JPH0749839A - System and device for certification utilizing chaos, device to be certified, and method for certification - Google Patents

Abstract

PURPOSE:To disable the mechanism of certification to easily be solved even if certification information to be sent is intercepted and to make it difficult to forge the device by constituting the certification system which utilizes the chaos by using the certification device and the device to be certified which can make a mutual communication. CONSTITUTION:The certification device 1 is an automatic ticket examination machine which decides the validity of a user's commutation ticket or an ID card certification device. The device 2 to be certified is the commutation ticket or ID card that a user carries. The certification device 1 consists of a CPU 11, a ROM 12, a RAM 13, a communication circuit 14, and a magnetic disk device 15. A sequence X1 of numbers which have no periodicity is generated with a sequence of numbers of chaos as a style showing the irregular behavior of a dynamical system. Programs which calculates the same recurrence formula are stored in the ROM 12 of the certification device 1 and the ROM 22 of the device 2 to be certified. The certification device 1 sends a sequence number (n) to the device 2 to be certified through a communication circuit 14. This sequence number (n) is used as information for certifying the device 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an authentication system, an authentication device that performs authentication, an authenticated device that is authenticated, and an authentication method.

More specifically, the present invention relates to a specific area such as an entrance of a research institute or an office of a company, an automatic ticket gate of a station, or an entrance of a membership store where only specific members can come and go. TECHNICAL FIELD The present invention relates to an authentication system for contactlessly authenticating an ID card, a commuter pass, or a membership card possessed by a visitor at an entrance place, an authentication device and an authenticated device that constitute this authentication system, and an authentication method.

[0003]

[Background Art] Depending on a research institute or office of a company, when the employee enters the research institute or office, an ID is entered at the entrance.
You may have to authenticate with a card or certification card. In addition, when passing through the automatic ticket gate of a station, the passenger needs to be authenticated by the automatic ticket gate for the commuter pass.

Cards such as ID cards and commuter passes (devices to be authenticated) and devices for authenticating the cards (authentication devices)
There are a contact method and a contacted method as a coupling method between the and.

A magnetic card is a typical example of the contact method. Data recorded on the magnetic card is read by the magnetic head, or predetermined data is written on the magnetic card by the magnetic head. Further, like an IC card, there is a device in which an authentication device having a metal contact and a device to be authenticated perform communication by bringing the contacts into contact with each other. The non-contact method is to perform communication without contact by electromagnetic induction or electromagnetic waves.

In particular, in the non-contact method using electromagnetic waves, an employee or a customer carrying a magnetic card, an ID card, a commuter pass, etc., takes out the card from a pocket or bag and uses it as an authentication device such as an automatic ticket gate. There is no need to insert, pull out, and put it back in your pocket. For example, you can leave your ID card or commuter pass in your pocket or just hang it on your chest like a name tag. You can expect the convenience of passing through the entrance or automatic ticket gates.

[0007] However, if communication is performed by such a non-contact method, it becomes easy to intercept an identification number or an authentication number transmitted by a device to be authenticated such as a card, and it is easy to forge the device to be authenticated from the intercepted information. May be done.

[0008]

DISCLOSURE OF THE INVENTION It is an object of the present invention to easily clarify the mechanism of authentication when the authentication device and the device to be authenticated communicate with each other in a contactless manner even if the communication authentication information is intercepted or tapped. And therefore counterfeiting these devices,
In particular, it is difficult to forge the device to be authenticated.

The chaos-based authentication system according to the present invention comprises an authentication device and a device to be authenticated which can communicate with each other.

The authentication device is determined by the storage means for storing the recurrence formula for generating a sequence having no periodicity, the determining means for determining the number n for designating the term of the recurrence formula, and the determining means. Information including the number n is used as authentication information.
Based on the number n determined by the determining unit, the transmitting unit transmitting to the device to be authenticated, the receiving unit receiving information including the result of processing the authentication information by the device to be authenticated, and the determining unit. And processing means for performing processing including calculation for obtaining the value of the n-th term of the recurrence formula, processing result of the authentication information received from the device to be authenticated, and result processed by the processing means. And a determination means for determining whether or not the device to be authenticated is valid according to the result of the comparison means.

The device to be authenticated receives the authentication information including the number n transmitted from the authentication device.
Storage means for storing the same recurrence formula as the recurrence formula stored in the authentication device, and the value of the n-th term of the recurrence formula based on the number n included in the received authentication information. It is provided with processing means for performing processing including the required calculation, and transmission means for transmitting information including the processing result by the processing means to the authentication device.

In the chaos-based authentication method according to the present invention, the authentication device and the device to be authenticated communicate with each other so that the authentication device authenticates the device to be authenticated.

