Abstract:
Provided is an electronic apparatus (EA) and a user authentication method thereof both can prevent information leakage and disadvantages caused by an unauthorized access to the EA. The EA is configured to store a combination of a recognizing-code and a key-code correlated therewith, the combination being in relationship with each of plural users, and to give a user an exclusive authority for executing a specific process if an inputted combination of a recognizing-code and a key-code=the stored combination of the recognizing-code and the key-code. In case of a request for accepting the specific process, if the inputted combination of the recognizing-code and the key-code is # the stored combination of the recognizing-code and the key-code, the EA notifies, without executing the specific process, initiating a receipt of instructing the specific process to user of the inputted combination.

Description:
INCORPORATION BY REFERENCE 
       [0001]    This application is based on and claims the benefit of priority from Japanese Patent Application No. 2014-234117 filed on Nov. 19, 2014, the entire contents of which are hereby incorporated by reference. 
       BACKGROUND 
       [0002]    The present disclosure relates a user authentication technology for the prevention of any unauthorized access to an electronic apparatus, the electronic apparatus being configured to be shared with plural users by, for example, network connections and concurrently to store secret or confidential information pieces. 
         [0003]    In a case where an electronic apparatus is operated in which information pieces are held that specific individuals or juridical persons stored and personal information pieces or in a case where a server that stores similar information pieces is brought into a remote read/write operation, it is requested to receive an authentication for a user who has a plan to access the electronic apparatus or the server in order for proving that the user has an authority to access the aforementioned information pieces. The most popular method for receiving an authentication is to input both a code that is indicative of a user ID (Identification) and a password (key encode) that makes a pair with the user ID. 
         [0004]    For example, in a case of an MFP that has facsimile and server functions as well as printer and scanner functions, an input/output image that is called a UI (User Interface) appears on a screen of an indicator provided on an operation panel or on a screen of an electronic information terminal connected via an external interface. 
         [0005]    Such an MFP is provided with a user authentication function (many MFPs have user authentication functions). When a user inputs, via the UI interface, the ID and the password, a verification is made whether or not the resulting paired ID and password are in coincidence with a pair of previously stored ID and password. If the result of the verification is true, the user is allowed to log in the MFP (the MFP is ready for operation). 
         [0006]    In more detail, the user inputs the user ID and the password via the UI, and then if the inputted pair of the user ID and the password are determined to be in coincidence with the pair of previously stored ID and password that are previously registered for a legitimate user, a specific operation is allowed to read out, for example, information pieces (such as an image data piece obtained by scanning a manuscript) which are correlated with the user ID. 
         [0007]    On the contrary, if the paired user ID and password is registered in the MFP, usually, the MFP causes the UI to display an error display. 
       SUMMARY 
       [0008]    A present disclosure provides an electronic apparatus that is configured to store a combination of a recognizing code and a key code that is correlated with the recognizing code, the combination being in relationship with each of plural users and allows a user exclusively to give an authority for executing a specific process if an inputted combination of a recognizing code and a key code is coincident with the stored combination of the recognizing code and the key code. In a case where a request for accepting the specific process, if the inputted combination of the recognizing code and the key code is not coincident with the stored combination of the recognizing code and the key code, the electronic apparatus according to the present disclosure notifies, without executing the specific process, a receipt of instructing the specific process to user who inputs the combination of the recognizing code and the key code for executing the specific process, which is a feature of the electronic apparatus according to the present disclosure. 
