COMMUNICATION DEVICE AND COMPUTER PROGRAM FOR THE COMMUNICATION DEVICE

Abstract

To provide a technique for properly changing a first password to a second password when the first password is used by multiple users.SOLUTION: A communication device, in a case where a change request is input by a specific user to change a first password to another password, under a situation where a memory stores the first password used by a plurality of users, transmits first information for receiving an instruction for changing the password to the other password in accordance with the change request, to each of a plurality of addresses indicated by multiple pieces of address information in the memory, and in a case where the first information is used in a first address out of the plurality of addresses and an instruction for changing the first password to the other password according to the change request is provided by a first user out of the plurality of users, after the first information has been transmitted to each of the plurality of addresses, stores a second password, which is the other password, in the memory instead of the first password.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] This specification discloses a technique for a communication device that allows a password to be changed. [Background technology]

[0002] Patent Document 1 discloses an MFP that stores, for each of a plurality of users, a personal identification number used by that user. When a specific user is selected from the plurality of users, the MFP regenerates the personal identification number stored in association with the specific user. [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] The above technology only assumes a situation where one PIN is used by one user. This specification provides a technology for appropriately changing a first password to a second password in a situation where a first password is used by multiple users. [Means for solving the problem]

[0005] The communication device disclosed in this specification includes an information sending unit that, when a change request to change the first password to another password is input by a specific user in a situation where a memory stores a first password used by a plurality of users in association with a plurality of pieces of destination information corresponding to the plurality of users, sends first information to each of a plurality of destinations indicated by the plurality of destination information in the memory to receive an instruction to change the password to the other password in accordance with the change request, and a storage control unit that, after the first information has been sent to each of the plurality of destinations, uses the first information at a first destination among the plurality of destinations to instruct a change to the other password in accordance with the change request by a first user among the plurality of users, stores a second password, which is the other password, in the memory instead of the first password.

[0006] According to this configuration, when a change request is input by a specific user in a situation where the memory stores a first password, the communication device transmits the first information to each of a plurality of destinations corresponding to a plurality of users who use the first password. As a result, a change to another password in accordance with the change request is instructed by a first user of the plurality of users who use the first password, and the second password is stored in the memory instead of the first password. In a situation where a plurality of users use the first password, a change from the first password to the second password can be appropriately executed.

[0007] A control method for implementing the above-mentioned communication device, a computer program, and a computer-readable recording medium storing the computer program are also novel and useful. [Brief description of the drawings]

[0008] [Figure 1] 1 shows the configuration of a communication system. [Diagram 2] The following is a sequence diagram of the process for resetting a password. [Diagram 3] 1 shows a flowchart of a reconfiguration process. [Figure 4] Case C1 where the password reset is successful is shown. [Diagram 5] Illustrated is a case C2 in which a reconfiguration request is received from a third party's terminal device. [Figure 6] A case C3 is shown in which a reconfiguration request is received from a third party's terminal device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (First Example) (Configuration of communication system 2; Figure 1) 1, the communication system 2 includes a printer 10, terminal devices 100 and 200, and a mail server 300. The printer 10 and the terminal devices 100 and 200 belong to the same LAN (abbreviation of Local Area Network) 4, and can communicate with each other via the LAN 4. The LAN 4 may be a wired LAN or a wireless LAN.

[0010] The LAN 4 is connected to the Internet 6. A mail server 300 is connected to the Internet 6. The mail server 300 is a server that sends and receives e-mails. A device on the LAN 4 (for example, the printer 10) can communicate with the mail server 300 via the Internet 6.

[0011] The terminal devices 100 and 200 are, for example, desktop PCs, smartphones, tablet PCs, notebook PCs, etc. The terminal device 100 is used by a first user and stores an email address MA1 used by the first user. The terminal device 200 is used by a second user and stores an email address MA2 used by the second user. In a modified example, the terminal devices 100 and 200 do not need to store the email addresses MA1 and MA2, and it is sufficient that the terminal devices 100 and 200 are capable of viewing emails addressed to the email addresses MA1 and MA2.

