Authentication device, authentication system, and authentication method

Abstract

The authentication device is provided with a first electromagnetic characteristic acquisition unit (210) that acquires the recorded electromagnetic characteristics of the first device to be authenticated, and a challenge data generation unit (220) that generates challenge data on the basis of the recorded electromagnetic characteristics. An expected value generation unit (230) that compares the recorded electromagnetic characteristics with the generated challenge data and generates a response data expected value as a result of the comparison; a challenge data transmission unit (240) that transmits the generated challenge data to a response device; and a response data reception unit (250) that receives response data relating to the second authenticated device from the response device. And a response data determination unit (260) that determines the authenticity of the second device to be authenticated by comparing the generated response data expected value with the received response data, and the response device compares the electromagnetic characteristics acquired from the second device to be authenticated with the transmitted challenge data and generates a comparison result as response data.

Description

Technical Field

[0001] The present disclosure relates to authentication technologies for electronic devices. Background Art

[0002] In the authentication of conventional electronic devices, the electromagnetic characteristics of an electronic device are measured, the measured electromagnetic characteristics are stored in advance, and then the electromagnetic characteristics of the device to be authenticated are measured, and the electromagnetic characteristics of the device to be authenticated are compared with the pre-stored electromagnetic characteristics, thereby determining the authenticity of the device to be authenticated (for example, Patent Document 1). In addition, a method of performing authentication by focusing on the spectrum of electromagnetic waves radiated from an electronic device as the electromagnetic characteristics of the electronic device has also been proposed (for example, Non-Patent Document 1).

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: U.S. Patent Application Publication No. 2010 / 0230597

[0006] Non-Patent Documents

[0007] Non-Patent Document 1: Hidego Kaji et al., Fundamental Study on Individual Identification Method of Electronic Devices Using Differences in Radiation Spectra Caused by Manufacturing and Mounting Variations, Technical Research Report of the Institute of Electronics, Information and Communication Engineers, Japan, The Institute of Electronics, Information and Communication Engineers, Feb. 20, 2019, Vol. 118, No. 457, pp. 163-167 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] According to the prior art, it is necessary to arrange an authentication device near the device to be authenticated (the device under authentication), and compare the electromagnetic characteristics of the device under authentication measured in this case with the electromagnetic characteristics pre-stored in the authentication device. In addition, assuming that the authentication device and the device under authentication are in different locations and authentication is to be performed via a communication network, it is necessary to load the electromagnetic characteristic data of the device under authentication onto the communication network and send it to the authentication device. When communicating via a communication network, if the communication data on the communication network is eavesdropped and the electromagnetic characteristic data of the device under authentication is leaked, there is a problem that an authentication may be performed in which a forged device is disguised as a genuine device under authentication.

[0010] The present disclosure has been completed to solve such problems, and an object thereof is to provide an authentication technology capable of preventing leakage of electromagnetic characteristics of a device under authentication when authenticating the device under authentication via a communication network.

[0011] Means for Solving the Problem

[0012] One aspect of the authentication device according to an embodiment of the present disclosure includes: a first electromagnetic characteristic acquisition unit that acquires at least one recorded electromagnetic characteristic from a storage device that pre - records the electromagnetic characteristics of a first device to be authenticated; a challenge data generation unit that generates a data set corresponding to the recorded electromagnetic characteristic, i.e., challenge data; an expected value generation unit that compares the recorded electromagnetic characteristic with the generated challenge data and generates an expected value of the response data as a comparison result; a challenge data transmission unit that transmits the generated challenge data to a response device; a response data reception unit that receives response data related to a second device to be authenticated from the response device; and a response data determination unit that compares the generated expected value of the response data with the received response data and determines the authenticity of the second device to be authenticated. The response device compares the electromagnetic characteristic obtained from the second device to be authenticated with the transmitted challenge data and generates a comparison result as the response data.

[0013] Effect of the Invention

[0014] According to the authentication device according to an embodiment of the present disclosure, since the electromagnetic characteristics of the device to be authenticated are not transmitted and received, leakage of the electromagnetic characteristics of the device to be authenticated can be prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 FIG. is a diagram showing a structural example of an authentication system including an authentication device and a response device.

[0016] Figure 2A FIG. is a diagram showing a structural example of the hardware of the authentication device and the response device.

[0017] Figure 2B FIG. is a diagram showing a structural example of the hardware of the authentication device and the response device.

[0018] Figure 3 FIG. is a flowchart of an authentication method.

[0019] Figure 4 FIG. is a diagram showing examples of electromagnetic characteristics (EMCi, EMCr), challenge data, response data, and expected values of response data. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] Hereinafter, various embodiments in the present disclosure will be described in detail with reference to the drawings. In addition, structural elements having the same or similar reference numerals in the drawings have the same or similar structures or functions, and repeated descriptions of such structural elements will be omitted.

[0021] Embodiment 1.

[0022] <Structure>

[0023] (Authentication System)

[0024] Refer to Figure 1 With reference to FIGS. 1 and 2, the structure of the authentication system including an authentication device and a response device according to Embodiment 1 of the present disclosure will be described. The authentication system of the present disclosure is a system for authenticating the authenticity of an authentication target device (second authentication target device) 100. That is, the authentication target device 100 is a device that requests authentication. The authentication target device 100 has inherent electromagnetic characteristics (EMC: electromagnetic characteristics). Hereinafter, using the first letter of "inherent" which represents "inherent", the inherent electromagnetic characteristics EMC will be denoted as electromagnetic characteristics EMCi.