         [0009]    Also, a present disclosure provides a user authentication method for use in conjunction with an electronic apparatus, wherein storing a combination of a recognizing code and a key code that is correlated with the recognizing code, the combination being in relationship with each of plural users, and allowing a user exclusively to give an authority for executing a specific process if an inputted combination of a recognizing code and a key code is coincident with the stored combination of the recognizing code and the key code. In a case where a request for accepting the specific process, if the inputted combination of the recognizing code and the key code is not coincident with the stored combination of the recognizing code and the key code, the method of the present disclosure causes the electronic apparatus to notify, without executing the specific process, a receipt of instructing the specific process to user who inputs the combination of the recognizing code and the key code for executing the specific process, which is a feature of the method according to the present disclosure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a schematic view of an example of an overall configuration to which are applied an electronic apparatus and a user authentication method therefor according to the present disclosure; 
           [0011]      FIG. 2  is a block diagram for illustrating an example of a configuration (electronic configuration) of an MFP  11  and an example of a configuration (electronic configuration) of an electronic information terminal  21  both of which are provided in an exemplary embodiment of the present disclosure; 
           [0012]      FIG. 3  is a memory configuration diagram that is illustrative of a content (memory map) of a memory part  120  in the exemplary embodiment of the present disclosure; 
           [0013]      FIG. 4  is a table that is illustrative of access authority levels that are determined by a relationship between each part of the MFP  11  and a user log-in level in the exemplary embodiment of the present disclosure; 
           [0014]      FIG. 5A  illustrates an example that appears on a display part  260  of the MFP  11  in the exemplary embodiment of the present disclosure. 
           [0015]      FIG. 5B  illustrates an example that appears on the display part  260  of the MFP  11  in the exemplary embodiment of the present disclosure; 
           [0016]      FIG. 6  is a flowchart that is illustrative of a process flow in the exemplary embodiment of the present disclosure; 
           [0017]      FIG. 7  illustrates examples of log-in message images  1205   a  and  1205   b  in the exemplary embodiment of the present disclosure; 
           [0018]      FIG. 8A  illustrates a display example on the display part  260  of the MFP  11  in the exemplary embodiment of the present disclosure; 
           [0019]      FIG. 8B  illustrates a display example on the display part  260  of the MFP  11  in the exemplary embodiment of the present disclosure; 
           [0020]      FIG. 9A  illustrates a display example on the display part  260  of the MFP  11  in the exemplary embodiment of the present disclosure; 
           [0021]      FIG. 9B  illustrates a display example on the display part  260  of the MFP  11  in the exemplary embodiment of the present disclosure; 
           [0022]      FIG. 10  is a memory configuration diagram that is illustrative of a content (memory map) of a memory part  120   a  in a medication of the exemplary embodiment of the present disclosure; and 
           [0023]      FIG. 11  illustrates a display example on the display part  260  of the MFP  11  in a modification of the exemplary embodiment of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0024]    Next, an exemplary embodiment of the present disclosure will be detailed with reference to the attached drawings. AS shown in  FIG. 1 , the present exemplary embodiment deals with an example case in which a user  30  logs in to an MFP (Multi-Function Peripheral)  11  that is connected to an information communication network  10  from an information terminal  21  such as a PC (Personal Computer) that is connected likewise to the information communication network  10 . 
         [0025]    The MFP  11  whose overall configuration and electrical configuration are shown in  FIG. 1  and  FIG. 2 , respectively, stores in its server portion  11   a  secret documents that are transmitted via a facsimile or read by a scanner part  150 . In addition, the MFP  11  is configured to authenticate a user using a user ID that is previously registered. The user ID registration is made before using the MFP  11  for establishing user identification and grasping the number of printed sheets per user. 
         [0026]    In the present exemplary embodiment, being authenticated as a regularly registered user whose user ID and password are registered in the MFP  11  is referred as “user authentication” and making the MFP  11  usable by a user regardless of whether or not he/she is a regularly registered user is referred to as “log-in (log in)”. 
         [0027]    Referring to  FIG. 1  and  FIG. 2 , in the MFP  11 , a BUS  100  is in connection with a CPU (Central Processing Unit)  110 , a memory part  120 , and an I/F (Interface) part  130 . 
         [0028]    These elements, the CPU  110  and the memory part  120 , and the I/F part  130  constitute a server part  11   a  (a portion enclosed by a dotted line). 
         [0029]    The CPU  11  controls the whole of the MFP  11  based on operation programs that are stored previously on the memory part  120 . The memory part  120  includes an image data memory part  120   c . The memory part  120  stores, other than the operation programs, setting (setting of installation environmental or the like) information that is unique for the MFP  11 , physical configuration information, information related to users who are registered in the MFP  11  for using the same. 
         [0030]    It is to be noted that the memory part  120  is made up of non-volatile memory devices and volatile memory devices, the non-volatile memory devices including, for example, a ROM (Read Only Memory), an HDD (Hard Disk Drive), and a flash memory, while the volatile memory devices including various RAMS (Random Access Memory). However, how to combine which type (character) of memory devices for usage is not a featured point of the present disclosure and therefore detailing these memory devices is omitted. 
