JP2008187679A - Regular product determination system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an authentication algorithm from being easily decoded even by analyzing a communication pattern between a regularity determination apparatus and a product to be determined. <P>SOLUTION: A small-sized information device 1 includes a random number working unit 13 which repeats, just set times, work processing for selecting any one of two random numbers transmitted from a host computer 110 and transmitting a working signal working the selected random number to the host computer 110. The host computer 110 includes: random number generating units 111, 112 for generating two random number for one time of work processing; an arithmetic result judging unit 115 which judges, iteratively just set times, whether the working signal or a working arithmetic result further applying arithmetic processing to the working signal is matched with any one of a plurality of determination arithmetic results operated using the random numbers; and a regular device determination unit 116 which determines the small-sized information device 1 as a regular product when all the determination results as many as the set times indicate matching, and permits a connection with the host computer 110. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a regular product determination system that determines the regularity of a product to be judged connected to a normality judgment device and authenticates that the product to be judged is a regular product.

  In general, in order to control a peripheral device from a host computer, it is necessary to provide a device driver suitable for each peripheral device on the host computer side. The peripheral device that is actually connected to the host computer is preferably an authorized product intended by the device driver developer.

  It is also assumed that the device driver is operated in an environment in which a compatible device other than a genuine product that is not intended is connected. Normally, the device driver is created to control the operation of a genuine product, so it cannot be said that the operation of even a compatible product can be reliably controlled. For this reason, when a compatible device is controlled by a device driver, an unexpected operation may be caused.

  For example, if a compatible device is connected to a reader equipped with a scanner that reads check paper, it will not match the device driver, resulting in paper jams, calibration errors, motor or circuit burn-in, etc. There is. In order to solve such a problem, Japanese Patent Application Laid-Open No. H10-228667 determines a normality of a product to be determined connected to a normality determination device and determines whether or not the product to be determined is a genuine product. An authentication system is described.

  Specifically, when a battery pack is attached to the notebook PC, the authentication system 10 starts operating to determine whether the attached battery pack is a genuine product. First, the random number generating means generates a random number a, and the generated random number a is transmitted to the battery pack through the communication bus and simultaneously stored in the comparing means. The battery pack calculates the function b = f (a) using the random number a by the first calculation means, and returns the calculation result b to the notebook PC through the communication bus. In the notebook PC 1, the function c = g (b) = g {f (a)} is calculated by the second calculation means using the calculation result b. The comparison means compares the calculation result c of the second calculation means with the stored random number a to determine whether a = c. If it is determined that a = c, the battery pack is certified as a genuine product.

As described above, in authentic authentication of a conventional product, there is a means in which an encryption algorithm / encryption key is embedded in a determination target product that is an object of authentic authentication, and the normality determination device confirms it. In the case of authentic authentication using an encryption algorithm, the driver built into the normality determination device generates a random number and sends it, and the product to be determined outputs the result of applying the encryption algorithm to the random number and the encryption key. There are many methods to return in response.
JP 2005-94128 A

  In the genuine product authentication system described in Patent Document 1, since a random number is generated by a random number generation means, a value obtained by applying a specific authentication algorithm to a random number is returned. It is easy to analyze the communication pattern between the device and the product to be judged, and there is a possibility that the authentication algorithm performed on the product to be judged side is analyzed by analyzing the communication pattern.

  However, if the authentication algorithm is deciphered, there is a possibility that the authentication algorithm is directly installed in the product to be determined. If the decrypted authentication algorithm is installed in a product other than the authorized product, it may be erroneously determined that the product is a genuine product where it must originally be determined to be a non-genuine product.

  The present invention has been made in order to solve the above-described problem, and determines the normality of a product to be determined connected to a normality determination device, and authenticates that the product to be determined is a genuine product. It is an object of the authentication system to prevent an authentication algorithm from being easily deciphered even if a communication pattern between a normality determination device and a product to be determined is analyzed.