The authentication device determines a number n for designating a term of a recurrence formula that generates a sequence having no periodicity, and transmits information including the determined number n to the device to be authenticated as authentication information. In addition, based on the number n determined above,
A process including a calculation for obtaining the value of the n-th term of the stored recurrence formula is performed.

The device to be authenticated is transmitted from the authentication device,
Processing for receiving the authentication information including the number n and including the calculation for obtaining the value of the n-th term of the recurrence formula which is the same as the recurrence formula stored by the authentication device and stored , Based on the number n included in the received authentication information, and transmits information including the processed result to the authentication device.

When the authentication device receives the information including the result of the authentication information processed by the authentication target device from the authentication target device, the authentication device compares the processing result of the authentication information received from the authentication target device with the processing result. According to the result of the comparison, it is determined whether the device to be authenticated is valid.

As described above, according to the present invention, the number designating the item of the sequence having no periodicity as the authentication information communicated between the authentication device and the device to be authenticated and the item of the sequence corresponding to the number. The values of and are used. Even if the number of the sequence and the value of the sequence term corresponding to the number are intercepted or eavesdropped, since the sequence has no periodicity, the recurrence formula for generating the sequence cannot be easily solved, Therefore, it is possible to make it difficult to forge these devices, particularly for the devices to be authenticated such as ID cards and commuter passes.

In a preferred embodiment of the present invention, as the number n determined by the authentication device, a number already determined is stored and a number other than this is determined or a random number is determined. This eliminates or has a very low probability of intercepting or eavesdropping on the same number. Therefore, even if the device to be authenticated is forged by using the intercepted or eavesdropped number and the value of the term of the recurrence formula, there is no possibility or very low possibility of utilizing the forged device.

In one embodiment of the present invention, the processing means of the authenticating device and the authenticated device, if the number n corresponds to a predetermined specific value, the n-th term of the recurrence formula. After the value is obtained, the value is further subjected to a predetermined operation, and when it is not equivalent, a calculation for obtaining only the value of the n-th term of the recurrence formula is performed. As a result, the authentication mechanism can be made more complicated, and its decryption can be made difficult.

In another embodiment of the present invention, the processing means of the authentication device and the device to be authenticated constitute a recurrence formula when the number n corresponds to a predetermined specific value. Calculate the value of the n-th term based on the recurrence formula after changing the above parameters, and if it is not equivalent, change the value of the n-th term without changing the above parameters. To calculate. As a result, it is possible to make it more difficult to decipher the recurrence formula, and to make it more difficult to forge the device to be authenticated.

In still another embodiment of the present invention, the storage means of the authenticating device and the authenticated device store a plurality of recurrence formulas for generating a sequence having no periodicity, and the processing of the authenticating device and the authenticated device is performed. The means performs a calculation for obtaining the value of the n-th term for each of the plurality of recurrence formulas, and further performs a predetermined calculation on the calculation results. By providing a plurality of recurrence formulas, the decryption can be made more difficult, and the forgery of the device to be authenticated can be made more difficult.

[0021]

【Example】

 (1) First embodiment

FIG. 1 shows an authentication device 1 according to the first embodiment.
FIG. 3 is a block diagram showing a configuration of an authentication system including a device to be authenticated 2

The authentication device 1 is, for example, an automatic ticket gate at a station for judging the validity of a passenger's commuter pass or a card authentication device for judging the validity of an employee's ID card. The device to be authenticated 2 is a commuter pass carried by a customer or an ID card carried by an employee, and is constituted by a so-called IC card or CPU card. The authentication device 1 and the device to be authenticated 2 communicate with each other by electromagnetic induction or electromagnetic waves (for example, microwave) by a non-contact method instead of the contact by the contact method.

The authentication device 1 includes a CPU 11, a ROM 12 and an RA.
It is composed of an M13, a communication circuit 14, and a magnetic disk device 15.

The CPU 11 performs processing for authentication and communication control according to a program stored in the ROM 12.

The ROM 12 stores a processing program for performing authentication and a communication control program. The processing program for performing authentication includes a program that calculates a recurrence formula that generates a sequence having no periodicity.

The RAM 13 temporarily stores received data, intermediate data of processing, and the like.

The communication circuit 14 transmits / receives data to / from the device to be authenticated 2, and includes a magnetic coil in the case of electromagnetic induction, and is composed of an electromagnetic wave transmitter and receiver in the case of electromagnetic waves such as microwaves. To be done.

The magnetic disk device 15 stores the sequence number n determined by the CPU 11. The RAM 13 may be substituted for the function of the magnetic disk device 15, and the magnetic disk device 15 may be omitted.

The device to be authenticated 2 includes a CPU 21, a ROM 22 and an R
It is composed of an AM 23 and a communication circuit 24.

