Information processing device, computer program product, and program recording medium

Abstract

The present invention provides an information processing device, a computer program product and a recording medium of the program, which prevent the following situation, that is, when the use right of the function possessed by the device is given to another user who does not have the use right in a state that the user did not expect, the device is used by the other user. The processor accepts a commission from a first user, the first user has the use right of the function possessed by the used device; outputs transfer information, the transfer information includes status information, and indicates that the use right of the function is transferred to a second user who does not have the use right of the function, the status information indicates the status of the shared resource to be used by the function, and indicates the status when the commission is accepted; when the transfer information is accepted, the use of the function is permitted or restricted based on the comparison result of the status of the shared resource when the transfer information is accepted and the status indicated by the status information contained in the accepted transfer certification information.

Description

Technical Field

[0001] The present invention relates to an information processing device and a recording medium of its program. Background Art

[0002] Sometimes, the authority to use a function of a device needs to be given to a user who does not have the authority to use the function.

[0003] Patent Document 1 discloses a system that grants a proxy user who cannot use a shared resource on a regular basis the right to use the shared resource for only a predetermined period in response to a request from a user who can use the shared resource on a regular basis.

[0004] [Prior art literature]

[0005] [Patent Document]

[0006] Patent Document 1: Japanese Patent Application Publication No. 2007-249912 Summary of the invention

[0007] [Problems to be solved by the invention]

[0008] However, when the permission to use the function of a device is granted to a user who does not have the permission, the state of the device may change from the time the permission is granted to the user until the user uses the device. In this case, the following situation may occur: the device is used by the user who has been granted the permission in a state that the user who has been granted the permission did not expect.

[0009] An object of the present invention is to prevent a situation in which a device is used by another user who does not have the use authority, in a state that the user has not intended, while granting the use authority of a function of the device to the other user.

[0010] [Technical means to solve the problem]

[0011] The invention of technical solution 1 is an information processing device, which has a processor, which accepts a commission from a first user, and the first user has the right to use the function of the device being used; outputs transfer information, the transfer information includes status information, and indicates that the right to use the function is transferred to a second user who does not have the right to use the function, the status information indicates the status of a shared resource to be used when using the function, and indicates the status when the commission is accepted; accepts the transfer information; and permits or restricts the use of the function based on a comparison result between the status of the shared resource when the transfer information is accepted and the status represented by the status information contained in the accepted transfer information.

[0012] The invention according to claim 2 is the information processing device according to claim 1, wherein the state of the shared resource can be changed by users other than the first user.

[0013] The invention of Technical Solution 3 is an information processing device according to Technical Solution 1 or Technical Solution 2, wherein the state information is a hash value representing the state of the shared resource.

[0014] The invention of Technical Solution 4 is an information processing device according to Technical Solution 3, wherein the shared resource includes multiple structures, the hash value is a value representing the state of at least a part of the multiple structures, and the processor further changes the structure that becomes the hash value generation object according to the utilization mode of the device by the second user to generate the hash value.

[0015] The invention of technical solution 5 is an information processing device according to technical solution 4, wherein the utilization form is a utilization period of the device, and the longer the utilization period is, the more the processor reduces the number of structures that become hash value generation objects.

[0016] The invention of Technical Solution 6 is an information processing device according to Technical Solution 3, wherein the shared resource includes multiple structures, the hash value is a value representing the state of at least a part of the multiple structures, and further, the higher the reliability of the second user, the more the processor reduces the number of structures that become the objects of hash value generation.

[0017] The invention of Technical Solution 7 is an information processing device according to any one of Technical Solutions 1 to Technical Solution 6, wherein the processor permits the use of the function when the state of the shared resource when accepting the transfer information is consistent with the state represented by the state information contained in the accepted transfer information, and permits the use of only the part of the shared resource that has the state when the delegation is received when the state of the shared resource when accepting the transfer information is inconsistent with the state represented by the state information contained in the accepted transfer information.

[0018] The invention of Technical Solution 8 is an information processing device according to any one of Technical Solutions 1 to Technical Solution 6, wherein the processor permits the use of the function when the state of the shared resource when accepting the transfer information is consistent with the state represented by the state information contained in the accepted transfer information, and does not permit the use of the shared resource as a whole when the state of the shared resource when accepting the transfer information is inconsistent with the state represented by the state information contained in the accepted transfer information.

[0019] The invention according to claim 9 is the information processing device according to claim 8, wherein the processor further notifies the second user of the reason for not permitting the use of the shared resource.

[0020] The invention of technical solution 10 is a recording medium storing a program that enables a computer to perform the following processing: accepting a commission from a first user, the first user having the right to use the function of the device being used; outputting transfer information that grants the right to use the function to a second user who does not have the right to use the function, the transfer information including status information, the status information indicating the status of a shared resource to be used when using the function and indicating the status when the commission was accepted; accepting the transfer information; and permitting or restricting the use of the function based on a comparison result between the status of the shared resource when the transfer information was accepted and the status indicated by the status information contained in the accepted transfer information.

[0021] [Effects of the Invention]

[0022] According to the invention of technical solution 1 and technical solution 10, the following situation can be prevented, that is, when the user who gives the use authority of the function of the device to other users who do not have the use authority is unexpectedly given, the device is used by the other users.

[0023] According to the invention of claim 2, it is possible to prevent the device from being used in a state that is not expected by the user who can change the state of the shared resource.

[0024] According to the invention of claim 3, compared with the case where information directly indicating the state of a shared resource is used, the amount of information to be processed can be reduced.

[0025] According to the invention of claim 4, permission for use of functions can be controlled according to the use mode of the device.

[0026] According to the invention of claim 5, as the utilization period becomes longer, the number of structures that are not the target of hash value generation increases, and utilization of the function can be permitted even if the state of the structure changes.

[0027] According to the invention of claim 6, as the reliability of the second user increases, the number of structures that are not the target of hash value generation increases, and even if the state of the structure changes, the use of the function can be permitted.

[0028] According to the invention of claim 7, when the state of the shared resource is changed during the period from when the request from the first user is received until when the second user uses the device, use of the changed portion can be restricted.

[0029] According to the invention of claim 8, it is possible to prevent a situation in which a shared resource is used by another user who does not have the use authority, in a state in which the user who has given the use authority of the function of the device to the other user does not have the use authority unexpectedly.

[0030] According to the invention of claim 9, the second user can recognize the reason why the use of the shared resource is not permitted. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a block diagram showing the structure of the information processing system according to the present embodiment.

[0032] Figure 2 This is a block diagram showing the hardware configuration of the authority management device according to the present embodiment.

[0033] Figure 3 It is a block diagram showing the functional structure of the authority management device according to this embodiment.

[0034] Figure 4 This is a diagram showing a flowchart showing a process when granting usage authority.

[0035] Figure 5 This is a diagram showing a flowchart showing a process when a device is used using the use authority.

[0036] Figure 6 A diagram showing a screen.