The present invention that can solve the above-mentioned problem is a regular product determination system that determines whether a product to be determined connected to a normality determination device is a regular product,
The judged product is
A random number processing unit that selects any one of a plurality of random numbers transmitted from the normality determination device and repeats the processing for transmitting the processed signal obtained by processing the selected random number to the normality determination device a set number of times. And
The normality determination device includes:
A random number generator for generating the plurality of random numbers per processing process;
Whether the processing signal or the processing operation result obtained by further performing arithmetic processing on the processing signal matches one of a plurality of determination calculation results calculated using each random number generated from the random number generator A calculation result determination unit that repeatedly determines whether or not the set number of times,
A regular product determination unit that determines that the product to be determined is a genuine product and permits connection with the normality determination device when all the determination results for the set number of times match. To do.

  According to the above configuration, the normality determination device generates a plurality of random numbers per processing process, and the product to be determined selects one of the plurality of random numbers transmitted from the normality determination device, The selected random number is processed. In this case, even if the communication pattern between the normality determination device and the device to be determined is analyzed, it cannot be easily determined which random number has been selected. If all the determination results for the set number of times match, the product to be determined is determined to be a regular product and connection with the normality determination device is permitted. Therefore, if the determination result does not match even once, communication is performed. It can be disallowed. Therefore, it is possible to prevent the normality determination processing algorithm from being easily deciphered and to restrict communication with the normality determination device when a compatible product is connected to the normality determination device. Therefore, it is possible to prevent malfunctions and failures due to incompatibility between the compatible product and the normality determination device.

In the present invention, the product to be determined has an information storage unit for storing random number processing information unique to the product to be determined.
The random number processing unit processes the selected random number into one of a processed signal processed using the random number processed information and a processed signal not using the random number processed information.

According to the above configuration, the selected random number can be processed into either a processing signal processed using the random number processing information or a processing signal not using the random number processing information. That is, a plurality of processing signal patterns can be set for each selected random number. For this reason, it is difficult to analyze the communication pattern from the determination target device to the normality determination device as compared to the case where only one processed signal pattern is set for each selected random number.
As in the past, when only one processing signal pattern is set, a processing signal using product-specific random number processing information is always returned in the processing processing, so that the normality determination device side only calculates the result once. Just make a decision. However, in order to ensure the reliability of the single calculation result determination, it is necessary to increase the random number or to complicate the algorithm itself. The present invention can enhance the reliability of the normality determination by appropriately adjusting the number of times of setting.

The random number generation unit generates two random numbers per processing process,
The random number processing unit transmits the processing signal by changing a pattern of the processing signal depending on whether the sum of the two random numbers is an even number or an odd number.

  According to the above configuration, it is possible to change the pattern of the processing signal in four ways depending on the combination of whether to select an even number, an odd number, or two random numbers. For this reason, it is difficult to analyze the communication pattern from the determination target device to the normality determination device as compared with the case where only one pattern of processing signals is set. Also, if the communication pattern is analyzed, there is a possibility that the four processing signal patterns can be narrowed down to two processing signal patterns depending on whether the sum of the two random numbers is an even number or an odd number. It is difficult to determine if it has been selected. For this reason, it is possible to prevent the legitimate product determination processing algorithm from being easily decoded.

  In the present invention, the random number processing unit performs a remainder operation in the processing. According to such a configuration, even if a plurality of random number values generated by analyzing the communication pattern from the normality determination device to the device to be determined are found, random number processing is performed from the result of the remainder calculation and the random number value. Since it is difficult to derive information, it is possible to prevent the legitimate product determination processing algorithm from being easily decoded.

  Hereinafter, an embodiment of a regular product determination system according to the present invention will be described in detail with reference to the drawings. In this embodiment, an information reading system including a host computer and a small information device that executes a reading process in response to an instruction from the host computer will be described as an example.