         [0031]    The communication I/F part  130 , which is used to connect the MFP  11  to an external devices, includes, for example, an interface (modem) that allows the MFP  11  to connect the telephone line for a facsimile transceiving and an interface (for parallel data transmission or for serial data transmission) that allows the MFP  11  to connect to an electronic terminal or the like, other than interfaces (such as various LANs) that allows the MFP  11  to connect to the information communication network  10 . 
         [0032]    Other than the aforementioned devices, the BUS  100  is in connection with an operation part  150 , a scanner part  150 , a printing part  160 , and another unit (such as a sorter unit). The operation part  140  is made up of, for example, a keyboard and an LCD (Liquid Crystal Display). 
         [0033]    The scanner part  150  reads an image of a manuscript or the like in an optical manner. Also, an ADF  150   a  is located on the image scanner part  150 . The ADF  150   a  is configured to feed out manuscripts (in the form of plural pages) that are piled on one another, one by one, in a sequential manner and to convey the resulting manuscript D to an upper surface of the scanner part  150 . 
         [0034]    The printing part  160  prints various processed results (including an image processed result of an externally inputted image data) by the CPU  110  on recording sheets or the like. 
         [0035]    On the other hand, in the electronic terminal  21 , a BUS  200  is connected with a CPU  210 , a memory part  220  and a communication I/F part  230 , and further an operation part  240 , a display part  260  and the like. 
         [0036]    This CPU  210  controls the whole of the electronic information terminal  21  based on operation programs that are stored previously on the memory part  220 . 
         [0037]    As the memory part  220 , a combination of an HDD and various RAMS is available that is used in many other memory devices, but a combination of a flash memory and a RAM may be available that is sometimes in other memory devices. 
         [0038]    The communication I/F part  230 , which is used to connects the electronic information terminal  21  to the information communication network  10 , is in the form of a wired interface and otherwise a wireless interface that complies with various protocols. 
         [0039]    Though the operation part  240  is, in general, in the form a keyboard that a user manipulates, some operation parts are operable by numeric buttons and several code buttons. 
         [0040]    The display part  260  is configured by using an LCD, but some are provided with a touch panel that the user  30  can manipulate. 
         [0041]    Here, a content that the memory part  120  stores in the present exemplary embodiment will be described.  FIG. 3  illustrates a relationship between allocated addresses in the memory part  120  and data pieces that are correspondingly recorded therein. In  FIG. 3 , each region is indicated in term of logical address, the size (such as the number of bytes) of data piece in one unit address varies depends on the content. In addition, from a view point of physical address, a set of data pieces (such as an image data pieces of one page) are sometimes stored in a plurality of discontinuous physical addresses in a separate manner. 
         [0042]    It is to be noted that the electronic information terminal  21  also has the memory part  220 , similar to the MFP  11  that has the memory part  120 . Thus, the content stored in the memory part  220  and how to use its regions (or memory spaces) are identical with those of commonly used computers and mobile terminal and therefore their descriptions and illustrations are omitted. 
         [0043]    As shown in  FIG. 3 , the memory part  120  is provided with a terminal information region  1201  (logical addresses x000-x009), a program region  1202  (logical addresses x010-x019), an equipment setting region  1203  (logical addresses x020-x029), a security region  1204  (logical addresses x030-x039), a message image region  1205  (logical addresses x040-x049), a user management region  1206  (logical addresses x050-x059), a log-in management region  1207  (logical addresses x060-x069), an operation region  1208  (logical addresses x070-x079), and a server region  1209  (logical addresses x080-x089). 
         [0044]    In this terminal information region  1201 , there are stored, as unique information pieces to the MFP  11 , a terminal unique address (such as an IP address) and a terminal unique ID (such as a MAC address). In addition, the program region  1202  stores programs that cause the MFP  11  to operate. 
         [0045]    The equipment setting region  1203  stores environmental conditions (that includes, for example, a specification information piece of consumable articles to be used and conditions for connection of peripheral equipment). 
