Abstract:
An authenticated user is provided with page information relating to a service to be provided, such as a service for ordering products. In the invention, the authenticated user is provided with page information in either a first or second form, wherein in the first form the page information includes an entry field for coupon information and in the second form the page information does not include the entry field for the coupon information. When coupon information input in the entry field is received, a determination is made whether or not the coupon information is valid. The number of times that the coupon information is determined to be invalid is counted and stored in association with the authenticated user. When the counted number does not exceed a predetermined value, the user is provided with the page information in the first form, while the page information is provided in the second form when the counted number exceeds the predetermined value.

Description:
FIELD OF THE INVENTION 
   The present invention relates to a technique for suppressing illicit use of an authentication system. 
   BACKGROUND OF THE INVENTION 
   The rapid spread of the Internet has triggered the emergence of services that market commercial products via the Internet. Such a service is called an on-line sales service. In some services, when a service user inputs an authentication code such as a coupon number or the like, given in advance, a Web server provides the perk such as a discount of a given amount to the user. 
   Upon providing services using on-line coupons, a prevention measure against illicit use of a coupon number by a malicious user must be taken. A conventional server gives the perk upon reception of a correct number input to a remote computer. Hence, a malicious user can receive the perk by inputting a large number of different coupon numbers at random. As a result, the service provider gives the benefits to unintended users, and suffers involuntary losses. 
   In order to prevent such illicit use, a complicated number to which a dummy number is appended or which is encrypted is assigned as a coupon number. As a result, a malicious user is forced to input a large number of numbers until he or she can acquire a correct coupon number. 
   However, the increase in computer&#39;s processing power upon speeding up of computers in recent years has allowed some malicious users to make use of computer programs to easily issue and input a large number of numbers and to illicitly acquire a coupon number. 
   As a measure against such illicit methods, a complicated coupon number may be used. However, as the coupon number is complicated, the number of requests issued until a malicious user illicitly acquires a coupon number increases. As a result, the load on the server that provides services becomes heavier, and authentic users who normally use the services may suffer disadvantages such as deterioration of performance and the like. 
   Also, when the coupon number is complicated, input errors by authentic users increase. 
   It is not easy for the administrator who provides services to determine whether an input error of a coupon number is made due to illicit use of the number by a malicious user or a coupon number is merely erroneously input by a user who is entitled to use the coupon number. 
   In order to prevent illicit use, like a cash withdrawal service using an ATM (automated teller machine), it is determined that an input by a malicious user is made if the number of wrong input for a corresponding ID exceeds a predetermined number, the service is suspended. However, when the coupon number is complicated and input errors of authentic users increase, the service use of many authentic users could be suspended, generating numerous inquiries to the administrator, and thus, resulting in huge management cost. 
   SUMMARY OF THE INVENTION 
   The present invention has been proposed to solve the conventional problems, and effectively suppress illicit accesses to an authentication system without increasing the burden on the administrator. 
   That is, the present invention is an authentication system for authenticating an authentication code input from a user terminal, the user terminal comprising display means for displaying either of a first form having an authentication code input field used to input the authentication code, and a second form without any authentication code input field, the authentication system comprising creation means for creating first display data required to display the first form on the basis of second display data required to display the second form, and script information required to display the authentication code input field, first transmission means for transmitting the first display data to the user terminal, reception means for receiving the authentication code input to the authentication code input field from the user terminal, authentication means for authenticating if the authentication code received by the reception means is authentic, counting means for counting the number of unauthentic authentication codes determined by the authentication means, save means for saving the count counted by the counting means in a memory, count checking means for checking if the count saved by the save means in the memory reaches a predetermined value and second transmission means for transmitting one of the first display data and the second display data in accordance with a checking result of the count checking means. 
   Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which similar reference characters designate the same or similar parts throughout the figures. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a diagram showing the arrangement of an on-line coupon system according to the embodiment of the present invention; 
       FIG. 2  shows the content of a user information table managed by a service server according to the embodiment of the present invention; 
       FIG. 3  shows the content of a coupon type-dependent information management table managed by a coupon server according to the embodiment of the present invention; 
       FIG. 4  shows the content of a coupon ID information management table managed by the coupon server according to the embodiment of the present invention; 
       FIG. 5  is a flowchart showing an overview of the processing sequence for a service that utilizes the on-line coupon system according to the embodiment of the present invention; 
       FIG. 6  shows a dialog which is sent from the service server to a user terminal and is displayed upon making authentication by the service server according to the embodiment of the present invention; 
       FIG. 7  shows an example of an order window displayed on the user terminal when login authentication has succeeded in the system according to the embodiment of the present invention; 
       FIG. 8  shows an example of a user information input window displayed on the user terminal according to the embodiment of the present invention; 
       FIG. 9  shows an example of an estimation window displayed on the user terminal according to the embodiment of the present invention; 
       FIG. 10  is a flowchart showing a checking process of an input coupon number according to the embodiment of the present invention; 
       FIG. 11  is a flowchart showing a display process of a coupon number input field according to the embodiment of the present invention; 
       FIG. 12  shows an example of an error dialog displayed on the user terminal according to the embodiment of the present invention; 
       FIG. 13  shows an example of an error dialog displayed on the user terminal according to the embodiment of the present invention; and 
       FIG. 14  is a block diagram showing the arrangement of a computer apparatus according to the embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A preferred embodiment of the present invention will now be described in detail with reference to the drawings. It should be noted that the relative arrangement of the components, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless it is specifically stated otherwise. 
   In this embodiment, on-line product sale is made. However, the present invention is not limited to such specific service, and can be applied to all kinds of services that give the perk to the users by inputting numbers, symbols, and the like. 
   &lt;System Arrangement&gt; 
     FIG. 1  shows the arrangement of an on-line coupon system according to the embodiment of the present invention. 
   Referring to  FIG. 1 , reference numeral  101  denotes a user terminal. A service user accesses from this terminal a service server  102  that provides a service via the Internet. The service server  102  performs processes such as user authentication, management of commercial products to be marketed, billing, and the like. Also, the service server  102  communicates with a coupon server  103  to provide a service perk to a user according to a result obtained from that server  103 . The coupon server  103  issues a coupon number as an authentication code. Upon reception of an inquiry from the service server  102 , the coupon server  103  checks if a coupon number is valid, and returns that result to the service server  102 . Note that the user terminal  101 , the service server  102 , and the coupon server  103  communicate with each other using TCP/IP. In this embodiment, the service server  102  and the coupon server  103  are independent servers. However, the service server  102  may also have the function of the coupon server  103 . The coupon server  103  issues a coupon number to the user terminal  101  via the service server  102  or directly. 
     FIG. 2  shows the contents of a user information table managed by the service server  102  in the embodiment of the present invention. 
   The service server  102  stores in a user information table  200  a user ID  201 , a password  202  used in user authentication, a latest login time  203 , a coupon number input error count  204 , and a latest coupon number input error time  205 , as shown in  FIG. 2 . 
     FIG. 3  shows the contents of a coupon type-dependent information management table  300  managed by the coupon server  103  in the embodiment of the present invention. 
   The coupon server  103  stores as a coupon type-dependent information management table  300  a service ID  301 , a service site ID  302  that provides that service, an issuance count  303  of a coupon number, a valid date  304  of a service for the service ID  301 , a use limit count  305  of an identical coupon number, a discount rate  306 , a unit discount amount  307 , and an upper limit  308  of the discount amount, as shown in  FIG. 3 . In this embodiment, the discount rate is held as %, and when the value of the discount rate  307  is “0”, a coupon that allows the user to receive a discount perk of an amount equal to the value stored in the unit discount amount  307  is issued. 
