Password authentication device and method therefor

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Industrial application field]

The present invention relates to a password authentication device that authenticates a user using a password, for example, in a personal computer, and a method thereof.

【0002】

[Conventional technology]

Conventionally, in the authentication of a user by a password, a method of assigning one password to one user has been adopted. However, according to this method, the password is easily stolen by, for example, a peep when entering the password.

【0003】

In order to prevent password theft, there is a method in which the user uses a difficult password, but the difficult password is difficult for the user to remember, and the user often makes a note of the password. If this memo is seen by a third party, the password will still be stolen.

【0004】

In order to deal with such a problem, for example, Japanese Patent Application Laid-Open No. 2-16243 assigns a plurality of passwords to one user and authenticates the user only when a part of the assigned passwords is correctly entered. Disclose the password authentication method. However, even with this method, if all passwords are peeked at when entering the password, an unauthorized user can easily break into the computer.

【0005】

[Problems to be Solved by the Invention]

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a password authentication device and a method thereof, in which passwords are less likely to be stolen and computer security can be reliably guaranteed. Another object of the present invention is to provide a password authentication device and a method thereof so that a password is not easily stolen even if typing for password input is snooped. Another object of the present invention is to provide a password authentication device and a method thereof, which makes it easy for a user to remember a password and eliminates the need for a memo of the password.

【0006】

[Means to achieve the task]

[Password Authentication Device] In order to achieve the above object, the password authentication device according to the present invention includes a number of passwords (N) and a plurality of passwords (PW).₁~ PW_N), And one of the above multiple passwords (PW)_iIndex data (I) indicating, 1 i N)_e), A password setting means that accepts and accepts a password (PW) input from the outside, a password PW that is accepted, and the index data I._ePW of any of the above multiple passwords indicated by_iThe password PW entered from the outside and the index data I are compared with each other._ePW of any of the above multiple passwords indicated by_iWhen the above matches, the password comparison / authentication means for authenticating the password PW input from the outside, the password PW input from the outside, and the index data I_ePW of any of the above multiple passwords indicated by_iWhen matches with, the index data I_e, Any other PW of the multiple passwords_jIt has an index data changing means for changing so as to indicate (j i, 1 j N).

【0007】

Preferably, the index data changing means is the plurality of password PWs.₁~ PW_NThe index data I_eTo change.

【0008】

Preferably, the password PW input from the outside and one of the plurality of passwords PW_iThe password comparison / authentication means further comprises a password encryption means for encrypting the password, and the password comparison / authentication means is either an encrypted password input from the outside or one of the plurality of encrypted passwords PW._iThe encrypted password PW entered from the outside and one of the encrypted passwords PW_iIf the above matches, the password PW entered from the outside is authenticated.

【0009】

The password setting means accepts one or more inquiry passwords used for inquiring the password, and the password comparison / authentication means compares the password PW input from the outside with the set inquiry password. Then, the index data I corresponds to the inquiry password that matches the password entered from the outside._ePW of any of the above multiple passwords indicated by_iDisplay information indicating.

【0010】

[Action of Password Authentication Device] In the password authentication device according to the present invention, a user uses a relatively simple password by assigning a plurality of passwords to one user and updating the passwords cyclically. Even in this case, prevent the snooped password from being used by unauthorized users. Further, the password authentication device according to the present invention allows the user to select a password that can be easily associated with each other as a plurality of passwords, so that the user can easily remember the password without making a memo.

【0011】

[Password setting means] The password setting means is, for example, a plurality of passwords (PW) selected and entered by the user by a GUI (graphical user interface) operation.₁~ PW_N), The number of entered passwords (N) is accepted, and among the accepted passwords, the password PW that is valid for the next password authentication_iIndex data I_eStore in the table associated with.

【0012】

[Password encryption means] The password encryption means encrypts, for example, the password entered by the user for authentication by a hash function (h (x)). Further, the password encryption means is, for example, index data I among the passwords set and stored._ePassword indicated by PW_iIs read from the above table and encrypted by the same hash function (h (x)).

【0013】

[Password comparison / authentication means] The password comparison / authentication means are a password PW input by the user and encrypted by the password encryption means, and a password PW read from the table and encrypted by the password encryption means._iTo determine if these encrypted passwords match. If these encrypted passwords match, the password comparison / authentication means authenticates that the entered password is correct, otherwise it does not authenticate that the entered password is correct, and the user's Deny access to your computer.

