COMMUNICATION DEVICE, COMPUTER PROGRAM FOR THE COMMUNICATION DEVICE, COMPUTER PROGRAM FOR THE SERVER, AND SERVER

Abstract

To provide a technology for changing a password of a communication device securely.SOLUTION: A communication device includes: a change instruction transmission unit which transmits a change instruction including identification information identifying the communication device to a server, the server storing the identification information and target user information corresponding to a user of a terminal device in association with each other, and the change instruction being a signal to instruct the server to transmit first authentication information to the terminal device by using the target user information; a second receiving unit which receives, after the first authentication information is transmitted from the server to the terminal device, input of the first authentication information from the user; an authentication information transmission unit which transmits, in a case where the input of the first authentication information is received, the first authentication information to the server; a notification receiving unit which receives, in a case where the first authentication information is transmitted to the server, a change permission notification from the server; and a change unit which changes the password of the communication device in a case where the change permission notification is received from the server.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present specification relates to a technique for changing a password on a communication device. [Background technology]

[0002] Patent Literature 1 discloses a technique for changing a personal identification number (PIN) for use in an MFP (abbreviation of Multi-Function Peripheral). In this technique, when an incorrect personal identification number is input by a user, the MFP executes a process for changing the personal identification number. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-016834 A Summary of the Invention [Problem to be solved by the invention]

[0004] SUMMARY OF THE DISCLOSURE Techniques are provided herein that may securely change a password on a communication device. [Means for solving the problem]

[0005] This specification discloses a communication device. The communication device may include a first reception unit that receives a predetermined instruction from a user to change a password of the communication device, a change instruction transmission unit that transmits a change instruction including identification information for identifying the communication device to a server when the predetermined instruction is received, the server stores the identification information in association with target user information corresponding to a user of a terminal device different from the communication device, and the change instruction is a signal for instructing the server to transmit first authentication information to the terminal device using the target user information stored in association with the identification information included in the change instruction, a second reception unit that receives an input of the first authentication information from the user after the first authentication information is transmitted from the server to the terminal device, an authentication information transmission unit that transmits the first authentication information to the server when the input of the first authentication information is received, a notification reception unit that receives a change permission notification from the server when the first authentication information is transmitted to the server, and a change unit that changes the password of the communication device when the change permission notification is received from the server.

[0006] According to the above configuration, when the communication device receives a predetermined instruction, it transmits a change instruction to the server. As a result, first authentication information is transmitted from the server to the terminal device, and the first authentication information is input to the communication device by a user of the terminal device. In this case, the communication device transmits the first authentication information to the server and receives a change permission notification from the server. As a result, the communication device changes the password. For this reason, the password of the communication device can be securely changed.

[0007] This specification also discloses a computer program for a server. The server may include a memory that stores identification information for identifying a communication device and target user information corresponding to a user of a terminal device different from the communication device in association with each other, and a computer. The computer program may cause the computer to function as the following units: a change instruction receiving unit that receives a change instruction including the identification information from the communication device; a first authentication information sending unit that sends first authentication information to the terminal device using the target user information stored in association with the identification information included in the change instruction when the change instruction is received from the communication device, where the first authentication information is input to the communication device by the user of the terminal device after being transmitted to the terminal device; an authentication information receiving unit that receives the first authentication information from the communication device when the first authentication information is input to the communication device; and a notification sending unit that sends a change permission notification to the communication device when the first authentication information is received from the communication device, where the change permission notification is a notification that permits the communication device to change a password.

[0008] According to the above configuration, when the server receives a change instruction from the communication device, it transmits the first authentication information to the terminal device. After that, when the first authentication information is input to the communication device by the user of the terminal device, the server receives the first authentication information from the communication device and transmits a change permission notice to the communication device. As a result, the password change is permitted in the communication device. Therefore, the password of the communication device can be securely changed.

[0009] A computer program for the above-mentioned communication device, a computer-readable recording medium storing the computer program, and a method executed by the communication device are also novel and useful. A computer-readable recording medium storing a computer program for the above-mentioned server, the server itself, and a method executed by the server are also novel and useful. Also, a communication system including a server, a communication device, and a terminal device is novel and useful. [Brief description of the drawings]

[0010] [Figure 1] 1 shows the configuration of a communication system. [Diagram 2] 1 shows a sequence diagram for registering a printer. [Diagram 3] The sequence diagram continues from Figure 2. [Figure 4] FIG. 1 shows a sequence diagram of a first embodiment for changing a password. [Diagram 5] FIG. 11 shows a sequence diagram of a second embodiment for changing a password. [Figure 6] FIG. 13 shows a sequence diagram of a third embodiment for changing a password. [Figure 7] FIG. 13 shows a sequence diagram of a fourth embodiment for changing a password. [Figure 8] FIG. 13 shows a sequence diagram of a fifth embodiment for changing a password. [Figure 9] The sequence diagram continues from FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] (First Example) (Communication system configuration; Figure 1) As shown in Fig. 1, the communication system 2 includes a terminal 10, a printer 100, and an intermediary server 200. The terminal 10 and the printer 100 are connected to a LAN (abbreviation of Local Area Network) 4, and can communicate with each other via the LAN 4. The LAN 4 is connected to the Internet 6, and the intermediary server 200 is installed on the Internet 6. Therefore, the terminal 10 and the printer 100 can communicate with the intermediary server 200 via the Internet 6. Hereinafter, the intermediary server 200 will be referred to as "server 200". This specification provides a technology that enables an administrator of the printer 100 to change the printer password set in the printer 100 in a situation where the administrator of the printer 100 has forgotten the printer password set in the printer 100.

[0012] (Terminal 10 Configuration) The terminal 10 may be a portable terminal such as a smartphone, a notebook PC, or a tablet PC, or may be a stationary terminal such as a desktop PC. The terminal 10 is used by an administrator who manages the printer 100. The terminal 10 includes an operation unit 12, a display unit 14, a communication interface 20, and a control unit 30. In the following, the interface will be referred to as "I / F".

[0013] The operation unit 12 is a button, a touch panel, or the like that is operated by a user. The user can input various instructions to the terminal 10 by operating the operation unit 12. The display unit 14 is a display for displaying various information. The communication I / F 20 is connected to the LAN 4.

