JP2010160536A - Information terminal, expiration date management system, program, and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology by which an information terminal can manage an accurate time. <P>SOLUTION: The information terminal 10 includes: a GPS reception part 15 for receiving a signal from an external time information source in each prescribed timing; a time sharing part 121 for acquiring GPS time data from a GPS signal, and acquiring shared time data to be shared with a server; and an expiration date determination part 122 for determining whether or not the measured time, GPS time and shared time of a time measurement part 124 are within an expiration date when the data and program determined of predetermined expiration date are executed, and permitting the execution of the data and program when all the times are within the expiration date. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for managing an expiration date.

  When using data, programs, etc. with expiration dates set on a terminal device, for example, a technology is known that determines the expiration date based on the time of a built-in clock inside an information terminal such as a car navigation device. It has been. However, in many cases, the time of the built-in clock can be adjusted by the user, and there is a possibility that data, programs, and the like are illegally used by returning the time to the expiration date.

  Therefore, in order to prevent the unauthorized use as described above, for example, a technique described in Patent Document 1 is known.

Japanese Patent Laid-Open No. 2004-21882

  In the technique described in Patent Document 1, the influence of the user's intentional time adjustment is eliminated by appropriately adjusting the time of the built-in clock based on the standard time broadcast from the base station, and the expiration date can be determined. It is done correctly.

  However, in the above technique, unauthorized use of data, programs, and the like is determined based on the standard time acquired from the base station. Therefore, if the time of the built-in clock is changed in a situation where the standard time cannot be acquired, there is a possibility that unauthorized use cannot be prevented.

  Therefore, an object of the present invention is to provide a technique that allows an information terminal and a server to share information related to time, and that the information terminal can maintain accurate time.

  In order to solve the above-described problems, the present invention stores the time that the information terminal shares with the server, and executes the expiration date determination based on the time.

  For example, an information terminal according to the present invention is an information terminal including means for executing at least one of data and a program for which a predetermined expiration date is determined, and includes an external device for each predetermined timing. Receiving means for acquiring an external time from a time information source; storing the external time in a storage means; transmitting the external time to a server; receiving a shared response indicating that the external time is shared from the server; A time sharing unit that stores the time as a shared time in the storage unit, and when at least one of the data and the program is executed, the time measured by the time measuring unit, the external time, and the shared time Is determined to be within the expiration date, and when all the times are within the expiration date, expiration date determination means for permitting execution of the information is provided. And wherein the Rukoto.

  As described above, according to the present invention, it is possible to provide a technology that enables an information terminal to hold an accurate time.

The best mode for carrying out the present invention will be described below with reference to the drawings.
<First embodiment>
FIG. 1 is a block diagram showing a functional configuration of an expiration date management system 1 according to the first embodiment of the present application.

  As illustrated, the expiration date management system 1 includes an information terminal 10 that functions as a car navigation device, and a server 20.

  The information terminal 10 includes a storage unit 11, a control unit 12, an input unit 13, a display unit 14, a GPS receiving unit 15, an input / output interface unit 16 (hereinafter referred to as an I / F unit), and a built-in clock. 17 and an information requesting unit 18.

  The storage unit 11 includes a GPS time storage area 111 and a shared time storage area 112.

  FIG. 2A is a schematic diagram of GPS time data stored in the GPS time storage area 111, and FIG. 2B is a schematic diagram of shared time data stored in the shared time storage area 112.

  The GPS time storage area 111 stores GPS time data as shown in FIG. The GPS time data is the latest time acquired from the GPS signal by the time sharing unit 121 described later.

  In the shared time storage area 112, shared time data as shown in FIG. The shared time data is the latest time acquired from the server 20 by the time sharing unit 121 described later.

  Next, processing executed by the control unit 12 will be described.

  The control unit 12 obtains GPS time data from a GPS (Global Positioning System) and executes time sharing processing with the server 20, and if the time previously shared with the server does not match the user, A warning unit 122 that issues a warning, a time limit determination unit 123 that determines whether or not a program or data for which an expiration date is set is valid, and a time measurement unit 124 that acquires time from the built-in clock 17 and performs a timing operation. And is composed of.

