JP2005208765A - Password authentication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a password authentication method which never carelessly disables a password even in case of a wrong input of password by a regular user. <P>SOLUTION: In this password authentication method to be used for individual authentication in use of digital equipment, a password inputted from an input means is collated with a password registered in a storage means, and an authentication means performs the authentication of the input password. When the input password does not match the registered password, whether or not the input password is similar to the registered password is determined. When the input password is similar as the result of the determination, the input of the password is counted as input frequency, and reinput of password is waited. When the count value of the input frequency is larger than a preset input frequency threshold, an invalidating operation such as prohibition of the input of password or invalidation of the registered password is performed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a password authentication method.

  In digital devices such as computer systems, a character string of finite length (hereinafter referred to as a password) is used to confirm whether the person who intends to use these devices is authorized. The authentication technology that confirms the user using the In this authentication method using a password, for example, the user inputs a user ID and a password, and the authentication means collates the registered password registered in association with the user ID and the input password, so that both passwords match. The device can be used only in such a case.

  Also, in such an authentication method using a password, if an incorrect password is input beyond the preset number of times of input (input number threshold) for the purpose of preventing a third party from estimating the password. For example, measures such as making the device incapable of inputting a password or invalidating a registered password corresponding to the user are performed (for example, see Patent Document 1). That is, a third party is prevented from repeatedly obtaining a registered password by repeatedly inputting the password until it matches the registered password.

As other measures for making it difficult to guess the registered password, for example, a method of increasing the number of characters of the registered password, a method of periodically changing the registered password, and the like are implemented.
JP-A-9-212458

  In the above-described conventional technique, even when a legitimate user inputs a password, there is a problem that the password cannot be used when a wrong password is input repeatedly.

  In addition, if the measures to increase the number of characters in the registered password and the measures to change the registered password regularly are adopted, incorrect input of the password and confusion with the password before the change occur, so that the user is mistaken. Since the possibility of entering a new password increases, the frequency at which the password cannot be used increases, which makes it unusable for the user.

  The present invention has been proposed based on the above-described conventional circumstances, and even if a legitimate user erroneously inputs a password, the password authentication method does not inadvertently disable the password. The purpose is to provide.

  The present invention employs the following means in order to achieve the above object. That is, the present invention is used for personal authentication when using a digital device, and compares the password input from the input means with the password registered in the storage means so that the authentication means authenticates the input password. Assuming an authentication method, if the input password and the registration password do not match, it is determined whether or not the input password and the registration password are similar. If the result of this determination is not similar, the input of the password is counted as the number of times of input, and the re-input of the password is awaited. Then, when the count value of the number of times of input is larger than a preset threshold value of the number of inputs, an invalid operation such as prohibiting the input of a password or invalidating a registered password is performed.

  In this way, when the input password is similar to the registered password, this password input is not included in the number of inputs counted for performing the invalid operation. Therefore, when the user inputs a similar password, the number of inputs until the invalid operation is performed does not decrease.

  Further, instead of the procedure, the number of times of password input is counted, and when the input password and the registered password do not match, it is determined whether or not the input password and the registered password are similar, If the results of this determination are similar, the same effect can be obtained even if the procedure for increasing the input count threshold is adopted.

  In addition, as a method of determining the similarity between the input password and the registered password, “characters less than the number of characters specified in advance in both passwords are different”, “characters in character positions specified in both passwords match”, “ A similar character group is set in advance, and in all character positions corresponding to both passwords, each character belongs to the same similar character group ”,“ in each character position corresponding to both passwords, each character Adopting a method that determines that the number of strokes is the same ”,“ the number of characters in both passwords is the same ”, and“ the input password matches a preset similar password ”. Can do.

  According to the present invention, if the input password is similar to the registered password, the input of the password is not included in the number of inputs counted to make the password input impossible or the registered password unavailable.