【0014】

[Index data changing means] The index data changing means determines that the passwords match by the password comparison / authentication means, and each time the password is authenticated, for example, the index data I_eThe new index data I is the value obtained by adding 1 to the remainder system for the number N of passwords in (= i)._eLet (= j) (I_e = (I_e mod N) + 1 = j). Thus, index data I_eIs changed cyclically between the numerical value 1 and the numerical value N, and the password PW used for password authentication in the password comparison / authentication means_i(= PW_Ie), Password set as PW₁~ PW_NAny one of is selected cyclically.

【0015】

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] Hereinafter, a password authentication method will be described as a first embodiment of the present invention.

【0016】

[Computer 1] FIG. 1 is a diagram illustrating a configuration of a computer 1 to which the password authentication method according to the present invention is applied. The computer 1 is, for example, a personal computer for a single user, and includes a CPU 10 including a microprocessor and its peripheral circuits and the like, a memory 12 including a semiconductor memory and the like, a display device 14 such as a CRT display, an input including a keyboard and a mouse, and the like. It is composed of a device 16 and a storage device 18 such as a hard disk device and a proppy disk device. The computer 1 loads and executes the password authentication software 2 and other software stored in the storage device 18 into the memory 12 by these components.

【0017】

[Password Authentication Software 2] FIG. 2 is a diagram showing a configuration of password authentication software 2 executed by the computer 1 shown in FIG. As shown in FIG. 2, the password authentication software 2 is composed of a password setting unit 20, an encryption unit 22, a password management unit 24, a password input unit 26, and a password comparison / authentication unit 28.

【0018】

With these components, password authentication software 2 can be used by N users of computer 1 (maximum N)._max) Is set, and each time the user enters the password correctly, the password that the user should use next is cyclically selected from the set N passwords.

【0019】

[Password setting unit 20] FIG. 3 illustrates a first password setting GUI image displayed on the screen of the display device 14 (FIG. 1) by the password setting unit 20 shown in FIG. 2 in the first embodiment. It is a figure. The password setting unit 20 (FIG. 2) displays, for example, the password setting GUI image shown in FIG. 3 on the screen of the display device 14. For example, the user can easily remember any number of N passwords PW that are easy to associate with each other in the default password window of the password setting GUI image (Fig. 3).₁~ PW_NWrite (Apple, Orange, ..., Peach) and check one of the windows to specify the password order. In addition, the user can use the password PW.₁~ PW_NMaximum number of N_maxIs set in the corresponding window.

【0020】

In addition, if the user forgets which of the set passwords to use, the user checks a window that specifies whether to initialize (reset) the password that the user should use. If the user specifies to perform a reset, the password PW used for the reset_resetIs specified in the corresponding window, and which password the user will use after reset is specified in the corresponding window. Alternatively, the user checks the appropriate window if he chooses to ask the system operator to reset the password.

【0021】

The password setting unit 20 accepts the user's operation on the displayed GUI image from the input device 16 and accepts the password PW.₁~ PW_NAnd its number N, maximum number N_maxEtc. are output to the encryption unit 22. In the password setting GUI shown in FIG. 3, the set password is actually displayed in hidden letters using "*" for confidentiality. In addition, for the sake of brevity, the password PW below₁~ PW_NNumber N is the maximum number N that can be set_max(N = N_max) The case is a concrete example.

【0022】

[Encryption unit 22] The encryption unit 22 (Fig. 2) includes a password PW input from the password input unit 26 and a password PW input from the password setting unit 20.₁~ PW_NIs encrypted using, for example, the hash function h (x). The encryption unit 22 encrypts the password PW input from the password input unit 26 to obtain an encrypted password S._i(= h (PW)) is output to the password comparison / authentication unit 28, and the password PW input from the password setting unit 20.₁~ PW_NEncrypted password Se obtained by encrypting₁~ Se_N(= h (PW)₁) ~ H (PW)_N)) Is output to the password management unit 24. Further, the encryption unit 22 is the maximum number of data N input from the password setting unit 20._maxAnd other information is output to the password management unit 24 without encryption.