         [0046]    The security region  1204  stores security setting items that are very important for establishing a safeguarded connection of the MFP  11  to the information communication network  10 , the setting items including a list restricted protocols, a list of block ports, and a list of IP filters and service settings which are for restricting an access to the MFP  11 . 
         [0047]    As one of the security settings, in the present exemplary embodiment, there is provided (as will be detailed later) restricting an access right to each of the parts (each process function) that constitute the MFP  11 . As criteria for determining an access right, there are provided types of log-in which include “management user”, “registered user”, “temporary user”, and “unknown user”. 
         [0048]    The “management user” is a user who is in charge of conducting maintenance tasks that include, for example, adding or changing a setting of the MFP  11  and deleting an unnecessary stored data piece. 
         [0049]    In addition the registered user” is a regular user (except for the “management user”) whose user ID and password are registered in the MFP  11 . 
         [0050]    The “temporary user” is a user in which a limited (guest) user and a registered user, the former user being, though his /her user ID and password are not registered in the MFP  11 , he/she is permitted to use the MFP  11  in limited process functions and/or operation time duration, the latter being corresponding to a person who cannot be regarded as a registered user due to the fact that he/she has forgotten his/her password. 
         [0051]    Further, the “unknown user” corresponds to a user, for example, who attempts to log in to the MFP  11  by using a user ID that is not registered in the MFP  11 . 
         [0052]    The message image region  1205  stores character strings of plural messages that are indicative of result of user authentication as a bit map image or raster image such as a JPEG image (one of the compressed formats). 
         [0053]    The message image region  1205  is divided into a registered-user oriented image group and an unknown-user oriented image group. As the registered-user oriented image group, log-in message images  1205   a - 1 ,  1205   a - 2 ,  1205   a - 3  and more (herein after which will be referred simply as “log-in message image” as necessary) are stored, while log-in message images  1205   b - 1 ,  1205   b - 2 ,  1205   b - 3  and more (herein after which will be referred simply as “log-in message image” as necessary) are stored. 
         [0054]    It is to be noted that details of the message images will be described later. In addition, though in the message image region  1205 , it is possible to provide a management-user oriented image group and a temporary-user oriented image group, other than the registered-user oriented image group and the unknown-user oriented image group, describing the former two image groups is omitted in describing the present exemplary embodiment. 
         [0055]    The user management region  1206  stores, as information pieces to be used for identifying all the users who are so registered in the MFP  11  as to access the same, for example, the user ID, a user attribute (the management user, the registered user, the temporary user, or the unknown user), the password, a personal name (that conceptually covers a cooperate name, common name, nick name, handle name, and the like), the latest log-in date and time, and the latest log-out date and time. 
         [0056]    The log-in management region  1207  stores current information pieces of a user who has already logged in to the MFP  11  which include an address of a connected terminal (IP address assigned to an electronic information terminal or the like), and the log-in type  1207   a.    
         [0057]    The operation region  1208  is a region that the CPU  110  (see  FIG. 2 ) uses for, say, converting or sorting various information pieces. 
         [0058]    Further, the server region  1209  is a region that is used for storing text data pieces of facsimile received document and image data pieces of the documents that are read by the scanner part  150  as well as spooling (that is, storing temporarily) a printing data piece to undergo a printing job by the printing part  160  as described above. 
         [0059]    Further, the server region  1209  stores a dummy data piece that is made up of an image data piece and a character string both of which fail to provide significant meanings. 
         [0060]    It is to be noted that a region that is lower than the server region  1209  (an address subsequent to the logic address x090) is assigned for another use but whose description is omitted. 
         [0061]    At this stage, an explanation is made as to a relationship between the aforementioned user log-in type  1207   a  and the user access right to each the parts that constitute the MFP  11 . 
         [0062]    Referring to  FIG. 4 , for example, in a case where the log-in type  1207   a  is the “management user”, it is possible for him/her to access the printing process and scanning process. In addition, only the “management user” is allowed to access the equipment setting region  1203 , the security region  1204 , and the user management region  1206  (thus, no description is made as to access rights from the users other than the “management user” to the equipment setting region  1203 , the security region  1204 , and the user management region  1206 ). As apparent from the above, the “management user” is capable of accessing all the regions (all the attributes) in the server region  1209 . 