The CPU 21 performs processing for receiving authentication and communication control according to a program stored in the ROM 22.

The ROM 22 stores a processing program for receiving authentication and a communication control program. The processing program for receiving the authentication includes a program that calculates the same recurrence formula as the recurrence formula stored in the authentication device 1.

The RAM 23 temporarily stores received data, intermediate data of processing, and the like.

The communication circuit 24 sends and receives data to and from the authentication device 1, and is similar to the communication circuit 14 of the authentication device 1.

An example of a recurrence formula for generating a sequence x _i (i = 1 to n) having no periodicity is a sequence in so-called chaos. Chaos is a nickname that refers to the irregular behavior of a deterministic dynamic system. As an example of the recurrence formula (difference equation) that describes this irregular behavior,
There are the following (A) to (C).

(A) x _{n + 1} = C ₁₁ + C ₁₂ · x _n ² + C ₁₃ · y _n , y _{n + 1} = C ₁₄ · x _n

(B) x _{n + 1} = C ₂₁ · x _n + C ₂₂ · tan ⁻¹
(X _n ) + C ₂₃ · y _n , y _{n + 1} = C ₂₄ · x _n

(C) x _{n + 1} = C ₃₁ · x _n + C ₃₂ · x _n /
(1 + x _n ) ² + C ₃₃ · y _n , y _{n + 1} = C ₃₄ · x _n

Here, C ₁₁ to C ₃₄ are coefficients and take a real number value. Depending on the value of this coefficient, the sequence of numbers generated by the above recurrence formula may have periodicity or may be fixed. In some cases, the value may converge to the value. Therefore, a coefficient is selected in advance so that a sequence having no periodicity is generated, and a program for calculating a recurrence formula having this coefficient is stored in the ROM 12
And stored in the ROM 22. For example, the above recurrence formula (A)
Then, C ₁₁ = 1, C ₁₂ = -1.4, C ₁₃ = 0.3, C ₁₄ = 1
And the recurrence formula

X _{n + 1} = 1-1.4x _n ² + 0.3y _n , y _{n + 1} = x _n is known as one of recurrence formulas for generating a sequence having no periodicity.

FIG. 2 is a flowchart showing the processing flow of the authentication device 1 and the device to be authenticated 2.

The ROM 12 of the authentication device 1 and the R of the device to be authenticated 2
A program for calculating the same recurrence formula is stored in the OM22. Regarding the initial values x ₀ and y ₀ , the same values are stored in the ROM 12 and the ROM 22, respectively.

The authentication device 1 determines the value of the number n in the sequence (step 101). The value of this number n is an integer of 1 or more.

As a method of determining this number, there are a method (1) of determining a number different from the number determined in the past and a method (2) of randomly determining a number by a random number.

As the former method (1), there is a method of deciding the numbers in a fixed order (for example, 1 to 2 in order, 2, 3, ... N), a method of deciding by a random number, or the like. When the number is decided in a fixed order, the same number as the number decided in the past is not decided. Even when the authentication device 1 is powered off, the last-selected number among the numbers determined in the past is stored in the magnetic disk device 15 so that the power is turned on next time. In this case, it is possible to avoid determining the same number by determining the numbers after the stored number.

On the other hand, in the case of determining with a random number, the number determined in the past may be selected again, so the number determined in the past is stored in the magnetic disk device 15. Then, when the number is determined, the number selected by a random number or the like is compared with all the numbers stored in the magnetic disk device 15. As a result of comparison, the same number as the selected number
If it is not among the numbers stored in the magnetic disk device 15, the selected number is adopted and becomes the determined number. This number is also stored in the magnetic disk device 15,
It will be referred to when determining the future number. If there is the same number as the selected number, that number is not adopted and the number is selected again and compared with all the numbers stored in the magnetic disk device 15.

The determined number is stored in the magnetic disk device 15 even if the authentication device 1 is powered off, when the power is turned on next time, all the numbers determined in the past are stored. This is because the number is saved.

In method (1), since the same number is prevented from being generated, it is possible to prevent forgery of the device to be authenticated using the same number.

Method (2) of determining the number by the latter random number
In the case of the former (1), it is not necessary to store the number determined in the past and compare the selected number with all the past numbers. Therefore, it is advantageous when a huge number of users, such as automatic ticket gates at stations, are quickly handled. Although the same number may be generated, the probability is low, and it is very difficult to forge a device to be authenticated using the same number.

Next, the authentication device 1 transmits the determined sequence number n to the device to be authenticated 2 through the communication circuit 14 (step 102). The sequence number n is used as authentication information for authenticating the device to be authenticated 2.