【0023】

[Password Management Unit 24] FIG. 4 is a diagram illustrating a format of password data stored in the memory 12 (FIG. 1) by the password management unit 24 shown in FIG. The password management unit 24 is the encrypted password Se entered from the encryption unit 22.₁~ Se_NAnd the maximum number data N_maxAnd the encrypted password Se, which is used for comparison when the user enters the password_i(S_Ie) Index data I_e(1 I_e, I N) is associated with, for example, a table format as shown in FIG. 4, and stored in the memory 12 (FIG. 1).

【0024】

The password management unit 24 reads the password data shown in FIG. 4 from the memory 12 and stores it in the storage device 18 when the computer 1 is powered off, and when the computer 1 is started. , Read from the storage device 18 and store in the memory 12.

【0025】

In addition, the password management unit 24 determines the index data I when the user inputs the password PW._eEncrypted password Se_iIs output to the password comparison / authentication unit 28.

【0026】

Further, when the set password is used for the first time, the password management unit 24 responds to the user's check on the GUI image window shown in FIG. 3, and the index data I_eTo initialize. That is, the user has a password PW₁~ PW_NWhen the password management unit 24 is set to use from above, the index data I_eIf the numerical value 1 is set as the initial value of and the user sets the index data I to be used from below, the password management unit 24 will perform the index data I._eNumerical value N as the initial value of_maxTo set. In the following explanation, for the sake of simplification of the explanation, unless otherwise specified, the user password PW.₁~ PW_NA specific example is the case where is set to be used from above.

【0027】

Further, in the password management unit 24, when the user inputs the correct password, that is, the password comparison / authentication unit 28 causes the encrypted password Se._i, S_iIndex data I shown in FIG. 4 each time it is determined that_eMaximum number of data N_m_axThe value obtained by adding the numerical value 1 to the remainder system for the new index data I_eBy (I_e= (I_e mod N_max) + 1), Index data I_eTo change.

【0028】

In addition, the user password PW₁~ PW_NIf is set to be used in order from the bottom, the password management unit 24 will perform index data I every time the user enters the correct password._eMaximum number of values obtained by subtracting the numerical value 1 from data N_maxResidual system for (I_e-1 0), or the maximum number N_max(I_e-1 = 0), the new index data I_eBy [I_e= (I_e-1) mod N_m_ax (I_e-1 0), N_max(I_e-1 = 0)] Index data I_eTo change.

【0029】

In addition, the password management unit 24 has a password PW for resetting the password._resetWhen the encrypted password encrypted by the encryption unit 22 is entered, the index data I shown in FIG._eIs the value set by the user for the password setting GUI image shown in Fig. 3, and the password is reset. Further, when the system operator performs an operation for resetting the password on the input device 16, the password management unit 24 determines the index data I._eIs set to the value set by the user, and the password is reset.

【0030】

[Password Input Unit 26] The password input unit 26 displays a GUI image for password input (not shown because it is the same image as the conventional one) when the user turns on the computer 1 and starts it up. Displayed in (Fig. 1). When the user performs an operation of inputting a password to the displayed GUI image for password input, the password input unit 26 accepts the input password PW and outputs it to the encryption unit 22.

【0031】

[Password Comparison / Authentication Unit 28] The password comparison / authentication unit 28 is the encrypted password S entered from the encryption unit 22._iAnd the encrypted password Se entered from the password management unit 24If they match, the user who entered the password is authenticated as a legitimate user, access to other programs (not shown) is permitted, and the password management unit 24 to that effect. Notify to. In addition, the password comparison / authentication unit 28 does not recognize the user who entered the password as a legitimate user in other cases, and does not allow access to other programs.

【0032】

[Password setting / authentication operation of computer 1] The password setting and password authentication operation of the password authentication software 2 on the computer 1 will be described below.

【0033】

[Password setting operation] First, the password setting operation will be described with reference to FIG. FIG. 5 is a flowchart showing the password setting operation (S100) by the password authentication software 2 (FIG. 2).