[0025] Due to manufacturing errors, assembly errors, etc. of each structural component and printed wiring board, even if the authentication target device 100 is manufactured according to the same design as other authentication target devices (not shown), the authentication target device 100 has different electromagnetic characteristics EMCi for each device. As such electromagnetic characteristics EMCi, for example, there are radiated electromagnetic noises radiated into space by the operation of the authentication target device 100, and conductive electromagnetic noises conducted in the cable when the authentication target device 100 operates. In addition, as other examples of the electromagnetic characteristics EMCi, there are reflection characteristics (S parameter S 11 characteristics) observed from a specific external I / F such as a power connector or signal connector of the authentication target device 100 regardless of the operation (turning on / off of the power supply) of the authentication target device 100, through characteristics (S parameter S nm characteristics; n and m are numbers assigned to a plurality of external I / Fs) between a plurality of external I / Fs, F parameters, Z parameters, Y parameters, etc. converted from S parameters. These are generally characteristics represented by a frequency axis, but the electromagnetic characteristics EMCi of the authentication target device 100 can also be characteristics represented by a time axis such as a reflection waveform when a step wave or pulse wave is applied to a specific external I / F of the authentication target device 100 or a through waveform in another external I / F. In addition, as the electromagnetic characteristics EMCi, a combination of a plurality of electromagnetic characteristics can also be used. In the example of the authentication target device 100, for example, it includes an electrical device or an electronic device, or an electrical component or an electronic component, but as long as electromagnetic characteristics can be obtained, it is not limited to these examples. For example, it can also be a mechanical component that does not include an electrical circuit.

[0026] To authenticate the authenticity of the authentication target device 100, as Figure 1As shown in the figure, the authentication system of the present disclosure includes an authentication device 200, a storage device 500, and a response device 300. The communication between the authentication device 200 and the response device 300 is carried out via a wired or wireless communication network 400. The storage device 500 is a device that pre-records the electromagnetic characteristics EMCi of one or more authenticated devices. Hereinafter, using the first letter of "registered" which means "recorded", the electromagnetic characteristics EMCi of the authenticated device (the first authenticated device) recorded in the storage device 500 are denoted as electromagnetic characteristics EMCr.

[0027] (Authentication device)

[0028] The authentication device 200 is a device that authenticates the authenticity of the authenticated device 100. To achieve such a purpose, the authentication device 200 includes an electromagnetic characteristic acquisition unit (the first electromagnetic characteristic acquisition unit) 210, a challenge data generation unit 220, an expected value generation unit 230, a challenge data transmission unit 240, a response data reception unit 250, and a response data determination unit 260 as functional units.

[0029] (Electromagnetic characteristic acquisition unit)

[0030] The electromagnetic characteristic acquisition unit 210 is a functional unit that acquires at least one electromagnetic characteristic EMCr from the storage device 500. The electromagnetic characteristic acquisition unit 210 supplies the acquired electromagnetic characteristic EMCr to the challenge data generation unit 220 and the expected value generation unit 230. In addition, the supply of data can also be carried out via a control unit (not shown) provided in the authentication device 200. The same applies hereinafter.

[0031] (Challenge data generation unit)

[0032] The challenge data generation unit 220 is a functional unit that generates challenge data corresponding to the electromagnetic characteristic EMCr acquired by the electromagnetic characteristic acquisition unit 210. The challenge data generation unit 220 supplies the generated challenge data to the challenge data transmission unit 240 and the expected value generation unit 230.

[0033] (Expected value generation unit)

[0034] The expected value generation unit 230 is a functional unit that compares the electromagnetic characteristic EMCr acquired by the electromagnetic characteristic acquisition unit 210 with the challenge data generated by the challenge data generation unit 220 and generates a response data expected value as a comparison result. The expected value generation unit 230 supplies the generated response data to the response data determination unit 260.

[0035] (Challenge data transmission unit)

[0036] The challenge data transmission unit 240 is a functional unit that transmits the challenge data generated by the challenge data generation unit 220 to the response device 300 via the communication network 400.

[0037] (Response data receiving unit)

[0038] The response data receiving unit 250 is a functional unit that receives, via the communication network 400, response data related to the authenticated device 100 generated by the response device 300.

[0039] (Response data determination unit)

[0040] The response data determination unit 260 is a functional unit that compares the response data expectation value generated by the expectation value generation unit 230 with the response data received by the response data receiving unit 250 to determine the authenticity of the authenticated device 100.

[0041] (Response device)

[0042] The response device 300 is a device that generates response data based on the electromagnetic characteristics EMCi of the authenticated device 100 and the challenge data received from the authentication device 200, and responds to the authentication device 200 by sending the generated response data. To achieve this purpose, the response device 300 includes an electromagnetic characteristics acquisition unit (second electromagnetic characteristics acquisition unit) 310, a challenge data receiving unit 320, a response data generation unit 330, and a response data sending unit 340 as functional units.

[0043] (Electromagnetic characteristics acquisition unit)

[0044] The electromagnetic characteristics acquisition unit 310 is a functional unit that acquires the electromagnetic characteristics EMCi of the authenticated device 100. The electromagnetic characteristics acquisition unit 310 supplies the acquired electromagnetic characteristics EMCi to the response data generation unit 330. In addition, the supply of data may also be performed via a control unit (not shown) provided in the response device 300. The same applies hereinafter.