[0037] Explanation of symbols

[0038] 10: Rights Management Device

[0039] 12: All-in-one machine

[0040] 24: Processor

[0041] 26: Identification Department

[0042] 28: Functional Management Department

[0043] 30: Transfer Certificate Issuance Department

[0044] 32: Shared Resource Determination Department

[0045] 34: Status information generation unit

[0046] 36: Transfer Certificate Acceptance Department

[0047] 38: Status information reading unit

[0048] 40: Functional Utilization Permission Department DETAILED DESCRIPTION

[0049] Reference Figure 1 The information processing system according to this embodiment is described. Figure 1 An example of the configuration of the information processing system according to the present embodiment is shown.

[0050] As an example, the information processing system of this embodiment includes a rights management device 10 as an example of an information processing device, a multifunction machine 12 as an example of an image processing device, a server 14, and a terminal device 16A and a terminal device 16B. The information processing system may also include devices other than these. The number of each device included in the information processing system is only an example, and the number of each device is not limited to Figure 1 In addition, the information processing system may not include the server 14 or the terminal device 16A and the terminal device 16B.

[0051] The rights management device 10, the multifunction machine 12, the server 14, the terminal device 16A, and the terminal device 16B have the function of communicating with other devices. The communication can be either wired communication using a cable or wireless communication. That is, each device can be physically connected to other devices through a cable to send and receive information to each other, or can send and receive information to each other through wireless communication. As wireless communication, for example, short-range wireless communication or Wi-Fi (registered trademark) is used. Wireless communication of specifications other than these can also be used. Short-range wireless communication is, for example, Bluetooth (registered trademark), Radio Frequency Identifier (RFID) or Near Field Communication (NFC). Each device can also communicate with other devices via communication paths such as a local area network (LAN) or the Internet.

[0052] The authority management device 10 is a device configured in such a way that the functions available to users are managed by the devices managed by the authority management device 10. For example, the authority management device 10 temporarily grants the right to use the function to a user who does not have the right to use the function. For example, the multifunction machine 12 is managed by the authority management device 10. Of course, devices other than the multifunction machine 12 can also be managed by the authority management device 10.

[0053] The multifunction machine 12 is an example of a device managed by the authority management device 10 , and is an image processing device having at least one of a scanning function, a printing function, a copying function, and a facsimile function.

[0054] The authority management device 10 may also be included in the multifunction machine 12. That is, the authority management device 10 may also be incorporated into the multifunction machine 12, and the multifunction machine 12 has the function of the authority management device 10. In this case, the multifunction machine 12 manages the functions that can be used in the multifunction machine 12 by the user who uses the multifunction machine 12, which is its own device. Moreover, the multifunction machine 12 temporarily grants the user who does not have the right to use the function that can be used in the multifunction machine 12 the right to use the function. In addition, the multifunction machine 12 in which the authority management device 10 is incorporated is equivalent to an example of an information processing device.

[0055] The server 14 is a device that stores various data. For example, image data is sent from the multifunction machine 12 to the server 14 and stored in the server 14. In addition, the image data can also be sent from the server 14 to the multifunction machine 12 and printed by the multifunction machine 12.

[0056] The terminal device 16A and the terminal device 16B are personal computers (hereinafter referred to as "PC"), tablet PCs, smartphones, mobile phones, or the like.

[0057] Below, refer to Figure 2 The hardware structure of the authority management device 10 is described below. Figure 2 An example of the hardware structure of the authority management device 10 is shown in FIG.

[0058] The rights management device 10 includes, for example, a communication device 18 , a user interface (UI) 20 , a storage device 22 , and a processor 24 .

[0059] The communication device 18 is a communication interface, and has the function of sending information to other devices and receiving information sent from other devices. The communication device 18 may have a wireless communication function or a wired communication function. The communication device 18 may communicate with other devices by using short-range wireless communication, or may communicate with other devices via a communication path such as a LAN or the Internet.

[0060] UI20 is a user interface, including a display device and an operating device. The display device is a liquid crystal display or an electroluminescence (EL) display, etc. The operating device is a keyboard, an input key, or an operating panel, etc. UI20 can also be a UI such as a touch panel that has both a display device and an operating device. In addition, a microphone can be included in UI20, and a speaker that emits sound can also be included in UI20.

[0061] The storage device 22 is a device that constitutes one or more storage areas for storing various information. The storage device 22 is, for example, a hard disk drive, various memories (such as random access memory (RAM), dynamic random access memory (DRAM) or read-only memory (ROM), etc.), other storage devices (such as optical disks, etc.) or a combination thereof. One or more storage devices 22 are included in the rights management device 10.

[0062] The processor 24 is configured to control the operation of each unit of the authority management device 10. For example, the processor 24 may communicate with each device using the communication device 18, may cause the display device of the UI 20 to display information, may receive information input via the UI 20, may cause the information to be stored in the storage device 22, and may read information from the storage device 22. The processor 24 may also have a memory.

[0063] In addition, the multifunction machine 12, the server 14, and the terminal device 16 also have a communication device, a UI, a storage device, and a processor.

[0064] Below, refer to Figure 3 An example of the functional structure of the authority management device 10 will be described. Figure 3 An example of the functional structure of the authority management device 10 is shown in FIG. The functions of each structure shown below are realized by the processor 24 .

[0065] The identification unit 26 is configured to identify a user using the device. For example, the identification unit 26 receives user identification information for identifying a user, and identifies the user using the device based on the user identification information. The device used may be the multifunction device 12 or another device. The user identification information is, for example, the user's name, user ID, or user account. The identification unit 26 may receive user identification information input by the user operating the UI 20, or may read the user identification information from an integrated circuit (IC) card storing the user identification information.

[0066] When the authority management device 10 is incorporated into the multifunction machine 12, the identification unit 26 receives user identification information input into the multifunction machine 12, which is its own device, and identifies the user who uses the multifunction machine 12. For example, when logging into the multifunction machine 12, the user identification information is input into the multifunction machine 12, and the identification unit 26 identifies the user who logs into the multifunction machine 12 based on the user identification information. The identification unit 26 can also authenticate the user based on the user identification information. For example, the identification unit 26 can also determine whether the user represented by the received user identification information has the authority to log into the multifunction machine 12, thereby allowing or prohibiting the user from logging into the multifunction machine 12.

[0067] The function management unit 28 is configured to manage the functions that the user identified by the identification unit 26 can use in the device used. The user who can use the function is a user who has the right to use the function. For example, corresponding to each user, the user identification information of the user and the function information indicating the function that the user has the right to use are pre-associated, and the right management information indicating the association is stored in the storage device 22 or other devices. The function management unit 28 determines the function that the user has the right to use by determining the function associated with the user identification information of the user identified by the identification unit 26 in the right management information. If the user identified by the identification unit 26 has the right to use a certain function, the function management unit 28 permits the user to use the function. If the user identified by the identification unit 26 does not have the right to use a certain function, the function management unit 28 restricts the user from using the function. The so-called restriction of the use of the function means not permitting the use of all the functions (that is, prohibiting the use of all the functions) or permitting the use of part of the function but not permitting the rest of the function.

[0068] When the authority management device 10 is incorporated in the multifunction machine 12, the function management unit 28 manages the functions that can be used by the user identified by the identification unit 26 in the multifunction machine 12. For example, the function management unit 28 determines whether the user who has logged into the multifunction machine 12 has the authority to use the function that can be used in the multifunction machine 12, and permits or restricts the user's use of the function based on the determination result.