【0034】

As shown in FIG. 5, in step 102 (S102), when the user performs an operation for starting password setting for the input device 16 (FIG. 1), the password setting unit 20 (FIG. 2) performs this operation. Is accepted, and the GUI image for password setting (Fig. 3) is displayed on the display device 14. The user sets the necessary information as described above for the password setting GUI image displayed on the display device 14. Further, the password management unit 24 adds the index data I to the password data shown in FIG._eStores the initial value of.

【0035】

In step 104 (S104), the password management unit 24 sets the password PW set by the user for the password setting GUI image and is accepted by the password setting unit 20.₁~ PW_NMaximum number of N_maxIs stored in the password data.

【0036】

In step 106 (S106), the password management unit 24 assigns the numerical value 1 to the variable i and initializes it.

【0037】

In step 108 (S108), the password setting unit 20 sets the i-th password PW set by the user for the password setting GUI image._iIs accepted and output to the encryption unit 22. The encryption unit 22 is the password PW input from the password setting unit 20._iIs encrypted with the hash function h (x), and the encrypted password Se_iIs generated and output to the password management unit 24. The password management unit 24 has an encrypted password S._iIs stored in the password data as the i-th encrypted password.

【0038】

In step 110 (S110), the password management unit 24 increments the variable i (i = i + 1).

【0039】

In step 112 (S112), the password management unit 24 has a maximum number of values of the variable i N._maxJudge whether it is larger or not, and the maximum number of values of variable i is N_maxIf it is larger than, the process ends, and in other cases, the process returns to S108.

【0040】

[Password Authentication Operation] The password authentication operation will be described below with reference to FIG. FIG. 6 is a flowchart showing the password authentication operation (S200) by the password authentication software 2 (FIG. 2).

【0041】

As shown in FIG. 6, when the user starts the computer 1 in step 202 (S202), the password input unit 26 displays a GUI image (not shown) for password input on the display device 14 (FIG. 1). .. The password management unit 24 uses the encrypted password Se included in the password data (Fig. 4).₁~ Se_NFrom index data I_eEncrypted password S indicated by_IeThe encrypted password Se, which is compared in the password comparison / authentication unit 28Select as.

【0042】

In step 204 (S204), the password input unit 26 requests the user to input the password via the password input GUI image displayed on the display device 14. When the user inputs the password PW in response to the password input request, the password input unit 26 accepts the password input by the user and outputs the password to the encryption unit 22.

【0043】

In step 206 (S206), the encryption unit 22 encrypts the password PW input from the password input unit 26 by the hash function h (x), and the encrypted password S_iIs generated and output to the password comparison / authentication unit 28.

【0044】

In step 208 (S208), the password comparison / authentication unit 28 uses the encrypted password Se entered from the password management unit 24.And the encryption password S entered from the encryption unit 22_iTo determine whether or not they match. The password comparison / authentication unit 28 proceeds to the process of S210 if they match, and returns to the process of S204 in other cases.

【0045】

In step 210 (S210), the password comparison / authentication unit 28 authenticates that the user who entered the password is a legitimate user of computer 1 and permits access to other software and the like (not shown) of computer 1. Then, notify the password management unit 24 to that effect. The password management unit 24 responds to the authentication of the password comparison / authentication unit 28 and indexes the index data I._e, Index data I_eMaximum number of N_maxChange to the value obtained by adding the numerical value 1 to the remainder system for (I)_e= (I_e mod N_max) +1), end password authentication.

【0046】

[Effect of password authentication by password authentication software 2] As explained above, when password authentication is performed by password authentication software 2, the password is changed cyclically, so that computer security can be guaranteed. Further, when the password is authenticated by the password authentication software 2, even if the typing for entering the password is peeked, the password to be used next is changed sequentially, so that the password is not easily stolen. In addition, when password authentication is performed with password authentication software 2, multiple passwords that are easy to associate and remember can be set, making it easier for users to remember passwords and eliminating the need for memos, reducing the risk of password theft. it can.

【0047】

[Modification example] By appropriately changing the password authentication operation shown in FIG. 6, the password shown in FIG. 4 can be enabled in order from the bottom. Further, the operation of the password authentication software 2 may be changed so that the password management unit 24 can be requested to display the decrypted password data in case the user forgets the password. Further, the password authentication software 2 may be changed so as to perform the password authentication process by omitting the encryption unit 22 and comparing / authenticating the unencrypted passwords according to the configuration / use. Further, it goes without saying that the password authentication method according to the present invention can be made compatible with a multi-user computer system by modifying a plurality of password data shown in FIG. 4 so that the password management unit 24 manages them. Absent.