[0045] (Challenge data receiving unit)

[0046] The challenge data receiving unit 320 is a functional unit that receives, via the communication network 400, challenge data from the authentication device 200. The challenge data receiving unit 320 supplies the received challenge data to the response data generation unit 330.

[0047] (Response data generation unit)

[0048] The response data generation unit 330 is a functional unit that generates response data by comparing the electromagnetic characteristics EMCi supplied from the electromagnetic characteristics acquisition unit 310 with the challenge data supplied from the challenge data receiving unit 320. The response data generation unit 330 supplies the generated response data to the response data sending unit 340.

[0049] (Response data sending unit)

[0050] The response data transmission unit 340 is a functional unit that transmits the response data generated by the response data generation unit 330 to the authentication device 200 via the communication network 400.

[0051] In addition, the response device 300 may be a device different from the authenticated device 100 as Figure 1 shown in the figure, or may be integrated with the authenticated device 100. In the case where the response device 300 is integrated with the authenticated device 100, for example, the authenticated device 100 includes the functional units of the response device 300.

[0052] Next, with reference to Figure 2A and Figure 2B , a structural example of the hardware of the authentication device 200 and the response device 300 will be described. The functional units included in the authentication device 200 and the response device 300 are implemented by a processing circuitry. The processing circuitry may be Figure 2A the dedicated processing circuit 600 shown in Figure 2B , or may be the processor 700 that executes the program stored in the execution memory 800 shown in

[0053] In the case where the processing circuitry is the dedicated processing circuit 600, the dedicated processing circuit 600 corresponds to, for example, a single circuit, a composite circuit, a programmed processor, a parallel-programmed processor, an ASIC (application specific integrated circuit), an FPGA (field-programmable gate array), or a combination thereof. Each functional unit of the authentication device 200 and the response device 300 may be implemented by a plurality of independent processing circuits, or each functional unit may be implemented by a single processing circuit.

[0054] In the case where the processing circuitry is the processor 700, the functional units of the authentication device 200 and the response device 300 are implemented by software, firmware, or a combination of software and firmware. The software and firmware are described in the form of programs and stored in the memory 800. The processor 700 realizes the functions of the respective functional units by reading and executing the programs stored in the memory. Here, in the example of the memory 800, it includes non-volatile or volatile semiconductor memories such as RAM (random access memory), ROM (read-only memory), flash memory, EPROM (erasable programmable readonly memory), EEPROM (electrically erasable programmableread-only memory), magnetic disks, floppy disks, optical disks, high-density disks, minidisks, and DVDs.

[0055] Alternatively, a part of the functional units of the authentication device 200 and the response device 300 can be implemented by dedicated hardware, and a part can be implemented by software or firmware. In this way, the processing circuitry can implement the above-described respective functions by hardware, software, firmware, or a combination thereof.

[0056] <Operation>

[0057] Next, with reference to Figure 3 and Figure 4 the operation of the authentication system of the present disclosure will be described. First, the electromagnetic characteristics EMCi of the device under authentication 100 and the identification information of the device under authentication 100 are pre-recorded in the storage device 500. As described above, the electromagnetic characteristics EMCi of the device under authentication 100 recorded in the storage device 500 are referred to as electromagnetic characteristics EMCr. The recording of the electromagnetic characteristics EMCi is performed for each device under authentication assumed for authentication later.

[0058] The authentication system operates in response to the generation of an authentication request for the device under authentication 100 from the device under authentication 100 or another external system (not shown) to the authentication device 200. In response to the generation of the authentication request, in step ST101, the electromagnetic characteristics acquisition unit 210 of the authentication device 200 acquires the electromagnetic characteristics EMCr of the device under authentication 100 that is the object from one or more electromagnetic characteristics recorded in the storage device 500.

[0059] In step ST102, the challenge data generation unit 220 obtains a data set corresponding to the electromagnetic characteristic EMCr, i.e., challenge data. The "data set corresponding to the electromagnetic characteristic EMCr" refers to the following data set: at least including a group of an X-axis value X on the X-axis of the electromagnetic characteristic EMCr and a Y-axis value Y related to the X-axis value X in a two-dimensional graph representing the electromagnetic characteristic EMCr, and this group is a group (X, Y) of the X-axis value X and the Y-axis value Y where the Y-axis value Y has a value smaller than the maximum value and larger than the minimum value of the electromagnetic characteristic EMCr.

[0060] As an example, the challenge data generation unit 220 generates a group [Xn, Yn] (n is an integer) of a plurality of X-axis values (Xn; for example, frequency or time) of the electromagnetic characteristic EMCr and a threshold value of the Y-axis value (Yn; for example, gain, phase, or signal waveform) corresponding to each X-axis value as challenge data. In the case of generating challenge data by combining a plurality of electromagnetic characteristics, the challenge data can be, for example, a group of threshold values Y1n and Y2n of different characteristics corresponding to the value (Xn) of the common X-axis, or can also be in the form of [Xn, Y1n, Y2n,...] (n is an integer). The challenge data generation unit 220 randomly generates such challenge data each time an authentication request is generated. That is, regarding all or a part of the number of n on the X-axis, the value (Xn) of the X-axis, and the Y-axis threshold value Yn corresponding to Xn, even for the same authenticated device 100, it is randomly generated each time an authentication request is generated.

[0061] In addition, as another example, the challenge data generation unit 220 can also generate a group [Xn, Y] (n is an integer) of a plurality of X-axis values Xn and a common and single Y-axis threshold value Y among the plurality of X-axis values as challenge data.