[0012] (Printer 10 Configuration) The printer 10 is a peripheral device (i.e., a peripheral device of the terminal devices 100 and 200) capable of executing a printing process. The printer 10 can also execute a web server function. The web server function is a function of transmitting web page data corresponding to a web page to a terminal device (e.g., the terminal device 100) in response to the terminal device accessing a web server in the printer 10. The web page is, for example, a page for managing the settings of the printer 10. Note that the printer 10 may be a multi-function device capable of executing a scanning process, a FAX process, and the like in addition to the printing process and the web server function. The printer 10 includes a LAN interface (hereinafter, the interface will be referred to as "I / F") 20 and a control unit 30. The LAN I / F 20 is an I / F for executing communication via the LAN 4, and is connected to the LAN 4.

[0013] The control unit 30 includes a CPU 32 and a memory 34. The CPU 32 executes various processes in accordance with a program 40 stored in the memory 34. The memory 34 is composed of a volatile memory, a non-volatile memory, etc. The memory 34 further stores an account table 42.

[0014] The account table 42 is a table that stores account information, multiple email addresses, and multiple temporary keys in association with each other. The account information is information for logging in to the web server function of the printer 10. The account information includes an account name AN ​​and a password PW1. The account information is used by multiple users. The web server function can be used by multiple users who know the account information. In a modified example, the account information may not include an account name, but may include only a password. In another modified example, the account information may include multiple account names.

[0015] The multiple email addresses in the account table 42 correspond to multiple users who use the account information. In this embodiment, the account table 42 stores an email address MA1 corresponding to a first user and an email address MA2 corresponding to a second user. Note that the email addresses MA1 and MA2 are merely examples, and the account table 42 may store, for example, three or more email addresses.

[0016] A temporary key is a key (i.e., a character string) that has a predetermined expiration date. The predetermined expiration date is, for example, one hour. Note that the temporary key "abc1" in the figure is merely an example. In general, a temporary key is a character string that is generated randomly and is difficult for a third party to guess (for example, a long character string of 10 characters or the like).

[0017] In the account table 42, one temporary key is stored in association with each of a plurality of email addresses. The temporary key is generated and stored in the account table 42 when a reset command (see T22 in FIG. 2) described later is received as a trigger, and the temporary key is deleted from the account table 42 when a predetermined expiration date has passed since the temporary key was stored in the account table 42. In a modified example, the printer 10 may store a list of temporary keys in advance. Then, when a reset command described later is received as a trigger, the printer 10 may select from the list the same number of temporary keys as the number of email addresses in the account table 42, and store the same number of temporary keys in the account table 42.

[0018] (Password reset process; Figure 2) The process of resetting a password in the account table 42 of the printer 10 will be described with reference to Fig. 2. Note that, in the following, unless otherwise specified, the process executed by the CPU 32 of the printer 10 may be described mainly in terms of the printer 10, rather than the CPU 32, from the viewpoint of ease of understanding. Also, in the following, the printer 10 and the terminal devices 100, 200 communicate via the LAN 4 and the LAN I / F 20. In the following, unless otherwise specified, the descriptions "via the LAN 4" and "via the LAN I / F 20" may be omitted.

[0019] When a specific request is input to the terminal device 100 by the first user (for example, when the IP address of the printer 10 is input), the terminal device 100 transmits a top screen command requesting top screen data to the printer 10 at T10. The top screen data is web page data corresponding to a top screen for logging in to the server function of the printer 10. For example, the top screen command is an HTTP (short for Hyper Text Transfer Protocol) command. The top screen includes an input field for account information and a reset button for receiving a request from the user to reset a password.

[0020] When the printer 10 receives the top screen command from the terminal device 100 in T10, the printer 10 transmits top screen data to the terminal device 100 in T14.

[0021] When the terminal device 100 receives the top screen data from the printer 10 in T14, it displays a top screen corresponding to the top screen data in T16. In this case, the first user of the terminal device 100 does not want to log in to the server function but wants to reset his / her password. For example, when the first user forgets his / her password, he / she selects the reset button.