     FIG. 4  shows the content of a coupon ID information management table  400  managed by the coupon server  103  in the embodiment of the present invention. 
   The coupon server  103  stores in a coupon ID information management table  400  a coupon ID  401 , a service ID  402 , a coupon use count  403  for this ID, a previous coupon use amount  404  for this ID, and a user ID  405  corresponding to the coupon ID, as shown in  FIG. 4 . In this embodiment, if the user ID is −1, this coupon ID is not associated with any user since it is not issued or it is generally used for users. 
   &lt;Coupon Service Flow&gt; 
     FIG. 5  is a flowchart showing an overview of a coupon service providing process. 
   In step S 501 , the service server  102  performs login authentication for the user on the basis of the ID and password input at the user terminal  101 .  FIG. 6  shows a login dialog which is displayed on the user terminal  101  by sending login authentication dialog display data from the service server  102  to the user terminal  101 . The user inputs a user ID in an input field  601  and a password in an input field  602 , and clicks a “Login” button  603 . The service server  102  checks with reference to the user information table  200  if a combination of the user ID and password received from the user terminal  101  is stored. As a result, if such combination of the user ID and password exists, login authentication of the user succeeds and is authorized by the service server  102 . 
     FIG. 7  shows an order window  700  as an example of a first form which is displayed on the user terminal  101  when login authentication has succeeded. This window displays article names, unit prices of articles, and various buttons. The service user inputs the quantity of an article to be purchased in an input field  704 . Also, a coupon number input field  705  is displayed depending if various conditions (to be described later) are satisfied. 
   Note that the service server  102  creates order window display data required to displays article names, unit prices of articles, various buttons, and quantity input fields and holds that data in a memory. When the service server  102  detects that login authentication of the user has succeeded, it sends the held the order window display data to the user terminal  101 . When various conditions (to be described later) are satisfied and the coupon number input field  705  is to be displayed, the service server  102  appends information required to display the coupon number input field  705  to the held order window display data (second form display data having no coupon number input field) to create order window display data with a coupon number input field, and sends it to the user terminal  101 . 
   Upon clicking a “to input the ordered information”  701  in  FIG. 7 , the service server  102  checks the input information received from the user terminal  101 . For example, the server  102  checks if an integer equal to or larger than “0” is input to each quantity input field  704 . If no problem is found, the server  102  sends the user registration data required to display a user information input window ( FIG. 8 ) on the user terminal  101  to the user terminal  101 . In this case, the server  102  recognizes (selects) the article or articles with the quantity input field  704  to which a value equal to or larger than “1” is input in step S 502 . If the input information received from the user terminal  101  includes an arbitrary number or character string input to the coupon number input field  705 , the service server  102  begins to communicate with the coupon server  103 . Note that authentication of the coupon number will be described later. 
   When the user fills all the required information on the user information input window  800  in  FIG. 8  displayed on the user terminal  101  and then clicks the “estimate” button  801 , the service server  102  receives the user information (delivery address information of articles) input at the user terminal  101  in step S 503 . The flow advances to step S 504 , and the service server  102  reads out the unit price data of each article corresponding to the user&#39;s choice recognized in step S 502  from its database, multiplies the quantity received in step S 502  and adds a shipping charge and consumption tax to calculate an estimated amount. The server  102  sends the estimate window display data embedded with a value calculated as the estimated amount to the user terminal  101 , so that the calculated estimated amount is displayed on an estimate window  900  shown in  FIG. 9 . The estimate window  900  displays a perk (discount amount) according to the coupon number input, shipping charge, consumption tax, and the like in addition to the article name, the article price, and the ordered quantity, as shown in  FIG. 9 . When the service user clicks the “order” button  901  on the estimate window in  FIG. 9 , an order command is transmitted from the user terminal  101  to the service server  102 , which receives this order command, and executes a settlement process and an order placement process in step S 505 , thus ending the order flow. 