[0069] The transfer certificate issuing unit 30 is configured to receive a request from a user who has the right to use the function of the device being used, generate transfer information indicating that the right to use the function is transferred to a user who does not have the right to use the function, and output the transfer information. As described later, the transfer certificate issuing unit 30 outputs the transfer information including the status information generated by the status information generating unit 34.

[0070] Hereinafter, a user who has the right to use a function is referred to as a "first user", and a user who does not have the right to use a function but is given the right to use a function is referred to as a "second user". In addition, below, the operation of giving the right to use a function to the second user is sometimes referred to as transferring the right to use a function to the second user.

[0071] The transfer information is information indicating that the right to use the function indicated by the transfer information is temporarily transferred to the second user. That is, the transfer information is information proving that the function indicated by the transfer information is temporarily permitted to be used by the second user. As described above, the right to use granted to the second user is a right to temporarily permit the use of the function. As described later, the second user is temporarily permitted to use the function indicated by the transfer information by using the transfer information.

[0072] The transfer information includes, for example, function information indicating the function that is permitted to be used; restriction information indicating the period or number of times the function is permitted to be used; and information proving that the use of the function is temporarily permitted. For example, the second user is permitted to use the function indicated by the function information within the period indicated by the restriction information, or is permitted to use the function indicated by the function information for the number of times indicated by the restriction information. The transfer information may include both user identification information for identifying the first user and user identification information for identifying the second user.

[0073] For example, when the authority management device 10 is built into the multifunction machine 12 , the function information included in the assignment information is information indicating the function of the multifunction machine 12 that is permitted to be used by the second user.

[0074] Outputting the transfer information may include displaying the transfer information on a display device of the UI 20, sending the transfer information to another device (e.g., the terminal device 16 of the second user) through communication, sending the transfer information to the address of the second user, printing the transfer information, or a combination thereof. The address of another device or the address of the second user is specified by the first user when the first user entrusts the transfer of the use right, for example.

[0075] The transfer certificate issuing unit 30 may also encode the transfer information and output the encoded transfer information. For example, the transfer certificate issuing unit 30 may also generate a barcode or a two-dimensional code (such as a Quick Response (QR) code (registered trademark)) representing the transfer information and output it. At this time, the barcode or two-dimensional code representing the transfer information is displayed on the display device of the UI 20, or sent to the terminal device 16 of the second user, or printed.

[0076] For example, when the first user identified by the identification unit 26 operates UI20 to instruct the execution of the permission transfer process for granting the use right to the second user, the transfer certificate issuing unit 30 displays a list of functions that the first user has the use right on the display device of UI20. When the first user specifies the device to be used, a list of functions that the first user has the use right in the function group that can be used in the specified device is displayed on the display device of UI20. When the first user operates UI20 and selects a function for which the use right is granted to the second user from the list and instructs the transfer of the use right, the transfer certificate issuing unit 30 accepts the instruction, generates and outputs transfer information indicating that the use right of the function selected by the first user is transferred to the second user. In addition, the first user can also operate UI20 to input the user identification information of the second user. In this case, the user identification information of the second user can also be included in the transfer information.

[0077] In the case where the authority management device 10 is incorporated in the multifunction machine 12, when the first user who has logged into the multifunction machine 12 instructs execution of the authority transfer process, the transfer certificate issuing unit 30 displays a list of functions that the first user has the authority to use among the function group that can be used in the multifunction machine 12, which is the first user's own device, on the display device of the UI 20. The first user selects a function that the second user has the authority to use from the list.

[0078] The shared resource determination unit 32 is configured to determine the shared resources to be used when utilizing a function. For example, when the first user specifies a function for which the second user is given permission to utilize, the shared resource determination unit 32 determines the shared resources to be utilized when the function is utilized. For example, corresponding to each function, function information representing the function and shared resource information representing the shared resources to be utilized when the function is utilized are pre-associated, and shared resource management information representing the association is stored in the storage device 22 or other devices. When specifying a function for which the second user is given permission to utilize, the shared resource determination unit 32 determines the shared resources associated with the specified function in the shared resource management information, thereby determining the shared resources to be utilized when the function is utilized.

[0079] As another example, the first user may also specify a shared resource to be used when using a function. For example, consider that the first user specifies a function that the second user is authorized to use, and specifies a shared resource to be used when using the function. When the first user specifies a shared resource, the shared resource determination unit 32 determines the shared resource specified by the first user as the shared resource to be used when using the function.

[0080] Shared resources include, for example, the physical structure of a device used by a user, the logical structure of the device, information stored in the device, the physical structure of other devices other than the device, the logical structure of the other devices, or information stored in the other devices.

[0081] Taking the shared resources related to the multifunction machine 12 as an example for explanation, the data of the destination table for managing telephone numbers or addresses (such as e-mail addresses or Internet Protocol (IP) addresses), the paper feed box that the multifunction machine 12 has and stores paper for printing, or the storage area that stores data generated by the multifunction machine 12 (such as a storage area called a private document box, etc.) are equivalent to an example of a shared resource. The data of the destination table can be stored in the multifunction machine 12 or in a device other than the multifunction machine 12 (such as the server 14). The storage area as a shared resource can be a storage area formed in the multifunction machine 12 or a storage area formed in a device other than the multifunction machine 12 (such as the server 14). That is, the shared resources related to the multifunction machine 12 can be a shared resource of the multifunction machine 12 or a shared resource of a device other than the multifunction machine 12 as long as it is a shared resource to be used when using a function in the multifunction machine 12.

[0082] A user having the right to use a shared resource is permitted to use the shared resource. The user having the right to use a shared resource may be a user having the right to use a function of the shared resource, or a user having the right to use a shared resource that is defined independently of the right to use the function.

[0083] Furthermore, the shared resource is managed by the manager of the shared resource. The manager may be a user who has the right to use the function of the shared resource, or may be another user other than the user who has the right to manage the shared resource. The state of the shared resource may be changed by the manager. For example, the state of the shared resource may be changed by another user other than the first user who has granted the right to use the function of the shared resource to the second user.

[0084] The state information generating unit 34 is configured to generate state information indicating the state of the shared resource determined by the shared resource determining unit 32, and include the state information in the transfer information generated by the transfer certificate issuing unit 30. Including the state information in the transfer information may be done by embedding the state information in the transfer information or by attaching the state information to the transfer information.

[0085] The transfer certificate issuing unit 30 outputs the transfer information including the status information. Furthermore, the transfer certificate issuing unit 30 may encode the transfer information including the status information and output it. For example, the transfer certificate issuing unit 30 may generate a barcode or a two-dimensional code representing the transfer information including the status information and output it.

[0086] The state information generating unit 34 generates state information indicating the state of the shared resource when the first user is entrusted to grant the right to use the function to the second user. The time when the first user is entrusted to grant the right to use the function to the second user may be when the first user operates the UI 20 to instruct the transfer of the right to use, when the transfer certificate issuing unit 30 accepts the instruction, or when the first user performs operations related to the transfer of the right to use (for example, the time from when the first user instructs the transfer of the right to use until the transfer information is generated).