[0062] In addition, as another example, the challenge data generation unit 220 can also generate a plurality of shared X-axis values Xn that are fixed values pre-shared in the authentication device 200 and the response device 300 or shared variable values generated by a common tool each time an authentication request is generated for the X-axis, and generate a plurality of Y-axis threshold values Yn that are different from each other with respect to the plurality of shared X-axis values for the Y-axis as challenge data.

[0063] In addition, as another example, the challenge data generation unit 220 can also generate a plurality of shared X-axis values Xn that are fixed values pre-shared in the authentication device 200 and the response device 300 or shared variable values generated by a common tool each time an authentication request is generated for the X-axis, and generate a common and single Y-axis threshold value Y with respect to the plurality of shared X-axis values for the Y-axis as challenge data.

[0064] In addition, as an example, each time an authentication request is generated, the challenge data generation unit 220 may generate a plurality of X-axis values Xn and a part or all of the Y-axis thresholds Y or Yn corresponding to each X-axis value as random values.

[0065] In step ST103, the expected value generation unit 230 compares the electromagnetic characteristics EMCr with the generated challenge data and generates an expected value of the response data as a comparison result. That is, the expected value generation unit 230 generates an expected response data expected value for the generated challenge data. For example, the expected value generation unit 230 compares the electromagnetic characteristics EMCr of the device under authentication 100 with the generated challenge data. If the level of the electromagnetic characteristics EMCr corresponding to the specified Xn is Yn or higher, it is set to "1", and if it is less than Yn, it is set to "0" to generate an n-bit bit string (first data) as the expected value of the response data. In addition, a method of generating response data based on electromagnetic characteristics and challenge data like this is also preset in the response data generation unit 330 of the response device 300.

[0066] In step ST104, the challenge data transmission unit 240 transmits the challenge data to the response device 300 via the communication network 400 in parallel with or before or after the generation of the expected value of the response data.

[0067] The challenge data transmitted from the authentication device 200 in this way is received by the challenge data reception unit 320 of the response device 300 via the communication network 400 (step ST201).

[0068] In step ST202, the electromagnetic characteristic acquisition unit 310 acquires the electromagnetic characteristics EMCi of the device under authentication 100 to be authenticated based on the reception of the challenge data. For example, the electromagnetic characteristics EMCi recorded as data in the device under authentication 100 are taken out, or if it is a characteristic such as S-parameters, it is measured by a function equivalent to a network analyzer (if it is a characteristic such as F, Z, Y-parameters, it is also converted, and if it is a response characteristic to a step wave or a pulse wave, it is measured by a function equivalent to a signal generator and a function equivalent to an oscilloscope).

[0069] Next, in step ST203, the response data generation unit 330 compares the acquired electromagnetic characteristics EMCi of the device under authentication 100 to be authenticated with the received challenge data and generates the comparison result as response data. According to the above example, similar to the operation of the expected value generation unit 230, if the level of the electromagnetic characteristics EMCi corresponding to the Xn specified by the challenge data is Yn or higher, it is set to "1", and if it is less than Yn, it is set to "0" to generate an n-bit bit string (second data) as the response data. The response data generation unit 330 delivers the generated response data to the response data transmission unit 340.

[0070] Next, in step ST204, the response data transmission unit 340 transmits the generated response data to the authentication device 200 via the communication network 400.

[0071] The response data transmitted from the response device 300 in this way is received by the response data reception unit 250 of the authentication device 200 via the communication network 400 (step ST105).

[0072] Finally, in step ST106, the response data determination unit 260 compares the response data expected value generated by the expected value generation unit 203 with the response data received by the response data reception unit 250 to determine the authenticity of the authenticated device 100. For example, the n-bit response data expected value generated by the expected value generation unit 230 is compared with the n-bit response data received by the response data reception unit 250. If they are exactly the same or a certain number of bits (for example, 85% or more of the total bits) are the same, the authenticated device is authenticated as genuine. The authentication result is transmitted to the authenticated device 100 that is the source of the authentication request or other external systems (not shown), etc.

[0073] Figure 4 It is a diagram showing examples of the electromagnetic characteristics (EMCi, EMCr), challenge data, response data, and response data expected value illustrated in the above operation description.

[0074] Reference numeral 211 is an example of the recorded electromagnetic characteristic EMCr of the authenticated device obtained by the electromagnetic characteristic acquisition unit 210 of the authentication device 200. As Figure 4 shown, the electromagnetic characteristic EMCr is a characteristic represented by a two-dimensional diagram composed of the X-axis and the Y-axis.

[0075] Reference numeral 221 is an example of the challenge data generated by the challenge data generation unit 220 of the authentication device 200, shown as challenge data composed of a group [Xn, Yn] (n is an integer) of a plurality of X-axis values of the electromagnetic characteristic (the X-axis is, for example, frequency or time) and the threshold value of the Y-axis value corresponding to the X-axis.

[0076] Reference numeral 311 is an example of the electromagnetic characteristic EMCi of the authenticated device 100 obtained by the electromagnetic characteristic acquisition unit 310 of the response device 300. As Figure 4 shown, the electromagnetic characteristic EMCi is a characteristic represented by a two-dimensional diagram composed of the X-axis and the Y-axis.