   &lt;Coupon Number Authentication Process&gt; 
     FIG. 10  is a flowchart showing a process for authenticating a coupon number input to the coupon number input field  705  on the order window  700  in  FIG. 7 . 
   In step S 1001 , the user inputs a coupon number to the coupon number input field  705  of an article to be purchased at the user terminal  101 . The user terminal  101  sends the article ID of an article with the quantity input field  704  to which “1” is input, and the input coupon number to the service server  102 . 
   In step S 1002 , the service server  102  passes the article ID and coupon number to the coupon server  103  to ask it to check if the coupon number sent from the user terminal  101  is correct. 
   In step S 1003 , the coupon server  103  searches the coupon ID information management table  400  for the article ID and coupon number sent from the service server  102 . In this embodiment, the article ID is equal to the service ID. Alternatively, the service server  103  may manage a service ID corresponding to a plurality of article IDs, and may issue an inquiry using that ID. 
   The coupon server  103  checks in step S 1004  if a corresponding record is found. If no record is found, the coupon server  103  returns an error code that advises so to the service server  102 . 
   In step S 1005 , the service server  102  adds 1 to the coupon number input error count  204  in the user information table  200 , and substitutes the current time in the latest error input time  205 . 
   In step S 1006 , the service server  102  displays an error dialog. At this time, the service server  102  creates error dialog display data required to display an error dialog  1200  shown in  FIG. 12  if the value stored in the coupon number input error count  204  of the user information table  200  falls within an allowable range. The service server  102  transmits the display data to the user terminal  101 , which displays the error dialog. Upon reception of a click input of a “return” button  1201  on the error dialog  1200 , the server  102  sends the order window display data with the coupon number input field of the corresponding article to the user terminal  101  to display the order window with the coupon number input field, thus prompting the user to re-input the coupon number. 
   If the value stored in the coupon number input error input  204  falls outside the allowable range, the server  102  creates error dialog display data required to display an error dialog  1300  shown in  FIG. 13  and sends it to the user terminal  101 , thus displaying that dialog. In this embodiment, whether or not the value falls within the allowable range is checked by comparing the value stored in the input error count  204  with a prescribed count (e.g., 10 times) specified in advance by the service server  102 . This checking process may be done by setting a prescribed input error count in the coupon type-dependent information management table  300  of the coupon server  103 , and specifying it for each coupon ID. Upon reception of a click input of a “return” button  1301  on the error dialog  1300 , the order window display data, (second display data) which is created in advance and does not display any coupon number input field of the corresponding article, is read out, and is transmitted to the user terminal  101 . In this way, the order window (second form) without any coupon number input field is displayed, thus inhibiting the user from inputting any coupon number. 
   If the record of the coupon ID is found in step S 1004 , the server  103  searches the coupon type-dependent information management table  300  for the service ID and site ID of a service site to acquire the record of the corresponding service. 
   The coupon server  103  checks in step S 1008  if the input coupon number is a valid coupon number. This checking process is done based on the following conditions. The valid date  304  of the coupon is checked from the coupon type-dependent information management table  300 , and if the valid date has expired, it is determined that the coupon number is invalid. The user ID  405  of the coupon ID information management table  400  is compared with the user ID sent from the service server  102 . If the user ID  405  of the coupon ID information is −1 or the user ID  405  of the coupon ID information management table is equal to the user ID sent from the service server  102 , the next checking process is done. Otherwise, it is determined that the user ID is invalid for that coupon ID. The coupon use count  403  is acquired from the coupon ID information management table, and is compared with the use limit count  305  of an identical coupon number in the coupon type-dependent information management table  300 . If the coupon use count  403  is equal to or larger than the use limit count  304 , it is determined that the coupon number is invalid. Next, the use amount  404  of the coupon ID information management table  400  is compared with the upper limit  308  of the discount amount of the coupon type-dependent information management table  300 . If the use amount  404  is equal to or larger than the discount upper limit amount  308 , it is determined that the coupon number is invalid. 