After transmission, the authentication device 1 has a program for calculating a recurrence formula stored in the ROM 12 and an initial value x _0.
And y ₀ , the recurrence formula is calculated to obtain the value of the n-th term (n-th term) x _n corresponding to the sequence number n (step 10
3). After that, the authentication device 1 enters a waiting state for receiving the information transmitted from the device to be authenticated 2 (steps 104 and 10).
Five).

Upon reception of the sequence number n sent from the authentication device 1, the device to be authenticated 2 shifts from the sleep state to the operating state (steps 110 and 111). And ROM
The program for calculating the recurrence formula stored in 22 is executed, and the value of the n-th term x _n corresponding to the received sequence number n is obtained as in the authentication device 1 (step 112). After the calculation, the sequence number n, the value of the n-th term x _n , and the device to be authenticated 2
Is transmitted to the authentication device 1 (step 113).
).

The device to be authenticated 2 transmits the received sequence number n to the authentication device 1 for the following reason. That is, in a place such as an automatic ticket gate, when the automatic ticket gate (authentication device 1) transmits the sequence number n by electromagnetic waves, it is not always necessary to specify and transmit the commuter ticket (device to be authenticated 2).
In this way, when the number n is transmitted without specifying the device to be authenticated 2, the value of the n-th item x _n returned from the device to be authenticated 2 and the value of the n-th item x _n calculated by the authentication device 1 are calculated. This is because the sequence number n is required when matching the value. Therefore, when the device to be authenticated 2 that receives the number n from the authentication device 1 is specified, the device to be authenticated 2 does not need to dare to return the number n.

The device to be authenticated 2 transmits the ID number to the authentication device 1 because the employee may be identified by the ID number in the office or the like, and the legitimacy of the employee may be checked. . In this case, the ID number of the employee is registered in the authentication device 1, and this number is collated with the ID number transmitted from the device to be authenticated 2. In places such as automatic ticket gates at stations where it is not necessary to identify visitors, this I
No D number is required.

The authentication device 1 has the number n from the device to be authenticated 2,
Upon receiving recurrence formula of the values of the n terms x _n, and the ID number, compares the value of the n terms x _n which has received and the value of the n terms x _n authentication device 1 is calculated itself (step 106).

If these values match, the device to be authenticated 2 is confirmed to be authentic (steps 107 and 108).
). If these values do not match, the device to be authenticated 2
Is judged not to be legitimate (steps 107, 109)
).

For example, in the automatic ticket gate of a station, when the commuter pass is confirmed to be valid, the automatic ticket gate opens the gate to permit the passage of passengers. If it is determined that the commuter pass is not authentic, the automatic ticket gate closes the gate and passengers cannot pass through. In the case of office or laboratory doors, if the ID card is confirmed to be legitimate, the door will automatically open, and employees will be able to enter the office or laboratory, and it will be judged that it is not legitimate. The door won't open.

In the processing of step 107, the above-mentioned ID number may be collated if necessary.

Since the sequence generated by the recurrence formula stored in the authentication device 1 and the device to be authenticated 2 has no periodicity, even if the value of the number n and the value of the n-th term x _n are intercepted or tapped. Even if it does, the recurrence formula that defines the relationship between these values cannot be easily obtained. Also, the value of the number n and the nth
The same applies when the value of the term x _n is encrypted and the code is decrypted and the value of the number n and the value of the n-th term x _n are decrypted.

Further, the number n transmitted by the authentication device 1 is
Since it is a different value for each transmission or a random value by random numbers, even if a third party intercepts or eavesdrops the number n and its calculation result x _n , the same number n is received next. There is no possibility or very low probability. Therefore, the intercepted or eavesdropped number n and the nth term x
_{Even if} the device to be authenticated is forged using the value of _n , there is no possibility or very low possibility of using the forged device.

As described above, it becomes difficult to forge the device to be authenticated 2 such as a commuter pass or an ID card.

As a first modification of the first embodiment described above,
The authentication device 1 and the device to be authenticated 2 store the recurrence formula in the state where the coefficient is undecided in the ROM 12 and the ROM 22, and the authentication device 1 gives the value of the coefficient of the recurrence formula to the device to be authenticated 2 together with the number n. There is something.

In this modified example, the authentication device 1 stores one or more kinds of coefficient sets in the ROM 12 and determines one of them, and the authenticated device 2 together with the sequence number n.
Send to. The authentication device 1 and the device to be authenticated 2 are
The coefficient of the set is applied to the recurrence formula and the recurrence formula is calculated to obtain the value of the n-th term x _n . Of course, the coefficients stored in the ROM 12 generate a sequence having no periodicity.

As a second modification, the authentication device 1 and the device to be authenticated 2 do not hold the predetermined initial values x ₀ and y ₀ , but the authentication device 1 determines the initial values x ₀ and y _0. , N, and these initial values are also given to the device to be authenticated 2.