  Therefore, even if a legitimate user erroneously inputs a password, if the password is a similar password that is highly likely to be input by the user, the number of inputs until the invalid operation is performed does not change.

  For this reason, even if a legitimate user repeatedly enters a wrong password, it is possible to prevent an invalid operation from being performed carelessly.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a flowchart showing a procedure of a password authentication method of the present invention, and FIG. 2 is a schematic functional block diagram of a password authentication device 10 to which the method is applied.

  For example, when the password authentication apparatus 10 is provided in an image forming apparatus 20 such as a copying machine, as shown in FIG. 5, the password authentication apparatus 10 includes an image forming unit 21 that copies a document and forms an image, and a user. It is installed between the operation unit 22 composed of a touch panel or the like that gives a copy condition, a copy execution instruction or the like to the image forming unit 21. At this time, the password authentication apparatus 10 authenticates the password input from the operation unit 22 and notifies the image forming unit 21 of an instruction from the operation unit 22 only when the authentication is successful.

  As shown in FIG. 2, the password authentication device 10 includes a storage unit 3 including a hard disk, a memory, and the like in which a user ID for identifying a user, a registered password, and a password input count N described later are stored in association with each other. An input means 1 (such as the operation unit 22 is the input means 1 in the example shown in FIG. 5) and an authentication means 2 for authenticating the input password are provided. I have. The authentication unit 2, the input frequency comparison unit 4 and the threshold setting unit 5 described later may be configured by hardware such as a circuit or software such as a program. For example, it can be configured by a microcomputer and a program executed by the microcomputer stored in a memory such as a ROM.

  As shown in FIG. 1, when the user inputs a password together with the user ID from the input unit 1 (S <b> 1 in FIG. 1), the authentication unit 2 stores the registered password and the input count N corresponding to the user ID from the storage unit 3. Read and compare the registered password with the input password.

  In the comparison, first, the matching determination unit 2a included in the authentication unit 2 determines whether or not both passwords are completely matched (S2 in FIG. 1). At this time, when it is determined that the two passwords do not match, the similarity determination unit 2b included in the authentication unit 2 determines whether or not the two passwords are similar (S3 in FIG. 1).

  This similarity determination can be made based on, for example, the number of positions where the characters do not match at the character positions corresponding to the input password and the registered password. In other words, when the number of positions that do not match is smaller than a preset similarity threshold, it is determined that they are similar.

  For example, a case where “2” is set as the similarity threshold in the similarity determination unit 2b will be described. At this time, if the registered password is 4 characters “1234” and the input password is “1335”, the characters in the second and fourth positions from the left do not match in both passwords. Therefore, the number of unmatched positions is “2”, and it is determined that the two passwords are not similar. Also, in this example, when the input password is “1235”, the number of unmatched positions is “1”, and therefore, both passwords are determined to be similar.

  In the present embodiment, the similarity threshold can be arbitrarily set by the threshold setting means 5.

  If it is determined in the above similar determination (S3 in FIG. 1) that both passwords are not similar (when the input password in the above example is “1335”. FIG. 1 S3: No), the similarity determination unit 2b The number N of inputs is incremented by 1 (S4 in FIG. 1), the number N of inputs is input to the input number comparison means 4, and the number N of inputs is stored in the storage means 3 in association with the user ID.

  At this time, the input number comparison means 4 compares the input number threshold value a set in advance via the threshold value setting means 5 with the input number N of inputs (S5 in FIG. 1), and N> a. In such a case, the input unit 1 or the storage unit 3 is instructed to perform an invalid operation such as making the input unit 1 unable to input a password or invalidating a registered password corresponding to the input user ID (FIG. 1). S5: Yes → S6). If N ≦ a, the input number comparison means 4 puts the input means 1 into a password input standby state (S6: No in FIG. 1).

  For example, when the input count threshold “a” is “3”, the invalidation operation is executed when the input count N is “4” or more, that is, when a password that does not match or resemble the registered password is input four times in succession. Will be.