[0014] The control unit 30 includes a CPU 32 and a memory 34. The CPU 32 executes various processes in accordance with an OS (short for Operating System) program 40 stored in the memory 34. The memory 34 is composed of a volatile memory, a non-volatile memory, etc. The OS program 40 is a program for realizing basic operations of the terminal 10.

[0015] (Configuration of Printer 100) The printer 100 is a peripheral device (for example, a peripheral device of the terminal 10) capable of executing a printing function. In a modified example, the printer 100 may be a multi-function device capable of executing a scanning function, a FAX function, etc. in addition to the printing function. The printer 100 has a serial number SN1 that is information for identifying the printer 100. The printer 100 includes an operation unit 112, a display unit 114, a print execution unit 116, a communication I / F 120, and a control unit 130.

[0016] The operation unit 112 is a button, a touch panel, or the like that is operated by a user. The user can input various instructions to the printer 100 by operating the operation unit 112. The display unit 114 is a display for displaying various information. The print execution unit 116 has a printing mechanism such as an inkjet type or a laser type. The communication I / F 120 is connected to the LAN 4.

[0017] The control unit 130 includes a CPU 132, a volatile memory 134A, and a non-volatile memory 134B. The CPU 132 executes various processes in accordance with a program 140 stored in the non-volatile memory 134B.

[0018] (Configuration of Server 200) The server 200 is a server that mediates various communications for changing the password of the printer 100. The server 200 includes a communication I / F 220 and a control unit 230. The communication I / F 220 is connected to the Internet 6. In this embodiment, the printer password is not notified to the server 200 from the printer. Therefore, the printer password is not stored in the server 200.

[0019] The control unit 230 includes a CPU 232 and a memory 234. The CPU 232 executes various processes in accordance with a program 240 stored in the memory 234. The memory 234 is configured by a volatile memory, a non-volatile memory, etc. The memory 234 further stores an account table 242 and a device table 244.

[0020] The account table 242 is a table that stores one or more pieces of account information corresponding to one or more users. The account information is information required to log in to the server 200, and is information in which a user ID and a server password are associated with each other. In the following, the password is referred to as "PW". In this embodiment, an email address is used as the user ID. In a modified example, the user ID may be a character string specified by the user instead of an email address. In the example of FIG. 1, the user ID "user@user.co.jp", which is the email address of the user of the terminal 10 (i.e., the administrator of the printer 100), is associated with the server PW "SP1" and stored. In the following, the user ID "user@user.co.jp" is simply referred to as "U1".

[0021] The device table 244 is a table that stores information about one or more devices (e.g., printers). The device table 244 stores a user ID, a serial number, and an access token in association with each other. The access token is information used when performing communication between the server 200 and a device identified by the associated serial number. In the example of FIG. 1, the user ID "U1", the serial number SN1, and the access token "AT" are stored in association with each other in the device table 244.

[0022] (Printer registration sequence; Figures 2 and 3) Next, a process for registering information related to the printer 100 in the server 200 will be described with reference to Figures 2 and 3. In the following, for ease of understanding, when describing the process executed by the CPU of each device (e.g., 32, 132, 232), the CPU will not be described as the subject, but each device (e.g., terminal 10, printer 100, server 200) will be described as the subject. Furthermore, unless otherwise specified, communication between each device is performed via a communication I / F (e.g., 20, 120, 220). Therefore, when describing communication between each device below, the expression "via a communication I / F" will be omitted.

[0023] 2, the account table 242 stores account information (i.e., user ID "U1" and server PW "SP1") of the user of the terminal 10 (i.e., the administrator of the printer 100). Also, in the initial state of FIG. 2, the device table 244 does not store information about the printer 100 (i.e., the serial number and the access token).

[0024] When the printer 100 receives a power-on operation from the administrator at T10, the printer 100 is powered on at T12. At this time, the printer 100 determines that information about the printer 100 itself has not yet been registered in the server 200. Specifically, the printer 100 determines that the printer 100 has not yet been registered in the server 200 because the Access Token has not been stored in the non-volatile memory 134B. In this case, the printer 100 displays a notification screen SC1 on the display unit 114 at T14. The notification screen SC1 includes a message that prompts the user to register information about the printer 100 with the server 200.

[0025] The administrator who has viewed the notification screen SC1 uses the terminal 10 to perform an operation for registering information about the printer 100 in the server 200. Specifically, first, the terminal 10 accepts an access instruction from the administrator in T20 to access the web server function of the printer 100. The access instruction includes a designation of an IP address (not shown) of the printer 100. In this case, the terminal 10 transmits an access request to the printer 100 in T12 using a web browser program (not shown). The following processes executed by the terminal 10 are also executed using the web browser program, unless otherwise stated to use another program.

[0026] When the printer 100 receives an access request from the terminal 10 in T22, it transmits top screen data representing the top screen SC2 to the terminal 10 in T24.

[0027] When the terminal 10 receives the top screen data from the printer 100 in T24, in T26, the terminal 10 displays the top screen SC2 on the display unit 14. The top screen SC2 includes the current status of the printer 100 ("Idle" in the example of FIG. 2) and a number of buttons for changing various settings of the printer 100 (for example, a "Register to Server" button, a "Change Password" button, etc.).

[0028] The terminal 10 accepts selection of the “Register in Server” button in the top screen SC2 in T30. In this case, the terminal 10 transmits an access request to the server 200 in T32.

[0029] When the server 200 receives an access request from the terminal 10 in T32, the server 200 transmits login screen data representing the login screen SC3 to the terminal 10 in T34.

[0030] When the terminal 10 receives the login screen data from the server 200 in T34, in T36, the terminal 10 displays a login screen SC3 on the display unit 14. The login screen SC3 includes a message prompting the user to enter account information (i.e., a user ID and a server PW) for logging in to the server 200, a user ID input field, a server PW input field, an OK button, and a cancel button.

[0031] (Continuation of Figure 2; Figure 3) 3, the terminal 10 accepts a login operation from the administrator. The login operation includes an operation of inputting a user ID "U1" and a server PW "SP1" on a login screen SC3. In this case, the terminal 10 transmits a login request including the input user ID "U1" and server PW "SP1" to the server 200 in T42.