FIG. 3 is a flow chart showing the flow of processing of the third modification of the first embodiment. The process of determining, transmitting, and obtaining the value of the n-th term of the recurrence formula of the sequence number n is the same as that described above (steps 201 to 203).

In step 204, it is judged whether the determined number n is a predetermined specific number. The specific number is, for example, an even number, an odd number, or 7
And the like. All numbers may be specific numbers. The same specific number is determined in advance between the authentication device 1 and the device to be authenticated 2 and is stored in the ROM 12 and the ROM 22.

If the determined number n is a specific number, a predetermined calculation f is further applied to the value of the n-th term x _n obtained in step 203 (step 205). If the number n is not the specific number, the calculation f is not performed.

The predetermined operation f is, for example, four arithmetic operations such as subtracting 5 from the value of the n-th term x _n , multiplying the value of x _{n by} a constant 8.3, or the square root of the value of x _n. It is an operation such as calculation. The authentication device 1 also performs this predetermined calculation.
The same thing is determined in advance between the device to be authenticated and the device to be authenticated 2, and the RO
It is stored as a program in M12 and ROM22.

The device to be authenticated 2 also calculates the recurrence formula from the received number n to obtain the value of the n-th term x _n (step 212).
~ 214). If the number n is a specific number, a predetermined calculation f is applied to the value of x _n , otherwise the calculation f is not executed (steps 215 and 216). After this calculation, the calculation result and, if necessary, the received number n and ID number are transmitted to the authentication device 1 (step 217).
), And is received by the authentication device 1 (steps 206 and 207).
).

The authentication device 1 compares its own calculation result with the received calculation result (step 208). If these calculation results match, the device to be authenticated 2 is confirmed to be legitimate (steps 209 and 210). If these calculation results do not match, it is judged that the device to be authenticated 2 is not authentic (steps 209 and 211).

Further, as described above, in this confirmation processing, confirmation by the ID number may be performed.

As described above, when the number n is a specific number, a predetermined operation f is applied to the calculation result of the recurrence formula, and when the number n is not a specific number, the operation f is not applied, so that the number n It becomes more difficult to decipher the relational expression with the calculation result, and the forgery of the device to be authenticated 2 can be made more difficult.

4 and 5 are flow charts showing the flow of processing of the fourth modified example. In this modification, the value of the coefficient of the recurrence formula is changed when the number n is a specific number.

The ROM 12 of the authentication device 1 and the R of the device to be authenticated 2
The OM 22 stores in advance a program for calculating the same recurrence formula with the determined coefficient. The ROM is also used for the coefficient changing process performed when the number n is a specific number.
The same processing program is stored in the ROM 12 and the ROM 22, and the same coefficient values to be changed are also stored. The coefficient values after the change are preselected so that the sequence is not periodic.

The authentication device 1 determines the number n in the sequence (step 301) and transmits the number n to the device to be authenticated 2 (step 302). After the transmission, it is determined whether the number n is a specific number (step 303). The specific number is the same as that described in the third modified example.

If the number n is not a specific number, the ROM
A recurrence formula in which the value of the coefficient is determined, which is stored in advance in 12, is calculated to obtain the value of the n-th term x _n (step 304).

If the number n is a specific number, the coefficient changing processing program changes the value of one or more coefficients of the recurrence formula (step 305).
It is also possible to store a set of two or more kinds of coefficients in the ROM 12 and the ROM 22 and select and change one set from the set according to the value of the specific number.

Then, the value of the n-th term x _n is obtained based on the recurrence formula in which the coefficient value is changed (step 306).
). After that, the coefficient is returned to the original value (step 307).
).

After receiving the number n (steps 314 and 315), the device to be authenticated 2 also determines whether or not the number n is a specific number (step 316), similarly to the authentication device 1.

If the number n is not a specific number, the ROM
A recurrence formula in which the value of the coefficient is determined, which is stored in advance in 22, is calculated to obtain the value of the n-th term x _n (step 317).

If the number n is a specific number, the coefficient changing processing program changes the value of one or more coefficients of the recurrence formula to the same value as the changed value of the authentication device 1 (step 318). ). Then, the value of the n-th term x _n is obtained based on the recurrence formula in which the value of the coefficient is changed (step 319). Thereafter, the coefficient values are restored (step 320).

After these processes, the value of the n-th term x _n and, if necessary, the number n and the ID number are transmitted to the authentication device 1 (step 321) and received by the authentication device 1 (step 308, 309).

The authentication device 1 compares its own calculation result with the received calculation result (step 310). If these calculation results match, the device to be authenticated 2 is confirmed to be authentic (steps 311 and 312). If these calculation results do not match, it is judged that the device to be authenticated 2 is not authentic (steps 311 and 313).