FIG. 1 is a block diagram showing internal processing of the information reading system according to the embodiment of the present invention. In order to control the operation of the small information device 1 from the host computer 110, a device driver dedicated to the small information device is registered on the host computer side. In the present embodiment, it is possible to determine whether or not the small information device 1 connected to the host computer 110 is a genuine product with respect to a device driver registered in the host computer 110. In other words, the small information device 1 that is actually connected to the host computer 110 has a function of determining that it is a legitimate product intended by a device driver developer or the like.
(Mechanical configuration of small information equipment)
First, an outline of the small information device 1 will be described. The small-sized information device 1 according to the present embodiment conveys a substantially U-shaped paper sheet formed in a casing with a cut sheet such as a check loaded in an ASF (Auto Sheet Feeder) serving as a paper feeding unit. While being conveyed along the path, it is configured to be able to read a double-sided image printed on a cut sheet and read magnetic ink characters on the cut sheet.

Various reading devices are provided in a portion corresponding to the bottom portion of the U-shaped paper conveyance path through which the check is conveyed. An ASF capable of loading a plurality of checks is provided on the upstream side of the paper transport path. The plurality of checks loaded in the ASF are separated one by one and sent out into the paper transport path.
The check sent from the ASF into the paper transport path is discharged from the discharge port by a paper transport roller, an intermediate transport roller, a discharge roller, and the like.

  An image reading device (optical character reading device: OCR) that reads images printed on both sides of the check is installed at the bottom of the U-shaped paper conveyance path. The image reading apparatus irradiates light on one surface of a check conveyed on the paper conveyance path, receives the reflected light through a plurality of light receiving elements (photoelectric conversion elements), and converts the received light into an electrical signal. An image for one line is acquired. In this embodiment, a two-dimensional image of a check is acquired by sequentially reading images printed on the check line by line.

  Further downstream of the image reader, a magnetic ink character reader (MICR (Magnetic Ink Character Reader)) that reads magnetic ink characters is installed. The magnetic ink character reader is a sensor for reading magnetic ink characters printed on the surface of a check. This magnetic ink character reading device performs reading in a state where a check is pressed against the surface of the magnetic ink character reading device by a pressing lever disposed oppositely. For a check, a magnetic ink character recording area in which information such as an account number is printed with magnetic ink characters is read.

  The image reading apparatus and magnetic ink character reading apparatus described above are controlled by a CPU (Central Processing Unit). A ROM (Read Only Memory) stores a control program read and executed by the CPU. As described above, in the normal use, the small information device 1 reads various information printed on the cut sheet conveyed along the sheet conveyance path by the corresponding reading devices, and reads the read information to the host computer 110. It can be sent.

(About the host computer)
On the other hand, the host computer is a normal personal computer, and a dedicated device driver for controlling the operation of the small information device 1 is registered in advance. In response to an instruction from the device driver, various reading devices, a conveyance mechanism, and the like provided in the small information device 1 are controlled to execute a check reading process. In the present embodiment, it is determined whether or not the small information device 1 connected to the host computer 110 is a legitimate product corresponding to a device driver registered in the host computer 110.

(Regarding legitimate product judgment processing of information reading system)
Next, regular product determination processing executed by the information reading system of this embodiment will be described. FIG. 1 is a control block diagram for explaining regular product determination processing of the information reading system of this embodiment.
In the information reading system of the present embodiment, every time the system is started, it is determined whether or not the small information device 1 connected to the host computer 110 is a legitimate product corresponding to the device driver registered in the host computer 110. It is comprised so that it may determine.

  The host computer 110 mainly includes two random number generation units 111 and 112, a transmission unit 113 that transmits the generated random number to the small information device 1, and a reception unit 114 that receives a processed signal transmitted from the small information device 1. A calculation result determination unit 115 that determines whether the calculation results match, and a normal device that determines that the small information device 1 is a genuine product and permits communication with the host computer 110 when the calculation results match. A determination unit 116 and a random number storage unit 117 are provided.

In this embodiment, the number of executions of calculation result determination performed in one regular product determination process is set, and the random number generators 111 and 112 are set to generate a random number every time the calculation result determination is performed. ing. Here, one random number is generated from each of the random number generator 111 and the random number generator 112, and two random numbers are used in one calculation result determination. When the random number generators 111 and 112 generate random numbers, the generated random numbers are stored in the random number storage unit 117.
Hereinafter, a case where two random numbers are generated in one calculation result determination will be described as an example, but the present invention is not limited to this. In other words, it is only necessary to generate a plurality of random numbers in one calculation result determination. If a large number of random numbers are generated, the communication pattern can be more difficult to be analyzed.

