the application when the user performs an operation to start the application (S16).

[0052] The control unit 52 of the control device 50 causes the communication unit 51 to transmit a beacon signal to notify the presence of the control device 50 (S17). The communication unit 51 transmits the beacon signal at predetermined time intervals. The beacon signal may also be called an advertisement signal. The beacon signal is transmitted continuously.

[0053] When the user moves near door 81, communication unit 21 of information terminal 20 receives a beacon signal. Note that door 81 is, for example, a door provided in a private area of ​​facility 80 (see FIG. 1 ), but may also be a door provided at the entrance of facility 80 or a door provided in a common area other than the entrance. When communication unit 21 receives the beacon signal, information processing unit 22 starts pre-authentication (S18 to S23) between information terminal 20 and control device 50. In other words, as long as the app of information terminal 20 is running, reception of the beacon signal triggers the start of pre-authentication without requiring any special operation by the user.

[0054] First, the information processing unit 22 establishes a wireless communication connection between the information terminal 20 (communication unit 21) and the control device 50 (communication unit 51) (S18). This wireless communication is wireless communication through a local communication network, such as short-range wireless communication based on a communication standard such as Bluetooth (registered trademark).

[0055] Thereafter, the information processing unit 22 causes the communication unit 21 to transmit the server certificate to the control device 50. That is, the communication unit 21 transmits the server certificate to the control device 50 (S19).

[0056] The communication unit 51 of the control device 50 receives the server certificate. The control unit 52 verifies the signature included in the received server certificate using the public key B included in the root certificate stored in the storage unit 53 (S20). If the signature verification is successful, the control unit 52 determines the usage conditions included in the server certificate (S21). The usage conditions may be, for example, a time-related requirement (whether the server certificate is within its expiration date), etc.

[0057] If the control unit 52 determines that the usage conditions are satisfied, it generates a session key using public key A included in the server certificate (S22). The control unit 52 encrypts the generated session key with public key A and causes the communication unit 51 to transmit the encrypted session key to the information terminal 20 (S23). The information processing unit 22 decrypts the session key using private key A, and thereafter, encrypted communication is established between the information terminal 20 (information processing unit 22) and the control device 50 (control unit 52) ​​by using the session key.

[0058] When the user moves closer to the door 81, the user performs a predetermined unlocking operation on the operation reception unit 24 of the information terminal 20 to unlock the electric lock 60. The operation reception unit 24 receives the unlocking operation (S24). The unlocking operation is, for example, the first operation performed by the user after starting the app. Unlike the operation of turning the thumb turn or door knob, the unlocking operation is a simple operation by which the user expresses their intention to unlock, such as a touch operation on the operation reception unit 24. The unlocking operation here is an operation unrelated to the start of pre-authentication.

[0059] The information processing unit 22 of the information terminal 20 causes the communication unit 21 to transmit the unlock request to the control device 50 (S25).

[0060] The communication unit 51 of the control device 50 receives the unlocking request. The control unit 52 unlocks the electric lock 60 based on the received unlocking request (S26).

[0061] In this way, in the information processing system 10, the management terminal 30 can use the server certificate and the root certificate to safely grant the information terminal 20 the authority to unlock the electric lock 60. Furthermore, because the information processing system 10 uses a public key certificate, the control device 50 can determine whether the information terminal 20 has the authority to unlock the electric lock 60 even if the information of the information terminal 20 has not been registered in the control device 50 in advance.

[0062] Furthermore, in the information processing system 10, pre-authentication (S18 to S23) is performed before the unlocking operation is accepted (S24), so that verification of the signature included in the server certificate can be completed before the unlocking operation is performed. Therefore, the information processing system 10 can unlock the electric lock 60 in a relatively short time after the unlocking operation is accepted, compared to a configuration in which authentication (S18 to S23) is performed when the unlocking operation is accepted. In other words, the information processing system 10 has the advantage that the user can quickly unlock the electric lock 60.

[0063] [Operation Example 2] Next, a description will be given of Operation Example 2 of the information processing system 10. Fig. 6 is a sequence diagram of Operation Example 2 of the information processing system 10.

[0064] The processing of steps S16 to S23 is the same as in Operation Example 1, and therefore detailed description thereof will be omitted. After the processing of step S23, when the user moves closer to the door 81, the user performs a predetermined unlocking operation to unlock the electric lock 60 via the operation reception unit 54 of the control device 50. The operation reception unit 54 receives the unlocking operation (S24a).

[0065] The control unit 52 of the control device 50 causes the communication unit 51 to transmit the unlocking permission request to the information terminal 20 (S25a).

[0066] The communication unit 21 of the information terminal 20 receives the unlocking permission request. In response to the received unlocking permission request, the information processing unit 22 causes the communication unit 21 to transmit an unlocking permission command to the control device 50 (S25b). That is, the communication unit 21 transmits the unlocking permission command to the control device 50.

[0067] The communication unit 51 of the control device 50 receives the unlock permission command. The control unit 52 unlocks the electric lock 60 based on the received unlock permission command (S26).

[0068] The processing of steps S25a to S25b may be omitted, and the electric lock 60 may be unlocked after the processing of step S25a. The processing of steps S25a to S25b has the advantage that the user can be notified that the electric lock 60 will be unlocked via the information terminal 20. The user is notified by sound output from the information terminal 20, vibration of the information terminal 20, or the like.

[0069] In this way, the user may perform the unlocking operation on the control device 50 instead of the information terminal 20. In the operation example 1, the user needs to take out the information terminal 20 and perform the unlocking operation on the information terminal 20, but in the operation example 2, the user can unlock the electric lock 60 by operating the operation reception unit 54 of the control device 50, and there is no need to take out the information terminal 20. This has the advantage that the user can easily unlock the electric lock 60.

[0070] [Operation Example 3] Next, a description will be given of Operation Example 3 of the information processing system 10. Fig. 7 is a sequence diagram of Operation Example 3 of the information processing system 10.

[0071] As shown in Figure 7, in operation example 3, steps S31 to S32 are added between steps S17 and S18 in operation example 1, and steps S33 to S35 are added between steps S24 and S25.

[0072] The measuring unit 25 measures the received signal strength of the beacon signal (S31), and the information processing unit 22 determines whether the measured received signal strength exceeds a threshold (S32). The threshold is stored in the storage unit 23, for example.

[0073] If it is determined in step S32 that the measured received signal strength is equal to or less than the threshold, it is possible that the information terminal 20 is somewhat far from the control device 50 and the user has no intention of unlocking the door 81. For this reason, pre-authentication (S18 to S23) is not performed.

[0074] On the other hand, if it is determined that the measured received signal strength exceeds the threshold, it is considered that the user is located near the control device 50 and intends to unlock the door 81. Therefore, when the information processing unit 22 determines that the measured received signal strength exceeds the threshold, it performs pre-authentication (S18 to S23).

[0075] The operation reception unit 24 of the information terminal 20 receives the unlocking operation (S24), and the communication unit 21 receives the wireless communication signal transmitted by the communication unit 51 of the control device 50 (S33). The measurement unit 25 measures the received signal strength of the received wireless communication signal (S34), and the information processing unit 22 determines whether the measured received signal strength exceeds a threshold value (S35).

[0076] In step S34, the measuring unit 25 may measure the received signal strength of any wireless communication signal transmitted by the communication unit 51 of the control device 50. The wireless communication signal transmitted in step S33 may be, for example, a status notification signal from the control device 50. In step S35, a threshold determination may be performed based on the received signal strength immediately before or immediately after step S24, and the processes of steps S44 and S45 may be executed immediately before step S24.

[0077] In this way, the information processing system 10 can prevent unnecessary communication by performing pre-authentication when the user is located near the control device 50 and is considered to have the intention to unlock the door 81. In other words, there are advantages in that the power consumption of the information terminal 20 and the control device 50 can be reduced and the user can quickly unlock the electric lock 60.

[0078] Furthermore, in the third operational example, a threshold value for the received signal strength can be set for each information terminal 20, so that an appropriate threshold value can be set according to the individual wireless communication characteristics of the information terminal 20.

[0079] Furthermore, by setting the threshold value used for the determination in step S35 to be larger than the threshold value used for the determination in step S32, it becomes possible to start pre-authentication when the information terminal 20 is located relatively far from the control device 50, and unlock the electric lock 60 when the information terminal 20 is located relatively close to the control device 50. In other words, there is an advantage that the user can unlock the electric lock 60 quickly and safely.

[0080] [Operation Example 4] Next, a description will be given of Operation Example 4 of the information processing system 10. Fig. 8 is a sequence diagram of Operation Example 4 of the information processing system 10.

[0081] As shown in Figure 8, in operation example 4, steps S41 to S42 are added between steps S19 and S20 in operation example 2, and steps S43 to S45 are added between steps S24a and S25a.

[0082] The measurement unit 55 measures the received signal strength of the wireless communication signal including the server certificate (S41), and the control unit 52 determines whether the measured received signal strength exceeds a threshold (S42). The threshold is stored, for example, in the storage unit 23. Note that in step S41, the measurement unit 55 may measure the received signal strength of the wireless communication signal for measurement (i.e., the wireless communication signal not including the server certificate) transmitted by the communication unit 21 of the information terminal 20.

[0083] If it is determined in step S42 that the measured received signal strength is equal to or less than the threshold, it is possible that the information terminal 20 is far from the control device 50 and that a third party other than the user has attempted to unlock the door fraudulently. Therefore, the process from step S20 onwards is not executed.

[0084] On the other hand, if it is determined that the measured received signal strength exceeds the threshold, it is considered that the user is located near the control device 50 and intends to unlock the door 81. Therefore, when the control unit 52 determines that the measured received signal strength exceeds the threshold, the processes of steps S20 to S24a are executed, similarly to the second operation example.

[0085] When the operation receiving unit 54 receives an unlocking operation in step S24a, the measuring unit 55 measures (S44) the received signal strength of the wireless communication signal (S43) transmitted by the communication unit 21 of the information terminal 20. The control unit 52 determines whether the measured received signal strength exceeds a threshold value (S45).

[0086] In step S44, the measurement unit 55 may measure the received signal strength of any wireless communication signal transmitted by the communication unit 21 of the information terminal 20. The wireless communication signal transmitted in step S43 may be, for example, a status notification signal from the information terminal 20. In step S45, a threshold determination may be performed based on the received signal strength immediately before or immediately after step S24a, and the processes of steps S44 and S45 may be executed immediately before step S24a.

[0087] In this way, the information processing system 10 can prevent unnecessary communications by performing the processes of steps S20 to S23 when the user is located near the control device 50 and is considered to have the intention to unlock the door 81. In other words, the power consumption of the information terminal 20 and the control device 50 can be reduced.

[0088] Furthermore, by setting the threshold value used for the determination in step S45 to be larger than the threshold value used for the determination in step S42, it becomes possible to start pre-authentication when the information terminal 20 is located relatively far from the control device 50, and unlock the electric lock 60 when the information terminal 20 is located relatively close to the control device 50. In other words, there is an advantage that the user can unlock the electric lock 60 quickly and safely.

[0089] Furthermore, in the fourth operational example, a threshold value for the received signal strength can be set for each control device 50, making it possible to set an appropriate threshold value according to the individual wireless communication characteristics of each control device 50. The wireless communication characteristics of the control device 50 are thought to vary depending on the physical shape of the control device 50, the installation location of the control device 50, and the like.

[0090] In addition, in steps S41 and S44, the measurement unit 55 may measure the received signal strength multiple times, and in steps S42 and S45, the control unit 52 may determine whether the average value of the received signal strength measured multiple times exceeds a threshold. In other words, the control unit 52 may determine whether the received signal strength exceeds a threshold based on the results of multiple measurements. This allows the control unit 52 to make a more accurate determination of the received signal strength when, for example, the received signal strength fluctuates widely.

[0091] Furthermore, after authenticating the information terminal 20 in step S22, the control unit 52 may correct (update) the threshold value used for the determination in step S42 to a more appropriate value based on the received signal strength measured by the measurement unit 55. For example, when there is a large difference between the measured received signal strength and the threshold value, the control unit 52 corrects the threshold value so as to reduce the difference between the received signal strength and the threshold value. This allows the control unit 52 to determine the received signal strength using a more appropriate threshold value the next time the lock is unlocked or thereafter.

[0092] Furthermore, after unlocking the electric lock 60 in step S26, the control unit 52 may correct (update) the threshold value used for the determination in step S45 to a more appropriate value based on the received signal strength measured by the measurement unit 55. For example, if there is a large difference between the measured received signal strength and the threshold value, the control unit 52 corrects the threshold value so as to reduce the difference between the received signal strength and the threshold value. This allows the control unit 52 to determine the received signal strength using a more appropriate threshold value the next time the lock is unlocked or thereafter.

[0093] [Operation Example 5] Next, a description will be given of Operation Example 5 of the information processing system 10. Fig. 9 is a sequence diagram of Operation Example 5 of the information processing system 10.

[0094] As shown in FIG. 9, in the operation example 5, step S51 is added between steps S19 and S41 in the operation example 4, and step S52 is added between steps S41 and S42.

[0095] In step S51, the transmission power measurement unit 26 of the information terminal 20 measures the transmission power of the wireless communication signal (in FIG. 9 , the wireless communication signal including the server certificate) whose received signal strength is to be measured. Also in step S51, the information processing unit 22 causes the communication unit 21 to transmit transmission power information indicating the measured transmission power to the control device 50. That is, the communication unit 21 transmits the transmission power information to the control device 50.

[0096] The communication unit 51 of the control device 50 receives transmission power information from the information terminal 20. The measurement unit 55 measures the received signal strength of the wireless communication signal including the server certificate (S41). The control unit 52 corrects the measured received signal strength according to the transmission power indicated by the transmission power information (S52), and determines whether the corrected received signal strength exceeds a threshold (S42). The control unit 52 performs corrections such as normalizing the received signal strength by the transmission power.

[0097] If the received signal strength is corrected by the transmission power in this way, the control unit 52 can more accurately determine the received signal strength.

[0098] Note that step S51 may be added between step S18 and step S19. In other words, the order of transmission of the transmission power information and the server certificate may be reversed.

[0099] [Operation Example 6] Incidentally, it is not essential that the control device 50 and the electric lock 60 be provided on the door 81 as shown in Fig. 1 above. For example, the control device 50 and the electric lock 60 may be provided on a portable lockbox or a movable object (mobile body) such as a bicycle. Fig. 10 is an external view of an electrically assisted bicycle equipped with the control device 50 and the electric lock 60.

[0100] 10 , the control device 50 may be realized as a hand switch of the power-assisted bicycle 90, and the electric lock 60 may be realized as a circle lock of the power-assisted bicycle 90. In the power-assisted bicycle 90, the control device 50 and the electric lock 60 are electrically connected by, for example, a wire.