[0087] For example, the state information is a hash value indicating the state of the shared resource. The state information generation unit 34 generates a hash value indicating the state of the shared resource using a cryptographic hash function such as a one-way hash function. Furthermore, the state information generation unit 34 includes the generated hash value in the transfer information indicating that the right to use the function of the shared resource is transferred to the second user.

[0088] The transfer certificate issuing unit 30 outputs the transfer information including the hash value generated by the status information generating unit 34. Alternatively, the transfer certificate issuing unit 30 may generate a barcode or a two-dimensional code representing the transfer information including the hash value and output it.

[0089] The transfer certificate accepting unit 36 ​​is configured to accept the transfer information. The transfer information can be input to the authority management device 10 via the UI 20, or can be input to the authority management device 10 by reading it using a reading device such as a camera or a scanner. For example, when a two-dimensional code representing the transfer information is generated and output, when the second user extends the two-dimensional code to the reading device, the reading device reads the two-dimensional code, and the transfer certificate accepting unit 36 ​​accepts the two-dimensional code.

[0090] The state information reading unit 38 is configured to read the state information contained in the transfer information accepted by the transfer certificate accepting unit 36. For example, when the transfer certificate accepting unit 36 ​​accepts the two-dimensional code, the state information reading unit 38 decodes the two-dimensional code to generate the transfer information from the two-dimensional code, and reads the state information (e.g., hash value) from the transfer information.

[0091] When the transfer certification accepting unit 36 ​​accepts the transfer information, the shared resource specifying unit 32 specifies the shared resource to be used when the function indicated by the function information included in the accepted transfer information is used.

[0092] The function utilization permission unit 40 is configured to permit or restrict the use of the function indicated by the function information contained in the transfer information based on the transfer information accepted by the transfer certificate accepting unit 36. The processing performed by the function utilization permission unit 40 is described in detail. When the transfer information is accepted by the transfer certificate accepting unit 36, and the shared resource is determined by the shared resource determination unit 32 based on the accepted transfer information, the function utilization permission unit 40 determines the state of the shared resource when the transfer information is accepted by the transfer certificate accepting unit 36. Next, the function utilization permission unit 40 permits or restricts the use of the function indicated by the function information contained in the transfer information based on the comparison result between the state of the shared resource when the transfer information is accepted by the transfer certificate accepting unit 36 ​​and the state indicated by the state information read from the transfer information by the state information reading unit 38. In the following, for convenience, the state of the shared resource when the transfer information is accepted by the transfer certificate accepting unit 36 ​​is referred to as the "first state", and the state indicated by the state information read from the transfer information by the state information reading unit 38 is referred to as the "second state".

[0093] If the first state and the second state are consistent, the function use permission unit 40 permits the use of the function indicated by the function information included in the assignment information. If the first state and the second state are inconsistent, the function use permission unit 40 restricts the use of the function. The function use permission unit 40 may not permit the use of all the functions, or may permit the use of part of the functions but not permit the rest of the functions.

[0094] When a hash value is used as the state information, the function use permission unit 40 generates a hash value indicating the state of the shared resource when the transfer certificate acceptance unit 36 ​​accepts the transfer information, compares the generated hash value (hereinafter referred to as the "first hash value") with the hash value (hereinafter referred to as the "second hash value") read by the state information reading unit 38, and permits or restricts the use of the function according to the comparison result. The function use permission unit 40 permits the use of the function when the first hash value and the second hash value are consistent, and restricts the use of the function when the first hash value and the second hash value are inconsistent.

[0095] The information processing system of this embodiment is described in further detail below. It is assumed below that the authority management device 10 is incorporated into the multifunction machine 12, and the multifunction machine 12 has the same function as the authority management device 10. Furthermore, it is assumed that the multifunction machine 12 is a device used by a user, and the use authority of the function used in the multifunction machine 12 is given to a second user.

[0096] Below, refer to Figure 4 The process of granting the use authority to the second user will be described below. Figure 4 A flowchart representing the processing is shown in FIG.

[0097] First, when the first user inputs the user identification information of the first user into the multifunction machine 12, the first user is identified by the identification unit 26. When the first user selects a function for which the second user has the right to use and instructs the transfer of the right to use, the function management unit 28 determines whether the first user has the right to use the function (S01). If the first user does not have the right to use the function (S01, No), the process ends.

[0098] If the first user has the right to use the function (S01, yes), the shared resource determination unit 32 determines whether the shared resource is used when using the function (S02). In addition, the transfer certificate issuing unit 30 receives a transfer instruction of the use right and generates transfer information indicating that the use right of the function is transferred to the second user.

[0099] If the shared resource is to be used (S02, Yes), the state information generating unit 34 generates state information indicating the state of the shared resource and includes the state information in the transfer information (S03). Then, the transfer certificate issuing unit 30 outputs the transfer information including the state information (S04).

[0100] If the shared resource is not used (S02, No), the state information is not generated, and the transfer certificate issuing unit 30 outputs the transfer information (S04).

[0101] The second user receives the outputted transfer information.

[0102] Below, refer to Figure 5 The processing when the multifunction machine 12 is used using the use authority will be described. Figure 5 A flowchart representing the processing is shown in FIG.

[0103] When the second user inputs the transfer information into the multifunction machine 12, the transfer certificate accepting unit 36 ​​accepts the transfer information (S10).

[0104] The function use permission unit 40 specifies the function for which the second user is authorized to use (S11) based on the transfer information accepted by the transfer certification accepting unit 36. The function indicated by the function information included in the transfer information is the function for which the second user is authorized to use.

[0105] If the transfer information accepted by the transfer certification accepting unit 36 ​​includes the status information, the status information reading unit 38 reads the status information included in the transfer information from the transfer information (S12).

[0106] If a shared resource is to be used when utilizing a function for which the second user is authorized to utilize (S13, yes), the function utilization permission unit 40 compares the state of the shared resource when the transfer information is accepted by the transfer certificate acceptance unit 36 ​​(i.e., the first state) with the state represented by the state information read from the transfer information (i.e., the second state) (S14).

[0107] If the first state and the second state match each other ( S14 , Yes), the function utilization permission unit 40 permits utilization of the function for which utilization authority is granted to the second user ( S15 ).

[0108] If the first state and the second state match each other ( S14 , No), the function utilization permission unit 40 restricts utilization of the function ( S16 ).

[0109] If the shared resource is not used when using the function for which the second user is authorized to use ( S13 , No), the function use permission unit 40 permits use of the function ( S15 ).

[0110] For example, the function use permission unit 40 permits the use of the function that uses the shared resource when the first state and the second state are consistent, and does not permit the use of the entire shared resource when the first state and the second state are inconsistent. When the first state and the second state are consistent, the function use permission unit 40 permits the use of the shared resource to be used when using the function.