         [0063]    As for the “registered user, it is possible for him/her to access the printing process and scanning process. In addition, regarding the server region  1209 , the “registered user” is allowed to only a data piece or region both of which are assigned with the user ID of the “registered user” (that is, the preceding data piece or region is one that this user recorded or is one that was recorded for being read out by this user having this user ID. 
         [0064]    As for the “temporary user”, he/she is allowed only to spool a small amount of printing data, the spooling being set differently from the printing process, and if he/she inputs the password later and then is authenticated as the “registered user”, he/she is allowed to complete printing on the recording sheets. In addition, regarding the scanning process, and if he/she inputs the password later and then is authenticated as the “registered user”, he/she is allowed for complete reading out from the server region  1209 . 
         [0065]    In a case of the “unknown user”, though a request for a printing process is accepted, an inputted printing data piece is made invalid. This invalidating process may be in the form of an immediate deletion of the inputted printing data piece (deletion without spooling) or in the form of recording the inputted printing data piece in the server region  1209 , within a small capacity range that is separately set, in order for the management user or specific registered users to read out. In addition, though a request for a scanning process is accepted, a data piece obtained at the scanner part  150  is made invalid (Details of the invalidating process of the scanning process is similar to that of the printing process). 
         [0066]    Hereinbelow, an explanation is made as to a process of a log-in to the MFP  11  which is made for using the MFP  11  by way of the electronic information terminal  21 . 
         [0067]    As described above, for using the MFP  11 , it is necessary, after completion of a user registration in the MFP  11 , to receive a user authentication, via the electronic information terminal  21 , from the MFP  11 , but this user authentication can be obtained from the operation part  140  of the MFP  11 . However, it is difficult to think of an unauthorized log-in from the operation part  140  by Brute-force attack and therefore no descriptions are omitted as to the log-in at the operation part  140  and subsequent authentication procedure. 
         [0068]    At this stage, it is presumed that the electronic information terminal  21  has a function, when the MFP  11  requests to enter information pieces that are related to the user authentication, which causes the display part  260  to display an input screen by, for example, a browser (a software program for reading information) for accepting inputs from the operation part  240 . 
         [0069]    Further, in the present exemplary embodiment, the following descriptions are made in which log-in cases by the “registered user” and the “unknown user” cases are used as examples, but the cases of the “management user” and the “temporary user” should be applied to cases of the “registered user” and the “unknown user”, respectively. 
         [0070]    Hereinbelow, with reference to  FIGS. 5A and 5B - FIGS. 9A and 9B , a description will be made as to a flow of a process that reads facsimile received image data pieces or the like from the server region  1209  via the electronic information terminal  21 . It is to be noted that in a flowchart shown in  FIG. 6 , the left side of a dotted line illustrates a process executed by the electronic information terminal  21 , while the right side of the dotted line illustrates a process executed by the MFP  11 . 
         [0071]    In this case, the user  30  activates, for example, a software program for browsing (whose detailed explanation will be omitted) on the electronic information terminal  21 . Then, as shown in  FIG. 5A , a browsing screen  2601  appears on the display part  260 , a data reading request is transmitted from the server region  1209  to the MFP  11  (Step St 11 ). 
         [0072]    The MFP  11 , when receives the data reading request from the electronic terminal  21 , requests the electronic information terminal to display a log-in screen and to enter a user ID and a user password (Step St 12 ) 
         [0073]    In response to this request, as shown in  FIG. 5B , on the display part  260 , a log-in screen  260 , an input auxiliary screen  2603  that includes a screen key board (software key board), and the like appear (Step St 13 ). 
         [0074]    When a user ID and a user password are inputted into specific portions of the log-in screen  2602  that has appeared (Step St 14 ), the resulting user ID and user password are transmitted to the MFP  11 . 
         [0075]    Such input operations are conducted usually by the user  30  using the operation part  240 , the input auxiliary screen  2603 , or the like. However, sometimes, such input operations may be conducted using a certain software program that is activated on the electronical information terminal  21 . There are many cases of repeating the aforementioned unauthorized log-in by Brute-force attack due to using such a software program. 
         [0076]    The MFP  11  determines whether or not the received user ID is registered in the user management region  1206 . If the result is true, the MFP  11  determines whether or not the received password that is paired or combined with the received user ID is coincident with the registered user password in the user management region  1206  (Step St 15 ). 
