JP2016086337A - Cipher key sharing system and cipher key sharing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize cipher key sharing with simple processing, while assuring confidentiality of the cipher key.SOLUTION: A first device DV10 includes: a unique signal generation part 10 for outputting a device unique signal according to an input signal; a first cipher key generation part 30 for generating a cipher key generation signal K for generating a cipher key, from a signal outputted from the unique signal generation part 10 and a first fixed signal NA; and a first key sharing information calculation part 50 for calculating key sharing information corresponding to a cipher key generation signal K. A second device DV20 includes: a difference decoding part 60 for decoding a difference signal between a cipher key generation signal K generated by the first cipher key generation part 30 and a second fixed signal NB, according to a second fixed signal NB, generated from a signal outputted from the fixed signal generation part 10 according to an input signal and the first fixed signal NA, and key sharing information calculated by the first key sharing information calculation part 50; and a second cipher key generation part 130 for generating a cipher key generation signal K from the second fixed signal NB.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a system for sharing an encryption key and a method for sharing an encryption key.

  Using a device-specific information generation apparatus or a physically unclonable function (PUF), a device-specific encryption key can be generated in the device.

  Here, in Patent Document 1 below, as a method for sharing the encryption key among a plurality of devices, there is a key sharing method based on public key encryption technology by using the key as a secret key for public key encryption. It is disclosed.

JP 2013-31151 A

  In the encryption key sharing method described in Patent Document 1, a large amount of processing is required in order to use a public key encryption technique that uses a multiple-length power residue operation, and as a result, the processing takes time. There is a problem. In addition, in order to change the key shared between the devices every time, when changing the common key stored in the device according to the random number flowing in the communication path, the common key stored in the device On the other hand, there is a problem that a side channel attack becomes possible.

  The present invention has been made to solve the above-described problems, and realizes sharing of the key whose value changes each time by a simpler process while ensuring the confidentiality required for the encryption key. An object of the present invention is to provide an encryption key sharing system and encryption key sharing method.

  In order to solve the above problems, the present invention is an encryption key sharing system for sharing an encryption key between a first device and a second device, and the first device is device-specific according to an input signal. A first cipher for generating an encryption key generating signal for generating an encryption key from the signal output from the signal generating means and the signal output from the signal generating means and a predetermined first fixed signal. A key generating unit; and a first key sharing information calculating unit that calculates key sharing information for the encryption key generation signal generated by the first encryption key generating unit. In accordance with the signal output in advance from the unique signal generating means, the second fixed signal generated from the first fixed signal, and the key sharing information calculated from the first key sharing information calculating means, the first Created by encryption key creation means Differential decryption means for decrypting a differential signal between the signal key generation signal and the second fixed signal, and second encryption key creation for creating an encryption key generation signal from the signal obtained by the differential decryption means and the second fixed signal An encryption key sharing system comprising means is provided.

  In order to solve the above problem, the present invention provides an encryption key sharing system for sharing an encryption key between a first device and a second device, the first device responding to an input signal. An encryption key generation signal for generating an encryption key by adding a unique signal generation means for outputting a device-specific signal, a signal output from the unique signal generation means and a predetermined first fixed signal. A first adding means to be created; and a second adding means for adding the codeword signal to the encryption key generation signal, wherein the second device outputs a signal output beforehand from the unique signal generating means in response to the input signal. And a first subtracting means for subtracting a second fixed signal obtained by adding the first fixed signal from a signal generated by the second adding means, and a first subtracting means. Calculate the syndrome for Second syndrome calculating means for calculating a syndrome for the signal generated by the first syndrome calculating means or the second adding means, and storing a syndrome for the second fixed signal calculated in advance; Second subtracting means for subtracting the syndrome for the second fixed signal stored in the syndrome calculating means from the syndrome for the signal generated by the adding means, and further, the first syndrome calculating means or the second subtracting means Encryption key sharing comprising: decryption means for decrypting the syndrome calculated by the above; and third addition means for creating an encryption key generation signal by adding the signal generated by the decryption means and the second fixed signal Provide a system.