  On the other hand, if it is determined in the above similar determination (S3 in FIG. 1) that both passwords are similar (when the input password in the above example is “1235”; FIG. 1 S3: Yes), the similarity determination unit 2b Puts the input means 1 into a password input standby state. Therefore, when it is determined that both passwords are similar, the input of this password is not counted as the number of times of input N.

  As described above, in the present invention, even if the input password does not match the registered password, the input of the password that is determined to be similar is the number of inputs that are counted to perform the invalid operation. Not included. For this reason, even if the user incorrectly inputs the password, if the input password is a password similar to the registered password that is likely to be input by the user, the input will not be involved in the execution of the invalid operation. .

  By the way, when it is determined in the above match determination (S2 in FIG. 1) that both passwords match (S2 in FIG. 1: YES), the match determination unit 2a sets the number of times of input N to “0” and stores the number of times. The means 3 is stored in association with the user ID (S7 in FIG. 1), and the device provided with the password authentication device 10 is made available for use by the user as a successful authentication (S8 in FIG. 1).

  In the above-described embodiment, in order to count the number N of password inputs for each user ID, when the value of the number N of inputs is changed, the password is stored in the storage unit 3 in association with the input user ID. However, the input of this user ID is not an essential requirement. For example, when only the password is input from the input unit 1, the input number comparing unit 4 may be configured to hold the value of the input number N.

  In the above description, the password input count N is counted only when the determination results of both passwords are not similar. However, when the password is input, the input count N is counted, Of course, when the determination results are similar, the value of the number N of inputs may be decreased by one.

  By the way, in the said embodiment, although the determination of similarity of both passwords was performed based on the number of the position where each character does not correspond in the character position corresponding to an input password and a registration password, it is not restricted to this. .

  As another method, for example, when the characters at the character positions of the passwords specified in advance match in both passwords, such as “determine that they are similar when the third and fourth from the top match” You may judge.

  As another method, when a similar character group is set in advance and each character belongs to the same similar character group at all corresponding character positions of the input password and the registered password, both passwords are similar. You may determine that there is. For example, if {1, 2, 3, 4, 5} is set as one similar character group and {6, 7, 8, 9, 0} is set as another similar character group, 1 and 2 are similar. Although determined, 1 and 0 are not determined to be similar. Therefore, when the registered password is “1234”, the input password “2234” is determined to be similar, but the input password “0234” is determined to be not similar.

  Further, the similar character group may be a character having the same number of strokes. That is, if the registered password is “Ai Aia”, the number of strokes of each character is 3, 2, 2, 2, 3, and therefore it is determined that the input password “Ah Ua” is similar, and the input password “ "Ah ah" is judged not to be similar.

  In addition, it is possible to adopt a method of determining that both passwords are similar when the number of characters of the input password and the registered password is the same, or when the input password matches a preset similar password.

  Furthermore, the above similar determination need not be performed under a single condition, and a plurality of conditions may be combined.

(Embodiment 2)
FIG. 3 is a flowchart showing a procedure of another embodiment of the password authentication method of the present invention, and FIG. 4 is a functional block diagram of the password authentication apparatus 10. 3 and 4, the same procedures and blocks as those in the first embodiment are denoted by the same reference numerals.

  Below, based on FIG.3 and FIG.4, only the point which is different from the said Embodiment 1 is demonstrated.

  As shown in FIG. 3, as in the first embodiment, when a password is input from the input means 1 (S1 in FIG. 3), the match determination unit 2a determines whether or not both passwords match ( FIG. 3 S2).

  Here, when the match determination unit 2a determines that the two passwords do not match, the match determination unit 2a increments the input count N by 1 and inputs the value of the input count N to the input count comparison means 4. (FIG. 3 S31).