[0077] Reference numeral 331 is response data constituted by the following 7-bit bit string: By comparing the challenge data 221 received by the challenge data receiving unit 320 with the electromagnetic characteristics 311 of the device under authentication 100 obtained by the electromagnetic characteristics acquisition unit 310, and through the response data generation unit 330, if the level of the inherent electromagnetic characteristics 311 corresponding to Xn on the X-axis specified by the challenge data 221 is Yn or higher, it is set to "1", and if it is less than Yn, it is set to "0", thereby generating the 7-bit bit string. In this way, the response data generation unit 330 compares the Y-axis threshold Yn with the Y-axis values corresponding to multiple X-axis values Xn of the electromagnetic characteristics 311, determines which one of the Y-axis threshold Yn and the Y-axis value of the electromagnetic characteristics 311 is larger, and generates 7-bit data.

[0078] Reference numeral 231 is an expected value of response data constituted by the following 7-bit bit string: By comparing the electromagnetic characteristics 211 obtained by the electromagnetic characteristics acquisition unit 210 with the challenge data 221 generated by the challenge data generation unit 220, and through the expected value generation unit 230, if the level of the electromagnetic characteristics 211 corresponding to Xn on the X-axis specified by the challenge data 221 is Yn or higher, it is set to "1", and if it is less than Yn, it is set to "0", thereby generating the 7-bit bit string. In this way, the expected value generation unit 230 compares the Y-axis threshold Yn with the Y-axis values corresponding to multiple X-axis values Xn of the electromagnetic characteristics 211, determines which one of the Y-axis threshold Yn and the Y-axis value of the electromagnetic characteristics 211 is larger, and generates 7-bit data.

[0079] The response data 331 is received by the response data receiving unit 250 of the authentication device 200 via the communication network 400 by the response data sending unit 340 of the response device 300. The response data determination unit 260 compares the response data 331 with the response data expected value 231 generated by the expected value generation unit 230. If the response data 331 is exactly the same as the response data expected value 231 or a certain number of bits match between the response data 331 and the response data expected value 231, the authentication device 200 authenticates that the device under authentication is genuine.

[0080] As described above, in the case of authenticating an electronic device using the device's inherent electromagnetic characteristics, each time an authentication request is generated, challenge data corresponding to the device's inherent electromagnetic characteristics is randomly generated, sent via the communication network, and authentication is performed using the response data corresponding to the challenge data. Therefore, authentication via the communication network can be performed. In addition, even if the challenge data or response data is eavesdropped on the communication network, since the device's inherent electromagnetic characteristics are concealed, it is also possible to prevent false authentication based on forgery or the like.

[0081] Embodiment 2.

[0082] For the embodiments after Embodiment 2, the repeated descriptions of the common points with Embodiment 1 are omitted, and the differences from Embodiment 1 are described as much as possible.

[0083] The overall structural diagram of the authentication system including the authentication device and the response device in Embodiment 2 is the same as that in Embodiment 1, as Figure 1 shown.

[0084] In Embodiment 2, each time an authentication request is generated, the challenge data generation unit 220 generates a group [Xn, Y] (n is an integer) of multiple X-axis values (Xn; the X-axis is, for example, frequency or time) of the electromagnetic characteristic EMCr and a common and single Y-axis threshold (Y) with respect to the multiple X-axis values as challenge data.

[0085] The challenge data generation unit 220 may also randomly generate multiple X-axis values Xn and a common and single Y-axis threshold Y each time an authentication request is generated.

[0086] The expected value generation unit 230 compares the Y-axis threshold Y with the Y-axis values corresponding to the multiple X-axis values Xn of the electromagnetic characteristic 211, and determines which one of the Y-axis threshold Y and the Y-axis value of the electromagnetic characteristic 211 is larger.

[0087] The response data generation unit 330 compares the Y-axis threshold Y with the Y-axis values corresponding to the multiple X-axis values Xn of the electromagnetic characteristic 311, and determines which one of the Y-axis threshold Y and the Y-axis value of the electromagnetic characteristic 311 is larger.

[0088] By generating challenge data in this way, the effect of reducing the data volume of the challenge data compared with Embodiment 1 can be obtained.

[0089] Embodiment 3.

[0090] The overall structural diagram of the authentication system including the authentication device and the response device in Embodiment 3 is the same as that in Embodiment 1, as Figure 1 shown.

[0091] In Embodiment 3, multiple X-axis values are pre-shared in the authentication device 200 and the response device 300. The challenge data generation unit 220 obtains the shared multiple X-axis values by referring to the memory. The shared multiple X-axis values may always be the same, or may be changed according to a predetermined fixed rule each time an authentication request is generated.

[0092] In the case where multiple X-axis values are shared like this, the challenge data generation unit 220 can also generate, for the X-axis, fixed values pre-shared in the authentication device 200 and the response device 300 or variable values generated and shared by a common tool each time an authentication request is made, that is, the shared multiple X-axis values Xn, and for the Y-axis, generate multiple Y-axis thresholds Yn that are different from each other with respect to the shared multiple X-axis values.

[0093] In addition, the challenge data transmission unit 240 can also transmit only the generated multiple Y-axis thresholds Yn among the multiple X-axis values Xn and the multiple Y-axis thresholds Yn generated by the challenge data generation unit 220 as [Yn] (n is an integer).

[0094] With such a structure, an effect can be obtained that the data amount of the challenge data can be further reduced compared to Embodiment 2.

[0095] Embodiment 4.