  In order to solve the above problem, the present invention provides an encryption key sharing system for sharing an encryption key between a first device and a second device, wherein the first device receives a first input signal. A first unique signal generating means for outputting a device specific signal in response to the signal, adding the signal output from the first unique signal generating means and a predetermined first fixed signal to obtain an encryption key. A first adder for generating an encryption key generation signal for generation; and a first syndrome calculation unit for calculating a syndrome for the encryption key generation signal, wherein the second device is responsive to the second input signal. A second specific signal generating means for outputting a device specific signal, a signal output in advance from the first specific signal generating means in response to the first input signal, and a second in advance according to the second input signal. Output from the two unique signal generation means A second fixed signal obtained by adding the first fixed signal and the first fixed signal is subtracted from the device specific signal output from the second specific signal generating means according to the second input signal. 1 subtracting means, a second syndrome calculating means for calculating a syndrome for the signal output from the first subtracting means, a syndrome calculated by the first syndrome calculating means, and a second syndrome calculating means. A second adding means for adding the syndromes; a decoding means for decoding the signal generated by the adding means; a signal generated by the decoding means and a second fixed signal; And a second subtracting unit for generating an encryption key generation signal by subtracting the device-specific signal output in response to the input signal of 2. To.

  In order to solve the above problem, the present invention provides an encryption key sharing system for sharing an encryption key between a first device and a second device, wherein the first device receives a first input signal. A first specific signal generating means for outputting a device specific signal in response to the first specific syndrome generating means, and a first syndrome calculating means for calculating a syndrome for the signal output from the first specific signal generating means. The second fixed signal obtained by adding the signal output from the first unique signal generating means in advance according to the first input signal and the predetermined code word signal is the first fixed signal. A subtracting means for subtracting from the syndrome calculated by the syndrome calculating means; a decoding means for decoding the signal generated by the subtracting means; and a second fixed signal for outputting a device-specific signal in accordance with the second input signal. An encryption key generation signal for generating an encryption key by adding the signal generation means, the signal generated by the decryption means and the second fixed signal, and the signal output from the second unique signal generation means And a second syndrome calculating means for calculating a syndrome for the signal output from the second eigensignal generating means, and the first device preliminarily corresponds to the second input signal according to the second input signal. Second subtracting means for subtracting the first fixed signal obtained by adding the signal output from the two unique signal generating means and the codeword signal from the syndrome calculated by the second syndrome calculating means. Second decoding means for decoding the signal generated by the second subtraction means, the signal generated by the second decoding means and the first fixed signal, and the first eigensignal generation means Providing further encryption key sharing system comprising a second adding means for creating an encryption key generation signal by adding the output signal.

  In order to solve the above problem, the present invention shares an encryption key between a first device including a unique signal generating unit that outputs a device-specific signal in response to an input signal, and the second device. An encryption key sharing method, wherein a first device generates an encryption key generation signal for generating an encryption key from a signal output from a unique signal generation means and a predetermined first fixed signal. 1, a second step of calculating key sharing information for the encryption key generation signal in the first device, and a signal output from the unique signal generation unit in advance according to the input signal in the second device In accordance with the second fixed signal generated from the first fixed signal and the key sharing information calculated in the second step, the encryption key generation signal generated in the first step and the second fixed signal Difference An encryption key sharing method comprising: a third step of decrypting a signal; and a fourth step of creating an encryption key generation signal from the signal obtained in the third step and the second fixed signal in the second device I will provide a.

  In order to solve the above problem, the present invention shares an encryption key between a first device including a unique signal generating unit that outputs a device-specific signal in response to an input signal, and the second device. An encryption key sharing method for generating an encryption key by adding a signal output from a unique signal generation means and a predetermined first fixed signal in a first device. In the first device, a second step of adding the codeword signal to the encryption key generation signal in the first device, and output from the unique signal generation means in advance in accordance with the input signal in the second device In a second device, a third step of subtracting a second fixed signal obtained by adding the generated signal and the first fixed signal from the signal generated in the second step; Third Calculating a syndrome for the signal generated in the step, or calculating a syndrome for the signal generated in the second step, and subtracting a syndrome for the second fixed signal stored in advance; In the second device, a fifth step of decoding the syndrome calculated in the fourth step, and, in the second device, adding the signal generated in the fifth step and the second fixed signal. And a sixth step of generating an encryption key generation signal.

  In order to solve the above-described problem, the present invention provides a first device including first unique signal generation means for outputting a device-specific signal according to the first input signal, and a second input signal. An encryption key sharing method for sharing an encryption key with a second device including second unique signal generation means for outputting a device-specific signal, wherein the first device generates the first unique signal. A first step of adding a signal output from the means and a predetermined first fixed signal to generate an encryption key generation signal for generating an encryption key; A second step of calculating a syndrome with respect to the generated signal; and a signal output from the first specific signal generating unit in advance according to the first input signal and a second input signal in the second device Second unique signal in advance A second fixed signal obtained by adding the signal output from the generating means and the first fixed signal is obtained from the second specific signal generating means according to the second input signal. A third step of subtracting from the signal; a fourth step of calculating a syndrome for the signal generated in the third step in the second device; and a second step of calculating in the second device of the second device. In the second step, a fifth step of adding the syndrome and the syndrome calculated in the fourth step, a sixth step of decoding the signal generated in the fifth step in the second device, and A device-specific signal output from the second specific signal generation means according to the second input signal from the signal generated in the sixth step and the second fixed signal Providing an encryption key sharing method and a seventh step of creating the encryption key generation signal by subtracting.

  In order to solve the above-described problem, the present invention provides a first device including first unique signal generation means for outputting a device-specific signal according to the first input signal, and a second input signal. An encryption key sharing method for sharing an encryption key with a second device including second unique signal generation means for outputting a device-specific signal, wherein the first device generates the first unique signal. A first step of calculating a syndrome with respect to a signal output from the means; a signal output from the first unique signal generating means in advance according to the first input signal in the second device; A second step of subtracting the second fixed signal obtained by adding the codeword signal from the syndrome calculated in the first step, and the second device generates the second fixed signal in the second step. The third step of decoding the received signal, and the second device, adding the signal generated in the third step and the second fixed signal to the signal output from the second eigensignal generating means And a fourth step of generating an encryption key generation signal for generating an encryption key, and a fifth step of calculating a syndrome for the signal output from the second unique signal generation means in the second device. In the first device, the first fixed signal obtained by adding the signal output from the second specific signal generating means in advance according to the second input signal and the codeword signal is A sixth step of subtracting from the syndrome calculated in step 5, a seventh step of decoding the signal generated in the sixth step in the first device, and a first device The eighth step of creating the encryption key generation signal by adding the signal obtained in the seventh step and the first fixed signal and the signal output from the first unique signal generation means, An encryption key sharing method is provided.

  According to the present invention, it is possible to provide an encryption key sharing system and an encryption key sharing method that can realize encryption key sharing by simpler processing.

It is a block diagram which shows the basic composition of the encryption key sharing system which concerns on Embodiment 1 of this invention. It is a block diagram which shows the structural example of the encryption key sharing system shown by FIG. It is a block diagram which shows the 1st modification of the encryption key sharing system shown by FIG. It is a block diagram which shows the 2nd modification of the encryption key sharing system shown by FIG. It is a block diagram which shows the 3rd modification of the encryption key sharing system shown by FIG. It is a block diagram which shows the structure of the encryption key sharing system which concerns on Embodiment 2 of this invention. It is a block diagram which shows the structure of the encryption key sharing system which concerns on Embodiment 3 of this invention. It is a block diagram which shows the modification of the encryption key sharing system shown by FIG. It is a block diagram which shows the structure of the encryption key sharing system which concerns on Embodiment 4 of this invention. It is a block diagram which shows the modification of the encryption key sharing system shown by FIG. It is a flowchart which shows the basic procedure of the encryption key sharing method which concerns on embodiment of this invention. 12 is a flowchart showing a specific example of the encryption key sharing method shown in FIG. It is a flowchart which shows the modification of the encryption key sharing method shown by FIG. It is a flowchart which shows the encryption key sharing method which concerns on other embodiment of this invention. It is a flowchart which shows the encryption key sharing method which concerns on other embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same reference numerals indicate the same or corresponding parts.