  In addition to the above, the control unit 12 searches for an optimum route connecting the departure point and the destination, and performs an operation as car navigation for guiding the user. Since such navigation control is common, detailed description is omitted.

  The time sharing unit 121 acquires GPS time data included in the GPS signal detected by the GPS receiving unit 15 by GPS satellite navigation.

  Specifically, the time sharing unit 121 receives a GPS signal output from the GPS receiving unit 15 at every predetermined timing, and acquires the GPS time included in the signal. Then, the time sharing unit 121 updates the GPS time storage area 111 with the acquired GPS time data.

  Further, the time sharing unit 121 may be configured to acquire a GPS signal each time an expiration date determination process is performed by a later-described time limit determination unit 123.

  Next, the time sharing unit 121 outputs a time sharing request to the server 20. The time sharing unit 121 outputs a time sharing request to the server 20 even when the GPS signal cannot be acquired and the GPS time acquisition fails. The timing for outputting the time sharing request may be the time when the information terminal 10 makes an information request to the server 20. The information request is requested from the information request unit 18 of the information terminal 10 described later.

  Specifically, the time sharing unit 121 includes the latest GPS time data stored in the GPS time storage region 111 and the latest GPS time data stored in the shared time storage region 112 acquired from the server 20 by the time sharing unit 121 described later. The shared time data is transmitted to the server 20 via the network 800.

  When the GPS time acquisition fails and there is no GPS time data, the time sharing unit 121 transmits information indicating that in place of the GPS time data. Further, even when the time has not been shared with the server 20 before and the shared time data does not exist, information indicating that no data exists is transmitted to the server 20 instead of the shared time data.

  Also, the time sharing request can be transmitted as a single piece of information when other information is exchanged between the information terminal 10 and the server 20, for example. This can be realized by concatenating time data with a predetermined delimiter code between other information and encrypting the whole. At this time, for encryption, for example, a common key encryption decided in advance can be used. Alternatively, the common key used for encryption may be encrypted with a public key published by the server 20 and transmitted together with the encrypted data. When the server 20 receives the data, it decrypts the cipher and extracts the time data.

  Thereafter, when the server 20 receives a shared response output in response to the time sharing request, the time sharing unit 121 updates the shared time data stored in the shared time storage area 112 to the latest shared time data.

  When the warning unit 122 receives a warning request from the server 20, the warning unit 122 issues a warning notifying the user that the shared time data may be operated. The warning can be realized, for example, by outputting a warning sound or displaying a warning screen.

  The warning unit 122 may update the shared time data stored in the shared time storage area 112 with the terminal time data included in the warning request.

  When data or a program for which a time limit executable by the control unit 12 is predetermined is executed, the time limit determination unit 123 determines a predetermined expiration date of the data or program and the time measured by the time measurement unit 124 at this time. , The GPS time data, and the three times indicated by the shared time data are collated. When all the times are within the expiration date, the time limit determination unit 123 permits the execution of the data and the program. The time limit judging unit 123 ends the execution process without permitting the execution of the data or the program when even one of the above times exceeds the valid time limit.

  Note that when the execution of the program is not permitted, the time limit determination unit 123 may be configured to display a message screen on the display unit 14 indicating that the expiration date has exceeded.

  The time measuring unit 124 measures time when the information terminal 10 is operating. For example, when the information terminal 10 is turned on, the time measuring unit 124 acquires time from the built-in clock 17 and starts a time measuring operation. The user can arbitrarily adjust the time via the input unit 13.

  The input unit 13 receives an instruction operation from the user. For example, the user can perform operations related to the navigation function and adjust the time measured by the time measuring unit 124 via the input unit 13.

  The display unit 14 displays an image based on the image signal such as a map or a warning screen described later.