         [0077]    (In Case of Registered User) 
         [0078]    In Step St 15 , if the combination of the user ID and the user password that are transmitted from the electronic information terminal  21  is found to be registered, the MFP  11  authenticates the user who transmitted the data reading request in step St 11  as the “registered user” (Step St 21 ). 
         [0079]    Here, explanations are made as to the log-in message images  1205   a - 1 ,  1205   a - 2 ,  1205   a - 3  and more, and the log-in message images  1205   b - 1 ,  1205   b - 2 ,  1205   b - 3  and more which are stored in the message image region  1205 . 
         [0080]    Among the memory maps that are indicative of the content of the memory part  120 , especially, only the content of message image region  1205  is indicated in the form of an image. 
         [0081]    In the present exemplary embodiment, when the user (regardless of whether or not he/she is a registered user) logged in to the MFP  11 , the MFP  11  causes the electronic information terminal  21  to display a message that is indicative of the log-in completion. 
         [0082]    However, the message to the normally registered user is displayed with a commonly used typeface such as courier (or gothic) as seen from the log-in message images  1205   a - 1 ,  1205   a - 2 ,  1205   a - 3  and more, while the message to the non-normally registered user is displayed with an obfuscated character string as seen from the log-in message images  1205   b - 1 ,  1205   b - 2 ,  1205   b - 3  and more. 
         [0083]    This obfuscated character string means at least one character or message from which even an OCR software program or the like of the computer can extract a significant or meaningful word. 
         [0084]    In detail, as seen from the log-in message images  1205   b - 1 ,  1205   b - 2 ,  1205   b - 3  and more, the obfuscated character string is a modified character string by making a partial combination between two adjacent characters (making it difficult to recognize individual characters), differentiating extremely the heights of the characters (making it to recognize lines), and overwriting a bar line on a character string (making the feature of each character unclear or vague). 
         [0085]    Other than the aforementioned obfuscation modes, sometimes, there are provided other obfuscation modes that include inclining characters in different angles, causing each character to differentiate the upper end the lower end in width, and partial or total combination of these modes. 
         [0086]    In addition, the message image group for the unknown user which includes the log-in message images  1205   b - 1 ,  1205   b - 2 ,  1205   b - 3  and more does not use an message that is indicative of a refusal for an authentication as the normal registered but uses an image that is indicative of a message of the fact of the log-in completion with an obfuscated character string. 
         [0087]    In the above-described Step St 21 , if the user who transmitted the reading data request is authenticated as the “registered user”, the MFP  11  transmits the log-in message image  120   a  (here, the log-in message image  1205   a - 1 ) (Step St 22 ). 
         [0088]    At this stage, referring to  FIG. 8A , the electronic information terminal  21  deletes the log-in screen  2602  that appears on the display part  260  (Step St 23 ) and causes the received log-in message image  1205   a  to appear, as a message screen  2604 , on the display part  260  and concurrently causes a message  2601   a  that urges the user to enter items including a data number to be read to appear in the browsing screen  2601  (Step St 24 ). 
         [0089]    When the items including the data number to be read from the server region  1209  are entered in response to the display of the message  2601   a  (Step St 25 ), the resulting information pieces are transmitted to the MFP  11 . Entering items including the data number in response to the message  2601   a  is presumed to be made by the  30  using, for example, the operation part  240  or the input auxiliary screen  2603 . 
         [0090]    Then, the MFP  11 , in response to the entered items including the data number, reads the designated data piece from the server region  1209  (Step St 26 ) and transmits the resulting data piece to the electronic information terminal  21 . 
         [0091]    At last stage, the electronic information terminal  21  causes the data pieces that are read from the server region  1209  to appear on the browsing screen  2601  as seen from  FIG. 8B  (Step St 27 ), and the process is terminated. 
         [0092]    (In case of unknown user) 
         [0093]    In Step St 15 , if the combination of the user ID and the user password that are transmitted from the electronic information terminal  21  is found not to be registered, the MFP  11  authenticates the user who transmitted the data reading request in step St 11  as the “unknown user” (Step St 31 ). 