  The small information device 1 is mainly a receiving unit 11 that receives a signal transmitted from the host computer 110, and is a small product that is information used for processing performed on the small information device 1 side in the genuine product determination process and is a regular product. Select one of the two random numbers transmitted from the host computer 110 and the information storage unit 12 that stores the random number processing information unique to the information device, and use the random number processing information stored in the information storage unit 12, A random number processing unit 13 that performs processing on the selected random number and a transmission unit 14 that transmits a signal to the host computer 110 are provided. The processed signal processed by the random number processing unit 13 is transmitted to the host computer 110 via the transmission unit 14.

Next, a specific flow of the regular product determination process in the information reading system of this embodiment will be described.
FIG. 2 is a flowchart for explaining the genuine product determination process of the present embodiment.
First, prior to the regular product determination process, a check sheet for determination in which random number processing information is written in magnetic ink characters is set in the ASF installed on the upstream side of the paper conveyance path of the small information device 1, and from the host computer 110 A reading process is executed according to the reading command. The magnetic ink characters read by the magnetic ink character reading device are stored as random number processing information M in the information storage unit 12.

  In this state, when receiving an instruction to execute regular product determination processing via an interface (not shown) of the host computer 110 (step S11: Yes), the random number generation units 111 and 112 generate the random numbers r1 and r2, respectively, and the transmission unit Two random numbers r1 and r2 are transmitted to the small information device 1 via 113 (step S12). At this time, the generated random numbers r1 and r2 are temporarily stored in the random number storage unit 117. The random number processing unit 13 selects one of the two random numbers r1 and r2 received by the receiving unit 11, processes the selected random number (step S21), and transmits the processed signal C to the host computer 110. (Step S22).

Here, the random number processing performed by the random number processing unit 13 will be described. FIG. 3 shows a value (processing signal C) that the random number processing unit 13 opposes to the host computer 110 by either of two random numbers r1 and r2.
The random number processing unit 13 returns a different value for each random number depending on whether the sum of the received random numbers r1 and r2 is an even number or an odd number.

If the sum of the random numbers r1 and r2 is an even number and the selected random number is r1, then r1 × r1modPQ. If the sum of the random numbers r1 and r2 is an odd number and the selected random number is r1, then r1 × MmodPQ. To the host computer 110 as a machining signal C.
PQ is a common prime number included in the small information device 1 and the host computer 110. Mod means a remainder operation.
R2 × r2modPQ is selected when the sum of the random numbers r1 and r2 is an even number and the selected random number is r2, and r2 when the sum of the random numbers r1 and r2 is an odd number and the selected random number is r2. XMmodPQ is returned to the host computer 110 as the machining signal C.

Let's apply specific values to these. Prime number: PQ = 71, random number processing information: M = 65, random number: r1 = 10, random number: r2 = 43. The processing signals C are as follows.
(1) r1 × r1modPQ = 10 × 10 mod 71 = 100 remainder obtained by dividing 71 = 29
(2) r1 * MmodPQ = 10 * 65mod71 = remainder of dividing 650 by 71 = 11
(3) r2 × r2modPQ = 43 × 43mod71 = 1, remainder of 1849 divided by 71 = 3
(4) r2 × MmodPQ = 43 × 65mod71 = 2795 remainder divided by 71 = 26
It becomes.

Any of the above values is transmitted to the host computer 110 as the machining signal C. When this is repeated for a set number of times, the communication pattern between the small information device 1 and the host computer 110 is analyzed, and the communication pattern is narrowed down to two out of four depending on whether r1 + r2 is even or odd. There is a possibility that. When r1 + r2 is an even number, the above (1) and (3) are returned as the processed signal C, but it cannot be determined whether the random number processing unit 13 has selected any of the random numbers r1 and r2. Therefore, there is no possibility of analyzing which of the expressions (1) or (3) is processed.
On the other hand, when r1 + r2 is an odd number, the above (2) and (4) are returned as the processed signal C, but it is also determined whether the random number processing unit 13 has selected either random number r1 or r2. Therefore, there is no possibility of analyzing whether the processing is performed according to the formula (2) or (4).