  Subsequently, the similarity determination unit 2b determines whether or not both passwords are similar (S3 in FIG. 3). In this similarity determination, when the similarity determination unit 2b determines that both passwords are similar, the similarity determination unit 2b increases the input number threshold value a set in the input number comparison unit 4 in advance by one. Then, the input unit 1 is set in a password input standby state (S32 in FIG. 3).

  When the similarity determination unit 2b determines that the two passwords are not similar, the similarity determination unit 2b instructs the input number comparison unit 4 to compare the input number N with the input number threshold value a. At this time, the processing performed by the input number comparison means 4 is the same as that in the first embodiment (FIG. 3, S5: Yes → S6, and S5: No).

  As described above, in this embodiment, even when the input password does not match the registered password, the input count threshold value a is increased when it is determined that the password is similar. That is, the input of the password is not counted as the number of times of input for performing the invalid operation. For this reason, even if a legitimate user enters the password incorrectly, if the entered password is a password similar to the registered password that is likely to be entered by the person, the entry will be invalid. Not involved in.

  In addition, the structure demonstrated by each said embodiment shows a specific example, and does not limit the technical scope of this invention. It is possible to design arbitrarily within the range where the effects of the present invention are exhibited.

  The present invention has an effect of preventing the password from being inadvertently disabled even if a legitimate user erroneously inputs the password, such as a device requiring authentication. It is useful as a password authentication method.

The flowchart which shows the password authentication method of this invention. Schematic functional block diagram of a password authentication device to which the present invention is applied The flowchart of the password authentication method of other embodiment of this invention. Schematic functional block diagram of a password authentication device to which the present invention is applied Schematic functional block diagram of an image forming apparatus to which the present invention is applied

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Input means 2 Authentication means 2a Match determination part 2b Similarity determination part 3 Memory | storage means 4 Input frequency comparison means 5 Threshold setting means 10 Password authentication apparatus 20 Image forming apparatus N Input frequency a Input frequency threshold

Claims (8)

In a password authentication method used for personal authentication when using a digital device, a password input from an input means is compared with a password registered in a storage means, and the authentication means authenticates the input password.
Determining whether the input password and the registration password are similar if the input password and the registration password do not match; and
Only when the determination result is not similar, the step of counting the input of the password as the number of input,
If the count value of the number of times of input is larger than a preset threshold value of the number of times of input, the step of prohibiting the input of a password or invalidating the registered password;
A password authentication method comprising: In a password authentication method used for personal authentication when using a digital device, a password input from an input means is compared with a password registered in a storage means, and the authentication means authenticates the input password.
Counting the number of times the password is entered;
Determining whether the input password and the registration password are similar if the input password and the registration password do not match; and
Only when the result of the determination is similar, increasing a preset input count threshold;
If the count value of the number of times of input is greater than the threshold value of the number of times of input, prohibiting input of a password, or invalidating a registered password; and
A password authentication method comprising:   The similarity determination determines that both passwords are similar when the number of positions where the characters do not match is smaller than a preset similarity threshold at the corresponding character positions of the input password and the registered password. The password authentication method according to claim 1 or 2.   3. The similarity determination according to claim 1 or 2, wherein the passwords are determined to be similar when the characters at the character positions designated in advance match at the character positions corresponding to the input password and the registered password. The password authentication method described.   The similarity determination is performed by setting a similar character group in advance, and when all the characters corresponding to the input password and the registered password belong to the same similar character group, the two passwords are similar. The password authentication method according to claim 1, wherein the password authentication method is determined to be present.   3. The determination according to claim 1, wherein the similarity determination determines that both passwords are similar when the number of strokes of each character matches at all character positions corresponding to the input password and the registration password. Password authentication method.   The password authentication method according to claim 1 or 2, wherein the similarity determination determines that both passwords are similar when the number of characters of the input password and the registered password is the same.   The password authentication method according to claim 1 or 2, wherein the similarity determination determines that the input password is similar to a registered password when the input password matches a preset similar password.

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