  The GPS receiving unit 15 acquires a GPS signal at every predetermined timing. Further, the GPS receiving unit 15 outputs GPS time data to the time sharing unit 121 when acquisition of the GPS signal is successful, and information indicating that when it fails.

  The I / F unit 16 connects the information terminal 10 to other devices and the network 800 so that data can be transmitted and received.

  The built-in clock 17 is mounted inside the information terminal 10 and performs timekeeping operation using an RTC (Real Time Clock) to provide time.

  The information request unit 18 requests information from the information terminal 10 to the information server 20. The requested information is, for example, surrounding traffic information, but is not limited thereto. Further, instead of requesting information from the information terminal 10 to the server 20, the information terminal 10 may report information to the server 20. The information to be reported is, for example, the current position of the information terminal 10, but is not limited thereto. The information received by the information request unit 18 is used for display using the display unit 14.

  Returning to FIG. 1, the server 20 will be described.

  The server 20 includes a storage unit 21, a control unit 22, an input / output interface unit 26 (hereinafter referred to as an I / F unit), a built-in clock 27, and an information providing unit 28.

  The storage unit 21 includes a terminal time storage area 211.

  The terminal time storage area 211 stores terminal time data. The terminal time data is time data that has previously been subjected to time sharing processing with the information terminal 10 and is stored as shared time data in the information terminal 10.

  The control unit 22 acquires the time from the time determination unit 221 that determines the accuracy of the past shared time, the time sharing unit 222 that manages the time shared with the information terminal 10, and the built-in clock 27, and performs the time counting operation. And a time measurement unit 223 to be performed.

  Specifically, when the time determination unit 221 receives a time sharing request transmitted from the information terminal 10, first, the sharing time data included in the time sharing request, the terminal time data stored in the terminal time storage area 211, Compare

  Since the terminal time data is the shared time data in the information terminal 10 that has been shared with the information terminal 10 before, the two should be the same. If they do not match, the validity of the shared time data in the information terminal 10 is suspected, so the time determination unit 221 generates a warning request including the terminal time data and transmits it to the information terminal 10.

  Next, the time sharing unit 222 overwrites the terminal time data stored in the terminal time storage area 211 with the GPS time data included in the time sharing request, and updates it.

  Then, the time sharing unit 222 outputs a shared response including the shared GPS time data (updated terminal time data) to the information terminal 10. Of course, the sharing response may not include the GPS time data directly but may be information notifying that the GPS time data transmitted as the time sharing request is shared.

  If the GPS time data is not included in the time sharing request, the time sharing unit 222 acquires the time from the time measuring unit 124, overwrites the terminal time data with this time, and the terminal time data Is output as a shared response.

  The I / F unit 26 connects the server 20 to other devices and the network 800 so that data can be transmitted and received.

  The time measuring unit 224 measures time when the server 20 is operating. Here, it is assumed that the time measured by the time measuring unit 224 is always adjusted to an accurate time by the network 800, the system administrator, or the like.

  The built-in clock 27 is mounted inside the server 20 and performs a time measuring operation using an RTC (Real Time Clock).

  The information providing unit 28 receives an information request from the information terminal 10 and performs an operation of providing the requested information to the information terminal 10. When it is a report instead of an information request from the information terminal 10, an operation for receiving the report may be performed.

  Next, the hardware configuration of the information terminal 10 will be described. FIG. 8 is a block diagram showing an electrical configuration of the information terminal 10.

  As shown in FIG. 8, the information terminal 10 is a general computer on which a program operates. The information terminal 10 can rewrite various data, for example, as shown in FIG. 8 (schematic diagram of the computer 900), a CPU (Central Processing Unit) 901 that is a main part of the computer and controls each device centrally. An external storage device 903 that stores various programs, data generated by the programs, and the like, a CD (Compact Disk), a DVD (Digital Versatile Disk), etc. A reading / writing device 905 that reads / writes information from / to a portable storage medium 904, an input device 906 such as a switch and a touch panel, an output device 907 such as a display, and a NIC (Network Interface Card) for connection to a communication network. And a communication device 908 such as a general computer 900.