Further, as described above, in this confirmation processing, confirmation by the ID number may be performed.

When the number n in the sequence is a specific number, by changing the value of the coefficient of the recurrence formula, it becomes more difficult to decipher the relational expression between the number n and the calculation result x _n, and the authenticated object is authenticated. Forgery of the device 2 can be made difficult.

(2) Second embodiment

FIG. 6 is a flow chart showing the flow of processing of the second embodiment. The configurations of the authentication device 1 and the authenticated device 2 are the same as those in FIG.

In the second embodiment, the first recurrence formula and the second recurrence formula for generating a sequence having no periodicity are calculated, and the calculation results are combined. Programs for calculating the first and second recurrence formulas are stored in the ROM 12 and the ROM 22.

The authentication device 1 determines the number n ₁ of the sequence,
This is transmitted to the device to be authenticated 2 (steps 401 and 402).
). There are two methods for determining the sequence number n ₁ as in the first embodiment described above. After determining the number n ₁ , the authentication device 1 calculates the first recurrence formula and obtains the value of the n ₁ -th term x _n1 (step 403).

The device to be authenticated 2 shifts from the sleep state to the operating state by receiving the number n ₁ (step 41).
2, 413). Then, similar to the authentication device 1, the first recurrence formula is calculated, and the value of the n _1st term x _n1 is obtained (step
414).

Next, the device to be authenticated 2 itself has the number n in the sequence.
₂ is determined (step 415). As a method of determining the number n ₂ , there are a method of using a fixed constant in advance and a method of determining with a random number. Then, the nth of the second recurrence formula
The value of the _second term x _n2 is determined (step 416).

[0092] Next, calculation is performed for synthesizing the values of the n ₂ term x _n2 of the value of the n ₁ wherein x _n1 of the first recurrence formula second recurrence formula (step 417). As the synthesis operation, there is a sum, product of these values, or a method of substituting into a predetermined function to obtain the result of the function. For this composition operation,
The same calculation is defined in advance between the authentication device 1 and the device to be authenticated 2, and the programs for executing the combination calculation are stored in the ROM 12 and the ROM 22.

The sequence number n ₂ and the result of the combining operation, and if necessary, the sequence number n ₁ and the ID number are transmitted from the device to be authenticated 2 to the authentication device 1 (step 418) and received by the authentication device 1 (step 418). Steps 404, 405).

After receiving these pieces of information from the device to be authenticated 2, the authentication device 1 obtains the value of the n ₂ -th term x _n2 of the _second recurrence formula based on the received sequence number n ₂ (step 406). .
Then, as in the case of the device to be authenticated 2, an operation of combining the value of x _{n1 and} the value of x _n2 is performed (step 407).

After that, the authentication device 1 compares the result of the combination calculation received from the device to be authenticated 2 with the result of the combination calculation itself (step 408). If these results match, the device to be authenticated 2 is confirmed as legitimate (steps 409 and 410), and if they do not match, it is determined not to be legitimate (steps 409 and 411).

In this confirmation process, the ID is issued if necessary.
Confirmation by number is performed.

By combining a plurality of calculation results of recurrence formulas that generate a sequence having no periodicity, it becomes even more difficult to decipher the relationship between the number n and the calculation results, making it difficult to forge a card. .

As a modified example of the second embodiment, the device to be authenticated 2 does not perform the combining operation and the n ₁ -th term x of the _first recurrence formula is used.
_In some cases, the value of _{n1 and} the value of the n _{2 nd} term x _n2 of the _second recurrence formula are transmitted to the authentication device 1 as they are. The authentication device 1 also does not perform the synthesis operation, and if the values of x _n1 and x _n2 received from the device to be authenticated 2 match the values of x _n1 and x _n2 calculated by itself, the authentication device 1 is authenticated. The device 2 is confirmed to be legitimate, and if either of them does not match, it is judged to be not legitimate.

As another modification, there is one in which the composition operation is performed only when the number n ₁ determined by the authentication device 1 is the specific number, and the composition operation is not performed otherwise.

(3) Third embodiment

The third embodiment is as follows. The configurations of the authentication device 1 and the authenticated device 2 are the same as those in FIG.

The authentication device 1 transmits a signal for changing the device to be authenticated 2 from the sleep state to the operating state.

Upon receiving this signal, the device to be authenticated 2 enters the operating state and determines the sequence number n. As a method of determining the number n, there is a method of determining using a random number. Then, the device to be authenticated 2 obtains the value of the n-th term x _n of the recurrence formula, and the number n,
The value of the n-th term x _n and, if necessary, the ID number are transmitted to the authentication device 1.