[0032] When the server 200 receives a login request from the terminal 10 in T42, the server 200 executes authentication in T50. Specifically, the server 200 judges whether or not the combination of the user ID "U1" and the server PW "SP1" included in the received login request is stored in the account table 242. In this case, since the combination is stored in the account table 242 (see the initial state in FIG. 2), the server 200 judges that the authentication is successful. In this case, the server 200 generates a PIN code "1234" in T52, and associates the user ID "U1" included in the received login request with the PIN code "1234" and stores them in the memory 234. Then, the server 200 transmits PIN code screen data representing a PIN code screen SC4 to the terminal 10 in T54. If the server determines in T50 that the combination of the user ID and server PW included in the received login request is not stored in the account table 242, i.e., if authentication fails, it does not execute the processes from T52 onwards.

[0033] When the terminal 10 receives the PIN code screen data from the server 200 in T54, it causes the display unit 14 to display a PIN code screen SC4 in T56. The PIN code screen SC4 includes a message indicating that a PIN code should be entered into the printer (printer 100 in this case) to be registered in the server 200, and the PIN code "1234". Therefore, the administrator can know that the PIN code "1234" displayed on the PIN code screen SC4 should be entered into the printer 100.

[0034] In T60, the printer 100 accepts a server registration operation from the administrator who has viewed the PIN code screen SC4, and in T62, causes the printer 100 to display a PIN code entry screen SC5 on the display unit 114. The PIN code entry screen SC5 includes a message prompting the user to enter a PIN code, a PIN code entry field, and an OK button.

[0035] When the printer 100 accepts, in T64, input of the PIN code "1234" into the PIN code input screen SC5 and selection of the OK button, in T66, it transmits a registration request to the server 200. The registration request includes the input PIN code "1234" and the serial number SN1 of the printer 100.

[0036] When the server 200 receives a registration request from the printer 100 in T66, the server 200 executes authentication in T70. Specifically, the server 200 judges whether or not the PIN code "1234" included in the received registration request has been stored in the memory 234. In this case, since the PIN code "1234" has been stored in the memory 234 (see T52), the server 200 judges that the authentication has been successful. In this case, the server 200 generates an Access Token "AT" in T72. Hereinafter, the Access Token "AT" may be simply referred to as "AT". Next, the server 200 identifies the user ID "U1" (see T52) stored in the memory 234 in association with the PIN code "1234". Then, the server 200 stores the identified user ID "U1", the serial number SN1 included in the registration request, and the generated Access Token "AT" in the device table 244 in association with each other. As a result, information about the printer 100 is registered in the server 200 .

[0037] In T74, the server 200 transmits "AT" to the printer 100. Note that if the PIN code included in the registration request has not been stored in the memory 234 in T70, that is, if authentication has failed, the server 200 does not execute the processes from T72 onwards.

[0038] When the printer 100 receives the "AT" from the server 200 in T74, the printer 100 registers the "AT" in the non-volatile memory 134B in T76. As a result, a so-called constant connection is established between the printer 100 and the server 200, although this is not shown in the figure. By using the constant connection, the server 200 can transmit a signal to the printer 100 across the firewall of the LAN 4 to which the printer 100 belongs, even if it does not receive a request from the printer 100. In other words, the constant connection is a connection that can execute server-push type communication. The constant connection is, for example, a connection that complies with XMPP (short for eXtensible Messaging and Presence Protocol).

[0039] When the printer 100 completes the registration of "AT", in T80 it transmits a registration completion notification indicating that the registration in the server 200 has been completed to the terminal 10. The registration completion notification includes registration completion screen data representing a registration completion screen SC6.

[0040] When the terminal 10 receives a registration completion notification from the printer 100 in T80, in T82, the terminal 10 displays a registration completion screen SC6 on the display unit 14. The registration completion screen SC6 includes a message indicating that registration to the server 200 has been completed. By looking at the registration completion screen SC6, the administrator can know that registration to the server 200 has been completed.

[0041] (PW change sequence; Figure 4) Next, the process of changing the PW of the printer 100 will be described with reference to Fig. 4. The process of Fig. 4 is executed after the process of Fig. 3 is completed. In addition, in the initial state of Fig. 4, the printer PW "PP1" is set in the printer 100. The process of Fig. 4 is executed, for example, when the administrator forgets the printer PW "PP1" that is set in the printer 100.

[0042] When the printer 100 accepts a PW change operation from the administrator in T110, the printer 100 transmits a PW change instruction to the server 200 in T112. The PW change instruction includes the serial number SN1 of the printer 100 itself. Also, when the printer 100 accepts a PW change operation from the administrator in T110, the printer 100 displays a PIN code entry screen SC5 (see FIG. 3) on the display unit 114 in T113.

[0043] When the server 200 receives a PW change instruction from the printer 100 in T112, the server 200 generates a PIN code "2345" in T114 and stores in the memory 234 in association with the serial number SN1 included in the PW change instruction and the generated PIN code "2345".

[0044] Then, in T116, the server 200 identifies the user ID "U1." Specifically, the server 200 identifies the email address "U1," which is the user ID associated with the serial number SN1 included in the PW change instruction, in the device table 244. Note that if there is no user ID associated with the serial number SN1 in the device table 244, the server 200 does not execute the processes from T120 onward.

[0045] In T120, the server 200 sends an email EM1 including the PIN code "2345" generated in T114 to the email address "U1" that is the identified user ID as the destination.

[0046] The administrator has stored in advance in the terminal 10 an email setting for receiving the email EM1 sent to the email address "U1" as the destination. Therefore, the terminal 10 receives the email EM1 from the server 200 in T120. In this case, the terminal 10 displays the email EM1 in T122 using a mailer program (not shown). The body of the email EM1 contains a message indicating that a PIN code should be entered into the printer (printer 100 in this case) whose PW is to be changed, and the PIN code "2345". By looking at the email EM1, the administrator can know that the PIN code "2345" described in the email EM1 should be entered into the printer 100.

[0047] In T130, the printer 100 accepts input of the PIN code "2345" on the PIN code input screen SC5 (see T113) and selection of the OK button from the administrator who has viewed the email EM1. In this case, the printer 100 transmits the input PIN code "2345" and the serial number SN1 of the printer 100 to the server 200 in T132. In this manner, the PIN code "2345" is directly input to the printer 100 by the administrator. It is highly likely that a person who can directly input the PIN code "2345" to the printer 100 is a legitimate user of the printer 100. For this reason, the PW of the printer 100 can be changed to a more secure one.

[0048] When the server 200 receives the PIN code "2345" and the serial number SN1 from the printer 100 in T132, the server 200 executes authentication in T134. Specifically, the server 200 judges whether or not the combination of the received PIN code "2345" and the serial number SN1 is stored in the memory 234. In this case, since the combination is stored in the memory 234 (see T114), the server 200 judges that the authentication has been successful. In this case, the server 200 transmits a change permission notice to the printer 100 in T136. The change permission notice is a notice that permits the printer 100 to change the PW. Note that, if the server 200 determines in T134 that the above combination is not stored in the memory 234, that is, if the authentication has failed, the server 200 does not execute the processes from T136 onward.

[0049] When the printer 100 receives a change permission notification from the server 200 in T136, in T140, the printer 100 displays a new PW input screen SC7 on the display unit 114. The new PW input screen SC7 includes a message prompting the user to input a new printer PW, a printer PW input field, and an OK button.

[0050] When the printer 100 receives, in T142, input of a new PW "PP2" into the printer PW input field from the administrator and selection of the OK button, the printer 100 changes the printer PW from "PP1" to "PP2" in T144. In this way, the administrator can change the printer PW from "PP1" to "PP2" by inputting the new PW "PP2" into the new PW input screen SC7 displayed on the printer 100. Then, in T146, the printer 100 displays a completion screen SC8 on the display unit 114. The completion screen SC8 includes a message indicating that the change of the printer PW has been completed. The administrator can know that the change of the printer PW has been completed by looking at the completion screen SC8.

[0051] (Effects of the first embodiment) In this way, when the printer 100 accepts a PW change operation from the administrator (T110), it transmits a PW change instruction to the server 200 (T112). When the server 200 receives the change instruction from the printer 100, it transmits an email EM1 including the PIN code "2345" to the terminal 10 (T120). After that, when the PIN code "2345" is entered into the printer 100 by the administrator (T130), the printer 100 transmits the PIN code "2345" to the server 200 (T132). When the server 200 receives the PIN code "2345" from the printer 100, it transmits a change permission notice to the printer 100 (T134). As a result, the printer 100 receives the change permission notice from the server 200, and changes the printer PW in response to the input of the new PW "PP2" in the printer 100 (T144). In this way, the PW of the printer 100 can be changed only when the PIN code "2345" transmitted from the server 200 to the terminal 10 is transmitted from the printer 100 to the server 200 and a printer change permission notification is received by the printer 100. Therefore, the PW of the printer 100 can be changed securely.

[0052] Here, a first comparative example is assumed in which the PW of the printer 100 is changed without using the terminal 10 and the server 200. In this comparative example, if a PW change operation (see T110 in FIG. 4) is performed on the printer 100, the PW of the printer 100 can be changed. That is, anyone who has physical access to the printer 100 can change the PW of the printer 100. In contrast, in this embodiment, in order to change the PW of the printer 100, the PIN code "2345" must be entered into the printer 100. Then, the PIN code "2345" is sent to the server 200 with the email address of a registered user (i.e., a user who is highly likely to be a regular user of the printer 100) as the destination. For this reason, in this embodiment, it is highly likely that only a user registered in the server 200 can change the printer PW. Therefore, the PW of the printer 100 can be changed more securely.

[0053] In addition, in this embodiment, when changing the PW of the printer 100 to the new PW "PP2", the administrator does not need to input the old PW "PP1" into the printer 100. Therefore, even in a situation where the administrator has forgotten the old PW "PP1", the administrator can change the PW of the printer 100.

[0054] Here, a second comparative example is assumed in which, in a situation where the administrator has forgotten the PW before the change, the administrator changes the PW by using a question (so-called "secret question") whose answer is preset by the administrator. In the second comparative example, the administrator inputs an answer to the secret question, and if the answer is successfully authenticated, the administrator is permitted to change the PW. On the other hand, in this embodiment, if the administrator obtains the PIN code "2345" by viewing the email EM1 sent to his / her own terminal, the administrator can change the printer PW even if the administrator has forgotten the printer PW before the change. In general, the secret question is a question related to personal information. Therefore, the answer to the secret question can be guessed from, for example, the administrator's SNS (short for Social Networking Service) or the like. On the other hand, the PIN code "2345" is information contained in the email EM1 sent to the administrator's email address registered in the server 200 as the destination, and is therefore information that can only be obtained by the administrator. Therefore, compared to the answer to the secret question, the PIN code "2345" contained in the email EM1 is less likely to be known by a third party. Therefore, in this embodiment, in a situation where the administrator has forgotten the previous printer PW, the printer PW can be changed more securely compared to the second comparative example.

[0055] Also, a third comparative example is assumed in which the server 200 stores only the PIN code "2345" without associating the serial number SN1 with the PIN code "2345". In this comparative example, when the PIN code "2345" is input to a printer other than the printer 100 for which the administrator wants to change the PW, the PIN code "2345" is sent to the server 200 from the printer. In this case, since the PIN code "2345" is stored, the server 200 determines that the authentication is successful and sends a change permission notice to the printer. Therefore, in the third comparative example, the PW of a printer other than the printer 100 for which the administrator wants to change the PW can be changed. On the other hand, in this embodiment, the serial number SN1 of the printer 100 and the PIN code "2345" are stored in association with each other (T114 in FIG. 4). Then, the server 200 determines whether the combination of the serial number SN1 and the PIN code "2345" is stored (T134). Therefore, when the PIN code "2345" is entered into a printer other than the printer 100 for which the administrator wishes to change the PW, the serial number of the printer and the PIN code "2345" are sent from the printer to the server 200. In this case, the server 200 determines that the authentication has failed because the combination of the serial number and the PIN code "2345" of the printer is not stored, and does not send a change permission notice to the printer. Therefore, in this embodiment, only the printer PW of the printer 100 for which the administrator wishes to change the PW can be changed. In a modified example, the server 200 does not need to store the serial number SN1 and the PIN code "2345" in association with each other.

[0056] (Correspondence) The terminal 10, the printer 100, and the server 200 are examples of a "terminal device," a "communication device (and second external device)," and a "server," respectively. The display unit 14 of the terminal 10 is an example of a "display unit." The PIN code "2345" and the PIN code "1234" are examples of "first authentication information" and "specific information," respectively. The combination of the user ID "U1" and the server PW "SP1," and the user ID "U1" are "target user information" and "email address," respectively. The serial number SN1 is an example of "identification information." The PW change operation of T110 in FIG. 4 is an example of a "predetermined instruction." The email EM1 is an example of a "first email." The printer PW "PP1" and the printer PW "PP2" are examples of an "old password" and a "new password," respectively.

[0057] The process of T66 in Fig. 3 is an example of a process executed by a "registration request transmitting unit" of the "communication device." The process of T110, the process of T112, the process of T130, the process of T136, the process of T140, and the process of T144 in Fig. 4 are examples of a process executed by a "first receiving unit," a "change instruction transmitting unit," a "second receiving unit," a "notification receiving unit," a "display control unit," and a "change unit," respectively, of the "communication device."

[0058] The processes of T66 and T72 in Fig. 3 are examples of processes executed by the "registration request receiving unit" and the "second storage control unit" of the "server", respectively. The processes of T112, T120, T132, and T136 in Fig. 4 are examples of processes executed by the "change instruction receiving unit", "first authentication information transmitting unit", "authentication information receiving unit", and "notification transmitting unit" of the "server", respectively.

[0059] (Second embodiment; Figure 5) Next, a second embodiment will be described with reference to Fig. 5. The second embodiment differs from the first embodiment in that a Security Token is further used. The initial state of Fig. 5 is the same as the initial state of Fig. 4. The processes of T210 to T213 of Fig. 5 are the same as the processes of T110 to T113 of Fig. 4.

[0060] In T214, the server 200 generates a PIN code "2345" and a security token "ST". Hereinafter, the security token "ST" may be simply referred to as "ST". After generating the PIN code "2345" and "ST", the server 200 associates the serial number SN1 included in the PW change instruction (see T132 in FIG. 4), the generated PIN code "2345", and the generated "ST" and stores them in the memory 234. The processing from T216 to T222 is the same as the processing from T116 to T122 in FIG. 4.

[0061] Furthermore, in T224, the server 200 transmits the generated "ST" to the printer 100 by using the constant connection (not shown) already established between the printer 100 and the server 200. As a result, although not shown, the printer 100 stores the "ST" received from the server 200 in the volatile memory 134A. In a modified example, the printer 100 may store the "ST" in the non-volatile memory 134B.

[0062] The process of T230 is the same as the process of T130 in Fig. 4. In T232, the printer 100 transmits to the server 200 the input PIN code "2345", "ST" stored in the volatile memory 134A, and the serial number SN1 of the printer 100.

[0063] When the server 200 receives the PIN code "2345", "ST", and the serial number SN1 from the printer 100 in T232, the server 200 executes authentication in T234. Specifically, the server 200 judges whether or not the combination of the received PIN code "2345", the received "ST", and the received serial number SN1 is stored in the memory 234. In this case, since the combination is stored in the memory 234 (see T214), the server 200 judges that the authentication has been successful. In this case, the server 200 transmits a change permission notification to the printer 100 in T236. Note that, if the above combination is not stored in the memory 234 in T234, that is, if the authentication has failed, the server 200 does not execute the process from T236 onwards. The processes in T240 to T246 are the same as the processes in T140 to T146 in FIG. 4.

[0064] (Effects of the second embodiment) In the second embodiment, as in the first embodiment, the PW of the printer 100 can be securely changed. In particular, "ST" is information generated by the server 200 when the server 200 receives a PW change instruction from the printer 100 (T212 in FIG. 5). Then, "ST" is sent to the printer 100 (T224), but is not displayed on the printer 100. In other words, "ST" is information that is not obtained by the user. On the other hand, the serial number SN1 is information that is displayed, for example, on the casing or instruction manual of the printer 100, and is information that can be obtained by the user.

[0065] Here, assume a situation in which a third party obtains the serial number SN1 and PIN code "2345" of the printer 100 for which the administrator wants to change the PW, and the third party inputs the serial number SN1 and the PIN code "2345" to a printer different from the printer 100. In this case, the different printer transmits the PIN code "2345" and the serial number SN1 to the server 200. In such a situation, in the configuration of the first embodiment, the server 200 stores the combination of the PIN code "2345" and the serial number SN1 received from the different printer, so it determines that the authentication has been successful and transmits a change permission notice to the different printer. As a result, there is a risk that the PW of the different printer will be changed by the third party. On the other hand, in the configuration of the second embodiment, the different printer does not store "ST". Also, as described above, the third party cannot obtain "ST". Therefore, the server 200 does not receive "ST" from the different printer, so it determines that the authentication has failed. For this reason, the server 200 does not transmit the change permission notice to the different printer. Therefore, the PW of the different printer cannot be changed by a third party. In this way, in the second embodiment, even if the PIN code “2345” and the serial number SN1 are obtained by a third party, the PW of the different printer is prevented from being changed by a third party.

[0066] (Correspondence) The security token "ST" is an example of "second authentication information." The processing of T224 in FIG. 5 is an example of processing executed by an "authentication information receiving unit" of a "communication device." Moreover, the processing of T214 and the processing of T224 in FIG. 5 are examples of processing executed by a "first memory control unit" and a "second authentication information transmitting unit" of a "server," respectively.

[0067] (Third embodiment: Figure 6) Next, a third embodiment will be described with reference to Fig. 6. The third embodiment differs from the first embodiment in that an email including a URL (short for Uniform Resource Locator) indicating the location in server 200 of a login screen for logging in to server 200 is sent. The initial state in Fig. 6 is similar to the initial state in Fig. 4. The processes from T310 to T316 in Fig. 5 are similar to the processes from T110 to T116 in Fig. 4.

[0068] In T320, the server 200 sends an email EM2 including a URL to the email address “U1” that is the user ID identified in T316. The URL indicates the location in the server 200 of login screen data representing the login screen SC3 (see T36 in FIG. 2).

[0069] When the terminal 10 receives the email EM2 from the server 200 in T320, it uses a mailer program to display the email EM2 in T322. The body of the email EM2 contains a message urging the user to log in to the server 200 using the URL, and the above-mentioned URL. By looking at the email EM2, the administrator can know that he or she should log in to the server 200, and can obtain the PIN code "2345" by logging in to the server 200. In particular, since the URL is described in the email EM2, the administrator does not need to input the URL to access the server 200.

[0070] When the terminal 10 accepts an operation to select a URL in the email EM2 from the administrator in T330, the terminal 10 transmits an access request to the server 200 in T332. The processes of T332 to T336 are similar to the processes of T32 to T36 in Fig. 2. Moreover, the processes of T340 to T350 are similar to the processes of T40 to T50 in Fig. 3.

[0071] The server 200 identifies the PIN code "2345" in T352. Specifically, first, the server 200 identifies, in the device table 244, the serial number SN1 associated with the user ID "U1" that was successfully authenticated in T350. Next, the server 200 identifies the PIN code "2345" (see T314) associated with the identified serial number SN1. After identifying the PIN code "2345", the server 200 transmits PIN code screen data representing a PIN code screen SC9 to the terminal 10 in T354.

[0072] When the terminal 10 receives the PIN code screen data from the server 200 in T354, it causes the display unit 14 to display a PIN code screen SC9 in T356. The PIN code screen SC9 includes a message indicating that a PIN code should be entered into the printer (printer 100 in this case) whose PW is to be changed, and the PIN code "2345". Therefore, the administrator can know that the PIN code "2345" displayed on the PIN code screen SC9 should be entered into the printer 100. The subsequent processing is the same as the processing from T130 to T146 in FIG. 4.

[0073] (Effects of the third embodiment) In the third embodiment, as in the first embodiment, the PW of the printer 100 can be changed securely. In particular, in the third embodiment, when changing the PW of the printer 100, two-step authentication is performed using login to the server 200 (T340 to T350) and authentication of the PIN code "2345" (T134 in FIG. 4, which is referred to in FIG. 6). Therefore, the PW of the printer 100 can be changed more securely.

[0074] (Correspondence) The email EM2, the URL, and the login screen SC3 are examples of a “second email”, “location information”, and “login screen”, respectively. The process of T320 in Fig. 6 is an example of a process executed by the “email sending unit” of the “server”.

[0075] (Fourth embodiment: Fig. 7) Next, a fourth embodiment will be described with reference to Fig. 7. The fourth embodiment differs from the first embodiment in that the printer 100 displays a notification screen that prompts the user to log in to the server 200. The initial state of Fig. 7 is the same as the initial state of Fig. 4. The processes of T410 and T412 in Fig. 7 are the same as the processes of T110 and T112 in Fig. 4.

[0076] In T413, the printer 100 displays a notification screen SC10 on the display unit 114. The notification screen SC10 includes a message urging the user to log in to the server 200, a URL indicating the location in the server 200 of login screen data representing the login screen SC3 (see T36 in FIG. 2), a PIN code input field, and an OK button. By looking at the notification screen SC10, the administrator can know that he or she should log in to the server 200, and can obtain the PIN code "2345" by logging in to the server 200. The processing in T414 is similar to the processing in T114 in FIG. 4.

[0077] When the terminal 10 accepts, in T420, an operation of inputting the URL in the notification screen SC10 by the administrator who has viewed the notification screen SC10, in T432, it transmits an access request to the server 200. The processes from T432 to T456 are similar to the processes from T332 to T356 in Fig. 5. After that, the same processes as from T130 to T146 in Fig. 4 are executed.

[0078] (Effects of the Fourth Embodiment) In the fourth embodiment, as in the first embodiment, the PW of the printer 100 can be securely changed. The display unit 114 of the printer 100 is an example of an "output unit". The notification screen SC10 is an example of "notification information". The process of T413 in FIG. 7 is an example of a process executed by the "output control unit" of the "communication device".

[0079] (Fifth embodiment: Figs. 8 and 9) Next, a fifth embodiment will be described with reference to Figures 8 and 9. The fifth embodiment differs from the first embodiment in that the PW of the printer 100 is changed via the web server of the printer 100. The initial state of Figure 8 is the same as the initial state of Figure 4. The processes of T510 and T512 in Figure 8 are the same as the processes of T110 and T112 in Figure 4. Furthermore, the processes of T514 and T516 are the same as the processes of T114 and T116 in Figure 4.

[0080] In T520, the server 200 sends an email EM3 including the serial number SN1 of the printer 100 and the generated PIN code "2345" to the email address "U1" that is the user ID identified in T516.

[0081] When the terminal 10 receives the email EM3 from the server 200 in T520, it uses a mailer program to display the email EM3 in T522. The text of the email EM3 contains the serial number SN1 of the printer 100, a message urging the user to access the web server of the printer 100 identified by the serial number SN1 and enter the PIN code, and the PIN code "2345". The processes from T530 to T536 are the same as those from T20 to T26 in FIG. 2.

[0082] (Continuation of Figure 8; Figure 9) The terminal 10 accepts selection of the "change password" button in the top screen SC2 (see FIG. 2) in T540 of Fig. 9. In this case, the terminal 10 transmits selection information indicating that the "change password" button has been selected to the printer 100 in T542.

[0083] When the printer 100 receives the selection information from the terminal 10 in T542, it transmits PIN code entry screen data representing the PIN code entry screen SC11 to the terminal 10 in T544.

[0084] When the terminal 10 receives the PIN code entry screen data from the printer 100 in T544, in T546, it displays a PIN code entry screen SC11 on the display unit 14. The PIN code entry screen SC11 includes a message prompting the user to enter a PIN code, a PIN code entry field, and an OK button.

[0085] In T550, the terminal 10 accepts the input of the PIN code “2345” into the PIN code input field in the PIN code input screen SC11 and the selection of the OK button. In this case, the terminal 10 transmits the input PIN code “2345” to the printer 100 in T552.

[0086] When the printer 100 receives the PIN code "2345" from the terminal 10 at T552, the printer 100 transmits the PIN code "2345" and the serial number SN1 of the printer 100 to the server 200 at T554.

[0087] When the server 200 receives the PIN code "2345" and the serial number SN1 from the printer 100 in T554, the server 200 executes authentication in T556. The specific processing of T556 is similar to the processing of T134 in Fig. 4. Moreover, the processing of T558 is similar to the processing of T136 in Fig. 4.

[0088] When the printer 100 receives the change permission notification from the server 200 in T558, it transmits new PW input screen data representing the new PW input screen SC12 to the terminal 10 in T560.

[0089] When the terminal 10 receives the new PW input screen data from the printer 100 in T560, in T562, it displays the new PW input screen SC12 on the display unit 14. The new PW input screen SC12 includes a message prompting the user to input a new printer PW, a printer PW input field, and an OK button.