[0096] The overall structural diagram of the authentication system including the authentication device and the response device in Embodiment 4 is the same as that in Embodiment 1, as Figure 1 shown.

[0097] In Embodiment 4, multiple X-axis values are pre-shared in the authentication device 200 and the response device 300. The challenge data generation unit 220 obtains the shared multiple X-axis values by referring to the memory. The shared multiple X-axis values can be always the same or can be changed according to a fixed rule each time an authentication request is generated.

[0098] In the case where multiple X-axis values are shared like this, the challenge data generation unit 220 can also generate, for the X-axis, fixed values pre-shared in the authentication device 200 and the response device 300 or variable values generated and shared by a common tool each time an authentication request is made, that is, the shared multiple X-axis values Xn, and for the Y-axis, generate a common and single Y-axis threshold Y with respect to the shared multiple X-axis values Xn.

[0099] In addition, the challenge data transmission unit 240 can also transmit only the generated single Y-axis threshold Y among the generated multiple X-axis values Xn and the single Y-axis threshold Y as [Y].

[0100] With such a structure, an effect can be obtained that the data amount of the challenge data can be significantly reduced.

[0101] Embodiment 5.

[0102] The overall structural diagram of the authentication system including the authentication device and the response device in Embodiment 5 is the same as that in Embodiment 1, as Figure 1 shown.

[0103] In Embodiment 5, the challenge data generation unit 220 may also randomly generate a Y-axis threshold of the electromagnetic characteristic EMCr with respect to the X-axis value outside a certain ratio range, for example, outside the range of ±10% of the Y value of the electromagnetic characteristic EMCr. The challenge data generation unit 220 in Embodiments 1 to 3 may also generate a Y-axis threshold outside a certain ratio range.

[0104] As a result, an effect can be obtained that even if the electromagnetic characteristic EMCi slightly changes due to environmental changes or aging deterioration, etc., the influence on the threshold determination can be reduced.

[0105] Embodiment 6.

[0106] The overall structural diagram of the authentication system including the authentication device and the response device in Embodiment 6 is the same as that in Embodiment 1, as Figure 1 shown.

[0107] In Embodiment 6, the expected value generation unit 230 and the response data generation unit 330 may also use the operation result of operating the bit string of the comparison result for the Y-axis threshold corresponding to the generated X-axis value according to a predetermined rule as the response data. For example, the expected value generation unit 230 and the response data generation unit 330 may encode or encrypt the bit string of the comparison result. The expected value generation unit 230 and the response data generation unit 330 in Embodiments 1 to 5 may also operate in the same manner.

[0108] As a result, an effect can be obtained that even if the challenge data and the response data are wiretapped multiple times, it is difficult to estimate the electromagnetic characteristic EMCi or the electromagnetic characteristic EMCr of the device to be authenticated.

[0109] In addition, the embodiments can be combined, or each embodiment can be appropriately changed or omitted.

[0110] Industrial Applicability

[0111] The authentication system of the present disclosure can be used as an authentication system for a device to be authenticated via a communication network.

[0112] Description of Reference Numerals

[0113] 100 Authenticated device, 200 Authentication device, 203 Expected value generation unit, 210 Electromagnetic characteristic acquisition unit (first electromagnetic characteristic acquisition unit), 211 Electromagnetic characteristic EMCr, 220 Challenge data generation unit, 221 Challenge data, 230 Expected value generation unit, 231 Response data expected value, 240 Challenge data transmission unit, 250 Response data reception unit, 260 Response data determination unit, 300 Response device, 310 Electromagnetic characteristic acquisition unit (second electromagnetic characteristic acquisition unit), 311 Electromagnetic characteristic EMCi, 320 Challenge data reception unit, 330 Response data generation unit, 331 Response data, 340 Response data transmission unit, 400 Communication network, 500 Storage device, 600 Processing circuit, 700 Processor, 800 Memory.

Claims

1. An authentication device, wherein, the authentication device includes: a first electromagnetic characteristic acquisition unit that acquires at least one recorded electromagnetic characteristic from a storage device that pre - records the electromagnetic characteristics of a first device to be authenticated; a challenge data generation unit that generates a data set corresponding to the recorded electromagnetic characteristic, namely challenge data; an expected value generation unit that compares the recorded electromagnetic characteristic with the generated challenge data and generates a response data expected value as a comparison result; a challenge data sending unit that sends the generated challenge data to a response device; a response data receiving unit that receives response data related to a second device to be authenticated from the response device; and a response data determination unit that compares the generated response data expected value with the received response data and determines the authenticity of the second device to be authenticated, wherein the response device compares the electromagnetic characteristic obtained from the second device to be authenticated with the sent challenge data and generates a comparison result as the response data.

2. An authentication system, which includes: the authentication device according to claim 1; and the response device according to claim 1, wherein, the response device includes: a second electromagnetic characteristic acquisition unit that acquires the electromagnetic characteristic of the second device to be authenticated; a challenge data receiving unit that receives the sent challenge data; a response data generation unit that compares the acquired electromagnetic characteristic of the second device to be authenticated with the received challenge data and generates a comparison result as the response data; and a response data sending unit that sends the generated response data.

3. The authentication system according to claim 2, wherein, the response device and the second device to be authenticated are integrated.

4. The authentication system according to claim 2 or 3, wherein, the electromagnetic characteristics of the first device to be authenticated and the second device to be authenticated are characteristics represented by a two - dimensional graph composed of an X - axis and a Y - axis, the challenge data is generated as a set [Xn, Yn] of a plurality of X - axis values Xn and Y - axis thresholds Yn corresponding to each X - axis value, where n is an integer.