[0111] As another example, the function use permission unit 40 may permit the use of the function of using the shared resource when the first state and the second state are consistent, and permit the use of only the portion of the shared resource to be used when the function is used, which has the state when the transfer instruction of the use right of the function is accepted from the first user, when the first state and the second state are inconsistent. For example, the state information generation unit 34 stores in advance in the storage device 22 the state information indicating the state of the shared resource when the transfer instruction of the use right of the function is accepted from the first user. That is, the state information generation unit 34 stores in the storage device 22 the state information included in the transfer information. For example, after the transfer information of granting the use right of the function to the second user is generated, if the state of the shared resource to be used when the function is used is changed, the state information generation unit 34 generates state information indicating the state of the shared resource before the change and stores it in the storage device 22. The state information generation unit 34 generates state information indicating the state of the shared resource before the change and stores it in the storage device 22 every time the state of the shared resource is changed. The function use permission unit 40 permits use of a portion of the shared resource having a state indicated by the state information included in the transfer information input by the second user to the multifunction machine 12, and does not permit use of a portion having a state other than the state indicated by the state information. That is, the function use permission unit 40 permits use of a portion of the shared resource that has not been changed since the transfer information was generated, and does not permit use of a portion that has been changed since the transfer information was generated.

[0112] Here, as an example, it is assumed that the first user has the right to use the scan-and-forward function of the destination table, and the second user does not have the right to use the scan-and-forward function of the destination table.

[0113] The data in the destination table is an example of a shared resource to be used when the scan-forward function is used. In the destination table, for example, the name of the destination, the telephone number of the destination, and the address of the destination (such as an email address or IP address, etc.) are registered in association with each destination. Information other than these may also be registered in the destination table.

[0114] The scan-and-forward function is a function that generates image data representing a document by scanning the document, and sends the image data to a destination. For example, the document is scanned by the multifunction machine 12, and the image data generated by the scanning is sent from the multifunction machine 12 to a destination selected from a destination table. For example, the image data is sent to the destination via an e-mail or the like. Hereinafter, the image data generated by scanning is referred to as "scanned data".

[0115] The first user has the authority to send the scanned data to any of the destinations registered in the destination table by email, referring to all the destinations registered in the destination table. That is, the first user can send the scanned data to any destination selected from the destination table by email.

[0116] In this embodiment, it is assumed that the first user transfers the temporary use authority of the scan forwarding function for sending scan data by e-mail using the destination table to the second user.

[0117] First, when a first user inputs the user identification information of the first user into the multifunction machine 12 and requests to log in, the identification unit 26 identifies the first user based on the user identification information and permits the first user to log in to the multifunction machine 12 .

[0118] The function management unit 28 determines the function that the first user has the right to use. Furthermore, the first user operates the UI 20 to request the multifunction machine 12 to transfer the right to use the scan forwarding function of sending the scanned data by email using the destination list to the second user. The function management unit 28 accepts the request and confirms that the first user has the right to use the scan forwarding function of sending the scanned data by email using the destination list.

[0119] If it is confirmed that the first user has the right to use the scan forwarding function of sending scanned data by email using the destination list, the transfer certificate issuing unit 30 generates transfer information that grants temporary right to use the scan forwarding function of sending scanned data by email using the destination list to a user who does not have the right to use the scan forwarding function. The transfer information includes function information indicating the scan forwarding function of sending scanned data by email using the destination list.

[0120] Furthermore, the data of the destination table is determined as a shared resource by the shared resource determination unit 32. The state information generation unit 34 generates a hash value (i.e., a second hash value) of all the data of the destination table when receiving the entrustment from the first user, and includes the second hash value in the transfer information. The second hash value of all the data of the destination table is an example of state information indicating the state of the destination table.

[0121] The transfer certificate issuing unit 30 generates and outputs a barcode or a two-dimensional code indicating transfer information including a hash value of all data in the destination table. Here, as an example, the transfer certificate issuing unit 30 generates and outputs a QR code as an example of a two-dimensional code.

[0122] The QR code as the transfer information is displayed on the UI 20, or printed by the multifunction machine 12, or sent to the terminal device 16 (eg, the terminal device 16B) of the second user by short-range wireless communication, etc. Thus, the QR code is given to the second user.

[0123] In addition, the first user can also use the terminal device 16 (for example, the terminal device 16A) of the first user to entrust the multifunction machine 12 to transfer the use right of the scan-and-forward function to the second user. Information indicating the entrustment is sent from the terminal device 16A to the multifunction machine 12, and is received by the multifunction machine 12. As described above, the entrustment of the transfer of the use right can be performed by the multifunction machine 12 or by the terminal device 16 of the user who transfers the use right.

[0124] The second user inputs the QR code as the transfer information into the multifunction machine 12 so that the second user can use the scan-forward function in the multifunction machine 12. For example, when the QR code is extended to the reading device provided in the multifunction machine 12, the QR code is read by the reading device, and the transfer certificate receiving unit 36 ​​receives the QR data. The state information reading unit 38 decodes the QR code to generate the transfer information from the QR code, and reads the second hash value from the transfer information. Furthermore, the shared resource determination unit 32 determines the shared resource to be used when using the scan-forward function indicated by the function information contained in the transfer information, that is, the destination table.

[0125] The function use permission unit 40 generates a hash value (ie, a first hash value) indicating the state of the destination table when the transfer certificate acceptance unit 36 ​​accepts the QR code, and compares the first hash value with the second hash value read from the QR code.

[0126] If the first hash value matches the second hash value, the function use permission unit 40 permits the second user to use the scan forwarding function for sending scan data by e-mail using the destination table. In this case, the second user can use any destination registered in the destination table.

[0127] When the first hash value and the second hash value are inconsistent, the function use permission unit 40 restricts the use of the scan forwarding function for sending scanned data by e-mail using the destination table. For example, the second user is prohibited from using the scan forwarding function using the destination table. The function use permission unit 40 may also permit the second user to use the scan forwarding function, but prohibit the use of the destination table. In this case, the destination registered in the destination table is not displayed on the UI 20, and the second user operates the UI 20 to input the destination to use the scan forwarding function.

[0128] During the period from when the QR code as transfer information is given to the second user until the second user exercises the right to use based on the transfer information (i.e., until the second user uses the transfer information to use the multifunction machine 12), the destination table as a shared resource may be changed. For example, consider a situation where the destination manager is unaware that the temporary right to use the scan-forwarding function has been given by the first user to the second user who does not have the right to use the function, and adds a new destination to the destination table. As described above, when the destination table is changed, the following situation may occur, that is, the destination table is used by the second user in a state that the first user or the destination manager who manages the destination table did not expect. For example, if a new destination that the first user did not expect is added to the destination table at the time when the right to use the scan-forwarding function of the destination table is transferred to the second user, the second user becomes able to refer to the new destination, and the information of the new destination may be leaked to the second user. In addition, it is possible that the scan data is sent to the new destination through the operation of the second user. Unless the destination manager notifies the first user of the addition of the new destination, the first user cannot know that the new destination has been added to the destination list, and thus cannot have the opportunity to perform an operation for preventing the new destination from being used by granting the second user the use authority. Even if the first user knows that the new destination has been added to the destination list, the first user must perform an operation for preventing the new destination from being used by granting the second user the use authority, which is laborious.

[0129] In this embodiment, if the destination list is changed during the period from when the second user is granted the right to use the scan-forwarding function until the second user exercises the right to use based on the transfer information, the first hash value and the second hash value are inconsistent, and the second user is restricted from using the scan-forwarding function. Therefore, it is possible to prevent the second user from using the scan-forwarding function or the destination list in a state that the first user did not expect when the second user was granted the right to use the scan-forwarding function.