[0022] The first user of the terminal device 100 selects a reset button in the top screen in T20. As a result, the terminal device 100 transmits a reset command to the printer 10 in T22, requesting transmission of an e-mail including a reset URL (short for Uniform Resource Locator) and a cancel URL. The reset URL is a URL including information (e.g., a path) indicating a storage destination of a program for a reset process (see T50) described later, and a temporary key described later. The cancel URL is a URL including information indicating a storage destination of a program for a process for canceling a change of a password in the account table 42 to another password, and a temporary key described later. In this embodiment, the reset button is included in the top screen displayed on the terminal device 100 before logging in to the server function. In a modified example, the reset button may be included in a screen displayed on the terminal device 100 after logging in to the server function.

[0023] When the printer 10 receives a reconfiguration command from the terminal device 100 in T22, the printer 10 determines in T24 whether a login session using account information has been established with an external device (e.g., the terminal device 200). If the printer 10 determines that a login session has been established with an external device (YES in T24), the printer 10 proceeds to T28.

[0024] At T28, the printer 10 transmits login notification screen data to the terminal device 100 that transmitted the reset command. The login notification screen data is web page data corresponding to a login notification screen that notifies the user that a login session is currently established. The first user of the terminal device 100 can see the login notification screen and know that a login session is currently established and that the user cannot reset the password.

[0025] Furthermore, if the printer 10 determines that a login session has not been established with an external device (NO in T24), the printer 10 changes the state of the account table 42 from a prohibited state to a permitted state in T26.

[0026] The prohibited state is a state in which execution of a process for resetting a password is prohibited. Specifically, the prohibited state is a state in which no temporary keys are stored in the account table 42. Note that, in a modified example, the prohibited state may be a state in which a predetermined flag is set to a value indicating "prohibited" when a temporary key is stored in the account table 42.

[0027] The permitted state is a state in which execution of a process for resetting a password is permitted. Specifically, the permitted state is a state in which a temporary key is stored in the account table 42. In this embodiment, two email addresses MA1 and MA2 are currently stored in the account table 42. The printer 10 generates two temporary keys "abc1" and "abc2" at T24. The printer 10 then stores the temporary key "abc1" in the account table 42 in association with the email address MA1, and stores the temporary key "abc2" in the account table 42 in association with the email address MA2 (see 42 in FIG. 1). This changes the state of the printer 10 from the prohibited state to the permitted state. In a modified example, the permitted state may be a state in which a temporary key is stored in the account table 42 and a predetermined flag is set to a value indicating "permitted". In another modified example, the printer 10 may randomly generate a reset URL and store the reset URL in the account table 42. In this modified example, the permitted state may be a state in which the reset URL is stored in the account table 42, and the prohibited state may be a state in which the reset URL is not stored in the account table 42.

[0028] In the following T30 and T34, the printer 10 transmits reset emails RM1 and RM2 to the mail server 300. The reset email RM1 is an email addressed to the email address MA1 in the account table 42, and includes a reset URL including a temporary key "abc1" stored in association with the email address MA1, and a cancel URL including the temporary key "abc1". On the other hand, the reset email RM2 is an email addressed to the email address MA2 in the account table 42, and includes a reset URL including a temporary key "abc2" stored in association with the email address MA2, and a cancel URL including the temporary key "abc2". In a modified example, the printer 10 may transmit an instruction to transmit the reset emails RM1 and RM2 to the intermediary server. In this way, the intermediary server may transmit the reset emails RM1 and RM2 to the mail server 300.

[0029] When the mail server 300 receives the reset email RM1 from the printer 10 in T30, it transmits the reset email RM1 to the terminal device 100 corresponding to the email address MA1. When the terminal device 100 receives the reset email RM1 from the mail server 300 in T30, it displays the received reset email RM1 in T32.

[0030] Furthermore, in T34, the mail server 300 transmits the reset mail RM2 to the terminal device 200 corresponding to the mail address MA2. In T36, the terminal device 200 displays the reset mail RM2.

[0031] In this case, the first user of the terminal device 100 selects a reset URL in the reset email RM1 in T40. As a result, the terminal device 100 transmits an execution command to the printer 10 in T42 to cause the printer 10 to execute a reset process (see T50) described below. The execution command includes the reset URL in the reset email RM1 selected in T40.

[0032] When the printer 10 receives an execution command from the terminal device 100 in T42, the printer 10 executes a reconfiguration process in T50. The reconfiguration process will be described in detail later with reference to FIG.