5. The authentication system according to claim 2 or 3, wherein, the electromagnetic characteristics of the first device to be authenticated and the second device to be authenticated are characteristics represented by a two - dimensional graph composed of an X - axis and a Y - axis, the challenge data is generated as a set [Xn, Y] of a plurality of X - axis values Xn and a common and single Y - axis threshold Y among the plurality of X - axis values, where n is an integer.

6. The authentication system according to claim 2 or 3, wherein, the electromagnetic characteristics of the first device to be authenticated and the second device to be authenticated are characteristics represented by a two - dimensional graph composed of an X - axis and a Y - axis, the challenge data generation unit generates, for the X - axis, fixed values pre - shared in the authentication device and the response device or variable values generated and shared by a common tool each time an authentication request is made, namely a plurality of shared X - axis values Xn, and for the Y - axis, generates a plurality of Y - axis thresholds Yn that are different from each other with respect to the plurality of shared X - axis values. The challenge data transmitting unit transmits only the generated multiple Y-axis thresholds Yn among the generated multiple X-axis values Xn and the generated multiple Y-axis thresholds Yn as [Yn], where n is an integer.

7. The authentication system according to claim 2 or 3, wherein the electromagnetic characteristics of the first authenticated device and the second authenticated device are characteristics represented by a two-dimensional graph composed of an X-axis and a Y-axis, the challenge data generation unit generates, for the X-axis, fixed values pre-shared between the authentication device and the response device or variable values generated and shared by a common tool each time an authentication request is made, that is, multiple shared X-axis values Xn, and generates, for the Y-axis, a Y-axis threshold Y that is common and single with respect to the multiple shared X-axis values Xn, the challenge data transmitting unit transmits only the generated single Y-axis threshold Y among the generated multiple X-axis values Xn and the single Y-axis threshold Y as [Y].

8. The authentication system according to any one of claims 4 to 7, wherein some or all of the multiple X-axis values Xn and the Y-axis threshold Y or Yn corresponding to each X-axis value are generated as random values each time an authentication request is generated.

9. The authentication system according to claim 8, wherein the at least one recorded electromagnetic characteristic includes two electromagnetic characteristics, the challenge data generation unit generates, for each of the two or more electromagnetic characteristics, multiple X-axis values Xn and the Y-axis threshold Y or Yn corresponding to the multiple X-axis values Xn, and generates a combination of the X-axis value Xn and the Y-axis threshold Y or Yn as the challenge data.

10. The authentication system according to claim 9, wherein the expected value generation unit compares the Y-axis threshold Yn or Y with the Y-axis value corresponding to the multiple X-axis values Xn of the electromagnetic characteristics of the first authenticated device, determines which of the Y-axis threshold Yn or Y and the Y-axis value of the electromagnetic characteristics of the first authenticated device is larger, and generates first data of n bits, the response data generation unit compares the Y-axis threshold Yn or Y with the Y-axis value corresponding to the multiple X-axis values Xn of the electromagnetic characteristics of the second authenticated device, determines which of the Y-axis threshold Yn or Y and the Y-axis value of the electromagnetic characteristics of the second authenticated device is larger, and generates second data of n bits.

11. The authentication system according to claim 9, wherein the expected value generation unit compares the Y-axis threshold Yn or Y with the Y-axis value corresponding to the multiple X-axis values Xn of the electromagnetic characteristics of the first authenticated device, determines which of the Y-axis threshold Yn or Y and the Y-axis value of the electromagnetic characteristics of the first authenticated device is larger, generates first data of n bits, and performs a pre-determined operation on the generated first data, The response data generation unit compares the Y-axis threshold value Yn or Y with the Y-axis values corresponding to the multiple X-axis values Xn of the electromagnetic characteristics of the second authentication device, determines which one of the Y-axis threshold value Yn or Y and the Y-axis value of the electromagnetic characteristics of the second authentication device is larger, generates second data of n bits, and performs the predetermined operation on the generated second data.

12. An authentication method is an authentication method performed by an authentication device including a first electromagnetic characteristic acquisition unit, a challenge data generation unit, an expected value generation unit, a challenge data transmission unit, a response data reception unit, and a response data determination unit. The authentication method includes the following steps: The first electromagnetic characteristic acquisition unit acquires at least one recorded electromagnetic characteristic from a storage device that pre-records the electromagnetic characteristics of the first authentication device; The challenge data generation unit generates a data set corresponding to the recorded electromagnetic characteristic, i.e., challenge data; The expected value generation unit compares the recorded electromagnetic characteristic with the generated challenge data and generates a response data expected value as a comparison result; The challenge data transmission unit transmits the generated challenge data to the response device; The response data reception unit receives response data related to the second authentication device from the response device, and the response data is a result obtained by the response device comparing the electromagnetic characteristics acquired from the second authentication device with the transmitted challenge data; The response data determination unit compares the generated response data expected value with the received response data and determines the authenticity of the second authentication device.