[0130] When the first hash value and the second hash value do not match, the function use permission unit 40 may also notify the second user of the reason for not permitting the use of the shared resource. For example, the function use permission unit 40 may display information indicating the reason on the display device of the UI 20 or send it to the terminal device 16B of the second user. Figure 6 An example of the display of the reason why the use of the destination list as a shared resource is not permitted is shown in FIG. Figure 6 As shown, the function use permission unit 40 displays a screen 42 notifying the user of the reason on the display device of the UI 20. For example, a message indicating that "since the recipient list has been changed after the permission to use the scan-forward function has been granted to the second user, the scan-forward function and the recipient list cannot be used" is displayed on the screen 42.

[0131] Furthermore, the status information generating unit 34 may also store the data of the destination table before the change in the storage device 22 whenever the destination table is changed. At this time, when the multifunction machine 12 accepts the QR code as the transfer information, the status information generating unit 34 generates a hash value for each destination table before the change based on the data of the destination table before the change. The function utilization permission unit 40 compares the second hash value read from the QR code as the transfer information with each hash value generated based on the data of each destination table before the change, retrieves the data of the destination table that has generated a hash value consistent with the second hash value, and permits the second user to use the retrieved destination table. For example, the data of the destination table when the permission to use the scan-forwarding function is granted to the second user is pre-stored in the storage device 22, and the second hash value is consistent with the first hash value generated based on the data of the destination table. Therefore, the second user is permitted to use the destination when the permission to use the scan-forwarding function is granted to the second user. After the permission to use the scan-forward function is granted to the second user, if the destination table is changed, the second user is not allowed to use the changed destination table because the hash value generated based on the data in the changed destination table is inconsistent with the second hash value. In this case, the second user is still allowed to use the destination table when the permission to use the scan-forward function is granted to the second user. The destination table when the permission to use the scan-forward function is granted to the second user is equivalent to an example of a portion of the destination table as a shared resource that has not been changed since the transfer information was generated.

[0132] In the above example, the destination table is cited as an example of a shared resource, but a paper feed box or a private document box provided in the multifunction machine 12 may be used as a shared resource.

[0133] For example, the type of paper contained in the paper feed box is equivalent to an example of the state of the paper feed box. The first hash value is the state information as described below, that is, it indicates the type of paper contained in the paper feed box when the transfer information that grants the use right of the function of using the paper feed box to the second user is input to the multifunction machine 12. That is, the first hash value is the state information as described below, that is, it indicates the type of paper contained in the paper feed box when the second user exercises the use right based on the transfer information. The second hash value is the state information as described below, that is, it indicates the type of paper contained in the paper feed box when the multifunction machine 12 accepts the entrustment from the first user to grant the use right of the function of using the paper feed box to the second user. When the first hash value and the second hash value are consistent, the function utilization permission unit 40 permits the second user to use the function of using the paper feed box. When the first hash value and the second hash value are inconsistent, the function utilization permission unit 40 restricts the use of the function of using the paper feed box. For example, the function utilization permission unit 40 prohibits the second user from using the paper feed box.

[0134] For example, consider the following situation: when the second user is given the right to use the function of using the paper supply box, the paper supply box contains ordinary paper, but the paper contained in the paper supply box is changed from ordinary paper to high-grade paper until the second user uses the function. In this case, the paper supply box may be used by the second user in a state that the administrator who manages the paper or the first user did not expect. In the case where the first hash value and the second hash value are inconsistent, the second user is restricted from using the paper supply box, thereby preventing the paper supply box from being used by the second user in a state that the administrator or the first user did not expect.

[0135] Furthermore, the private document box is a storage area that is permitted to be used by a user (hereinafter referred to as a "shared target") who has the right to use the private document box. For example, the shared target of the private document box is in the state of the private document box. From the time when the right to use the function of the private document box is given to the second user until the second user uses the private document box by exercising the right to use the private document box, the shared target of the private document box may be changed. At this time, since the first hash value and the second hash value are inconsistent, the private document box with the changed shared target can be prevented from being used by the second user.

[0136] Modifications will be described below.

[0137] For example, the shared resource includes a plurality of structures. The state information generation unit 34 generates a hash value indicating the state of at least a portion of the plurality of structures. The state information generation unit 34 generates a hash value by changing the structure to be generated by the hash value according to the second user's use of the multifunction machine 12. For example, when the first user grants the second user the right to use the function, the first user specifies the second user's use of the multifunction machine 12.

[0138] Let's take the destination table as an example to explain. In the destination table, for example, corresponding to each destination, the name of the destination, the telephone number of the destination, and the address of the destination are registered in association. The name of the destination, the telephone number of the destination, and the address of the destination are the structure of the destination table as an example of a shared resource.

[0139] The state information generating unit 34 generates a hash value indicating the state of at least one of the name of the destination, the telephone number of the destination, and the address of the destination, based on the usage pattern of the multifunction machine 12 by the second user.

[0140] The usage form of the multifunction machine 12 is, for example, the period of use of the multifunction machine 12 by the second user. The period of use is specified by the first user, and information indicating the period of use is included in the transfer information. The longer the period of use is, the smaller the number of structures that are the objects of hash value generation is, and the hash value (i.e., the second hash value) is generated by the state information generation unit 34. The second hash value is included in the transfer information.

[0141] When the transfer information is input to the multifunction machine 12 and accepted by the transfer certificate accepting unit 36, the function use permission unit 40 determines the use period of the multifunction machine 12 by the second user based on the information indicating the use period contained in the transfer information. In addition, the function use permission unit 40 generates a hash value (i.e., a first hash value) indicating the state of the destination table when the transfer information is accepted by the transfer certificate accepting unit 36 ​​and indicating the state of the number of structures corresponding to the use period. The function use permission unit 40 compares the first hash value with the second hash value read from the transfer information, and permits or restricts the use of the scan-and-forward function according to the comparison result.

[0142] For example, if the use period is less than the lower limit threshold, the state information generation unit 34 generates a second hash value indicating the state of all structures contained in the destination table (e.g., the name of the destination, the telephone number of the destination, and the address of the destination). When the transfer information is input into the multifunction machine 12 and accepted by the transfer certificate acceptance unit 36, the function use permission unit 40 generates a first hash value indicating the state of all structures of the destination table when the transfer information is accepted by the transfer certificate acceptance unit 36, and permits or restricts the use of the scan forwarding function based on the comparison result between the first hash value and the second hash value. If the state of a part of the structure of the destination table is changed before the second user uses the transfer information to use the multifunction machine 12, the first hash value and the second hash value will be inconsistent, and thus the use of the scan forwarding function will be restricted. For example, even if only the name of the destination is changed, the first hash value and the second hash value will be inconsistent. Therefore, even if only the name of the destination is changed, the use of the scan forwarding function will be restricted. The same applies to the telephone number or address.

[0143] For example, it is assumed that the second user whose usage period is set to be less than the lower limit threshold is a user who is permitted to use the multifunction machine 12 for a short period of time (for example, a user who is permitted to use the multifunction machine 12 only once). By generating a hash value representing the state of all structures of the destination table, it is possible to prevent the scan forwarding function or the destination table from being used by the second user in a state that the administrator or the first user did not expect.