  The storage unit 11 of the information terminal 10 can be realized by the CPU 901 using the memory 902 or the external storage device 903, and the control unit 12 loads a predetermined program stored in the external storage device 903 into the memory 902. The input unit 13 can be realized by the CPU 901 using the input device 906, and the display unit 14 can be realized by the CPU 901 using the output device 907. The I / F unit 16 can be realized by the CPU 901 using the communication device 908.

  The predetermined program is downloaded from the storage medium 904 via the reading device 905 or from the network via the communication device 908 to the external storage device 903, and then loaded onto the memory 902 and executed by the CPU 901. You may do it. Alternatively, the program may be directly loaded on the memory 902 from the storage medium 904 via the reading device 905 or from the network via the communication device 908 and executed by the CPU 901.

  The time sharing process executed by the time sharing unit 121 of the information terminal 10 in the present embodiment configured as described above will be described with reference to FIG. FIG. 3 is a flowchart showing the flow of time sharing processing executed by the time sharing unit 121.

  When the time sharing unit 121 receives a GPS signal or information indicating that acquisition of the GPS signal has failed from the GPS receiving unit 15 at every predetermined timing, the time sharing unit 121 starts executing the processing.

  First, the time sharing unit 121 determines whether the GPS receiving unit 15 has successfully received a GPS signal (S11).

  Specifically, when receiving the GPS signal from the GPS receiving unit 15 (YES in S11), the time sharing unit 121 acquires the GPS time included in the GPS signal, and uses this as the latest GPS time data as a GPS time storage area. 111 is updated (S12).

  Further, when information indicating that the acquisition of the GPS signal has failed from the GPS receiver 15 (NO in S11), the process proceeds to step 13.

  Next, the time sharing unit 121 outputs a time sharing request to the server 20 (S13).

  Specifically, the time sharing unit 121 transmits GPS time data and shared time data to the server 20 via the network 800. In addition, when acquisition of GPS time data has failed in Step 11 or when shared time data does not exist, the time sharing unit 121 outputs information indicating that in place of each time data.

  Thereafter, the time sharing unit 121 receives a sharing response transmitted from the server 20 in response to the time sharing request (S14).

  Then, the time sharing unit 121 updates the shared time storage area 112 using the time data included in the sharing response as the latest shared time data (S15), and ends the process.

  Next, response processing to the time sharing request executed by the server 20 in the present embodiment will be described with reference to the flowchart shown in FIG. FIG. 4 is a flowchart showing the flow of response processing to the time sharing request executed by the server 20.

  When receiving the time sharing request from the information terminal 10, the control unit 22 of the server 20 starts the process.

  When receiving the time sharing request, the time determination unit 221 determines whether or not the sharing time data is included in the time sharing request (S21).

  If the shared time data is not included and information indicating that the time data does not exist is included instead (NO in S21), the process proceeds to step 24.

  When the shared time data is included in the time sharing request (YES in S21), the time determination unit 221 compares the shared time data with the terminal time data stored in the terminal time storage area 211. Then, it is determined whether or not they match (S22).

  If the shared time data and the terminal time data match (YES in S22), it is determined that the shared time data is accurate, and the process proceeds to step 24.

  When the two do not match (NO in S22), the time determination unit 221 outputs a warning request to the information terminal 10 that prompts a warning that the sharing time may have been operated (S23). Then, the time determination unit 221 outputs a shared response generation request to the time sharing unit 222 and proceeds to step 24.

  When receiving the shared response generation request, the time sharing unit 222 determines whether GPS time data is included in the time sharing request (S24).

  If the GPS time data is included (YES in S24), the time sharing unit 222 overwrites and updates the terminal time data stored in the terminal time storage area 211 with the GPS time data (S25). . Then, the shared response including the updated terminal time data is output to the information terminal 10 (S27), and the process ends.