【0048】

[Second Embodiment] Hereinafter, a second embodiment of the present invention will be described. According to the password authentication method shown as the first embodiment, the password is changed cyclically, so that the computer security can be surely guaranteed. However, for example, if the computer 1 is not accessed for a long period of time, the user may not be able to remember which number of the plurality of passwords will be valid next, or the password itself may not be remembered.

【0049】

In such cases, at the request of the user, while maintaining security, the user can be notified of the next valid password, or a hint for remembering the password can be given to the user. It is convenient. The password authentication method shown as the second embodiment changes the operation of the password authentication software 2 (Fig. 2) to inform the user which password is valid and a hint for remembering the forgotten password. Is made possible. In the second embodiment as well, unless otherwise specified, the processing content of each part of the password authentication software 2 is the same as that in the first embodiment.

【0050】

[Password setting unit 20] FIG. 7 illustrates a second GUI image for password setting displayed on the screen of the display device 14 (FIG. 1) by the password setting unit 20 shown in FIG. 2 in the second embodiment. It is a figure. The password setting unit 20 (FIG. 2) displays the second password setting GUI image illustrated in FIG. 7 on the screen of the display device 14 instead of the first password setting GUI image shown in FIG. Accept user actions.

【0051】

The password setting unit 20 displays a second password setting GUI image when the user first uses the computer 1 and when the password is updated. The latter of these, when updating the password, for example, the password setting unit 20 displays the second password setting GUI image only when the immediately preceding password authentication is completed normally, and is invalid. Prevent password updates by users.

【0052】

As shown in FIG. 7, in the second password setting GUI, in addition to the items that can be set using the first password setting GUI (initial setting password, etc. and items 1 and 2), the user can use the password itself. Password when requesting password authentication software 2 to display a hint to remember the password if you forget (Inquiry password PW that allows inquiry of questions and related items_hint: Item 3) can be set.

【0053】

In addition, in the second password setting GUI, the user has a password PW.₁~ PW_NPassword for requesting password authentication software 2 to notify which of the two is valid (inquiry password PW that allows you to inquire what number a valid password is._number: Item 4) can be set.

【0054】

In addition, in the second password setting GUI, if any of the passwords that have already been set is entered incorrectly, the password authentication software 22 displays how far the password is from the valid password. Whether or not (item 5) can be set.

【0055】

FIG. 8 is a diagram illustrating a GUI for setting related items displayed by the password setting unit for setting related items. Further, when the user performs an operation of setting a question / related item on the second password setting GUI, the password setting unit 20 displays the related item setting GUI illustrated in FIG. 8 on the display device 14. Display on screen and accept user settings. As shown in Fig. 8, in the GUI for setting related items, the password PW₁~ PW_N("Apple", "Orange", ..., "Peach" in Figure 8) Related items Hint to help you remember each₁~ Hint_N("My favorite fruit", "Florida", ..., "Perishable fruit" in Figure 8) can be set.

【0056】

For example, the user can enter the password PW in the default password window of the displayed password setting GUI image (Fig. 7).₁~ PW_NWrite (Apple, Orange, ..., Peach), check one of the windows to specify the order of passwords, and check the maximum number of passwords N_maxTo set.

【0057】

In addition, the user specifies whether or not to reset the password, and when resetting, the password PW used for resetting_resetSpecify, specify the password to be used after the reset, or specify to request the system operator to reset.

【0058】

In addition, the user specifies whether to inquire the question / related items, and when inquiring, the inquiry password PW_hintTo set. When the user specifies / sets the reference to these questions / related items, the password setting unit 20 displays the related item setting GUI shown in FIG. 8, and the user sets the password for the related item setting GUI. PW₁~ PW_NEach tip (related item Hint₁~ Hint_N) Is set.

【0059】

In addition, the user specifies whether to make it possible to query the number of valid passwords, and if so, the query password PW._numberTo set. The user also specifies whether to notify how far the entered password is from the valid password.

【0060】

The password setting unit 20 accepts the user's operation on the displayed GUI image (Figs. 7 and 8) from the input device 16 and accepts the password PW.₁~ PW_NAnd its number N, maximum number N_maxEtc. are output to the encryption unit 22. In the second embodiment as well, as in the first embodiment, in the password setting GUI shown in FIG. 3, the set password is actually used as "*" for confidentiality. It is displayed in hidden letters. In addition, for the sake of brevity, the password PW below₁~ PW_NNumber N is the maximum number N that can be set_max(N = N_max) The case is a concrete example.

【0061】

[Encryption unit 22] The encryption unit 22 (FIG. 2) has a password PW input from the password input unit 26 and a password PW input from the password setting unit 20 as in the first embodiment.₁~ PW_NIs encrypted using, for example, the hash function h (x). In addition, the encryption unit 22 is the reset password PW input from the password setting unit 20._reset, Inquiry password PW_number, PW_hintIs encrypted using, for example, the hash function h (x).

【0062】

The encryption unit 22 encrypts the password PW input from the password input unit 26 to obtain an encrypted password S._i(= H (PW)) is output to the password management unit 24 and the password comparison / authentication unit 28. In addition, the encryption unit 22 is the password PW input from the password setting unit 20.₁~ PW_N, PW_reset, PW_number, PW_hintEncrypted password Se obtained by encrypting each₁~ Se_N(= h (PW)₁) ~ H (PW)_N)), S_reset(= h (PW)_reset)), S_number(= h (PW)_number), S_hint(= h (PW)_hint)) Output each to the password management unit 24. Further, the encryption unit 22 is the maximum number of data N input from the password setting unit 20._maxAnd related items Hint₁~ Hint_NEtc. are output to the password management unit 24 without being encrypted.

【0063】

[Password Management Unit 24] FIG. 9 is a diagram illustrating the format of the second password data stored in the memory 12 (FIG. 1) by the password management unit 24 shown in FIG. 2 in the second embodiment. .. The password management unit 24 has the encrypted password Se entered from the encryption unit 22 as in the first embodiment.₁~ Se_NAnd the maximum number data N_maxAnd the encrypted password Se, which is used for comparison when the user enters the password_i(S_I_e) Index data I_e(1 I_e, I N) is associated with, for example, a table format as shown in FIG.

【0064】

In addition, the password management unit 24 is input from the encryption unit 22, and each reset password PW._resetAnd inquiry password PW_hint, PW_numberEncrypted password S corresponding to_reset, S_hint, S_number, Encrypted password Se₁~ Se_N, Maximum number data N_maxAnd index data I_eCorrespond with. Furthermore, the password management unit 24 has an encrypted password Se.₁~ Se_NRelated items Hint for each₁~ Hint_NWith a pointer indicating, the attached pointer and related items Hint₁~ Hint_NAnd associate with. The password management unit 24 stores these associated data in the memory 12 (FIG. 1) or the like.

【0065】

In addition, the password management unit 24 determines the index data I when the user inputs the password PW._e, Index data I_eEncrypted password S corresponding to_i, And the encrypted password S_reset, S_hint, S_numberIs output to the password comparison / authentication unit 28.

【0066】

Further, the password management unit 24 has the index data I as in the first embodiment._eInitializes, changes numerical values, and resets. In addition, the password comparison / authentication unit 28 has an encrypted password Se._iAnd the encrypted password S_hintIf it is determined that the data matches, the password management unit 24 sets the index data I, respectively._eValid encrypted password Se_iRelated items corresponding to Hint_iIs output to the password comparison / authentication unit 28.

【0067】

In addition, the password management unit 24 is the encrypted password Se that is input from the password input unit 26 via the encryption unit 22.And the encrypted password Se₁~ S_NCompare with and encrypted password SeEncrypted password S that matches_jThe index data J indicating is output to the comparison / authentication unit 28.

【0068】

[Password Comparison / Authentication Unit 28] The password comparison / authentication unit 28 has an encrypted password S corresponding to the password PW entered by the user, as in the first embodiment._iAnd the encrypted password SeIf matches, the user who entered the password is authenticated as a legitimate user.

【0069】

In addition, it is set to allow inquiries about questions and related matters (Fig. 7), and the encrypted password S corresponding to the password PW entered by the user._iAnd the encrypted password S_hintIf the password matches, the password comparison / authentication unit 28 will check the valid encrypted password Se._iRelated matters corresponding to Hint_iIs displayed on, for example, a GUI image for password input (not shown).

【0070】

In addition, it is set so that the number of valid passwords can be referred to, and the encrypted password S corresponding to the password PW entered by the user._iAnd the encrypted password S_numberIf the password matches, the password comparison / authentication unit 28 will check the valid encrypted password Se._iIndex data I showing the order of_eIs displayed on, for example, a password input image.

【0071】

In addition, a setting is made to indicate how far the password entered from the valid password is, and the encrypted password S corresponding to the password PW entered by the user._iAnd the encrypted password S_numberIf the above matches, the password comparison / authentication unit 28 uses the index data J to the index data I input from the password input unit 26._eThe subtracted value JI obtained by subtracting is displayed on the password input image, for example.

【0072】

[Password setting / authentication operation] The password setting and password authentication operation of the password authentication software 2 in the second embodiment will be described below.

【0073】

[Password setting operation] In the second embodiment, the password authentication software 2 performs the password setting operation in the same manner as in the first embodiment.

【0074】

As shown in FIG. 5, in step 102 (S102), when the user performs an operation for starting password setting for the input device 16 (FIG. 1), the password setting unit 20 (FIG. 2) performs this operation. Accepting the operation, the GUI image for password setting (Figs. 7 and 8) is displayed on the display device 14.

【0075】

When the user sets the necessary information for the password setting GUI image displayed on the display device 14 as described above, the encryption unit 22 encrypts the necessary information among the set information and sets the password. Output to management unit 24. The password management unit 24 associates the information input from the encryption unit 22 with each other as shown in FIG. 9, and generates password data. Further, the password management unit 24 adds the index data I to the password data shown in FIG._eStores the initial value of.

【0076】

In step 104 (S104), the password management unit 24 sets the password PW set by the user for the password setting GUI image and is accepted by the password setting unit 20.₁~ PW_NMaximum number of N_maxIs stored in the password data.

【0077】

In step 106 (S106), the password management unit 24 assigns the numerical value 1 to the variable i and initializes it.

【0078】

In step 108 (S108), the password setting unit 20 sets the i-th password PW set by the user for the password setting GUI image._iIs accepted and output to the encryption unit 22. The encryption unit 22 is the password PW input from the password setting unit 20._iIs encrypted with the hash function h (x), and the encrypted password Se_iIs generated and output to the password management unit 24. The password management unit 24 has an encrypted password S._iIs stored in the password data as the i-th encrypted password.

【0079】

In step 110 (S110), the password management unit 24 increments the variable i (i = i + 1).

【0080】

In step 112 (S112), the password management unit 24 has a maximum number of values of the variable i N._maxJudge whether it is larger or not, and the maximum number of values of variable i is N_maxIf it is larger than, the process ends, and in other cases, the process returns to S108.

【0081】

[Password Authentication Operation] Hereinafter, the password authentication operation in the second embodiment will be described with reference to FIG. 10. FIG. 10 is a flowchart showing the password authentication operation (S300) in the second embodiment.

【0082】

As shown in FIG. 10, when the user starts the computer 1 in step 302 (S302), the password input unit 26 displays a GUI image (not shown) for password input on the display device 14 (FIG. 1). .. Password management unit 24 is index data I_eEncrypted password S indicated by_I_e, Index data I_e, And the encrypted password S_reset, S_hint, S_num_berIs output to the password comparison / authentication unit 28.

【0083】

In step 304 (S304), the password input unit 26 requests the user to input the password via the password input GUI image displayed on the display device 14, as in S204 shown in FIG. When the user inputs the password PW in response to the password input request, the password input unit 26 accepts the password input by the user and outputs the password to the encryption unit 22.

【0084】

In step 306 (S306), the encryption unit 22 encrypts the password PW input from the password input unit 26 by the hash function h (x), and the encrypted password S_iIs generated and output to the password comparison / authentication unit 28.

【0085】

In step 308 (S308), the password comparison / authentication unit 28 uses the encrypted password Se., S_iDetermine if they match. The password comparison / authentication unit 28 proceeds to the process of S310 if they match, and returns to the process of S312 in other cases.

【0086】

In step 310 (S310), the password comparison / authentication unit 28 authenticates that the user who entered the password is a legitimate user of computer 1 and permits access to other software and the like (not shown) of computer 1. Then, notify the password management unit 24 to that effect. The password management unit 24 responds to the authentication of the password comparison / authentication unit 28 and indexes the index data I._e, Index data I_eMaximum number of N_maxChange to the value obtained by adding the numerical value 1 to the remainder system for (I)_e= (I_e mod N_max) +1), end password authentication.

【0087】

In step 312 (S312), the password comparison / authentication unit 28 uses the encrypted password S._i, S_resetDetermine if they match. If they match, the process proceeds to S314, and in other cases, the process proceeds to S316.

【0088】

In step 314 (S314), the password comparison / authentication unit 28 performs the encrypted password S._i, S_resetUpon notifying that they match, the password management unit 24 resets the index data I and outputs the reset index data I to the password comparison / authentication unit 28.

【0089】

In step 316 (S316), the password comparison / authentication unit 28 uses the encrypted password S._i, S_hintDetermine if they match. If they match, the password comparison / authentication unit 28 proceeds to the process of S318, and in other cases, proceeds to the process of S320.

【0090】

In step 318 (S318), the password comparison / authentication unit 28 uses the encrypted password Se._iRelated item indicated by the pointer attached to Hint_iIs displayed.

【0091】

In step 320 (S320), the password comparison / authentication unit 28 uses the encrypted password S._i, S_numberDetermine if they match. If they match, the password comparison / authentication unit 28 proceeds to the process of S322, and in other cases, proceeds to the process of S324.

【0092】

In step 324 (S324), the password comparison / authentication unit 28 determines the index data I._eIs displayed.

【0093】

In step 324 (S324), the password comparison / authentication unit 28 uses the encrypted password S._iAnd the encrypted password S₁~ S_NIt is determined whether or not any of the above matches, and if they match, the process proceeds to S326, and if not, the process returns to S304.

【0094】

In step 326 (S326), the password setting unit 24 outputs the index data J to the password comparison / authentication unit 28, and the password comparison / authentication unit 28 displays the subtraction value JI.

【0095】

[Effect of the invention]

As described above, according to the password authentication device and the method thereof according to the present invention, the password is less likely to be stolen and computer security can be reliably guaranteed. Further, according to the password authentication device and the method thereof according to the present invention, the password is unlikely to be stolen even if the typing for entering the password is snooped. Further, according to the password authentication device and the method thereof according to the present invention, it is possible for the user to easily remember the password and to eliminate the need for a memo of the password.

[Simple explanation of drawings]

[Figure 1]

It is a figure which illustrates the structure of the computer to which the password authentication method which concerns on this invention is applied.

[Figure 2]

It is a figure which shows the structure of the password authentication software executed by the computer shown in FIG.

[Fig. 3]

In the first embodiment, it is a figure which illustrates the password setting GUI image which the password setting part shown in FIG. 2 displays on the screen of the display device (FIG. 1).

[Fig. 4]

It is a figure exemplifying the format of the password data stored in the memory (FIG. 1) by the password management unit shown in FIG.

[Fig. 5]

It is a flowchart which shows the password setting operation (S100) by the password authentication software (Fig. 2).

[Fig. 6]

It is a flowchart which shows the password authentication operation (S200) by the password authentication software (Fig. 2).

[Fig. 7]

In the second embodiment, the password setting unit shown in FIG. 2 illustrates a second password setting GUI image displayed on the screen of the display device (FIG. 1).

[Fig. 8]

It is a figure which illustrates the GUI for setting the related item which the password setting part displays for setting the related item.

[Fig. 9]

FIG. 2 is a diagram illustrating a format of a second password data stored in a memory (FIG. 1) by the password management unit shown in FIG. 2 in the second embodiment.

[Fig. 10]

It is a flowchart which shows the password authentication operation (S300) in the 2nd Embodiment.

[Explanation of symbols]

1 ... Computer 10 CPU 12 ... Memory 14 Display device 16 Input device 18 Storage device 2 Password authentication software 20 Password setting section 22 Encryption part 24 Password management department 26 Password input section 28 Password comparison / authentication department