[0101] When the control device 50 is provided on an electrically assisted bicycle 90, the location of the control device 50 changes as the electrically assisted bicycle 90 moves. Here, the received signal strength measured by the control device 50 (measurement unit 55) is, in other words, radio wave strength, and radio waves are reflected by the walls and ground surrounding the control device 50. In other words, the received signal strength is affected by the location (environment) in which the control device 50 is located. For this reason, it is thought that the received signal strength will also fluctuate if the location of the control device 50 changes. For example, it is thought that the received signal strength will fluctuate when the control device 50 is located in a closed space and when the control device 50 is located in an open space.

[0102] Therefore, the control device 50 may determine the threshold value depending on the current location of the control device 50. Fig. 11 is a sequence diagram of an operation example 6 of the information processing system 10.

[0103] As shown in FIG. 11, in the sixth operation example, steps S61 and S62 are added between steps S19 and S41 in the fourth operation example.

[0104] In step S61, the position measurement unit 27 of the information terminal 20 measures the current position of the information terminal 20. Also in step S61, the information processing unit 22 causes the communication unit 21 to transmit position information indicating the measured current position of the information terminal 20 to the control device 50. That is, the communication unit 21 transmits the position information to the control device 50.

[0105] The communication unit 51 of the control device 50 receives location information from the information terminal 20. The location indicated by the received location information indicates the location of the information terminal 20, but can also be considered to indicate the location of the control device 50. The control unit 52 determines a threshold value based on the received location information (S62). For example, the memory unit 53 of the control device 50 stores threshold value information that associates areas (coordinate ranges) with threshold values ​​to be used in those areas. The threshold value is set to a value that is considered appropriate empirically or experimentally. The control unit 52 can determine the threshold value associated with the area to which the location (coordinates) indicated by the received location information belongs as the threshold value to be used in step S42.

[0106] The measuring unit 55 measures the received signal strength of the wireless communication signal including the server certificate (S41). The control unit 52 determines whether the measured received signal strength exceeds the threshold determined in step S62 (S42).

[0107] In this way, if the threshold value is appropriately determined according to the current location of the control device 50, the control unit 52 can more accurately determine the received signal strength by taking into account radio wave reflections at the current location of the control device 50, etc.

[0108] Note that step S61 may be added between step S18 and step S19. In other words, the order of sending the location information and the server certificate may be reversed. Also, step S62 may be added between step S41 and step S42.

[0109] [Operation Example 7] Next, a description will be given of the operation when it is determined in step S42 of Operation Example 4 that the received signal strength is equal to or less than the threshold. Fig. 12 is a sequence diagram of Operation Example 7 of the information processing system 10. Operation Example 7 is an operation example in which, when the received signal strength is equal to or less than the threshold, the user reviews the threshold.

[0110] 12, in Operation Example 7, after step S41 in Operation Example 4, the control unit 52 determines that the received signal strength measured in step S41 is equal to or less than the threshold (S42a). Thereafter, similar to Operation Example 4, the processes of steps S20 to S23 are performed, and encrypted communication is established between the information terminal 20 (information processing unit 22) and the control device 50 (control unit 52).

[0111] The control unit 52 of the control device 50 causes the communication unit 51 to transmit notification information to the information terminal 20 to notify that the received signal strength is equal to or less than the threshold (the requirement regarding the received signal strength is not satisfied) (S71). That is, the communication unit 51 transmits the notification information to the information terminal 20.

[0112] The communication unit 21 of the information terminal 20 receives the notification information. The information processing unit 22 displays a notification screen on the display unit 28 based on the received notification information (S72). For example, the notification screen displays a message indicating that the threshold needs to be revised. For example, if the notification information includes the current threshold and a measurement value of the received signal strength, the information processing unit 22 can display the current threshold and the measurement value of the received signal strength on the notification screen.

[0113] 12, the operation receiving unit 24 receives a correction operation for correcting the threshold value from the user (S73). The correction operation may be, for example, an operation of directly inputting the threshold value, or an operation of specifying N levels prepared in advance, such as lowering the threshold value by N levels.

[0114] The information processing unit 22 causes the communication unit 21 to transmit a correction command to the control device 50 based on the received correction operation (S74).

[0115] The communication unit 51 of the control device 50 receives the correction command from the information terminal 20. The control unit 52 corrects the threshold value based on the received correction command (S75). That is, the threshold value is corrected in accordance with the operation accepted in step S73.

[0116] Thereafter, the same processes as steps S24a to S26 of operation example 4 are performed. In determining the received signal strength in step S45, the threshold corrected in step S75 is used.

[0117] In this way, if the threshold value is appropriately corrected when it is determined that the received signal strength is equal to or less than the threshold value, the control unit 52 can more accurately determine the received signal strength.

[0118] In addition, the control device 50 may send notification information to the information terminal 20 (urging the user to review the threshold) on the condition that the received signal strength is determined to be below the threshold multiple times.

[0119] In addition, in the seventh operational example, the threshold is reviewed (corrected) immediately after the notification information is received, but the review (correction operation) may be performed at any timing within the period during which the information terminal 20 and the control device 50 are able to communicate. In this case, the information terminal 20 may inquire of the control device 50 about the most recent received signal strength and the current threshold at any timing within the period. This allows the user to correct the threshold at a convenient timing.

[0120] Although the above-described Operation Example 7 is based on Operation Example 4, it is also possible to correct the threshold value by operating the information terminal 20 at any timing after step S23.

[0121] [Operation Example 8] Next, another operation when it is determined in step S45 of Operation Example 4 that the received signal strength is equal to or less than the threshold will be described. Fig. 13 is a sequence diagram of Operation Example 8 of the information processing system 10. Operation Example 8 is an operation example in which, when the received signal strength is equal to or less than the threshold, the electric lock 60 is unlocked on the condition that the user performs an operation to explicitly permit unlocking.

[0122] The processing up to step S44 is the same as in operation example 4 ( FIG. 8 ). When the received signal strength is equal to or less than the threshold (the requirement regarding the received signal strength is not satisfied) (S45a), the control unit 52 of the control device 50 causes the communication unit 51 to transmit notification information prompting permission to unlock with the user's approval to the information terminal 20 (S81).

[0123] In step S82, a message or the like prompting the user to perform an unlock permission operation on the information terminal 20 is displayed on the notification screen. The operation accepting unit 24 accepts an unlock permission operation from the user to permit unlocking of the electric lock 60 (S83). The information processing unit 22 causes the communication unit 21 to send an unlock permission command to the control device 50 based on the accepted unlock permission operation (S84). That is, the communication unit 21 sends the unlock permission command to the control device 50.

[0124] The communication unit 51 of the control device 50 receives the unlock permission command. The control unit 52 unlocks the electric lock 60 based on the received unlock permission command (S26).

[0125] In this way, in Operation Example 8, even if the received signal strength is below the threshold, the electric lock 60 is unlocked if the user explicitly permits unlocking. This allows the user to unlock the electric lock 60 safely and quickly.

[0126] Note that the above operation example 8 is an operation example based on operation example 4, but it is also possible to unlock the electric lock 60 by explicitly operating the information terminal 20 at any timing after step S23.

[0127] [Operation Example 9] Operation examples 1 to 8 are operation examples when the electric lock 60 is unlocked. After the electric lock 60 has been unlocked in operation examples 2 to 8, the operation when the electric lock 60 is locked will be described. Fig. 14 is a sequence diagram of operation example 9 of the information processing system 10.