         [0094]    In a case where the MFP  11  authenticates the user who transmitted the data reading request in step St 11  as the “unknown user” in Step St 31 , the MFP  11  transmits the log-in message  1205   b  (here, the log-in message  1205   b - 1 ) for the unknown user to the electronic information terminal  21  (Step St 32 ). 
         [0095]    At this stage, referring to  FIG. 9A , the electronic information terminal  21  deletes the log-in screen  2602  that appears on the display part  260  (Step St 33 ) and causes the received log-in message image  1205   b  to appear, as a message screen  2604 , on the display part  260  and concurrently causes a message  2601   a  that urges the user to enter items including a data number to be read to appear in the browsing screen  2601  (Step St 34 ). 
         [0096]    That is to say, apparently, the log-in to the MFP  11  is completed and accessing to each part of the MFP  11  is made carried on. 
         [0097]    At this stage, for example, when on the electronic information terminal  21  a summary message appears which displays that the combination of the user ID and the user password that are transmitted from the electronic information terminal  21  is found not to be registered in the user management region  1206  (failure in the authentication), which results in that an OCR software program or the like that runs on the electronic information terminal may recognize that the inputted user ID and password are not registered (Step St 34 ′. 
         [0098]    If so, the Brute-force attack can be achieved by causing a combination of a user ID and a user password to change sequentially to enter the set portions of the log-in screen  2602 , the changing being made by a software program or the like that runs on the electronic information terminal  21  (Step St  14 ′) (the flow from Step St  34 ′ to Step St 14 ′ is indicated in dotted lines in  FIG. 6 . 
         [0099]    It is common sense that a user enters his/her memorized password when necessary and therefore the password (code) having a too long length (the number of digits) or having a combination of graphic symbols which are not readable as characters is inconvenient for the user. 
         [0100]    That is to say, in many cases, the code that constitutes a password is limited to a character string having as high as tens of digits as a fixed combination of characters each of which is a daily used one and some marks. 
         [0101]    The authentication using the preceding password may lead security vulnerability due to an unexpected log-in by a person other than a regular user, the unexpected log-in being resulted from a missing of the written password in being stored or viewing the password by an authorized person during inputting to UL. 
         [0102]    Further, so long as a password is in the form of a fixed character string that is constituted by the combination of the limited number of kinds of characters and a numeral of a limited number of digits, the password is analyzed by Brute-force attack that tries to conduct an authentication, over and over again, by changing the combination of every character combination until the correct password is found, which also may result in an authorized log-in. 
         [0103]    However, in the present exemplary embodiment, the log-in message image  1205   b  that is to be displayed in Step St 34 , as the message screen  2604 , on the display part  260  is in the form of an obfuscated character string. Thus, it is impossible for the software program that runs on the electronic information terminal  21  to decide whether or not the Brute-force attack should be repeated due to the failure in the authentication. 
         [0104]    The number of the combinations of user ID and password are very numerous. Thus, even though the user  30  tries to make a trial of an unauthorized log-in, the user  30  per se have to repeat input operations by changing the user ID and the pass word at each input operation, thereby providing a deterrence against such an unauthorized log-in. 
         [0105]    After the message  2601   a  is displayed in Step St 34 , when information pieces that include the data number to be read from the server region  1209  (Step St 35 ), the resulting information pieces are transmitted to the MFP  11 . 
         [0106]    The MFP  11 , when received these information pieces, reads the dummy data  1209   b  from the server region  1209  (Step St 36 ) and transmits the resulting data to the electronic information terminal  21 . 
         [0107]    At last stage, the electronic information terminal  21  displays the dummy data  1209   b  that the electronic information terminal  21  reads from the server region  1209  on the browsing screen  2601  (Step St 37 ) and the process is terminated.  FIG. 9B  illustrates a detailed example of the dummy data  1209   b.    
         [0108]    In a case where the above-described Step St 31  authenticates the user who has send the data reading request as the “unknown user”, even inputting the information pieces that include the data number to be read from the server region  1209 , no data is displayed on the browsing screen  2601  which is related the inputted data number. Instead, the images or character string such as the dummy data  1209   b  are displayed which fails to provide significant meanings. 