[0090] When the terminal 10 accepts, in T564, the input of the new PW "PP2" in the printer PW input field and the selection of the OK button, in T566, it transmits a PW change request to the printer 100. The PW change request includes the new PW "PP2" that has already been input.

[0091] When the printer 100 receives a PW change request from the terminal 10 in T566, it changes the printer PW from "PP1" to "PP2" in T568. Then, the printer 100 transmits a PW change completion notification including completion screen data representing the completion screen SC13 to the terminal 10 in T570.

[0092] When the terminal 10 receives a PW change completion notification from the printer 100 in T570, the terminal 10 displays a completion screen SC13 on the display unit 14 in T572. The completion screen SC13 includes a message indicating that the change of the printer PW has been completed. The administrator can know that the change of the printer PW has been completed by looking at the completion screen SC13.

[0093] (Effects of the Fifth Example) In the fifth embodiment, as in the first embodiment, the PW of the printer 100 can be securely changed. In particular, in this embodiment, the administrator does not directly input the PIN code "2345" to the printer 100, so there is no need to go near the printer 100 to input the PIN code "2345" to the printer 100. This improves the convenience of the administrator.

[0094] (Correspondence) The terminal 10 is an example of a "first external device." The display unit 14 of the terminal 10 is an example of a "display unit." The process of T560 in FIG. 9 is an example of a process executed by a "display control unit" of a "communication device."

[0095] Although specific examples of the technology disclosed in this specification have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. Modifications of the above embodiments are listed below.

[0096] (Variation 1) In T112 of FIG. 4, the printer 100 may transmit a PW change instruction including a new PW "PP2" in addition to the serial number SN1 to the server 200. In this case, the server 200 may store the serial number SN1, the PIN code "2345", and the new PW "PP2" in association with each other in T114. Then, the server 200 may transmit a change permission notification including the new PW "PP2" associated with the PIN code "2345" to the printer 100 in T136. In this case, the printer 100 can omit the processes of T140 and T142. In this variation, the "display control unit" of the "communication device" can be omitted.

[0097] (Modification 2) The terminal 10 may input the PIN code "2345" to the printer 100 via an NFC (abbreviation of Near Field Communication) connection. Specifically, instead of the process of T130 in FIG. 4, the administrator may bring the terminal 10 that has received the PIN code "2345" close to the printer 100. In this case, an NFC connection may be established between the terminal 10 and the printer 100, and the PIN code "2345" may be input to the printer 100 using the NFC connection. In another modification, the terminal 10 may input the PIN code "2345" to the printer 100 via a BT (abbreviation of Bluetooth (registered trademark)) connection. In another modification, the terminal 10 may input the PIN code "2345" to the printer 100 via a WFD (abbreviation of Wi-Fi Direct (registered trademark)) connection. Generally speaking, the method of inputting the "first authentication information" to the "communication device" is not particularly limited.

[0098] (Variation 3) When the "Register to Server" button is selected at T30 in FIG. 2, the terminal 10 may display a PIN code entry screen on the display unit 14. Then, when the terminal 10 receives input of the PIN code "1234" into the PIN code entry screen and input of the serial number SN1 of the printer 100 to be registered in the server 200, the terminal 10 may transmit a registration request including this information to the server 200. In this variation, the terminal 10 is an example of a "second external device." Also, in this variation, the "registration request transmission unit" of the "communication device" can be omitted.

[0099] (Variation 4) The processes of T32 to T36 in Fig. 2 and T40 to T56 in Fig. 3 can be omitted. In this case, printer 100 may display a screen for inputting a user ID and server PW when accepting a server registration operation (T60 in Fig. 3). In this case, printer 100 may transmit a registration request including the input user ID and server PW, and serial number SN1, to server 200. In this variation, the user ID and server PW are an example of "specific information".

[0100] (Variation 5) At T413 in FIG. 7, instead of displaying notification screen SC10 on display unit 114, printer 100 may cause print execution unit 116 to print a print medium including a URL. In this case, printer 100 may cause display unit 114 to display a screen including a PIN code input field after printing the print medium including the URL. In this variation, print execution unit 116 is an example of an "output unit." Also, causing print execution unit 116 to print a print medium including a URL is an example of a process executed by an "output control unit" of a "communication device."

[0101] (Variation 6) The administrator may execute each process in Figures 8 and 9 using a terminal different from the terminal 10. In this variation, the different terminal is an example of a "first external device."

[0102] (Variation 7) In the above embodiments, the processes in FIGS. 2 to 9 are implemented by software (for example, the OS program 40, the programs 140 and 240), but at least one of these processes may be implemented by hardware such as a logic circuit.

[0103] The technical elements described in this specification or drawings have technical utility either alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technologies illustrated in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of these objectives is itself technically useful. [Explanation of symbols]

[0104] 2: communication system, 4: LAN, 6: Internet, 10: terminal, 12, 112: operation unit, 14, 114: display unit, 20, 120, 220: communication I / F, 30, 130, 230: control unit, 32, 132, 232: CPU, 34, 234: memory, 40: OS program, 100: printer, 116: print execution unit, 134A: volatile memory, 134B: non-volatile memory, 200: intermediary server, 242: account table, 244: device table

Claims

1. A communication device, comprising: a first receiving unit that receives a predetermined instruction for changing a password of the communication device from a user; a change instruction transmission unit that transmits a change instruction to a server, the change instruction including identification information for identifying the communication device, when the specified instruction is accepted, the server stores the identification information in association with target user information corresponding to a user of a terminal device different from the communication device, the change instruction being a signal for instructing the server to transmit first authentication information to the terminal device by using the target user information stored in association with the identification information included in the change instruction; a second reception unit that receives an input of the first authentication information from the user after the first authentication information is transmitted from the server to the terminal device; an authentication information transmission unit that transmits the first authentication information to the server when the input of the first authentication information is accepted; a notification receiving unit that receives a change permission notification from the server when the first authentication information is transmitted to the server; a change unit that changes the password of the communication device when the change permission notification is received from the server; A communication device comprising:

2. The communication device further comprises: a display control unit that displays, on a display unit, an input screen for inputting a new password when the change permission notice is received from the server; The communication device according to claim 1 , wherein the change unit changes the password of the communication device from an old password to the new password when the new password is input on the input screen.