[0104] authentication apparatus 1 obtains a value of the n terms x _n recurrence formula by number n received, compares the value of x _n received from the prover 2, the value of his obtained x _n To do. If these values match, the device to be authenticated 2 is confirmed to be legitimate, and if they do not match, it is determined not to be legitimate.

As a modification of the third embodiment, the device to be authenticated 2 gives the initial values x ₀ and y ₀ of the recurrence formula to the authentication device 1, or the device to be authenticated 1 sends these initial values to the device 2 to be authenticated. Some give value.

As another modified example, the device to be authenticated 2 gives the value of the coefficient of the recurrence formula to the authentication device 1, or the authentication device 1 gives the value of the coefficient of the recurrence formula to the device to be authenticated 2. There are things.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an authentication system including an authentication device and a device to be authenticated.

FIG. 2 is a flowchart showing a processing flow of an authentication device and a device to be authenticated in the first embodiment.

FIG. 3 is a flowchart showing a processing flow of an authentication device and a device to be authenticated in a third modification of the first embodiment.

FIG. 4 is a flowchart showing a processing flow of an authentication device and a device to be authenticated in a fourth modification of the first embodiment.

FIG. 5 is a flowchart showing a processing flow of an authentication device and a device to be authenticated in a fourth modification of the first embodiment.

FIG. 6 is a flowchart showing a processing flow of an authentication device and a device to be authenticated in the second embodiment.

[Explanation of symbols]

 1 Authentication device 2 Authenticated device 11, 21 CPU 12, 22 ROM 13, 23 RAM 14, 24 Communication circuit 15 Magnetic disk device

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location G06K 19/10 G07B 11/00 501 8111-3E G07C 9/00 Z 9436-3E H04L 9/00 9/10 9 / 12 // B42D 15/10 501 L H04L 9/00 Z 8837-5L G09C 1/00

Claims (22)