  In any processing of (1) to (4), the remainder calculation (mod) is applied, and it is difficult to derive the processing algorithm even if the values of the random numbers r1 and r2 are analyzed. It can also be said that it is difficult to derive the value of the random number processing information M unique to the small information device used in the processing processes (2) and (4).

  Here, the sum of the random numbers r1 and r2 is r1 + r2 = 10 + 43 = 53, which is an odd number. When r1 = 10 is selected in step S21, the random number processing unit 13 transmits the value of (2) as the processing signal C to the host computer 110.

  Next, when the reception unit 114 of the host computer 110 receives the processing signal, the calculation result determination unit 115 uses the processing signal C or the processing calculation result X obtained by further processing the processing signal C and the random numbers r1 and r2. It is determined whether or not any one of the plurality of determination calculation results Y calculated in step S13 and step S14.

Here, calculation result determination processing performed by the calculation result determination unit 115 will be described. FIG. 4 shows a determination formula performed by the calculation result determination unit 115 depending on whether the sum of the two random numbers r1 and r2 is an even number or an odd number.
The calculation result determination unit 115 determines the calculation result according to the following determination formula depending on whether the sum of the random numbers r1 and r2 stored in the random number storage unit 117 is an even number or an odd number. Note that M2 = M × MmodPQ, which is a value stored in advance by the calculation result determination unit 115.

The judgment formula is as follows.
<Judgment formula when the sum of the random numbers r1 and r2 is an even number>
(5) C = r1 × r1modPQ
(6) C = r2 × r2modPQ
<Judgment formula when the sum of the random numbers r1 and r2 is an odd number>
(7) C × CmodPQ = M2 × r1 × r1modPQ
(8) C × CmodPQ = M2 × r2 × r2modPQ

  When the algorithm of the regular product determination processing of the present embodiment is applied to a compatible non-genuine product device in a state where the above judgment formula is clarified by the analysis of the host computer 110, random number processing is performed in the non-genuine product device. The value of information M is required. Even if it can be inferred from the analysis of the host computer 110 that M2 is M × MmodPQ, what the value of the random number processing information M must be brute-force tested. Therefore, it is impossible to derive M in a realistic time by setting the prime number PQ and the random number processing information M to sufficiently large values.

Here, since the sum of the random numbers r1 and r2 is an odd number, a processing calculation result X obtained by further processing the processing signal C transmitted from the small information device 1 in step S13 is obtained.
X = C × Cmod PQ = 11 × 11 mod 71 = 50
Further, in step S14, determination calculation results Y1 and Y2 are obtained to determine whether or not the calculation results match, and determination expressions (7) and (8) are determined.
(7) Y1 = M2 × r1 × r1 mod PQ = (M × M mod PQ × r 1 × r 1) mod PQ
= 65 × 65 mod 71 × 10 × 10 mod PQ = 36 × 100 mod 71
= 50
(8) Y2 = M2 * r2 * r2modPQ = (M * MmodPQ * r2 * r2) modPQ
= 65 × 65 mod 71 × 43 × 43 mod PQ = 36 × 1849 mod 71
= 66564 mod 71 = 37

  Therefore, in step S14, it is determined that the machining calculation result X obtained by further calculating the machining signal C matches Y1 of the two determination calculation results Y1 and Y2 calculated using the random numbers r1 and r2. Step S14: Yes), it is determined whether this determination process has been performed a set number of times (step S15). When the calculation result judgment is not performed for the set number of times (step S15: No), the process returns to step S12 to generate a random number again, and repeats the processing of step S21, step S22, step 13, step 14, and step 15. Execute.

  For example, if the set number of times is 20, the regular device determination unit 116 increments the number counter every time the determination of step S15 is performed, and all the calculation results match in the determination process of step S15 over 20 times. Determines that the small information device 1 connected to the host computer 110 is an authorized product, and permits connection with the host computer 110 (step S16). When the connection is permitted, normal processing corresponding to various commands transmitted from the host computer 110 is executed in response to an input instruction from the outside (step S17).