   If it is determined in step S 1008  that the coupon number is invalid, the coupon server  103  returns an error code that advises the service server  102 . A process to be executed at that time has already been described in step S 1005 . 
   If it is determined in step S 1008  that the coupon ID is valid, the coupon server  103  notifies the service server  102  of it, and the flow advances to step S 1009 . In step S 1009 , the service server  102  resets the coupon number input error count  204  of the user information table  200  to “0”, and the flow advances to step S 1010 . In step S 1010 , the server  102  creates user information input window display data required to display the user information input window  800 , and transmits it to the user terminal  101 , thus displaying the user information input window. 
   &lt;Coupon Number Input Field Display Process&gt; 
     FIG. 11  is a flowchart showing the display processing sequence of the coupon number input field  705 . A series of processes shown in  FIG. 11  are done before step S 1001  in  FIG. 10 . In this embodiment, whether or not the coupon number input field  705  is displayed is switched depending on conditions to be satisfied. 
   The service server  102  checks in step S 1101  if a corresponding record is stored in the coupon type-dependent information management table  300  associated with the article ID of interest. This inquiry process can be done by passing the article ID (service ID) and the site ID Of the service server  102  from the service server  102  to the coupon server  103 . The coupon server  103  searches the coupon type-dependent information management table  300  to check if a corresponding record is stored, and returns that result to the service server  102 . 
   If no record is stored in the coupon type-dependent information management table  300 , the server  102  reads out the order window display data held in advance from the memory, and sends it to the user terminal  101 , thus ending the process. That is, since no process for embedding information required to display the coupon number input field in the order window display data is performed, the order window display data held in the memory is sent intact, and no coupon number input field  705  for the corresponding article is displayed on the order window  700 . For example, various input fields of a scanner in  FIG. 7  are displayed without any coupon number input field  705 . 
   If a corresponding record is stored in the coupon type-dependent information management table  300 , the service server  102  checks in step S 1102  if the valid date of the coupon of the article ID is good. This inquiry process can also be done by passing the article ID (service ID) and the site ID of the service server  102  from the service server  102  to the coupon server  103 . The coupon server  103  checks the valid date  304  of the coupon number from the record retrieved from the coupon type-dependent information management table  300 , and returns to the service server  102  whether or not the current date is before the coupon&#39;s valid date. 
   If the valid date of the coupon number has expired, the server  102  reads out the order window display data cached from the memory, and sends it to the user terminal  101 , thus ending the process. That is, no coupon number input field  705  for the article corresponding to the article ID is displayed on the order window  700 . 
   If the valid date of the coupon number is good, the service server  102  checks in step S 1103  if the value stored in the coupon number input error count  204  of the corresponding user falls within the allowable range. This process for checking if the value of the coupon number input error count  204  falls within the allowable range is the same as the check method executed upon displaying an error code in step S 1006 . 
   If the value of the coupon number input error count  204  of the user falls within the allowable range, the service server  102  creates the order window display data with a coupon number input field as the first display data by appending information required to display the coupon number input field  705  on the order window display data as the second display data held in the memory, and transmits it to the user terminal  101  in step S 1105 . As a result, the coupon number input field  705  for the article corresponding to the article ID is displayed on the order window  700 . 
   If the value of the input error count  204  of the user falls outside the allowable range in step S 1003 , the service server acquires the latest input error time  205  of that user from the user information table  200 , and checks in step S 1104  if a prescribed time period (e.g., 10 min) has been expired from the current time. 
   In this embodiment, the latest input error time and input error count are managed for each user. Alternatively, the latest input error time for each coupon ID may be managed in the coupon ID information table  400  of the coupon server  103 , and the input error count may be checked for each article and service. 
   If it is determined in step S 1104  that the prescribed time period has elapsed, the service server  102  creates order window display data with a coupon number input field by appending information required to display the coupon number input field  705  to the order window display data held in memory, and transmits it to the user terminal  101 , thus displaying the coupon number input field  705  for the corresponding article on the order window  700 . At this time, the input error count  204  stored in the user information table  200  may be reset to “0”. 