[0033] (Resetting process; Figure 3) The resetting process will be described with reference to Fig. 3. Note that the printer 10 sets a predetermined count to "0" when the temporary key is generated at T26 in Fig. 2.

[0034] In S20, the CPU 32 determines whether the state of the printer 10 permits resetting. If the CPU 32 determines that the state of the printer 10 prohibits resetting (NO in S20), the CPU 32 proceeds to S22. For example, if an execution command is received after the expiration date of the temporary key, the state of the printer 10 is determined to be the prohibition state due to the expiration date.

[0035] In S22, the CPU 32 transmits prohibition notification screen data to the terminal device (see T42 in FIG. 2, hereinafter referred to as the "communication target terminal") that is the transmission source of the execution command. The prohibition notification screen data is web page data corresponding to a prohibition notification screen that notifies that password resetting is prohibited. This allows the user of the communication target terminal device to know that password resetting is prohibited by looking at the prohibition notification screen. Note that, for example, in the above-mentioned modified example in which the prohibited state is a state in which the reset URL is not stored in the account table 42, the prohibition notification screen may be a screen (e.g., 404 Not Found) indicating that the web page indicated by the reset URL included in the execution command does not exist. When S22 ends, the processing of FIG. 3 ends.

[0036] Furthermore, if the CPU 32 determines that the printer 10 is in an permitted state (YES in S20), the process proceeds to S30. In S30, the CPU 32 determines whether or not the temporary key in the execution command matches any of the multiple temporary keys in the account table 42. If the CPU 32 determines that the temporary key in the execution command matches any of the multiple temporary keys in the account table 42 (YES in S30), the process proceeds to S32.

[0037] In S32, the CPU 32 transmits input screen data to the communication target terminal. The input screen data is web page data corresponding to an input screen for inputting a new password.

[0038] In the next S34, the CPU 32 monitors whether a new password has been received from the terminal with which communication is to be performed. If a new password has been received from the terminal with which communication is to be performed (YES in S34), the CPU 32 proceeds to S36.

[0039] In S36, the CPU 32 stores the new password received in S34 in the account table 42, in place of the password currently stored in the account table 42. That is, the CPU 32 resets (i.e., changes) the password in the account table 42 to the password received from the terminal with which communication is to be performed.

[0040] In the next S38, the CPU 32 sends two types of completion emails to the mail server 300, indicating that the password reset has been completed. The two types of completion emails are a first completion email and a second completion email. The first completion email includes, as a destination, an email address (hereinafter, referred to as the "target email address") that is stored in association with a temporary key included in the execution command received from the terminal to which communication is to be performed. Meanwhile, the second completion email includes, as a destination, an email address other than the target email address among the multiple email addresses in the account table 42. The second completion email includes a different message from the first completion email (see MS in FIG. 4). The CPU 32 sends the second completion email to the mail server 300 for all email addresses other than the target email address among the multiple email addresses in the account table 42.

[0041] In the next step S40, the CPU 32 changes the state of the printer 10 from the permitted state to the prohibited state. Specifically, the CPU 32 deletes all temporary keys in the account table 42. With this configuration, it is possible to prevent a password from being reset again due to another user (e.g., a second user) using a reset URL after the password has been reset by a user (e.g., a first user) of the terminal to be communicated with. When S40 ends, the processing of FIG. 3 ends.

[0042] Furthermore, if the CPU 32 determines that the temporary key in the execution command does not match any of the multiple temporary keys in the account table 42 (NO in S30), the CPU 32 proceeds to S50. In S50, the CPU 32 increments the count.

[0043] In S52, the CPU 32 determines whether the current count is equal to or greater than a predetermined number (for example, "3") If the CPU 32 determines that the current count is equal to or greater than the predetermined number (YES in S52), the CPU 32 proceeds to S54.

[0044] In S54, the CPU 32 transmits a warning mail including the mail address as a destination to the mail server 300 for each of all mail addresses in the account table 42. The warning mail includes a message to warn the user of the incorrect use of the temporary key. When S54 ends, the CPU 32 proceeds to S40.