[0144] If the utilization period is greater than the lower threshold and less than the upper threshold, the status information generating unit 34 generates a second hash value indicating the state of a portion of the structure contained in the destination table (e.g., the destination phone number and the destination address). The upper threshold is a value indicating a period longer than the lower threshold. When the transfer information is input into the multifunction machine 12 and accepted by the transfer certificate accepting unit 36, the function utilization permission unit 40 generates a first hash value indicating the state of a portion of the structure of the destination table (e.g., the destination phone number and the destination address) when the transfer information is accepted by the transfer certificate accepting unit 36, and permits or restricts the use of the scan forwarding function based on the comparison result between the first hash value and the second hash value. If at least one of the destination phone number and the destination address is changed before the second user uses the transfer information to use the multifunction machine 12, the first hash value and the second hash value will be inconsistent, and thus the use of the scan forwarding function will be restricted. On the other hand, if only the name of the destination included in the destination table is changed, the first hash value and the second hash value still match each other, and therefore the use of the scan and forward function is still permitted.

[0145] For example, it is assumed that the second user whose usage period is set to be greater than the lower threshold and less than the upper threshold is a user permitted to use the multifunction machine 12 in the medium term. By generating a hash value from a part of the structure of the destination table and comparing it with the second hash value, even if the state of the structure that is not the object of hash value generation has changed, the use of the scan-and-forward function is still permitted.

[0146] If the use period is greater than the upper threshold, the state information generation unit 34 generates a second hash value as described below, which represents a part of the structure contained in the destination table, and the state of the structure is less than when the use period is less than the upper threshold. For example, the state information generation unit 34 generates a second hash value representing the address state of the destination. When the transfer information is input into the multifunction machine 12 and accepted by the transfer certificate acceptance unit 36, the function use permission unit 40 generates a first hash value representing the address state of the destination contained in the destination table when the transfer information is accepted by the transfer certificate acceptance unit 36, and permits or restricts the use of the scan forwarding function based on the comparison result of the first hash value and the second hash value. If the address of the destination is changed before the second user uses the transfer information to use the multifunction machine 12, the first hash value and the second hash value will be inconsistent, so the use of the scan forwarding function is restricted. On the other hand, if only the name or telephone number of the destination contained in the destination table is changed, the first hash value and the second hash value are still consistent, so the use of the scan forwarding function is still permitted.

[0147] For example, it is assumed that the second user whose usage period is set to be equal to or greater than the upper threshold is a user who is permitted to use the multifunction machine 12 for a long period of time. For example, a user who has been commissioned to perform a task is an example of the second user.

[0148] The structure that is not the object of hash value generation may also be a structure with a lower importance level than the structure that is the object of hash value generation. For example, the name of the recipient is a structure with a lower importance level than the telephone number and address of the recipient, so the hash value representing the name status of the recipient may not be generated. In this case, even if the name of the recipient with a low importance level is changed, deleted, or added, the second user is still allowed to use the scan-and-forward function. On the other hand, if the telephone number or address with a high importance level is changed, deleted, or added, the second user is restricted from using the scan-and-forward function. In this way, it is possible to prevent the telephone number or address from being used by the second user in a state that the administrator or the first user did not expect.

[0149] Furthermore, the higher the reliability of the second user, the smaller the number of structures to be generated as hash values. The reliability of the second user is specified by the first user, and information indicating the reliability is included in the transfer information. The higher the reliability, the smaller the number of structures to be generated as hash values ​​(i.e., the second hash value) is generated by the state information generation unit 34. The second hash value is included in the transfer information.

[0150] When the transfer information is input into the multifunction machine 12 and accepted by the transfer certificate accepting unit 36, the function use permission unit 40 determines the reliability of the second user based on the information indicating the reliability contained in the transfer information. In addition, the function use permission unit 40 generates a hash value (i.e., a first hash value) indicating the state of the destination table when the transfer information is accepted by the transfer certificate accepting unit 36 ​​and indicating the state of the number of structures corresponding to the reliability. The function use permission unit 40 compares the first hash value with the second hash value read from the transfer information, and permits or restricts the use of the scan-and-forward function according to the comparison result.

[0151] For example, if the reliability is less than the lower threshold, the state information generating unit 34 generates a second hash value indicating the state of all structures contained in the destination table (for example, the name of the destination, the telephone number of the destination, and the address of the destination). At this time, a first hash value indicating the state of all structures in the destination table when the transfer information is accepted by the transfer certificate accepting unit 36 ​​is generated, and the use of the scan forwarding function is permitted or restricted based on the comparison result between the first hash value and the second hash value. For example, it is assumed that the second user whose reliability is set to be less than the lower threshold is a user permitted to use the multifunction machine 12 for a short period of time.

[0152] If the reliability is above the lower threshold and below the upper threshold, the status information generating unit 34 generates a second hash value representing the status of a portion of the structure contained in the destination table (for example, the destination's telephone number and the destination's address). The upper threshold is a value representing a reliability higher than the lower threshold. At this time, a first hash value representing the status of a portion of the structure of the destination table (for example, the destination's telephone number and the destination's address) when the transfer information is accepted by the transfer certificate accepting unit 36 ​​is generated, and based on the comparison result of the first hash value and the second hash value, the use of the scan forwarding function is permitted or restricted. For example, it is assumed that the second user whose reliability is set to be above the lower threshold and below the upper threshold is a user who is permitted to use the multifunction machine 12 in the medium term.

[0153] If the reliability is above the upper threshold, the state information generating unit 34 generates a second hash value as described below, wherein the second hash value represents a state of a portion of the structure contained in the destination table, and is less than the state of the structure when the reliability is less than the upper threshold. For example, the state information generating unit 34 generates a second hash value representing the address state of the destination. At this time, a first hash value of the address state of the destination contained in the destination table when the transfer information is accepted by the transfer certificate accepting unit 36 ​​is generated, and based on the comparison result of the first hash value and the second hash value, the use of the scan forwarding function is permitted or restricted. For example, it is assumed that the second user whose reliability is set to be above the upper threshold is a user who is permitted to use the multifunction machine 12 for a long period of time.

[0154] In the above embodiment, the structure to be the target of hash value generation may be specified by the first user. If the destination table is used as an example for explanation, the entire destination table, only the name of the destination, only the phone number, only the address, or multiple structures may be the structure to be the target of hash value generation, and the first user may specify it.

[0155] The degree to which the use of the functions of the multifunction machine 12 is restricted may be changed according to the settings of the multifunction machine 12 or other environments.

[0156] For example, when the multifunction machine 12 is permitted to be used for a short period of time, such as during temporary use or a trial period, the degree of restriction may be relaxed in the case where the network (such as a LAN) that the multifunction machine 12 can use is isolated and not connected to an external network, so that data cannot be forwarded to the outside (such as outside the LAN), or the paper feeder of the multifunction machine 12 is locked. For example, even if information such as the destination table or network settings is changed, a hash value is generated in a manner that does not restrict the use of the scanning function or the use of the functions of the multifunction machine 12 as a whole. The case where a person who is not related to the company that manages the multifunction machine 12 is allowed to use the multifunction machine 12 temporarily is an example of short-term use.