   If it is determined in step S 1104  that the prescribed time period has not elapsed yet, the service server  102  reads out the order window display data cached in the memory, and transmits it to the user terminal  101 , thus ending the process. That is, since no coupon number input field  705  for the corresponding article is displayed on the order window  700 , input of the coupon number is inhibited. 
   In this manner, the process for checking if the prescribed time period has elapsed is done, and if the prescribed time period has not elapsed yet, the coupon number is inhibited from being input. With this arrangement, for example, the system can prevent any malicious user from acquiring a coupon number by automatically generating a large number of random numbers, and successively inputting them. The service server  102  can reduce an unwanted load upon reception of illicit coupon numbers. 
   Since the prescribed time period has elapsed, the coupon number input field  705  is re-displayed, and the user can input the coupon number again. That is, an authentic user who has manually repeated input errors without any malicious intention can make a re-input operation of the coupon number. 
   In this embodiment, whether or not the coupon number input field  705  is displayed is checked based on the time elapsed after the latest coupon number input error time of the user in step S 1104 . In place of the elapsed time, the latest coupon number input error time of the user may be compared with the login authentication time. That is, the latest login time  203  may be registered in the user information table  200  at the time of login authentication in step S 501 , and the latest login time  203  may be compared with the latest input error time  205  in step S 1104 . If the latest login time  203  is later than the latest input error time  205 , window display data with a coupon number input field may be transmitted. In this case, even when the user has made a prescribed number or more of input errors of the coupon number, if he or she logs out and logs in again, the coupon number input field  705  is displayed again on the order window  700 . Hence, the user can input the coupon number again. 
   In this way, when it is determined that the authentic user has manually repeated input errors, the system allows such user to re-input the coupon number. Hence, the user does not need to inquire the administrator, thus improving the system&#39;s usability. Consequently, the administrator is not required to answer any inquiries of users, greatly reducing his workload. 
   The system according to this embodiment allows the input of the coupon number under the condition that a login authentication has succeeded in step S 501 , and that the authenticated user ID is used in various subsequent processes. However, the present invention is not limited to this, and can be applied to a system which does not use login authentication as a condition. In this case, upon first reception of a coupon number from the user terminal  101 , the session ID of a session of interest, the coupon number input error count and the latest input error time may be stored in a session management table, and the session ID may be used instead of the user ID in various processes. 
   In this embodiment, the coupon number input field  705  is displayed on the order window  700  of articles. However, when the user can use the perk independently of orders of articles, the coupon number input field may be displayed on the user information input window  800  or estimate window  900 . When the coupon number input field is displayed on the estimate window  900 , re-estimation may be made after the coupon number is input. 
   In this embodiment, if the value of the coupon number input error count  204  has exceeded the predetermined value in step S 1103  in  FIG. 11 , the coupon number input field return condition is checked in step S 1104 . Alternatively, step S 1104  may be executed before step S 1103 . If the coupon number input field return condition is met, the flow may advance to the process in step S 1103  or S 1105  after the input error count  204  stored in the user information table  200  is reset to “0”. When time exceeds the input error count may be reset when either re-login from the user is accepted or when the login input delay exceeds a predetermine value set for unauthorized logins. 
   Note that various display data transmitted from the service server  102  to the user terminal are interpreted by a browser application installed in the user terminal  101 , and are displayed on the window of the browser application. Also, various display data are described using a page script language such as HTML (Hyper Text Markup Language) that can be interpreted by a browser application. 
   Finally, the arrangement of a computer apparatus which forms the user terminal  101 , the service server  102 , and the coupon server  103  will be described below with reference to the block diagram of  FIG. 14 . Each of these apparatuses may be implemented by a single computer or by distributing respective functions to a plurality of computers as needed. When the apparatus is implemented by a plurality of computers, they are connected via, e.g., a Local Area Network (LAN) or the like to communicate with each other. 