  When the GPS time data is not included (NO in S24), the time sharing unit 222 acquires the time from the time measurement unit 224, and overwrites and updates the terminal time data with this time (S26). Then, the shared response including the updated terminal time data is output to the information terminal 10 (S27), and the process ends.

  With the configuration as described above, the expiration date management system according to the present embodiment records the GPS time received by the information terminal 10 with the server 20 by collating the time with the time data recorded in the information terminal 10. Can be held as certain.

  Therefore, even when the time count of the information terminal 10 is intentionally adjusted, it is possible to accurately determine the expiration date by recording the reliable shared time data previously shared with the server 20 and Deadline management can be performed.

In addition, even when GPS signals cannot be received, more stable time management is possible by directly acquiring the time managed by the time measurement unit 224 of the server 20.
<Second Embodiment>
Next, the expiration date management system 2 according to the second embodiment of the present application will be described.

  The expiry date management system 2 is the first implementation in that it determines whether or not shared time data rewritten at the time of execution of data, a program, or the like is used as a process before the time sharing process is executed. Different from form. Hereinafter, differences from the first embodiment will be mainly described.

  FIG. 5 is a block diagram showing a functional configuration of the expiration date management system 2 according to the second embodiment of the present application.

  The expiration date management system 2 includes an information terminal 30 and a server 40 as shown in the figure.

  The storage unit 31 of the information terminal 30 includes a table storage area 313 that stores an expiration date determination table as shown in FIG.

  The expiration date determination table is data in which a predetermined expiration date is set, which is executed during a period from when the history management unit 325 described later shares time with the server 40 until there is next time sharing. History management information for registering information about programs and programs.

  The expiration date determination table includes an identifier storage area 313a for storing an identifier for identifying data or a program for which a predetermined expiration date has been executed, and a time measurement unit 124 when the data or program is executed. A timekeeping time storage area 313b for storing a timekeeping time, a GPS time storage area 313c for storing a GPS time when executed, and a shared time storage area 313d for storing a shared time when executed are provided. Yes.

  The history management unit 325 of the control unit 32 registers and manages the history in the expiration date determination table each time data or a program for which an expiration date is set is executed.

  Specifically, when the time limit determination unit 123 permits execution of data or a program, the history management unit 325 determines whether or not the identifier of the data or program is stored in the identifier storage area 313a. If it is not stored (when there is no history executed before), a new record is generated, and the time measured by the time measuring unit 124 at this time, GPS time data, shared time data, Are registered in the expiration date determination table.

  When the identifier of the data or program is stored in the identifier storage area 313a (when it has already been executed), the history management unit 325 registers time data registered in each storage area of the matching record. Are updated with the time measured by the time measuring unit 124 at this time, the GPS time data, and the shared time data, respectively. However, if the shared time stored in the shared time storage area 313d of the record is different from the shared time stored in the shared time storage area 112, the GPS time data stored in the GPS time storage area 313c of the record Alternatively, if a time past the shared time stored in the shared time storage area 313d of the record is stored in the timekeeping time storage area 313b of the record, the record is not updated and a new record is created. It may be produced and recorded. Alternatively, a new record may be created and recorded each time without updating the record.

  When the time sharing unit 121 receives a sharing response from the server 40 (when time sharing is executed), the history management unit 325 resets the expiration date determination table and deletes all records. As a result, the expiration date determination table stores only information about data and programs executed during the period from the time sharing with the server 40 until the next time sharing. Become.

  Next, processing executed by the time verification unit 326 and the time confirmation unit 424 will be described with reference to FIG. FIG. 7 is a flowchart showing the flow of processing executed by the time collation unit 326 and the time confirmation unit 424.

  First, processing executed by the time collating unit 326 will be described.

  The time collating unit 326 starts executing the time collating process as shown in FIG. 7 as a process before the time sharing unit 121 executes the time sharing process as shown in FIG.

  When the time sharing process is started, the time sharing unit 121 first outputs a request for starting the time verification process to the time verification unit 326.