13. An authentication method is an authentication method performed by an authentication system including an authentication device and a response device. The authentication device includes a first electromagnetic characteristic acquisition unit, a challenge data generation unit, an expected value generation unit, a challenge data transmission unit, a response data reception unit, and a response data determination unit. The response device includes a second electromagnetic characteristic acquisition unit, a challenge data reception unit, a response data generation unit, and a response data transmission unit. The authentication method includes the following steps: The first electromagnetic characteristic acquisition unit of the authentication device acquires at least one recorded electromagnetic characteristic from a storage device that pre-records the electromagnetic characteristics of the first authentication device; The challenge data generation unit of the authentication device generates a data set corresponding to the recorded electromagnetic characteristic, i.e., challenge data; The expected value generation unit of the authentication device compares the recorded electromagnetic characteristic with the generated challenge data and generates a response data expected value as a comparison result; The challenge data transmission unit of the authentication device transmits the generated challenge data to the response device; The challenge data reception unit of the response device receives the transmitted challenge data; The second electromagnetic characteristic acquisition unit of the response device acquires the electromagnetic characteristics of the second authentication device; The response data generation unit of the response device compares the acquired electromagnetic characteristics of the second authentication device with the received challenge data and generates a comparison result as response data; The response data transmission unit of the response device transmits the generated response data; The response data receiving unit of the authentication device receives response data related to the second device to be authenticated from the response device; The response data determination unit of the authentication device compares the generated expected value of the response data with the received response data to determine the authenticity of the second device to be authenticated.

14. The authentication method according to claim 13, wherein, The electromagnetic characteristics of the first device to be authenticated and the second device to be authenticated are characteristics represented by a two-dimensional graph composed of an X-axis and a Y-axis, The challenge data is generated as a set [Xn, Yn] of a plurality of X-axis values Xn and Y-axis thresholds Yn corresponding to each X-axis value, where n is an integer.

15. The authentication method according to claim 13, wherein, The electromagnetic characteristics of the first device to be authenticated and the second device to be authenticated are characteristics represented by a two-dimensional graph composed of an X-axis and a Y-axis, The challenge data is generated as a set [Xn, Y] of a plurality of X-axis values Xn and a common and single Y-axis threshold Y among the plurality of X-axis values, where n is an integer.

16. The authentication method according to claim 13, wherein, The electromagnetic characteristics of the first device to be authenticated and the second device to be authenticated are characteristics represented by a two-dimensional graph composed of an X-axis and a Y-axis, The challenge data generation unit generates, for the X-axis, fixed values pre-shared in the authentication device and the response device or variable values generated and shared by a common tool each time an authentication request is made, that is, a plurality of shared X-axis values Xn, and for the Y-axis, generates a plurality of Y-axis thresholds Yn that are different from each other with respect to the plurality of shared X-axis values, The challenge data sending unit sends only the generated plurality of Y-axis thresholds Yn among the generated plurality of X-axis values Xn and plurality of Y-axis thresholds Yn as [Yn], where n is an integer.

17. The authentication method according to claim 13, wherein, The electromagnetic characteristics of the first device to be authenticated and the second device to be authenticated are characteristics represented by a two-dimensional graph composed of an X-axis and a Y-axis, The challenge data generation unit generates, for the X-axis, fixed values pre-shared in the authentication device and the response device or variable values generated and shared by a common tool each time an authentication request is made, that is, a plurality of shared X-axis values Xn, and for the Y-axis, generates a common and single Y-axis threshold Y with respect to the plurality of shared X-axis values Xn, The challenge data sending unit sends only the generated single Y-axis threshold Y among the generated plurality of X-axis values Xn and single Y-axis threshold Y as [Y].

18. The authentication method according to any one of claims 14 to 17, wherein, Some or all of the plurality of X-axis values Xn and the Y-axis thresholds Y or Yn corresponding to each X-axis value are generated as random values each time an authentication request is generated.

19. The authentication method according to claim 18, wherein, The at least one recorded electromagnetic characteristic includes two electromagnetic characteristics, The challenge data generation unit generates, for each of the two or more electromagnetic characteristics, a plurality of X-axis values Xn and Y-axis thresholds Y or Yn corresponding to the plurality of X-axis values Xn, and generates a combination of the X-axis value Xn and the Y-axis threshold Y or Yn as the challenge data.

20. The authentication method according to claim 19, wherein the expected value generation unit compares the Y-axis threshold Yn or Y with the Y-axis values corresponding to the plurality of X-axis values Xn of the electromagnetic characteristics of the first authentication device, determines which one of the Y-axis threshold Yn or Y and the Y-axis values of the electromagnetic characteristics of the first authentication device is larger, and generates first data of n bits. The response data generation unit compares the Y-axis threshold Yn or Y with the Y-axis values corresponding to the plurality of X-axis values Xn of the electromagnetic characteristics of the second authentication device, determines which one of the Y-axis threshold Yn or Y and the Y-axis values of the electromagnetic characteristics of the second authentication device is larger, and generates second data of n bits.

21. The authentication method according to claim 19, wherein the expected value generation unit compares the Y-axis threshold Yn or Y with the Y-axis values corresponding to the plurality of X-axis values Xn of the electromagnetic characteristics of the first authentication device, determines which one of the Y-axis threshold Yn or Y and the Y-axis values of the electromagnetic characteristics of the first authentication device is larger, generates first data of n bits, and performs a predetermined operation on the generated first data. The response data generation unit compares the Y-axis threshold Yn or Y with the Y-axis values corresponding to the plurality of X-axis values Xn of the electromagnetic characteristics of the second authentication device, determines which one of the Y-axis threshold Yn or Y and the Y-axis values of the electromagnetic characteristics of the second authentication device is larger, generates second data of n bits, and performs the predetermined operation on the generated second data.

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