   Referring to  FIG. 14 , reference numeral  1401  denotes a Central Processing Unit (CPU) which controls a computer  1400  as a whole. Reference numeral  1402  denotes a Read Only Memory (ROM) which stores programs and parameters which need not to be changed. Reference numeral  1403  denotes a Random Access Memory (RAM) which temporarily stores programs and data supplied to an external apparatus or the like. Reference numeral  1404  denotes an external storage device which could be a hard disk or a memory card that is fixed in the computer  1400  or a floppy disk (FD), or an optical disk such as a Compact Disk (CD) or the like, or a magnetic or optical card, or an IC card, or a memory card, and the like that are removable from the computer  1400 . Reference numeral  1405  denotes an interface with input devices such as a pointing device, a keyboard, and the like, which receives user&#39;s operations and input data. Reference numeral  1406  denotes an interface with a monitor which displays data held and supplied by the computer  1400 . Reference numeral  1407  denotes a network interface used to connect a network line for Internet or the like. Reference numeral  1408  denotes a system bus which connects the units  1401  to  1407  together and allows them to communicate. 
   Other Embodiments 
   The embodiments of the present invention have been described. The present invention may be applied to either a system made up of a plurality of devices, or an apparatus including a single device. A coupon number is used as an authentication code. However, the present invention is not limited to one specific code, and a character string, a combination of numerals and characters, and the like may be used as an authentication code. 
   Note that the present invention includes a case wherein the invention is achieved by directly or remotely supplying a software program that implements the functions of the aforementioned embodiments to a system or apparatus. In this case, software is not required to have the form of a program as long as it has the program function. 
   Therefore, the program code itself installed in a computer to implement the functional process of the present invention using the computer implements the present invention. That is, the present invention includes the computer program itself for implementing the functional process. 
   The form of programming is not particularly limited, and an object oriented language, an interpreted language, or even scripts supplied to an OS, may be used as along as they implement the program functions. 
   Any recording medium may be used for supplying the program, such as, a floppy disk, a hard disk, an optical disk, a magnetooptical disk, a MO, a CD ROM, a CD R, a CD RW, a magnetic tape, a nonvolatile memory card, a ROM, a DVD (DVD ROM, DVD R). 
   As another program supply method, it may be supplied by establishing a connection to a home page on the Internet using a browser on a client computer, and downloading the computer program itself of the present invention or a compressed file containing an automatic installation function from the home page onto a recording medium such as a hard disk or the like. Also, the program code that forms the program of the present invention may be segmented into a plurality of files, which may be downloaded from different home pages. That is, the claims of the present invention include a WWW server which allows a plurality of users to download program files required to implement the functional process of the present invention by the computer. 
   Also, a storage medium such as a CD ROM, which stores the encrypted program of the present invention, may be delivered to the user, the user who has cleared a predetermined condition may be allowed to download the key information that decrypts the program from a home page via the Internet, and the encrypted program may be executed using that key information. 
   The functions of the aforementioned embodiments may be implemented not only by executing the readout program code on the computer but also by some or all of actual processing operations being executed by an OS or the like running on the computer. 
   Furthermore, the functions of the aforementioned embodiments may be implemented by some or all of actual processes executed by a CPU or the like arranged in a function extension board or a function extension unit, which is inserted in or connected to the computer. Once the program is read out from the recording medium it is written in a memory of the extension board or unit to be executed later. 
   The present invention can be applied to all services that give the perk to each user by inputting numbers, symbols, and the like. According to the present invention, illicit accesses to an authentication system can be effectively suppressed without imposing any heavy load on the administrator. 
   As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims. 
   CLAIM OF PRIORITY 
   This application claims priority from Japanese Patent Application No. 2004-020378 filed on Jan. 28, 2004, which is hereby incorporated by reference herein.