  When receiving the time sharing process start request from the time sharing unit 121, the time collating unit 326 stores the records in the expiration date determination table in the sharing time stored in the sharing time storage area 313 d and the sharing time storage area 112. The stored shared time data is compared to determine whether or not they match (S31).

  Here, the data and programs whose identifiers are registered in the expiration date determination table are executed during the period from the time sharing process with the server 40 to the next time sharing. Therefore, the sharing time stored in the sharing time storage area 313d and the sharing time data stored in the sharing time storage area 112 should match.

  If the two match (YES in S31), time collation unit 326 outputs collation information indicating that proper shared time data is held to server 40 (S36).

  If the two do not match (NO in S31), the time matching unit 326 outputs the record to the server 40, assuming that the shared time may have been tampered (S32).

  When the time confirmation unit 424 constituting the control unit 42 of the server 40 receives the record of the expiration date determination table from the information terminal 30 output in step 32, the time confirmation unit 424 starts executing the following confirmation process.

  First, the time confirmation unit 424 compares the shared time stored in the shared time storage area 313d of the received record with the terminal time data stored in the terminal time storage area 211 (S41).

  Since the terminal time data is the same time data as the shared time data previously shared with the information terminal 30, both of them should not match here.

  When confirming that the two do not match (NO in S41), the time confirmation unit 424 outputs the terminal time data to the information terminal 30 (S42).

  When the time collating unit 326 receives the terminal time data from the server 40 (S33), the expiration date of the data or program identified by the identifier stored in the identifier storage area 313a of the record output to the server 40, and the terminal time The data is compared (S34).

  When the terminal time data exceeds the expiration date (YES in S34), collation information indicating that the sharing time is invalid is output to the server 40 together with the record (S35), and the process is terminated.

  When receiving the collation information (S43), the time confirmation unit 424 determines whether or not the collation information indicates that the sharing time is illegal (S44).

If it is an indication that there is a fraud (YES in S44), the time confirmation unit 424
The collation information is stored in the storage unit 21 together with the ID for identifying the information terminal 30 (S45).

  When it does not indicate that there is an injustice (NO in S44), the time confirmation unit 424 ends the process.

  In addition, when the collation information which shows that there was fraud in step 45 is acquired, the server 40 may be configured to request a warning that the shared time data has been falsified from the warning unit 123 of the information terminal 30. good.

  Further, data such as records in the expiration date determination table and collation information exchanged between the information terminal and the server can be integrated and encrypted with other information and transmitted. As a result, the server can obtain accurate information without the unauthorized use report message being deleted by the user.

  With the configuration as described above, the expiration date management system 2 according to the second embodiment of the present invention determines whether or not the shared time data registered in the information terminal is used for determining the expiration date in an appropriate state. Can be determined.

  Specifically, even if a process such as tampering with the shared time data to execute unauthorized use of the data or program and later writing back to the correct shared time data is detected, The history can be managed collectively by the server.

  The present invention is not limited to the above embodiment. The above embodiment can be variously modified within the scope of the technical idea of the present invention.

  For example, the time information source for the information terminal to acquire the time is not limited to GPS, and any information source may be used as long as it is an information source capable of delivering accurate time information.

  In the above embodiment, an example in which the present invention is applied to a navigation apparatus has been described. However, the present invention can be applied to any other information apparatus.

FIG. 1 is a block diagram showing a functional configuration of an expiration date management system 1 according to an embodiment of the present invention. FIG. 2A is a schematic diagram of GPS time data stored in the GPS time storage area 111, and FIG. 2B is a schematic diagram of shared time data stored in the shared time storage area 112. FIG. 3 is a flowchart showing the flow of time sharing processing executed by the time sharing unit 121. FIG. 4 is a flowchart showing the flow of response processing to the time sharing request executed by the server 20. FIG. 5 is a block diagram showing a functional configuration of the expiration date management system 2 according to the second embodiment of the present application. FIG. 6 is a schematic diagram of an expiration date determination table. It is a flowchart which shows the flow of the process which the time collation part 326 and the time confirmation part 424 perform. FIG. 8 is a block diagram showing an electrical configuration of the information terminal 10.