         [0109]    As described above, the present exemplary embodiment allows, even in failure of a user authentication, for a log-in as the “unknown user” without notifying a message to the effect that user authentication is failed. In addition, deleting the log-in screen  2602  that is provided for inputting the user ID and user password will stop further inputting the user ID and user password causes, and apparently accessing to each part of the MFP  11  is made carried on. In such a way, the user ID and the password that are inputted using the OCR software program or the like are not recognized that they are not registered. Thereby, it is possible to achieve a prevention of unauthorized log-ins such as Brute-force attack that runs on the electronic information terminal. 
         [0110]    It is to be noted that the present disclosure is not limited to the above-described exemplary embodiment and therefore obviously various modification may be made within the scope of the spirit of the present disclosure. 
         [0111]    For example, the long-in message images  1205   a  and  1205   b  that the MFP  11  are not limited to the log-in message images  1205   a - 1  or the like and  1205   b - 1  or the like. On the contrary, for example, it is possible to select, every specified time or every day, only one log-in message image from among the long-in message images  1205   a - 1 ,  1205   a - 2 ,  1205   a - 3  and more and the long-in message images  1205   b - 1 ,  1205   b - 2 ,  1205   b - 3  and more, or to select any log-in message image from among the preceding log-in image images at random whenever the authentication is made (At that time, for the prevention of recognizing the time at which the log-in message image changes, for example, even though the log-in by the registered user is continued, changing the log-in message image will provide higher effects). 
         [0112]    In addition, the present exemplary embodiment provides, as the message screen  2604 , the long-in message images  1205   a - 1 ,  1205   a - 2 ,  1205   a - 3  and more and the long-in message images  1205   b - 1 ,  1205   b - 2 ,  1205   b - 3  and more, which the present disclosure provides as non-limited examples. 
         [0113]    For example, referring to  FIG. 10 , a memory part  120  (whose peripheral configuration is identical with that of the memory part  120  shown in  FIG. 2  and therefore detailing the peripheral configuration of the memory part  120   a  is omitted) stores, at a portion of the program region  1202   a  that occupies the logical addresses x010-x019, an image data creating program  1202   a - 1  and an obfuscating program  1202   a - 2 . 
         [0114]    In addition, in the log-in message region  1205   c  that occupies the logic address x040-x049, there are stored plural log-in messages each of which is made up of coded text data pieces. 
         [0115]    Thus, at a time when the user who has transmitted the data reading request is authenticated as either one of the “registered user” and “unknown user”, a message is selected from either one of the log-in messages  120   c - 1 ,  1205   c - 2 , and  1205   c - 3 . Then, the image data creating program  1202   a - 1  converts the resulting log-in message  2  to an image that is corresponded one of the long-in message images  1205   a - 1 ,  1205   a - 2 ,  1205   a - 3  and more and the long-in message images  1205   b - 1 ,  1205   b - 2 ,  1205   b - 3  and more. 
         [0116]    In addition, in a case where the user who has transmitted the data reading request is authenticated as the “unknown user”, the MFP  11 , using the obfuscating program  1202   a - 2 , converts the converted message image to an obfuscated message image and transmits the resulting or obfuscated message image to the electronic information terminal  21 . 
         [0117]    Further, when forming an obfuscated message image using the obfuscating program  1202   a - 2 , if the user who has transmitted the data reading request is authenticated as the “registered user”, the message image can be formed such that the character string such as the log-in message  1205   c - 4  or  1205   c - 5  is added with the name of the user who has been authenticated. 
         [0118]    For example, causing the log-in message  1205   c - 4  to display thereon a private name having a user number ( 1 ) who is registered in the user region  1206  will result in a condition of message screen  2604  shown in  FIG. 11 . 
         [0119]    In such a way, without having to display a success in authentication, it is easy for the user to recognize his/her success in authentication. 
         [0120]    It is to be noted the information piece to be added to the character string is not limited to the private name in the user management region  1206  and may be the authenticated user ID. This manner is applicable even when authentication of the “unknown user”. 
         [0121]    Of course, the present disclosure is not limited to the above-described MFP and needless to say that even an on-line database and a server are within the coverage range of the present disclosure. In even such cases, it is possible to expect a prevention of information leakage due to an unauthorized access such as Brute-force attack, thereby preventing disadvantages from spreading to the regular users who may suffer from a loss.