[0157] On the other hand, when the short-term use of the multifunction machine 12 is permitted, the degree of restriction may be strict when the network available to the multifunction machine 12 is connected to an external network and data can be forwarded to the outside. For example, when information such as the destination table or network settings is changed, a hash value is generated in such a way that the use of the scanning function or the use of the functions of the entire multifunction machine 12 is restricted.

[0158] Furthermore, when the multifunction machine 12 is permitted to be used for a long period of time, the degree of restriction may be relaxed if the second user is a highly reliable user, such as a member of a shared office where the multifunction machine 12 is installed, or a user belonging to the same company as the first user. For example, even if information such as the destination table or network settings is changed, the hash value is generated so that the use of the scanning function or the use of the functions of the multifunction machine 12 as a whole is not restricted.

[0159] On the other hand, when the long-term use of the multifunction machine 12 is permitted, the degree of strict restriction may be slightly strict in the case where the network available to the multifunction machine 12 is connected to an external network and data can be forwarded to the outside. For example, even if the destination table is changed, the hash value is generated in a manner that does not restrict the use of the scanning function or the use of the functions of the entire multifunction machine 12. On the other hand, when the network settings are changed, the hash value is generated in a manner that restricts the use of the scanning function or the use of the functions of the entire multifunction machine 12. The change in network settings may be, for example, a change in the settings of the IP address of the multifunction machine 12, or a change in the LAN cable connected to the network port when the multifunction machine 12 has multiple network ports. As a second user subject to such restrictions, for example, a permanent dispatched employee for dispatched business is envisioned. For example, consider: in order to develop a part of the software for a new product, an engineer (engineer) who is a dispatched employee is permitted to use the multifunction machine 12 for a relatively long period (for example, a period of six months). In this case, even if the second user is permitted to use the destination table to send data, in order to prevent erroneous sending, it is considered to restrict the use of the functions of the multifunction machine 12 when the network setting is changed. Furthermore, when the destination table is changed, the second user may not be permitted to use the changed destination table at all. If the first user who grants the second user the right to use the multifunction machine 12 changes the destination table, the second user may be permitted to use the changed destination table, and otherwise, the second user may not be permitted to use the changed destination table.

[0160] In addition, in the case where a hash value representing the overall state of the destination table is generated, when the destination included in the destination table is deleted, the first hash value and the second hash value will be inconsistent. In this case, the function utilization permission unit 40 may also permit the second user to use the scan-forwarding function. When the destination is deleted, since it is difficult to predict that information other than the destination table before deletion is used by the second user, the function utilization permission unit 40 may also permit the second user to use the function. For example, the data of the destination table before deletion is pre-stored in the storage device 22, and the function utilization permission unit 40 generates a hash value based on the data of the destination table stored in the storage device 22, and permits or restricts the use of the scan-forwarding function based on the comparison result of the hash value.

[0161] Furthermore, a hash value may be generated for information related to external transmission among the information contained in the destination table, while a hash value may not be generated for information related to internal transmission. The so-called internal refers to, for example, a device or user that belongs to the same intranet as the multifunction machine 12. The so-called external refers to, for example, a device or user that does not belong to the intranet. For example, the information related to external transmission is the address (such as an IP address, etc.) of a device that does not belong to the same intranet as the multifunction machine 12, or the email address of a user who does not belong to the same intranet as the multifunction machine 12. The information related to internal transmission is information related to Server Message Block (SMB) communication used in the same intranet as the multifunction machine 12.

[0162] In each of the embodiments, the so-called processor refers to a processor in a broad sense, including a general-purpose processor (such as a central processing unit (CPU), etc.) or a special-purpose processor (such as a graphics processing unit (GPU), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), a programmable logic element, etc.). Moreover, the actions of the processor in each of the embodiments may not be performed by only one processor, but by a plurality of processors located at physically separated positions. Moreover, the order of the actions of the processor is not limited to the order described in the embodiments, but may also be changed appropriately.

Claims

1. An information processing device comprising a processor, The processor accepting a request from a first user who has permission to use a function of the device to be used, Outputting transfer information to a second user who does not have the right to use the function, the transfer information including state information indicating that the right to use the function is transferred to the second user, the state information indicating the state of the shared resource when the request from the first user is accepted; receiving the transfer information from the second user, and The use of the function by the second user is permitted or restricted based on a comparison result between the state of the shared resource when the transfer information from the second user is received and the state indicated by the state information included in the received transfer information.

2. The information processing device according to claim 1, characterized in that The state of the shared resource can be changed by users other than the first user.

3. The information processing device according to claim 1 or 2, characterized in that: The state information is a hash value indicating the state of the shared resource.

4. The information processing device according to claim 3, characterized in that: The shared resource includes multiple structures. The hash value is a value indicating a state of at least a portion of the plurality of structures. The processor further generates a hash value by changing a structure to be generated as a target of hash value generation according to a usage pattern of the device by the second user.

5. The information processing device according to claim 4, characterized in that The usage mode is the period of use of the device. The processor reduces the number of structures to be targets of hash value generation as the utilization period becomes longer.

6. The information processing device according to claim 3, characterized in that: The shared resource includes multiple structures. The hash value is a value indicating a state of at least a portion of the plurality of structures. Furthermore, the processor reduces the number of structures to be targets of hash value generation as the reliability of the second user increases.

7. The information processing device according to claim 1 or 2, characterized in that: the processor permitting use of the function when the state of the shared resource when the transfer information is received matches the state indicated by the state information included in the received transfer information; When the state of the shared resource when the transfer information from the second user is received does not match the state indicated by the state information included in the received transfer information, the second user is permitted to use only the portion of the shared resource that is in the state when the delegation was received.

8. The information processing device according to claim 1 or 2, characterized in that: the processor permitting the second user to use the function when the state of the shared resource when the transfer information is received from the second user is consistent with the state indicated by the state information included in the received transfer information, If the state of the shared resource when the transfer information from the second user is received does not match the state indicated by the state information included in the received transfer information, the second user is not permitted to use the entire shared resource.

9. The information processing device according to claim 8, characterized in that: The processor further notifies the second user of the reason for not permitting the second user to use the shared resource.

10. A recording medium storing a program for causing a computer to execute the following processing: accepting a request from a first user who has permission to use a function of the device to be used, outputting transfer information to a second user who does not have the right to use the function, the transfer information including status information indicating that the right to use the function is transferred to the second user, the status information indicating the status of the shared resource when the entrustment from the first user is accepted, receiving the transfer information from the second user, The use of the function by the second user is permitted or restricted based on a comparison result between the state of the shared resource when the transfer information from the second user is received and the state indicated by the state information included in the received transfer information.

11. A computer program product, comprising a program for causing a computer to execute the following processing: accepting a request from a first user who has permission to use a function of the device to be used, outputting transfer information to a second user who does not have the right to use the function, the transfer information including status information indicating that the right to use the function is transferred to the second user, the status information indicating the status of the shared resource when the entrustment from the first user is accepted, receiving the transfer information from the second user, The use of the function by the second user is permitted or restricted based on a comparison result between the state of the shared resource when the transfer information from the second user is received and the state indicated by the state information included in the received transfer information.

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