1.2: Expiration date management system, 10.30: information terminal, 20.40: server, 11.21.31: storage unit, 12.22.32.42: control unit, 13: input unit, 14: display Part: 15: GPS receiving part, 16.26: I / F part, 17.27: built-in clock, 18: information requesting part, 28: information providing part, 800: network.

Claims (8)

An information terminal comprising means for executing at least one of data and a program having a predetermined expiration date,
Time measuring means;
Receiving means for acquiring an external time from an external time information source at every predetermined timing;
Time sharing for storing the external time in the storage unit when the external time is stored in the storage unit and transmitted to the server, and when a shared response indicating that the external time is shared is received from the server Means,
When at least one of the data and the program is executed, it is determined whether the time measured by the time measuring unit, the external time, and the shared time are within the expiration date, and all An information terminal comprising: time limit judging means for permitting the execution of the information when the time is within the valid time limit. The information terminal according to claim 1,
The external time information source is a GPS. The information terminal according to claim 1 or 2,
The time sharing means is
If the receiving unit fails to acquire the external time, it notifies the server to that effect, accepts a shared response including time data from the server, and stores the time data in the storage unit as a shared time An information terminal characterized by An information terminal according to any one of claims 1 to 3,
An identifier for identifying the data and program for the data and program executed in a period from when the time sharing means receives a shared response from the server until the next shared response is received, and the data And history management information in which the time indicated by the clock at the time when the program is executed, the external time stored in the storage unit, and the shared time stored in the storage unit are associated with each other is stored in the storage unit History management means,
Before the time sharing means receives the next sharing response,
Comparing the latest sharing time with the sharing time registered in the history management information, and when there is no coincidence, there is further provided time collating means for judging that the sharing time has been rewritten. Information terminal. An expiration date management system comprising an information terminal including means for executing at least one of data and a program for which a predetermined expiration date is set, and a server,
The information terminal
Time measuring means;
Receiving means for acquiring an external time from an external time information source at every predetermined timing;
Time sharing for storing the external time in the storage unit when the external time is stored in the storage unit and transmitted to the server, and when a shared response indicating that the external time is shared is received from the server Means,
When at least one of the data and the program is executed, it is determined whether the time measured by the time measuring unit, the external time, and the shared time are within the expiration date, and all A time limit judging means for permitting the execution of the information when the time is within the validity period,
The server
When the external time is received from the information terminal, the external time is stored in a storage unit as a terminal time shared with the information terminal, and a shared response indicating that the external time is shared is transmitted to the information terminal An expiration date management system comprising: a sharing means. The expiration date management system according to claim 5,
The time sharing means of the information terminal is
Further transmitting the sharing time to the server;
The server
An expiration date management system, further comprising: a time determination unit that urges the information terminal to warn when the shared time and the terminal time do not coincide with each other. A program that causes a computer to function as an information terminal including means for executing at least one of data and a program with a predetermined expiration date,
The computer,
Time measuring means,
Receiving means for acquiring an external time from an external time information source for each predetermined timing;
Time sharing for storing the external time in the storage unit when the external time is stored in the storage unit and transmitted to the server, and when a shared response indicating that the external time is shared is received from the server means,
When at least one of the data and the program is executed, it is determined whether the time measured by the time measuring unit, the external time, and the shared time are within the expiration date, and all A time limit judging means for permitting the execution of the information when the time of
A program characterized by functioning as An expiration date management method for managing an expiration date for at least one of data and a program with a predetermined expiration date,
Measuring time, and
Obtaining an external time from an external time information source at each predetermined timing;
Storing the external time in a storage means;
Transmitting the external time to a server;
Receiving a shared response indicating that the external time is shared from the server, storing the external time in the storage means as a shared time;
Determining whether the time measured by the time measuring means, the external time, and the shared time are within the validity period when at least one of the data and the program is executed; ,
And a step of permitting execution of the information when all times are within the expiration date.

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