[0045] Furthermore, if it is determined that the current count is smaller than the predetermined number (NO in S52), the process proceeds to S56. S56 is the same as S54. In the following S56, the CPU 32 transmits error screen data to the communication target terminal. The error screen data is web page data corresponding to an error screen notifying that the temporary key is incorrect. The user of the communication target terminal device can see the error screen and know that the temporary key is incorrect. When S56 ends, the process of FIG. 3 ends.

[0046] (Case C1; Figure 4) Case C1 in which the password reset is successful will be described with reference to Figure 4. Case C1 in Figure 4 is a continuation of Figure 2.

[0047] In T62, the printer 10 determines that the printer 10 is in a state in which reconfiguration is permitted (NO in S20 in FIG. 3). In T64, the printer 10 determines that the temporary key "abc1" in the execution command of T42 in FIG. 2 matches the temporary key "abc1" in the account table 42 (YES in S30). In T70, the printer 10 transmits input screen data to the terminal device 100 (i.e., the terminal to communicate with) (S32).

[0048] When the terminal device 100 receives input screen data from the printer 10 in T70, the terminal device 100 displays the input screen in T72. In this case, the first user of the terminal device 100 inputs a new password PW2 into the input screen in T74. In T76, the terminal device 100 transmits the password PW2 input in T74 to the printer 10.

[0049] When the printer 10 receives the password PW2 from the terminal device 100 in T74 (YES in S34 in FIG. 2), in T78 the printer 10 stores the password PW2 in the account table 42 in place of the password PW1 (S36).

[0050] In T80, the printer 10 sends a first completion email CM1 to the mail server 300, the destination of which is the email address MA1 stored in association with the temporary key "abc1" included in the execution command received from the terminal device 100 (S38 in FIG. 2). This causes the terminal device 100 to display the first completion email CM1 in T82. The first completion email CM1 includes a message MS1 indicating that the password reset has been completed by the first user of the terminal device 100 using the reset URL. This allows the first user to know that the password reset has been completed in response to the selection of the reset URL in T40 in FIG. 2.

[0051] Also, in T84, the printer 10 transmits a second completion email CM2 including an email address MA2 other than the email address MA1, which is the target email address, as a destination to the email server 300 (S38). As a result, the terminal device 200 displays the second completion email CM2 in T86. The second completion email CM2 includes a message MS2 indicating that the reset URL has been used by the first user corresponding to the email address MA1, which is the destination of the reset URL including the temporary key "abc1", to complete the password reset. This allows the second user to know that the password has been reset by a user other than the second user. Also, as shown in FIG. 4, the message MS2 includes the email address MA1 corresponding to the first user. This allows the second user to identify the user who reset the password.

[0052] In the next T90, the printer 10 changes the state of the printer 10 from the permitted state to the prohibited state (S40 in FIG. 3).

[0053] According to this case, when the reset button in the top screen is selected by the first user (T20 in FIG. 2), the printer 10 sends reset emails RM1, RM2 including a reset URL to multiple email addresses MA1, MA2 corresponding to multiple users who use the account information (T30, T34). As a result, the reset URL is selected by the first user of the multiple users who use the account information (T40), and the new password PW2 is stored in the account table 42 (T78 in FIG. 4). In a situation where multiple users use the account information, it is possible to appropriately change the password PW1 to the password PW2.

[0054] (Case C2; ​​Figure 5) With reference to FIG. 5, a case C2 in which a reconfiguration command is received from a third party's terminal device 900 will be described. For example, a malicious third party obtains the IP address of the printer 10, and operates the terminal device 900 to select the reconfiguration button in the top screen. In the initial state of this case, no one is logged in to the printer 10. T122 is similar to T22 in FIG. 2, except that the terminal device 900 is used. In T124, the printer 10 determines that a login session has not been established with an external device (NO in T24 in FIG. 2). T126 to T136 are similar to T26 to T36 in FIG. 2.

[0055] In this case, the third party guesses the temporary keys in the reset emails RM1 and RM2, and causes the terminal device 900 to transmit an execution command including the guessed temporary key multiple times. T142 is similar to T42 in FIG. 2, except that the terminal device 900 is used and the execution command includes the guessed temporary key "xyz1".