[0128] The control device 50 unlocks the electric lock 60 (S26). After the electric lock 60 is unlocked in step S26, the information processing unit 22 of the information terminal 20 causes the communication unit 21 to transmit a status notification signal to the control device 50 (S91). That is, the communication unit 21 transmits the status notification signal to the control device 50. The status notification signal is a signal for notifying the control device 50 that the information terminal 20 is located near the control device 50, and the content of the data included in the signal is not particularly limited.

[0129] The communication unit 51 of the control device 50 receives the status notification signal. The measurement unit 55 measures the received signal strength of the status notification signal (S92), and the control unit 52 determines whether the measured received signal strength exceeds a threshold (S93). The threshold used at this time (locking threshold) may be the same as or different from the threshold used to determine whether to unlock the electric lock 60 (unlocking threshold). The threshold may be determined empirically or experimentally as appropriate to enhance user convenience.

[0130] In step S93, while it is determined that the measured received signal strength exceeds the threshold, the electric lock 60 remains unlocked. If the control unit 52 determines in step S93 that the measured received signal strength is equal to or less than the threshold, it locks the electric lock 60 (S94).

[0131] In this way, the control device 50 can automatically lock the electric lock 60 when the user carrying the information terminal 20 moves away from the control device 50.

[0132] [Operation Example 10] Next, another operation will be described when locking the electric lock 60 after the electric lock 60 has been unlocked in Operation Examples 1 to 8. Fig. 15 is a sequence diagram of Operation Example 10 of the information processing system 10.

[0133] The control device 50 unlocks the electric lock 60 (S26). After the electric lock 60 is unlocked in step S26, the control unit 52 determines whether communication with the information terminal 20 has been interrupted for a certain period of time or longer (S101). The length of the certain period of time may be determined empirically or experimentally as appropriate.

[0134] The electric lock 60 remains unlocked for a certain period of time after communication with the information terminal 20 is lost. When the control unit 52 determines in step S101 that communication with the information terminal 20 has been lost for a certain period of time or longer, it locks the electric lock 60 (S102).

[0135] In this way, the control device 50 can automatically lock the electric lock 60 when the user carrying the information terminal 20 moves away from the control device 50 and communication between the information terminal 20 and the control device 50 is interrupted.

[0136] [Operation Example 11] Next, an operation when multiple information terminals 20 are located within the wireless communication range of one control device 50 will be described. Fig. 16 is a sequence diagram of Operation Example 11 of the information processing system 10. In the following description of Operation Example 11, the multiple information terminals 20 are distinguished into information terminal 20a and multiple information terminals 20b. The unlocking operation is performed on information terminal 20a.

[0137] The information terminal 20a and each of the plurality of information terminals 20b communicate with the control device 50, and perform the processes of steps S16 to S24 of the first operation example to complete the pre-authentication.

[0138] The information processing unit 22 of the information terminal 20a causes the communication unit 21 to transmit a wireless communication signal to the control device 50 (S111a). That is, the communication unit 21 transmits the wireless communication signal to the control device 50. The wireless communication signal is, for example, a status notification signal, but is not particularly limited to this. The wireless communication signal includes identification information of the information terminal 20a.

[0139] The communication unit 51 of the control device 50 receives a wireless communication signal. The measurement unit 55 measures the received signal strength of the wireless communication signal (S112a), and the control unit 52 stores the measured received signal strength in the memory unit 53 in association with the identification information of the information terminal 20a (S113a).

[0140] Similarly, the information processing unit 22 of the information terminal 20b causes the communication unit 21 to transmit a wireless communication signal to the control device 50 (S111b). The wireless communication signal includes identification information of the information terminal 20b.

[0141] The communication unit 51 of the control device 50 receives the wireless communication signal. The measurement unit 55 measures the received signal strength of the wireless communication signal (S112b), and the control unit 52 stores the measured received signal strength in the memory unit 53 in association with the identification information of the information terminal 20b (S113b).

[0142] Thereafter, the user of the information terminal 20a moves near the door 81 and performs a predetermined unlocking operation on the operation accepting unit 24 of the information terminal 20a to unlock the electric lock 60. The operation accepting unit 24 accepts the unlocking operation (S114). The acceptance of the unlocking operation triggers the information processing unit 22 to cause the communication unit 21 to send an unlocking request to the control device 50 (S115). That is, the communication unit 21 sends the unlocking request to the control device 50. The unlocking request includes identification information of the information terminal 20a.

[0143] The communication unit 51 of the control device 50 receives the unlock request. The measurement unit 55 measures the received signal strength of the unlock request (S116). The control unit 52 compares the received signal strength measured in step S116 with the received signal strength of a wireless communication signal transmitted by an information terminal 20b other than the information terminal 20a (i.e., the received signal strength stored in the storage unit 53 in step S113b). Hereinafter, the received signal strength measured in step S116 will be referred to as received signal strength a, and the multiple received signal strengths stored in the storage unit 53 in step S113b will also be referred to as received signal strength b.

[0144] If the received signal strength a exceeds the received signal strength b, it is estimated that the information terminal 20a is located closer to the control device 50 than the information terminal 20b. Therefore, when the control unit 52 determines that the received signal strength a is equal to or greater than the received signal strength b (S117), it unlocks the electric lock 60 (S118).

[0145] On the other hand, if the received signal strength a is equal to or less than the received signal strength b, it is estimated that the information terminal 20a is located farther from the control device 50 than the information terminal 20b, and the unlock request may have been sent by erroneous operation, etc. Therefore, when the control unit 52 determines that the received signal strength a is equal to or less than the received signal strength b, it does not unlock the electric lock 60 (not shown).

[0146] In this way, the information processing system 10 compares the received signal strength of the unlock request sent by the information terminal 20a with the received signal strength of the wireless communication signal sent by the information terminal 20b, and unlocks the electric lock 60 when it is estimated that the information terminal 20a is located closest to the control device 50. In the determination in step S117, the determination threshold can be considered to be determined based on the received signal strength b. This allows the user to unlock the electric lock 60 safely.

[0147] The requirement for unlocking the electric lock 60 is not limited to the requirement that the received signal strength a exceed the received signal strength b. For example, the requirement for unlocking the electric lock 60 may be that the received signal strength a is relatively high (within the top two or within the top 10%) among the multiple received signal strengths stored in the memory unit 53 before the unlocking operation is performed. In this way, in the determination in step S117, the determination threshold may be set based on the received signal strength b.

[0148] Alternatively, more simply, the processes of steps S112a to S113b may be omitted, and in step S117, it may be determined whether or not the received signal strength a exceeds a predetermined threshold value.

[0149] [Operation Example 12] Next, an operation when multiple control devices 50 are located within the wireless communication range of one information terminal 20 will be described. Fig. 17 is a sequence diagram of Operation Example 12 of the information processing system 10. In the following description of Operation Example 12, the multiple control devices 50 are distinguished into control device 50a and multiple control devices 50b. The unlocking operation is performed on control device 50a.

[0150] The information terminal 20 performs the processes of steps S16 to S24 of the first operation example with the control device 50a and each of the plurality of control devices 50b as communication partners, and completes the pre-authentication.

[0151] The control unit 52 of the control device 50a causes the communication unit 51 to transmit a beacon signal (S121a). That is, the communication unit 51 transmits the beacon signal. The beacon signal includes identification information of the control device 50a.

[0152] The communication unit 21 of the information terminal 20 receives the beacon signal. The measurement unit 25 measures the received signal strength of the beacon signal (S122a), and the control unit 52 stores the measured received signal strength in the memory unit 23 in association with the identification information of the control device 50a (S123a).

[0153] Similarly, the control unit 52 of the control device 50b causes the communication unit 51 to transmit a beacon signal (S121b). That is, the communication unit 51 transmits the beacon signal. The beacon signal includes identification information of the control device 50b.

[0154] The communication unit 21 of the information terminal 20 receives the beacon signal. The measurement unit 25 measures the received signal strength of the beacon signal (S122b), and the control unit 52 stores the measured received signal strength in the memory unit 23 in association with the identification information of the control device 50b (S123b).

[0155] Thereafter, the user of the information terminal 20 moves near the door 81 and performs a predetermined unlocking operation on the operation accepting unit 54 of the control device 50a to unlock the electric lock 60. The operation accepting unit 54 accepts the unlocking operation (S124). The acceptance of the unlocking operation triggers the control unit 52 to cause the communication unit 51 to send an unlocking permission request to the information terminal 20 (S125). That is, the communication unit 51 sends the unlocking permission request to the information terminal 20. The unlocking permission request includes identification information of the control device 50a.

[0156] The communication unit 21 of the information terminal 20 receives the unlock permission request. The measurement unit 25 measures the received signal strength of the unlock permission request (S126). The information processing unit 22 compares the received signal strength measured in step S126 with the received signal strength of a beacon signal transmitted by a control device 50b other than the control device 50a, which is stored in the memory unit 23 (i.e., the received signal strength of the beacon signal transmitted by the control device 50b, which is stored in the memory unit 23 in step S123b). Hereinafter, the received signal strength measured in step S126 will be referred to as received signal strength a, and the multiple received signal strengths stored in the memory unit 23 in step S123b will also be referred to as received signal strength b.

[0157] If the received signal strength a exceeds the received signal strength b, it is estimated that the control device 50a is located closer to the information terminal 20 than the control device 50b. Therefore, when the information processing unit 22 determines that the received signal strength a exceeds the received signal strength b (S127), it causes the communication unit 21 to send an unlock permission command to the control device 50a (S128). That is, the communication unit 21 sends the unlock permission command to the control device 50a. The communication unit 51 of the control device 50a receives the unlock permission command, and the control unit 52 unlocks the electric lock 60 based on the received unlock permission command (S129).

[0158] On the other hand, if the received signal strength a is equal to or less than the received signal strength b, it is estimated that the control device 50a is located farther from the information terminal 20 than the control device 50b, and the unlock permission request may have been sent due to an erroneous operation, etc. Therefore, when the information processing unit 22 determines that the received signal strength a is equal to or less than the received signal strength b, it does not send an unlock permission command, and the electric lock 60 is not unlocked (not shown).

[0159] In this way, the information processing system 10 compares the received signal strength of the unlock permission request sent by the control device 50a with the received signal strength of the beacon signal sent by the control device 50b, and unlocks the electric lock 60 when it is estimated that the control device 50a is located closest to the information terminal 20. In the determination in step S127, it can be considered that the determination threshold is determined based on the received signal strength b.

[0160] In the situation that is the premise of Operation Example 12, if a determination is made by simply setting a threshold value for the received signal strength, a user may be able to unlock both the electric lock 60 connected to the control device 50a and the electric locks 60 connected to multiple control devices 50b from the information terminal 20. In contrast, in Operation Example 12, only the electric lock 60 connected to the control device 50a located near the information terminal 20 is permitted to be unlocked, which makes it possible to prevent the electric lock 60 from being unlocked fraudulently.

[0161] The requirement for unlocking the electric lock 60 is not limited to the requirement that the received signal strength a exceed the received signal strength b. For example, the requirement for unlocking the electric lock 60 may be that the received signal strength a is relatively high (within the top two or within the top 10%) among the multiple received signal strengths stored in the memory unit 23 before the unlocking operation is performed. In this way, in the determination at step S127, the determination threshold may be set based on the received signal strength b.

[0162] Alternatively, more simply, the processes of steps S122a to S123b may be omitted, and in step S127, it may be determined whether or not the received signal strength a exceeds a predetermined threshold value.

[0163] [Modification] In the above operational examples 1 to 12, examples have been described in which a user unlocks or locks the electric lock 60 using the information terminal 20. Here, in operational examples 1 to 12, an administrator or the like may unlock or lock the electric lock 60 using the management terminal 30. In other words, the information terminal 20, communication unit 21, information processing unit 22, memory unit 23, operation reception unit 24, measurement unit 25, transmission power measurement unit 26, position measurement unit 27, and display unit 28 in operational examples 1 to 12 may be replaced with the management terminal 30, communication unit 31, information processing unit 32, memory unit 33, operation reception unit 34, measurement unit 35, transmission power measurement unit 36, position measurement unit 37, and display unit 38.

[0164] When the electric lock 60 is unlocked using the information terminal 20, the server certificate includes the public key A and a signature generated using the private key B, but when the electric lock 60 is unlocked using the management terminal 30, the server certificate includes the public key B and a signature generated using the private key B. The management terminal 30 can also be considered as an information terminal 20 that has the function of issuing server certificates to other information terminals.

[0165] Furthermore, in the above-described embodiment, in an operation example in which a method is adopted in which the control device 50 measures the received signal strength of a wireless communication signal received from the information terminal 20, the method may be replaced by a method in which the information terminal 20 measures the received signal strength of a wireless communication signal received from the control device 50. If the information terminal 20 determines the received signal strength, the amount of information processing by the control device 50 can be reduced.

[0166] Furthermore, in the above-described embodiment, the steps described in Operation Examples 1 to 12 may be combined in any manner. For example, in Operation Example 2 (FIG. 6), steps S33 to S35 of Operation Example 3 may be added between steps S24 and S25. FIG. 18 is a sequence diagram of such a modified example of the operation of information processing system 10.

[0167] 18, the information processing unit 22 of the information terminal 20 that has received the unlocking permission request in step S25a performs the processes of steps S33 to S35. The information processing unit 22 may transmit an unlocking permission command to the control device 50 in step S25b only when the received signal strength of the wireless communication signal that the information terminal 20 has received from the control device 50 exceeds a threshold value.

[0168] In the above embodiment, the electric lock 60 locks or unlocks the door 81 or the electrically assisted bicycle 90, but the electric lock 60 may also be an electric lock that locks and unlocks the door of a delivery box, a coin locker, or a safe deposit box, etc.

[0169] Furthermore, the control target of the control device 50 is not limited to the electric lock 60. The control device 50 may control any device that releases restrictions on the operation of an item. For example, the control target of the control device 50 may be an automatic door. The information processing system 10 can also be applied to cases where only specific individuals are permitted to control home appliances such as lighting devices and air conditioners.

[0170] In the above embodiment, the usage conditions are included in the server certificate. However, the usage conditions may be transmitted from the information terminal 20 or the management terminal 30 to the control device 50 in a secure manner, separately from the server certificate.

[0171] 5 (Operation Example 1), the usage conditions may be transmitted from the information terminal 20 to the control device 50 together with the signature of the management terminal 30 by encrypted communication using a session key (performed after step S23). By separating the server certificate and the usage conditions, it becomes possible to flexibly add or change the usage conditions without reissuing the server certificate. This technology can be applied not only to Operation Example 1, but also to Operation Examples 2 to 12.

[0172] Furthermore, although not illustrated in the above embodiment, the control device 50 (control unit 52) ​​may transmit pseudo information including a random number to the information terminal 20 after transmitting the server certificate in step S19 of FIG. 5 (Operation Example 1), and the information terminal 20 may sign the received pseudo information using the private key A and transmit the signed information to the control device 50. The control device 50 can prevent theft of the certificate by verifying the signature received from the information terminal 20 using the public key A included in the server certificate after step S18 and before step S21. This technique can be applied not only to Operation Example 1 but also to Operation Examples 2 to 12.

[0173] Furthermore, the control device 50 (control unit 52) ​​may verify the ID of the control device 50 contained in the server certificate in step S20 of FIG. 5 (Operation Example 1). This makes it possible to prevent the certificate for another control device from being reused. This technique can be applied not only to Operation Example 1 but also to Operation Examples 2 to 12.

[0174] [Effects, etc.] Hereinafter, examples of inventions obtained from the disclosure of this specification will be described, and effects, etc. obtained from the exemplified inventions will be explained.

[0175] Invention 1 is an information processing system 10 used to release a restriction on a device that restricts the operation of an item, the information processing system 10 including an information terminal 20 and a control device 50, wherein the information terminal 20 has a memory unit 23 storing a private key A, a public key A corresponding to the private key A, and a server certificate, and a communication unit 21 that transmits the server certificate to the control device 50, the server certificate including the public key A and a signature for the public key A, and the control device 50 has a memory unit 53 storing a root certificate including the public key, a communication unit 51 that receives the server certificate from the information terminal 20, and a control unit 52 that verifies the signature included in the server certificate using the public key included in the root certificate and releases the device restriction on the condition that the signature verification has been successful at the time the release operation is accepted by the information terminal 20 or the control device 50. The private key A, the public key A, the memory unit 23, the communication unit 21, the memory unit 53, and the communication unit 51 are examples of a first private key, a first public key, a first memory unit, a first communication unit, a second memory unit, and a second communication unit. The predetermined release operation corresponds to the predetermined unlocking operation in the above embodiment, and releasing the restriction on the device means unlocking the electric lock 60 in the above embodiment.

[0176] In such an information processing system 10, the verification of the signature is completed when the release operation is accepted, and therefore the time from when the user performs the release operation until the restriction on the device is released can be shortened compared to a system in which the signature verification is performed after the release operation is accepted.

[0177] Invention 2 is the information processing system 10 of Invention 1, in which the signature is generated using private key A, and the public key included in the root certificate is public key A. Invention 2 corresponds to the case in which the information terminal 20 of Invention 1 has a function of issuing server certificates to other information terminals.

[0178] Such an information processing system 10 can safely and quickly remove restrictions on devices using an information terminal 20 that can issue server certificates to other information terminals.

[0179] Invention 3 is the information processing system 10 of Invention 1, in which the signature is generated using private key B different from private key A, and the public key included in the root certificate is public key B corresponding to private key B. Private key B and public key B are examples of a second private key and a second public key.

[0180] Such an information processing system 10 can safely and quickly remove restrictions on devices using the information terminal 20 that receives a server certificate from the management terminal 30.

[0181] Invention 4 is an information processing system 10 of any of Inventions 1 to 3, in which the information terminal 20 has a measurement unit 25 that measures a first received signal strength of a wireless communication signal received by the communication unit 21 from the control device 50, and the communication unit 21 transmits a server certificate to the control device 50 on the condition that the measured first received signal strength exceeds a first threshold value.

[0182] Such an information processing system 10 can more safely remove restrictions on devices while preventing fraudulent activity by third parties by sending a server certificate to the control device 50 on the condition that the measured first received signal strength exceeds a first threshold value.

[0183] Invention 5 is information processing system 10 of any of Inventions 1 to 3, in which information terminal 20 has measurement unit 25 that measures a first received signal strength of a wireless communication signal received by communication unit 21 from control device 50, and communication unit 21 transmits information for releasing the restriction to control device 50 on the condition that control device 50 has successfully verified the signature included in the server certificate at the time the release operation is accepted and the measured first received signal strength exceeds a second threshold. The information for releasing the restriction is the unlocking permission request or unlocking permission command of the above embodiments.

[0184] Such an information processing system 10 can more safely release restrictions on equipment while preventing fraudulent activity by third parties by sending an unlocking permission command to the control device 50 on the condition that the measured first received signal strength exceeds a second threshold value.

[0185] Invention 6 is an information processing system 10 of any of Inventions 1 to 3, in which the control device 50 has a measurement unit 55 that measures a second received signal strength of a wireless communication signal received by the communication unit 51 from the information terminal 20, and the control unit 52 verifies the signature included in the server certificate, provided that the measured second received signal strength exceeds a third threshold.

[0186] Such an information processing system 10 can more safely remove restrictions on devices while preventing fraudulent activity by third parties by sending a server certificate to the control device 50 on the condition that the measured second received signal strength exceeds a third threshold value.

[0187] Invention 7 is an information processing system 10 of any of Inventions 1 to 3, in which the control device 50 has a measurement unit 55 that measures the second received signal strength of the wireless communication signal received by the communication unit 51 from the information terminal 20, and the control unit 52 releases the restriction on the device under the condition that the signature included in the server certificate has been successfully verified at the time the release operation is accepted and the measured second received signal strength exceeds a fourth threshold.

[0188] Such an information processing system 10 can lift restrictions on devices more safely while preventing fraudulent activity by third parties by lifting restrictions on devices on the condition that the measured third received signal strength exceeds a fourth threshold.

[0189] An eighth aspect of the present invention is the information processing system 10 of the seventh aspect, wherein the control unit 52 determines whether the second received signal strength exceeds a threshold value based on a plurality of measurement results.

[0190] Such an information processing system 10 can make a determination based on a more accurate second received signal strength when the second received signal strength fluctuates widely.

[0191] Invention 9 is the information processing system 10 of Invention 7, in which the information terminal 20 further has a transmission power measurement unit 26 that measures the transmission power of the wireless communication signal, the communication unit 21 transmits transmission power information indicating the measured transmission power to the control device 50, the communication unit 51 receives the transmission power information from the information terminal 20, and the control unit 52 corrects the second received signal strength based on the transmission power information.

[0192] Such an information processing system 10 can more accurately determine the second received signal strength.

[0193] Invention 10 is the information processing system 10 of Invention 7, in which the information terminal 20 further has a position measurement unit 27 that measures the position of the information terminal 20, the communication unit 21 transmits position information indicating the measured position to the control device 50, the communication unit 51 receives the position information from the control device 50, and the control unit 52 determines the fourth threshold value based on the received position information.

[0194] Such an information processing system 10 can determine the fourth threshold value according to the position of the information terminal 20 (≈ the position of the control device 50). If the fourth threshold value is appropriately determined according to the current position of the information terminal 20, the information processing system 10 can more accurately determine the second received signal strength by taking into account the reflection of radio waves at the current position of the information terminal 20, etc.

[0195] Invention 11 is the information processing system 10 of Invention 7, in which, if the requirement that the measured second received signal strength exceeds the fourth threshold is not met, the control unit 52 causes the communication unit 51 to send notification information to the information terminal 20 to notify that the requirement is not met.

[0196] Such an information processing system 10 can notify the user of the information terminal 20 that the device restriction cannot be lifted because the requirement regarding the second received signal strength is not satisfied.

[0197] Invention 12 is the information processing system 10 of Invention 11, in which the information terminal 20 has an operation receiving unit 24 that receives a correction operation for correcting the fourth threshold after notification information is received, the communication unit 21 transmits a correction command for the fourth threshold to the control device 50 based on the received correction operation, the communication unit 51 receives the correction command, and the control unit 52 corrects the fourth threshold based on the received correction command.

[0198] When the fourth threshold is too high and the second received signal strength is determined to be equal to or less than the fourth threshold, the information processing system 10 can appropriately correct the fourth threshold (to a lower value). If the fourth threshold is appropriately corrected, the information processing system 10 can more accurately determine the second received signal strength.

[0199] A thirteenth aspect of the present invention is the information processing system 10 of the eleventh aspect, wherein the information terminal 20 has an operation receiving unit 24 that receives a release permission operation to allow the release of the restriction after receiving the notification information, the communication unit 21 transmits a release permission command to the control device 50 based on the received release permission operation, the communication unit 51 receives the release permission command, and the control unit 52 releases the restriction based on the received release permission command. The release permission command corresponds to the predetermined unlock permission command in the above-described embodiment.

[0200] In the information processing system 10, even if the second received signal strength is equal to or less than the fourth threshold, the restriction on the device can be lifted by the user explicitly permitting unlocking, thereby enabling the user to safely and quickly lift the restriction on the device.

[0201] A fourteenth aspect of the present invention is the information processing system 10 of the seventh aspect, wherein the control unit 52 causes the device to restrict the operation of the item when the second received signal strength of the wireless communication signal received by the communication unit 51 from the information terminal 20 becomes equal to or less than a fourth threshold value after the restriction is released. The restriction on the operation of the item corresponds to the locking of the electric lock 60 in the above embodiment.

[0202] Such an information processing system 10 can restrict the movement of the article when the user carrying the information terminal 20 moves away from the control device 50 .

[0203] Invention 15 is the information processing system 10 of Invention 7, in which the control unit 52 causes the equipment to restrict the operation of the item if, after the restriction is lifted, communication with the information terminal 20 via the communication unit 51 is interrupted for a certain period of time or more.

[0204] Such an information processing system 10 can restrict the movement of the article when the user carrying the information terminal 20 moves away from the control device 50 and communication between the information terminal 20 and the control device 50 is interrupted.

[0205] Invention 16 is the information processing system 10 of Invention 7, in which the communication unit 51 receives multiple wireless communication signals from multiple other information terminals 20, the measurement unit 55 measures the received signal strength of each of the multiple wireless communication signals, and the fourth threshold is determined by the received signal strength of each of the multiple wireless communication signals.

[0206] The information processing system 10 can permit the removal of device restrictions for an information terminal 20 located near the control device 50 among the multiple information terminals 20 .

[0207] Invention 17 is the information processing system 10 of Invention 4, in which the communication unit 21 receives multiple wireless communication signals from multiple other control devices 50, the measurement unit 25 measures the received signal strength of each of the multiple wireless communication signals, and the second threshold is determined by the received signal strength of each of the multiple wireless communication signals.

[0208] In such an information processing system 10, the restriction on the device controlled by the control device 50 located near the information terminal 20 among the multiple control devices 50 can be removed.

[0209] Invention 18 is a control device 50 that releases restrictions on equipment that restrict the operation of an item, the control device 50 comprising: a memory unit 53 in which a root certificate including a public key is stored; a communication unit 51 that receives a server certificate including the public key A and a signature for the public key A from an information terminal 20 that has a memory unit 23 in which a private key A, a public key A corresponding to the private key A, and a server certificate is stored; and a control unit 52 that verifies the signature included in the server certificate using the public key included in the root certificate and releases the equipment restriction, provided that the signature verification has been successful at the time the release operation is accepted by the information terminal 20 or the control device 50.

[0210] Such a control device 50 can reduce the time it takes for the restriction on the device to be lifted after the user performs the lifting operation.

[0211] Invention 19 is an information processing method executed by an information processing system 10 used to release restrictions on equipment that restricts the operation of an item, the information processing system 10 comprising an information terminal 20 and a control device 50, the information terminal 20 comprising a memory unit 23 in which a private key A, a public key A corresponding to the private key A, and a server certificate are stored, and the control device 50 comprising a memory unit 53 in which a root certificate including the public key is stored, the information processing method comprising the steps of: the information terminal 20 transmitting a server certificate including the public key A and a signature for the public key A to the control device 50; the control device 50 receiving the server certificate from the information terminal 20; the control device 50 verifying the signature included in the server certificate using the public key included in the root certificate; and the control device 50 releasing the restrictions on the equipment, provided that the signature verification has been successful at the time the release operation is accepted by the information terminal 20 or the control device 50.

[0212] Such an information processing method can shorten the time it takes from when the user performs the cancellation operation until the restriction on the device is cancelled.

[0213] Invention 20 is an information processing method executed by a control device 50 that releases restrictions on equipment that restricts the operation of an item, wherein the control device 50 has a memory unit 53 in which a root certificate including a public key is stored, and the information processing method includes the steps of receiving a server certificate including public key A and a signature for public key A from an information terminal 20 that has a memory unit 23 in which a private key A, a public key A corresponding to private key A, and a server certificate are stored, a step of verifying the signature included in the server certificate, and a step of releasing the restriction on the equipment, provided that the signature included in the server certificate has been successfully verified using the public key included in the root certificate at the time the release operation is accepted by the information terminal 20 or the control device 50.

[0214] Such an information processing method can shorten the time it takes from when the user performs the cancellation operation until the restriction on the device is cancelled.

[0215] A twenty-first aspect of the present invention is a program for causing a computer to execute the information processing method of the nineteenth or twentieth aspect of the present invention.

[0216] According to this program, the computer can reduce the time it takes for the restriction on the device to be lifted after the user performs the lifting operation.

[0217] (Other Embodiments) Although the embodiments have been described above, the present invention is not limited to the above-described embodiments.

[0218] For example, in the above embodiment, the information processing system is realized by multiple devices, but it may also be realized as a single device. For example, the information processing system may be realized as a single device corresponding to any of an information terminal, a management terminal, and a control device. When the information processing system is realized by multiple devices, the components (especially functional components) of the information processing system may be allocated in any way among the multiple devices.

[0219] In the above-described embodiment, the processing performed by a specific processing unit may be performed by another processing unit. The order of multiple processing operations may be changed, or multiple processing operations may be performed in parallel.

[0220] In the above-described embodiments, each component may be realized by executing a software program suitable for that component, or by a program execution unit such as a CPU or processor reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory.

[0221] Furthermore, each component may be realized by hardware. For example, each component may be a circuit (or integrated circuit). These circuits may form a single circuit as a whole, or each may be a separate circuit. Furthermore, each of these circuits may be a general-purpose circuit or a dedicated circuit.

[0222] Furthermore, the general or specific aspects of the present invention may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a computer-readable recording medium such as a CD-ROM, etc. Furthermore, the general or specific aspects of the present invention may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium.

[0223] For example, the present invention may be realized as the information terminal, management terminal, control device, or electric lock system (control device and electric lock) of the above-described embodiments.

[0224] The present invention may also be realized as an information processing method executed by a computer such as the information processing system, information terminal, management terminal, or control device of the above-described embodiments. The present invention may also be realized as a program for causing a computer to execute the information processing method. The present invention may also be realized as a computer-readable non-transitory recording medium on which such a program is recorded.

[0225] The present invention may also be realized as an application program for causing a general-purpose information terminal to function as the information terminal or management terminal of the above-described embodiment, or as a computer-readable non-transitory recording medium on which such an application program is recorded.

[0226] In addition, the present invention also includes forms obtained by applying various modifications to each embodiment that a person skilled in the art would think of, or forms realized by arbitrarily combining the components and functions of each embodiment within the scope of the present invention.

[0227] REFERENCE SIGNS LIST 10 Information processing system 20, 20a, 20b Information terminal 21, 31, 51 Communication unit 22, 32 Information processing unit 23, 33, 53 Memory unit 24, 34, 54 Operation reception unit 25, 35, 55 Measurement unit 26, 36 Transmission power measurement unit 27, 37 Position measurement unit 28, 38 Display unit 30 Management terminal 50, 50a, 50b Control device 52 Control unit 60 Electric lock 80 Facility 81 Door 90 Electrically assisted bicycle

Claims

1. An information processing system used to release restrictions on equipment that restricts the operation of an item, comprising: an information terminal; and a control device, wherein the information terminal has: a first memory unit that stores a first private key, a first public key corresponding to the first private key, and a server certificate; and a first communication unit that transmits the server certificate to the control device, wherein the server certificate includes the first public key and a signature for the first public key; and the control device has: a second memory unit that stores a root certificate including a public key; a second communication unit that receives the server certificate from the information terminal; and a control unit that verifies the signature included in the server certificate using the public key included in the root certificate, and releases the restriction on the equipment on the condition that verification of the signature has been successful at the time the information terminal or the control device accepts a release operation.

2. The information processing system according to claim 1, wherein the signature is a signature generated using the first private key, and the public key included in the root certificate is the first public key.

3. The information processing system according to claim 1, wherein the signature is generated using a second private key different from the first private key, and the public key included in the root certificate is a second public key corresponding to the second private key.

4. An information processing system according to any one of claims 1 to 3, wherein the information terminal has a first measurement unit that measures a first received signal strength of a wireless communication signal received by the first communication unit from the control device, and the first communication unit transmits the server certificate to the control device on the condition that the measured first received signal strength exceeds a first threshold value.

5. The information processing system according to any one of claims 1 to 3, wherein the information terminal has a first measurement unit that measures a first received signal strength of a wireless communication signal received by the first communication unit from the control device, and the first communication unit transmits information to the control device to release the restriction, provided that the control device has successfully verified the signature included in the server certificate at the time the release operation is accepted and the measured first received signal strength exceeds a second threshold.

6. The information processing system according to any one of claims 1 to 3, wherein the control device has a second measurement unit that measures a second received signal strength of the wireless communication signal received by the second communication unit from the information terminal, and the control unit verifies the signature included in the server certificate on the condition that the measured second received signal strength exceeds a third threshold.

7. The information processing system according to any one of claims 1 to 3, wherein the control device has a second measurement unit that measures a second received signal strength of the wireless communication signal received by the second communication unit from the information terminal, and the control unit releases the restriction on the device on the condition that the signature included in the server certificate has been successfully verified at the time the release operation is accepted and the measured second received signal strength exceeds a fourth threshold.

8. The information processing system according to claim 7, wherein the control unit determines whether the second received signal strength exceeds the fourth threshold based on multiple measurement results.

9. The information processing system according to claim 7, wherein the information terminal further has a transmission power measurement unit that measures the transmission power of the wireless communication signal, the first communication unit transmits transmission power information indicating the measured transmission power to the control device, the second communication unit receives the transmission power information from the information terminal, and the control unit corrects the second received signal strength based on the transmission power information.

10. The information processing system of claim 7, wherein the information terminal further has a position measurement unit that measures the position of the information terminal, the first communication unit transmits position information indicating the measured position to the control device, the second communication unit receives the position information from the control device, and the control unit determines the fourth threshold value based on the received position information.

11. The information processing system of claim 7, wherein, if the requirement that the measured second received signal strength exceeds the fourth threshold is not met, the control unit causes the second communication unit to send notification information to the information terminal to notify that the requirement is not met.

12. The information processing system described in claim 11, wherein the information terminal has an operation receiving unit that receives a correction operation for correcting the fourth threshold after receiving the notification information, the first communication unit transmits a correction command for the fourth threshold to the control device based on the received correction operation, the second communication unit receives the correction command, and the control unit corrects the fourth threshold based on the received correction command.

13. The information processing system described in claim 11, wherein the information terminal has an operation receiving unit that receives a release permission operation to allow the removal of the restriction after the notification information is received, the first communication unit transmits a release permission command to the control device based on the received release permission operation, the second communication unit receives the release permission command, and the control unit releases the restriction based on the received release permission command.

14. The information processing system of claim 7, wherein the control unit causes the device to restrict the operation of the item when, after the restriction is lifted, the second received signal strength of the wireless communication signal received by the second communication unit from the information terminal becomes equal to or less than the fourth threshold value.

15. An information processing system according to any one of claims 1 to 3, wherein the control unit causes the device to restrict the operation of the item if, after the restriction is lifted, communication with the information terminal via the second communication unit is interrupted for a certain period of time or longer.

16. An information processing system as described in claim 7, wherein the second communication unit receives a plurality of wireless communication signals from a plurality of other information terminals, the second measurement unit measures the received signal strength of each of the plurality of wireless communication signals, and the fourth threshold is determined by the received signal strength of each of the plurality of wireless communication signals.

17. The information processing system of claim 5, wherein the first communication unit receives a plurality of wireless communication signals from a plurality of other control devices, the first measurement unit measures the received signal strength of each of the plurality of wireless communication signals, and the second threshold is determined by the received signal strength of each of the plurality of wireless communication signals.

18. A control device that releases restrictions on equipment that restricts the operation of an item, comprising: a memory unit in which a root certificate including a public key is stored; a communication unit that receives a server certificate including a first public key and a signature for the first public key from an information terminal that has a first memory unit in which a first private key, a first public key corresponding to the first private key, and a server certificate are stored; and a control unit that verifies the signature included in the server certificate using the public key included in the root certificate, and releases the restriction on the equipment on the condition that the signature has been successfully verified at the time the release operation is accepted by the information terminal or the control device.

19. An information processing method executed by an information processing system used to release restrictions on equipment that restricts the operation of an item, wherein the information processing system comprises an information terminal and a control device, the information terminal comprises a first memory unit in which a first private key, a first public key corresponding to the first private key, and a server certificate are stored, and the control device comprises a second memory unit in which a root certificate including a public key is stored, the information processing method comprising the steps of: the information terminal transmitting the server certificate including the first public key and a signature for the first public key to the control device; the control device receiving the server certificate from the information terminal; the control device verifying the signature included in the server certificate using the public key included in the root certificate; and the control device releasing the restriction on the equipment, on the condition that verification of the signature has been successful at the time the release operation is accepted by the information terminal or the control device.

20. An information processing method executed by a control device that releases restrictions on equipment that restricts the operation of an item, wherein the control device has a memory unit in which a root certificate including a public key is stored, and the information processing method includes the steps of receiving, from an information terminal having a first memory unit in which a first private key, a first public key corresponding to the first private key, and a server certificate are stored, the server certificate including the first public key and a signature for the first public key; verifying the signature included in the server certificate using the public key included in the root certificate; and releasing the restriction on the equipment, on the condition that the signature has been successfully verified at the time the release operation is accepted by the information terminal or the control device.

21. A program for causing a computer to execute the information processing method according to claim 19 or 20.

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