  On the other hand, if the calculation result does not match even once in step S14 (step S14: No), it is determined that the small information device 1 connected to the host computer 110 is an unauthorized product, and the host Connection with the computer 110 is not permitted (step S18). Thereby, the device driver registered in the host computer 110 cannot control the small information device 1 subjected to the regular product determination process. Therefore, when the small information device 1 is a compatible device of a regular product, it may not be compatible with the device driver and may cause a paper jam, a calibration error, or a motor or circuit burn-in. According to the present embodiment, since communication between the compatible device and the host computer is not permitted, it is possible to prevent these problems from occurring.

  Further, in the present embodiment, two random numbers are generated for one calculation result determination process, one of the random numbers is selected, and the processing signal is changed according to the selected random number. Therefore, even if the communication pattern between the host computer 110 and the small information device 1 is analyzed, it is possible to prevent the normality determination processing algorithm from being easily decoded, and a compatible device and host that do not match the device driver. Communication with a computer can be restricted. Accordingly, it is possible to prevent malfunctions and failures due to incompatibility with the device driver.

  Further, according to the present embodiment, the type of calculation used for the algorithm for the genuine product determination process is limited to multiplication, remainder calculation, and the like. Therefore, for example, in order to further increase the processing speed, even if the above-described regular product determination processing is to be realized by hardware, it can be realized at a lower cost.

  Further, in the present embodiment, when it is desired to change the strength of the normality determination process, the strength can be easily adjusted by changing the set number of times for performing the calculation result determination in step S14.

  In the present embodiment, the random number processing information M used in the random number processing in step S21 is acquired by reading the magnetic ink characters written on the check paper by the magnetic ink character reading device. It will never be done. Of course, the present invention can be applied even when the random number processing information M is registered in advance in the flash ROM or the like of the small information device 1. Further, if the set number of times is set as the random number processing information M, it is not necessary to read the random number processing information M from the check sheet for determination, and it is not necessary to register in advance in a regular product, thereby further enhancing the reliability of the regular product determination processing. be able to.

It is a block diagram which shows the internal process of the information reading system of this embodiment. It is a flowchart explaining the regular article determination process of this embodiment. It is the figure which showed the correspondence of two random numbers r1 and r2 and the value (processing signal C) against a host computer. It is the figure which showed the judgment type which a calculation result judgment part performs by whether the sum of two random numbers r1 and r2 is an even number or an odd number.

Explanation of symbols

1: small information device, 11: reception unit, 12: information storage unit, 13: random number processing unit, 14: transmission unit, 110: host computer, 111: random number generation unit, 112: random number generation unit, 113: transmission unit, 114: reception unit, 115: calculation result determination unit, 116: normality device determination unit

Claims (4)

A regular product determination system for determining whether a product to be determined connected to a normality determination device is a regular product,
The judged product is
A random number processing unit that selects any one of a plurality of random numbers transmitted from the normality determination device and repeats the processing for transmitting the processed signal obtained by processing the selected random number to the normality determination device a set number of times. And
The normality determination device includes:
A random number generator for generating the plurality of random numbers per processing process;
Whether the processing signal or the processing operation result obtained by further performing arithmetic processing on the processing signal matches one of a plurality of determination calculation results calculated using each random number generated from the random number generator A calculation result determination unit that repeatedly determines whether or not the set number of times,
A regular product determination unit that determines that the product to be determined is a genuine product and permits connection with the normality determination device when all the determination results for the set number of times match. Genuine product judgment system. The judged product has an information storage unit for storing random number processing information unique to the judged product,
The random number processing unit processes the selected random number into one of a processing signal processed using the random number processing information and a processing signal not using the random number processing information. The regular product judgment system described. The random number generation unit generates two random numbers per processing process,
The regular product determination system according to claim 2, wherein the random number processing unit changes the pattern of the processing signal depending on whether the sum of the two random numbers is an even number or an odd number.   The said random number processing part performs a remainder calculation in the said process, The regular product determination system in any one of Claim 1 to 3 characterized by the above-mentioned.

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