3. The communication device further comprises: an authentication information receiving unit that receives second authentication information from the server when the change instruction is transmitted to the server; the authentication information transmission unit transmits the first authentication information and the second authentication information to the server when input of the first authentication information is accepted; The communication device according to claim 1 , wherein the notification receiving unit receives the change permission notification from the server when the first authentication information and the second authentication information are transmitted to the server.

4. the target user information includes an email address of the user of the terminal device, A communication device as described in any one of claims 1 to 3, wherein the change instruction is a signal for instructing the server to send a first email including the first authentication information to the email address included in the target user information stored in association with the identification information included in the change instruction as a destination.

5. the target user information includes an email address of the user of the terminal device, the change instruction is a signal for instructing the server to transmit a second e-mail including location information to the e-mail address included in the target user information stored in association with the identification information included in the change instruction, the location information is information representing a location of login screen data representing a login screen for logging in to the server, The communication device according to claim 1 , wherein the first authentication information is transmitted to the terminal device when the terminal device logs in to the server after the login screen is displayed on the terminal device.

6. The communication device further comprises: An output unit; an output control unit that, when the predetermined instruction is accepted, causes the output unit to output notification information that prompts a user to log in to the server; The communication device according to claim 1 , wherein the first authentication information is transmitted to the terminal device when the terminal device logs in to the server after the notification information is output.

7. The communication device further includes an operation unit, The communication device according to claim 1 , wherein the second accepting unit accepts input of the first authentication information by the user operating the operation unit.

8. the communication device has a web server function, 7. The communication device according to claim 1, wherein the second reception unit receives input of the first authentication information via the web server function of the communication device when a first external device different from the communication device is used by the user.

9. The communication device further comprises:

9. The communication device according to claim 1 , further comprising: a registration request sending unit that sends a registration request to the server, the registration request including the identification information and specific information for identifying the target user information, the registration request being a signal requesting the server to associate and store the identification information and the target user information identified by the specific information.

10. A computer program for a communication device, comprising: The computer of the communication device is composed of the following parts: a first receiving unit that receives a predetermined instruction for changing a password of the communication device from a user; a change instruction transmission unit that transmits a change instruction to a server, the change instruction including identification information for identifying the communication device, when the specified instruction is accepted, the server stores the identification information in association with target user information corresponding to a user of a terminal device different from the communication device, the change instruction being a signal for instructing the server to transmit first authentication information to the terminal device by using the target user information stored in association with the identification information included in the change instruction; a second reception unit that receives an input of the first authentication information from the user after the first authentication information is transmitted from the server to the terminal device; an authentication information transmission unit that transmits the first authentication information to the server when the input of the first authentication information is accepted; a notification receiving unit that receives a change permission notification from the server when the first authentication information is transmitted to the server; a change unit that changes the password of the communication device when the change permission notification is received from the server; A computer program that functions as a

11. A computer program for a server, comprising: The server, a memory that stores, in association with each other, identification information for identifying a communication device and target user information corresponding to a user of a terminal device different from the communication device; A computer, The computer program causes the computer to operate in the following manner: a modification instruction receiving unit that receives a modification instruction including the identification information from the communication device; a first authentication information transmission unit that transmits first authentication information to the terminal device by using the target user information stored in association with the identification information included in the change instruction when the change instruction is received from the communication device, the first authentication information transmission unit being input to the communication device by the user of the terminal device after being transmitted to the terminal device; an authentication information receiving unit that receives the first authentication information from the communication device when the first authentication information is input to the communication device; a notification sending unit that sends a change permission notification to the communication device when the first authentication information is received from the communication device, the change permission notification being a notification that allows the communication device to change a password; A computer program that functions as a

12. The computer program further causes the computer to a first storage control unit that associates the first authentication information with second authentication information different from the first authentication information and stores the first authentication information in the memory; a second authentication information transmission unit that transmits the second authentication information to the communication device identified by the identification information when the change instruction including the identification information is received from the communication device; the authentication information receiving unit receives the first authentication information and the second authentication information from the communication device when the second authentication information is transmitted to the communication device and the first authentication information is input to the communication device; 12. The computer program product of claim 11, wherein the notification sending unit sends the change permission notification to the communication device when the first authentication information and the second authentication information are received from the communication device and the received first authentication information and the received second authentication information are associated and stored in the memory.

13. the target user information includes an email address of the user of the terminal device, The computer program according to claim 11 or 12, wherein the first authentication information sending unit, when receiving the change instruction including the identification information from the communication device, sends a first email including the first authentication information to the email address included in the target user information stored in association with the identification information included in the change instruction as a destination.

14. The computer program product according to claim 11 , wherein the first authentication information transmission unit transmits the first authentication information to the terminal device when logging in from the terminal device.

15. the target user information includes an email address of the user of the terminal device, The first authentication information transmission unit an email sending unit that, when the change instruction including the identification information is received from the communication device, sends a second email including location information to a destination address included in the target user information stored in association with the identification information included in the change instruction, the location information being information representing a location of login screen data representing a login screen for logging in to the server; 15. The computer program product according to claim 14, wherein the first authentication information transmission unit transmits the first authentication information to the terminal device when logging in from the terminal device after the login screen is displayed on the terminal device.

16. The computer program further causes the computer to a registration request receiving unit that receives a registration request including the identification information and specific information for identifying the target user information from a second external device; A computer program as described in any one of claims 11 to 15, which functions as a second storage control unit that, when the registration request is received from the second external device, associates the identification information with the target user information identified by the identification information and stores them in the memory.

17. A server, a memory that stores, in association with each other, identification information for identifying a communication device and target user information corresponding to a user of a terminal device different from the communication device; a modification instruction receiving unit that receives a modification instruction including the identification information from the communication device; a first authentication information transmission unit that transmits first authentication information to the terminal device by using the target user information stored in association with the identification information included in the change instruction when the change instruction is received from the communication device, the first authentication information transmission unit being input to the communication device by the user of the terminal device after being transmitted to the terminal device; an authentication information receiving unit that receives the first authentication information from the communication device when the first authentication information is input to the communication device; a notification sending unit that sends a change permission notification to the communication device when the first authentication information is received from the communication device, the change permission notification being a notification that allows the communication device to change a password; A server comprising:

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