[Embodiment 1]
FIG. 1 is a block diagram showing a basic configuration of an encryption key sharing system according to Embodiment 1 of the present invention, and FIG. 2 is a block diagram showing a configuration example of the encryption key sharing system shown in FIG. .
As shown in FIG. 1, the encryption key sharing system according to Embodiment 1 of the present invention is a system for sharing an encryption key between a first device DV10 and a second device DV20. The device DV10 includes a unique signal generation unit 10, a first encryption key generation unit 30, and a first key sharing information calculation unit 50. The second device DV20 is generated by the first encryption key generation unit 30. A differential decryption unit 60 that decrypts a differential signal between the encryption key generation signal and the fixed signal, and a second encryption key creation unit 130 are provided. Here, the differential decryption unit 60 includes a second key sharing information calculation unit 70 and a decryption unit 110.
If the result obtained by supplying the second fixed vector signal NB to the second key sharing information calculating unit 70 is stored in the second device DV20 in advance, the second key sharing information calculating unit 70 It becomes unnecessary.

  In addition, the unique signal generation unit 10 is configured by a device unique information generation apparatus 1 in which an output signal forms a PUF with respect to an input signal, as shown in FIG.

  As shown in FIG. 2, the first encryption key creation unit 30 is configured by, for example, an adder 3, and the first key sharing information calculation unit 50 is configured by a syndrome calculator 5. The second key sharing information calculation unit 70 is configured by, for example, the syndrome calculator 7, and the decryption unit 110 is configured by, for example, the subtracter 9 and the decoder 11. Furthermore, the second encryption key creation unit 130 is configured by an adder 13, for example.

  The first encryption key generation unit 30 is connected to the unique signal generation unit 10, and the first key sharing information calculation unit 50 is connected to the first encryption key generation unit 30.

  The decryption unit 110 is connected to the first key sharing information calculation unit 50 and the second key sharing information calculation unit 70, and the second encryption key creation unit 130 is connected to the decryption unit 110.

  Here, the subtractor 9 shown in FIG. 2 as a configuration example of the decoding unit 110 is connected to the syndrome calculator 5 and the syndrome calculator 7, and the decoder 11 is connected to the subtractor 9 and the adder 13.

The operation of the encryption key sharing system shown in FIG. 1 having the above configuration will be described below.
An input signal C is input to the unique signal generation unit 10. The data format of the input signal C depends on the configuration of the unique signal generation unit 10, but may be stored anywhere. That is, assuming that the first device DV10 is stolen, the input signal C should be stored in the second device DV20, while the unique signal generator 10 is included when communication is unnecessary. It is better to store it in the first device DV10.

  The first encryption key generation unit 30 generates an encryption key from a signal unique to the device DV10 generated by the unique signal generation unit 10 and an arbitrary first fixed vector signal NA registered in advance in the device DV10. An encryption key generation signal K having a value as a basis for the generation is created.

  Here, in the example shown in FIG. 2, the adder 3 outputs the vector signal R′1 on the Galois field of length n output from the device specific information generating apparatus 1 and the Galois field of length n. The vector signal N1 is added to create an encryption key generation signal KM. The vector signal N1 is fixed by being registered in the first device DV1. In addition, an error that changes within a range that can be corrected by the second device DV2 may be added to the result of addition of the vector signal R′1, the vector signal N1, or the vector signal R′1 and the vector signal N1 every time.

  The first key sharing information calculation unit 50 calculates a syndrome for the data created by the first encryption key creation unit 30.