[0056] T162 is the same as T62 in Fig. 4. In T164, the printer 10 determines that the temporary key "xyz1" in the execution command of T142 does not match any of the temporary keys in the account table 42 (NO in S30 in Fig. 3). In T168, the printer 10 increments the count (S50). In this case, at the present time, the terminal device 900 has repeatedly sent the execution command "3" times. In T170, the printer 10 determines that the count is equal to or greater than the predetermined number "3" (YES in S52).

[0057] In T180 and T184, the printer 10 transmits a warning mail including, as a destination, each of all the mail addresses MA1 and MA2 in the account table 42 to the mail server 300 (S54). As a result, the terminal device 100 displays the warning mail AM1 in T182, and the terminal device 200 displays the warning mail AM2 in T186. With this configuration, the first and second users can know that a third party has illegally attempted to reset their passwords.

[0058] Also, in T190, the printer 10 changes the state of the printer 10 from the permitted state to the prohibited state (S40), which makes it possible to inhibit a third party from resetting the password.

[0059] For example, a comparative example is assumed in which the reset URL does not include a temporary key. In this comparative example, if a third party learns the path of the program for the reset process, the third party may reset the password. In contrast, according to this case, even if a third party learns the path of the program for the reset process, the third party does not learn the temporary key, and the third party can be prevented from resetting the password by the judgment of T164. Note that the configuration of the comparative example described above may be adopted in the modified example.

[0060] (Case C3; Figure 6) 6, a description will be given of another case C3 in which a resetting command is received from a third party's terminal device 900. T222 to T236 are the same as T122 to T136 in FIG.

[0061] In this case, the first user of the terminal device 100 selects the cancel URL in the reset email RM1 in T240. As a result, the terminal device 100 transmits a cancel command to the printer 10 in T242. The cancel command is a command for causing the printer 10 to execute the processes from T244 onwards, which will be described later. The cancel command includes the cancel URL in the reset email RM1. The cancel command includes the temporary key "abc1".

[0062] In T244, the printer 10 judges whether the temporary key in the cancel command matches any of the temporary keys in the account table 42. In this case, the printer 10 judges that the temporary key "abc1" in the cancel command matches the temporary key "abc1" in the account table 42. In this case, the printer 10 changes the state of the printer 10 from the permitted state to the prohibited state in accordance with the cancel URL in the cancel command in T246. Specifically, the printer 10 deletes all the temporary keys in the account table 42. If it is judged that the temporary key in the cancel command does not match any of the temporary keys in the account table 42, the printer 10 skips the processes after T246 and ends the process in FIG. 6.

[0063] In the following T248, the printer 10 transmits the cancel screen data to the terminal device 100. The cancel screen data is web page data corresponding to a cancel screen indicating that the permission state of the resetting has been canceled. In T250, the terminal device 100 displays the cancel screen.

[0064] In this case, the third party also causes the terminal device 900 to transmit an execution command including a temporary key guessed by the third party, similarly to Fig. 5. T342 is the same as T142 in Fig. 5.

[0065] In T362, the printer 10 determines that the printer 10 is in the prohibited state (NO in S20 in FIG. 3). In T364, the printer 10 transmits prohibition notification screen data to the terminal device 900 (S22). In T368, the terminal device 900 displays the prohibition notification screen.

[0066] According to this configuration, the first user can select the cancel URL to prevent a third party from resetting the password.

[0067] (Correspondence) The printer 10 and the memory 34 are examples of a "communication device" and a "memory", respectively. The email addresses MA1 and MA2 are examples of "multiple pieces of destination information". The reset URL and the cancel URL are examples of "first information" and "second information", respectively. The temporary key in the reset URL is an example of a "specific identification information". The temporary keys "abc1" and "abc2" are examples of "first identification information" and "second identification information", respectively. The terminal device 100 is an example of an "external device". The selection of the reset button T20 in FIG. 2 is an example of a "change request". The terminal devices 100 and 200 are examples of a "first destination" and a "second destination", respectively. The passwords PW1 and PW2 are examples of a "first password" and a "second password", respectively. The second completion email CM2 and the first completion email CM1 are examples of a "first completion notification" and a "second completion notification", respectively. The warning emails of S54 and S56 in Fig. 3 are an example of a "specific notification." The login notification screen data of T28 in Fig. 2 is an example of a "predetermined notification."

[0068] T30 and T34 in Fig. 2 are examples of the processing realized by the "information transmission unit." T78 in Fig. 4 is an example of the processing realized by the "storage control unit."