[Claims] 1. An authentication device and a device to be authenticated which can communicate with each other, wherein the authentication device stores a recurrence formula for generating a sequence having no periodicity, and a term of the recurrence formula. Deciding means for deciding the number n for designating, transmitting means for transmitting information including the number n decided by the deciding means to the device to be authenticated as authentication information, and the device to be authenticated is the information for authentication. Based on the number n determined by the determining unit, the receiving unit receiving information including the result of processing
Processing means for performing processing including calculation for obtaining the value of the n-th term of the recurrence formula, comparing the processing result of the authentication information received from the device to be authenticated with the result processed by the processing means. The authentication information including the number n, which is transmitted from the authentication device, and includes a comparing unit that determines whether the authenticated device is valid according to the result of the comparing unit. Receiving means for receiving the same, a storage means for storing the same recurrence formula as the recurrence formula stored in the authentication device, and the n-th recurrence formula based on the number n included in the received authentication information. An authentication system using chaos, comprising a processing means for performing processing including calculation for obtaining a value of the th term, and a transmission means for transmitting information including a processing result by the processing means to the authentication device. 2. The chaos-based authentication system according to claim 1, wherein the deciding means of the authentication device stores the already decided number and decides other numbers. 3. The chaos-based authentication system according to claim 1, wherein the determination means of the authentication device determines a number by a random number. 4. The processing means of the authentication device and the device to be authenticated, after the value of the n-th term of the recurrence formula is obtained, when the number n corresponds to a predetermined specific value. Further, a predetermined operation is performed on the value, and if it is not equivalent, a calculation for obtaining only the value of the n-th term of the recurrence formula is performed. An authentication system using chaos described in the item. 5. The processing means of the authentication device and the device to be authenticated changes one or more parameters forming a recurrence formula when the number n corresponds to a predetermined specific value. A calculation for obtaining the value of the nth term based on the recurrence formula after the change, and if it is not equivalent, a calculation for obtaining the value of the nth term without changing the above parameters The authentication system using chaos according to any one of claims 1 to 3. 6. The storage means of the authentication device and the device to be authenticated stores a plurality of recurrence formulas that generate a sequence having no periodicity, and the processing means of the authentication device and the device to be authenticated are The calculation for obtaining the value of the n-th term for each of the plurality of recurrence formulas, and further performing a predetermined calculation on the calculation results, The method according to any one of claims 1 to 3. Authentication system using chaos. 7. A storage unit for storing a recurrence formula for generating a sequence having no periodicity, a determination unit for determining a number n for designating a term of the recurrence formula, and a number n determined by the determination unit. The information including the information is transmitted as authentication information to the device to be authenticated, the receiving device receives information including the result of processing the authentication information by the device to be authenticated, and is determined by the determining device. Based on the number n
Processing means for performing processing including calculation for obtaining the value of the n-th term of the recurrence formula, processing result of the authentication information received from the device to be authenticated,
An authenticating device using chaos, comprising: comparing means for comparing the result processed by the processing means, and judging means for judging whether the device to be authenticated is valid according to the result of the comparing means. 8. The authentication device using chaos according to claim 7, wherein the determining means stores the already determined number and determines the other numbers. 9. The authentication device using chaos according to claim 7, wherein the determining means determines a number by a random number. 10. The processing means, when the number n corresponds to a predetermined specific value, obtains the value of the n-th term of the recurrence formula and then further performs a predetermined operation on the value. Is applied, and if it is not equivalent, the calculation for obtaining only the value of the n-th term of the recurrence formula is performed, and the chaos according to any one of claims 7 to 9 is used. Authentication device. 11. The processing means, when the number n corresponds to a predetermined specific value, changes one or more parameters constituting the recurrence formula to obtain the modified recurrence formula. The calculation for obtaining the value of the n-th term is performed based on the above, and if not equivalent, the calculation for obtaining the value of the n-th term is performed without changing the parameter. An authentication device using the chaos according to claim 9. 12. The storage means stores a plurality of recurrence equations for generating a sequence having no periodicity, and the processing means stores the n-th term of each of the plurality of recurrence equations. The chaos-based authentication device according to any one of claims 7 to 9, wherein a calculation for obtaining a value is performed, and a predetermined operation is performed on the calculation result. 13. Storage means for storing a recurrence formula for generating a sequence having no periodicity, and receiving authentication information including a number n for designating a term of the recurrence formula, which is transmitted from the authentication device. Receiving means, processing means for performing processing including calculation for obtaining the value of the n-th term of the recurrence formula based on the number n included in the received authentication information, and information including processing results by the processing means A device to be authenticated using chaos, which is provided with a transmitting means for transmitting the. 14. The processing means, when the number n corresponds to a predetermined specific value, obtains the value of the n-th term of the recurrence formula and then further performs a predetermined operation on the value. The chaotic authenticated device according to claim 13, wherein the calculation is performed to obtain only the value of the n-th term of the recurrence formula, if not. 15. The processing means, when the number n corresponds to a predetermined specific value, changes one or more parameters constituting the recurrence formula to obtain the modified recurrence formula. The calculation for obtaining the value of the n-th term is performed based on the above, and if it is not equivalent, the calculation for obtaining the value of the n-th term is performed without changing the parameter. A device to be authenticated using the described chaos. 16. The storage means stores a plurality of recurrence equations for generating a sequence having no periodicity, and the processing means stores the n-th term of each of the plurality of recurrence equations. 14. The authenticated device utilizing chaos according to claim 13, which performs a calculation for obtaining a value and further performs a predetermined calculation on the calculation result. 17. A method of authenticating a device to be authenticated by the authentication device by communicating with the device to be authenticated and the device to be authenticated, wherein the device is a recurrence generating a sequence having no periodicity. The number n for designating the term of the formula is determined, information including the determined number n is transmitted to the authenticated device as authentication information, and the authenticated device processes the authentication information. The information including the result is received from the device to be authenticated, and the process including the calculation for obtaining the value of the n-th term of the stored recurrence formula is performed based on the determined number n. The processing result of the authentication information received from the authenticated device is compared with the processed result, and it is determined whether the authenticated device is valid according to the comparison result. The above number sent from the authentication device A process of receiving the authentication information including the number n and calculating the value of the n-th term of the recurrence formula that is the same as the recurrence formula stored by the authentication device and stored; An authentication method using chaos, which is performed based on the number n included in the received authentication information and transmits information including the processed result to the authentication device. 18. The chaos-based authentication method according to claim 17, wherein the determination of the number n is performed by storing the already determined number and determining the other numbers. 19. The chaos-based authentication method according to claim 17, wherein the number n is determined by a random number. 20. When the number n corresponds to a predetermined specific value, the authenticating device and the authenticated device further determine the value of the n-th term of the recurrence formula, and then determine the value. 20. The chaos according to any one of claims 17 to 19 is calculated by applying a predetermined calculation to, and if it is not equivalent, calculating only the value of the n-th term of the recurrence formula. The authentication method used. 21. When the number n corresponds to a predetermined specific value, the authenticating device and the authenticated device change one or more parameters constituting the recurrence formula and change the parameters. The calculation for obtaining the value of the n-th term based on the recurrence formula, and if not equivalent, the calculation for obtaining the value of the n-th term is performed without changing the parameter. 20. An authentication method using chaos according to claim 19. 22. The authentication device and the device to be authenticated store a plurality of recurrence formulas for generating a sequence having no periodicity, and a calculation for obtaining a value of an n-th term for each of the plurality of recurrence formulas. The authentication method using chaos according to any one of claims 17 to 19, further comprising: