JPH0363865A - Device for preventing unauthorized use of password - Google Patents

Abstract

PURPOSE:To prevent the annulment of a password due to slight erroneous input by a regular user occurring by providing the collation means of the password with a registration number, a correlation detection circuit to find the correlation value of a correct number with an error number, and a means to adjust the accumulation of the number of times of noncoincidence based on the size of the correlation value. CONSTITUTION:A CPU 4 sends the password obtained from a card and the password inputted with a key pad 1 to the correlation detection circuit 3, and the correlation detection circuit 3 calculates the correlation value of them, and sends it to the CPU 4. When the correlation value shows a value less than 1.0, the CPU 4 judges that it is due to an unauthorized user or the mis-operation of the regular user, and accumulates the value in which the correlation value is subtracted from 1.0 as the number of times of noncoincidence, and stores the accumulated number of times of noncoincidence in a host computer 5, and requests key input to the user again. Thereby, it is possible to prevent the annulment of the password due to the slight erroneous input such as the treacherous memory of the user or mis-key touch occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a password prevention device that verifies a password and prevents unauthorized use.

[Conventional technology]

Conventionally, devices to prevent unauthorized use of PIN numbers determine the number of incorrect PIN entries, and limit the number of incorrect entries per use, or limit the number of incorrect entries per day, and limit the total number of incorrect entries. It was determined that the password had been used fraudulently, and the PIN was invalidated.

[Problem to be solved by the invention]

With the conventional PIN unauthorized use prevention device described above, there is a limit on the cumulative number of incorrect inputs, so it is possible for the authorized user to misremember,
This system has the drawback of accumulating minor input errors such as key touch errors, making the password invalid even for authorized users.

SUMMARY OF THE INVENTION An object of the present invention is to provide a device for preventing unauthorized use of a personal identification number, which eliminates the disadvantage of being lost.

[Means to solve the problem]

The device for preventing unauthorized use of a PIN number of the present invention determines that the PIN number has been used fraudulently when the number of times that the verification results of the input PIN number do not match reaches a certain number of times, and sets the PIN number to invalidate the effectiveness of the PIN number. The unauthorized use prevention device includes a collation means for collating the entered PIN number and the registration number, a correlation detection circuit for determining the correlation value between the correct number and the erroneous number, and a correlation detection circuit that calculates the cumulative number of discrepancies based on the magnitude of the correlation value. and means for adjusting.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of a circuit for preventing unauthorized use of a personal identification number, showing a first embodiment of the present invention. As shown in the figure, this PIN number unauthorized use prevention circuit includes a keypad 1, a card reader 2, a correlation detection circuit 3, and a host computer 5 connected to the CPU 4 via a communication line. Consists of.

Next, the operation of this PIN number unauthorized use prevention circuit will be explained. First, the user inserts the card into the card reader 2 and inputs the password using the keypad 1. card reader 2
reads the PIN code on the card and the cumulative number of discrepancies and sends it to the CPU 4, or the card reader 2 reads the identification number on the card, and the CPU 4 sends the identification number to the host computer 5. The CPU 4 receives the registered password and the cumulative number of discrepancies. The CPU 4 sends the password obtained from the card and the password input using the keypad 1 to the correlation detection circuit 3, and the correlation detection circuit 3 calculates a correlation value between the two and sends it to the CPU 4. If the correlation value is 1.0, that is, they are exactly the same, the CPU 4 determines that the user is an authorized user, and if the correlation value is less than 1.0, it determines that it is an unauthorized user or an erroneous operation by the authorized user. The value obtained by subtracting the correlation value from .0 is accumulated as the number of disagreements, and the accumulated number of disagreements is displayed on the card or
The key is stored in the host computer 5 and the user is requested to manually enter the key again. The user performs the above operation again,
The devices operate similarly. Here, how to find the correlation value is
For example, a method is adopted in which the input PIN and registration number are binarized and a correlation value is calculated using the number of bits of the registration number as the denominator and the number of bits of the correctly input PIN as the numerator. The arrangement of the numeric keys gives weight to numbers close to the registration number so that the correlation value becomes high, thereby reducing the number of errors in entering the password due to key operation errors. In this manner, by determining a predetermined cumulative value of correlation values and adjusting the correlation value, it is possible to relieve the user from remembering incorrectly or inputting a password that is invalid due to an erroneous operation. Note that the correlation detection circuit can also be realized by software.

FIG. 2 is a block diagram of a device for preventing unauthorized use of a personal identification number, showing a second embodiment of the present invention. In this PIN unauthorized use prevention device, a keypad 1, a card reader 2, a correlation detection circuit 3, and a judgment circuit 6 are connected to a CPU 4 in the form of a bus, and the output of the correlation detection circuit 3 is connected to a judgment circuit 6.
U4 is connected to the host computer 5 via a communication line.

In this embodiment, the determination circuit 6 determines the degree of correlation, and a mismatch with a high degree of correlation (for example, a degree of correlation of 0195 or more) is determined.
This has the advantage that it is not treated as a mismatch, and the ability to protect against simple erroneous input by authorized users is further improved.

Note that the determination circuit can also be realized by software.

〔Effect of the invention〕

As explained above, the present invention provides a PIN code that can save a PIN number from being invalidated due to a user's misremembering or a minor erroneous input such as a key touch error by providing a correlation detection circuit that finds a correlation value between errors and correctness. This has the effect of providing a device for preventing unauthorized use of numbers.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a device for preventing unauthorized use of a PIN number showing a first embodiment of the present invention, and FIG. 2 is a block diagram of a device for preventing unauthorized use of a PIN number showing a second embodiment of the present invention. be. 1...Keypad, 2...Card reader, 3...
Correlation detection, 4...CPU, 5...Host computer,...Judgment circuit.

Claims (1)

[Claims] The PIN that is input in a PIN unauthorized use prevention device that determines that the PIN has been used fraudulently when the number of times that the input PIN does not match the verification result reaches a certain number of times, and invalidates the validity of the PIN. and a registration number; a correlation detection circuit for determining a correlation value between a correct number and an error number; and a means for adjusting the cumulative number of discrepancies based on the magnitude of the correlation value. Device to prevent unauthorized use of numbers.