[0069] Although specific examples of the present invention have been described above in detail, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and alterations of the specific examples exemplified above. Modifications of the above-mentioned embodiments are listed below.

[0070] (Variation 1) The "communication device" is not limited to the printer 10, but may be a scanner, a fax machine, a multi-function device, a PC, or the like.

[0071] (Modification 2) The "memory" is not limited to the memory 34 of the printer 10, but may be, for example, another device separate from the printer 10 (for example, a server).

[0072] (Variation 3) The "destination information" is not limited to the email address MA1, and may be, for example, an ID for identifying the terminal device 100 (for example, an ID for identifying an application program installed in the terminal device 100).

[0073] (Variation 4) In the above embodiment, the reset URL includes information indicating the storage location of the program for the reset process in Fig. 3. Alternatively, the reset URL may include information indicating the storage location of a program that causes printer 10 to generate a new password. In this case, printer 10 may store a new password generated by printer 10 in account table 42, instead of the password currently stored in account table 42. In this variation, the reset URL that includes information indicating the storage location of a program that causes printer 10 to generate a new password is an example of "first information."

[0074] (Modification 5) The second completion email CM2 does not have to be sent in T84 of Fig. 4. In this modification, the "first completion notification" can be omitted.

[0075] (Variation 6) The transmission of the first completion email CM1 in T80 of Fig. 4 does not have to be executed. In this variation, the "second completion notification" can be omitted.

[0076] (Variation 7) The second completion email CM2 includes the same message MS1 as the first completion email CM1, but may not include the message MS2. In this variation, the "message" can be omitted.

[0077] (Variation 8) The "external device" is not limited to the terminal device 100 that received the reset email RM1, but may be another terminal device different from the terminal device 100. In this case, for example, the first user may manually input the reset URL into the other terminal device.

[0078] (Modification 9) The process of S30 in Fig. 3 does not have to be executed. In this modification, the "specific identification information" can be omitted.

[0079] (Modification 10) The process of S40 after NO in S30 in Fig. 3 does not have to be executed. That is, the process of Fig. 5 does not have to be executed. In this modification, the "first prohibition unit" can be omitted.

[0080] (Modification 11) The processes of S54 and S56 in Fig. 3 do not have to be executed. In this modification, the "second notification transmission unit" can be omitted.

[0081] (Modification 12) The reset email does not need to include a cancel URL, and the process in Fig. 6 does not need to be executed. In this modification, the "second information" and the "second prohibition section" can be omitted.

[0082] (Modification 13) The process of S40 following YES in S30 in Fig. 3 does not have to be executed. In this modification, the "third prohibition unit" can be omitted.

[0083] (Modification 14) The process of T26 in Fig. 2 may be executed after receiving the execution command of T42. That is, the timing of sending the "predetermined notification" is not limited to T28 in Fig. 2, and may be after T42.

[0084] (Modification 15) The process of T28 in Fig. 2 does not have to be executed. In this modification, the "predetermined notification" can be omitted.

[0085] (Variation 16) The “first information” is not limited to the reset URL, but may be, for example, a part of the reset URL (for example, only a temporary key), or information indicating an input screen according to an application program installed on the terminal device 100.

[0086] (Variation 17) In the above embodiments, the processes in FIGS. 2 to 6 are implemented by software (for example, program 40), but at least one of these processes may be implemented by hardware such as a logic circuit.

[0087] In addition, the technical elements described in this specification or drawings exert technical utility 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 exemplified in this specification or drawings achieve multiple objectives simultaneously, and achieving one of those objectives is itself technically useful. [Explanation of symbols]

[0088] 2: communication system, 6: Internet, 10: printer, 20: LAN I / F, 30: control unit, 32: CPU, 34: memory, 40: program, 42: account table, 100: terminal device, 200: terminal device, 300: mail server, 900: terminal device, AN: account name, PW1, PW2: password, MA1, MA2: email address, RM1, RM2: reset email, AM1, AM2: warning email, CM1: first completion email, CM2: second completion email, MS1, MS2: message

Claims

1. 1. A communication device, comprising: an information transmitting unit that, when a change request for changing the first password to another password is input by a specific user in a state in which a memory stores a first password used by a plurality of users in association with a plurality of pieces of destination information corresponding to the plurality of users, transmits first information to each of the plurality of destinations indicated by the plurality of pieces of destination information in the memory to receive an instruction to change the first password to the other password in accordance with the change request; a storage control unit that stores, in the memory, a second password, which is the other password, in place of the first password, when a first destination among the plurality of destinations uses the first information after the first information has been transmitted to each of the plurality of destinations and a first user among the plurality of users issues an instruction to change the password to the other password in accordance with the change request; A communication device comprising:

2. The communication device further comprises:

2. The communication device according to claim 1, further comprising a first notification sending unit that sends a first completion notification indicating that the change to the other password in accordance with the change request has been completed to a second destination among the plurality of destinations, the second destination being different from the first destination where the first information was used, after the second password is stored in the memory.

3. 3. The communication device of claim 2, wherein the first notification sending unit further sends a second completion notification to the first destination where the first information was used after the second password was stored in the memory, indicating that the change to the other password in accordance with the change request has been completed.

4. the information transmission unit transmits the first information including first identification information to the first destination, and transmits the first information including second identification information different from the first identification information to the second destination; The communication device further comprises: a receiving unit that receives the first identification information included in the first information from a device used by the first user when the first information is used at the first destination; 4. The communication device according to claim 2 or 3, wherein the first completion notification includes a message notifying a second user corresponding to the second destination that a change to the other password in accordance with the change request has been instructed by the first user corresponding to the first destination, which is the destination of the received first identification information.

5. The information transmission unit transmits the first information including specific identification information to the first destination, the storage control unit, when receiving identification information that matches the specific identification information from an external device after transmitting the first information to the first destination, stores the second password in the memory; 5. A communication device according to claim 1, wherein if, after transmitting the first information to the first destination, identification information is received from the external device that does not match the specific identification information, the second password is not stored in the memory.

6. The communication device further comprises:

6. The communication device according to claim 5, further comprising a first prohibition unit that prohibits changing the password to another password using the first information when the identification information received from the external device does not match the specific identification information.

7. The communication device further comprises: The communication device according to claim 5 or 6, further comprising a second notification sending unit that, when receiving identification information from the external device that does not match the specific identification information, sends a specific notification indicating that the identification information that does not match the specific identification information has been received from the external device to each of the multiple destinations indicated by the multiple destination information in the memory.

8. the information transmission unit further transmits, in addition to the first information, second information for receiving an instruction of disapproval of the change to the other password in accordance with the change request, to each of the plurality of destinations; The communication device further comprises:

8. The communication device according to claim 1, further comprising: a second prohibition unit that prohibits changing to the other password using the first information when, after the first information and the second information are sent to each of the multiple destinations, the second information is used at the first destination and the first user instructs not to allow the change to the other password in accordance with the change request.

9. The communication device further comprises:

9. The communication device according to claim 1, further comprising a third prohibition unit that prohibits changing the password to another password using the first information after the first information is used at the first destination and the second password is stored in the memory.

10. The communication device further comprises: A communication device as described in any one of claims 1 to 9, further comprising a third notification sending unit that sends a predetermined notification to a terminal device corresponding to the specific user when the change request is input by the specific user and a communication session using the first password is established between the communication device and a device other than the communication device.

11. 11. The communication device according to claim 1, wherein the first information includes a URL (short for Uniform Resource Locator) for causing the communication device to execute a process for changing the first password to the other password.

12. A computer program for a communication device, comprising: The computer program controls the computer of the communication device to each of the following units: an information transmitting unit that, when a change request for changing the first password to another password is input by a specific user in a state in which a memory stores a first password used by a plurality of users in association with a plurality of pieces of destination information corresponding to the plurality of users, transmits first information to each of the plurality of destinations indicated by the plurality of pieces of destination information in the memory to receive an instruction to change the first password to the other password in accordance with the change request; a storage control unit that stores, in the memory, a second password, which is the other password, in place of the first password, when a first destination among the plurality of destinations uses the first information after the first information has been transmitted to each of the plurality of destinations and a first user among the plurality of users issues an instruction to change the password to the other password in accordance with the change request; A computer program that functions as a

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