  The calculation of the syndrome is performed, for example, by multiplying the parity check matrix of the error correction code from the right when the input to the first key sharing information calculation unit 50 is a row vector, or for each axis of the vector in the case of a cyclic code. The value is regarded as a coefficient of the (n−k−1) order or higher of the polynomial on the Galois field, and the remainder of the generating polynomial of the error correction code is obtained, or the remainder is calculated by the linear feedback shift register corresponding to the above polynomial. Can be done. In addition to the BCH code, Reed-Solomon code, Alternant code, Goppa code, etc., error correction codes used in McElice public key cryptography, Niederreitter public key cryptography, etc. can be used as the above error correction codes. .

  On the other hand, the second key sharing information calculation unit 70 generates a second fixed vector signal NB generated from the signal output from the unique signal generation unit 10 in advance according to the input signal C and the first fixed vector signal NA. The syndrome for is calculated.

  Here, in the example shown in FIG. 2, the signal D1 obtained by adding the signal R1 output from the device specific information generating apparatus 1 in advance according to the input signal C1 and the vector signal N1 to the first signal D1. 2 and the syndrome calculator 7 calculates a syndrome for the signal D1.

  If the result obtained by inputting the signal D1 to the syndrome calculator 7 in the second device DV2 is calculated in advance and stored in the second device DV2, the result calculated by the syndrome calculator 7 is used as a substitute. The syndrome calculator 7 can be removed from the second device DV2.

  Next, the decryption unit 110 decrypts the signal generated according to the syndrome calculated by the first key sharing information calculation unit 50 and the syndrome calculated by the second key sharing information calculation unit 70.

  Here, in the example shown in FIG. 2, the subtracter 9 subtracts the syndrome calculated by the syndrome calculator 7 from the syndrome S′1 calculated by the syndrome calculator 5, or in advance as described above. The stored syndrome is read and subtracted, and the decoder 11 decodes the signal obtained by the subtractor 9 and corrects the error, thereby generating a signal E1.

  Next, the second encryption key creation unit 130 creates an encryption key generation signal K from the signal obtained by the decryption unit 110 and the second fixed vector signal NB.

  Here, in the example shown in FIG. 2, the adder 13 adds the signal E1 generated by the decoder 11 and the signal D1, thereby creating the encryption key generation signal KM.

  In the above description, the second device DV2, DV20 has been described for one system, but a plurality of encryption key sharing systems are also conceivable.

  According to the encryption key sharing system according to the first embodiment as described above, between the first devices DV1 and DV10 and the second devices DV2 and DV20 without performing public key encryption processing with a large amount of calculation. The same key can be generated, the encryption key generation signal KM can be changed every time, and the signal R1 can be kept secret.

  Further, according to the present system, by changing the first fixed vector signal NA and the second fixed vector signal NB shown in FIG. 1, and in the example shown in FIG. 2, the vector signal N1 and the signal D1 are changed. Since the encryption key generation signals K and KM can be changed, respectively, even if the encryption key generation signals K and KM are leaked, a new challenge / response pair of the specific signal generation unit 10 or the device specific information generation apparatus 1 is obtained. That is, without consuming the challenge-response pair stored in the database in advance, by changing only the vector signal N1 and the signal D1 and restoring the confidentiality of the encryption key generation signals K and KM, The first device DV1, DV10 and the second device DV2, DV20 can share a secret encryption key.

FIG. 3 is a block diagram showing a first modification of the encryption key sharing system shown in FIG.
The encryption key sharing system shown in FIG. 3 has a configuration similar to that of the encryption key sharing system shown in FIG. 2, but the configuration is different in the following points.

  That is, the second device DV2a further includes an adder 14 connected to the adder 13 and an adder 15 connected to the syndrome calculator 7.

  A vector signal N′1 between the weight 0 and the error correction capability of the error correction code to be used, which changes each time key sharing is executed, is input to both adders 14 and 15, and the signal D1 is It is input to both adders 14 and 15.

  Also, the output of the adder 14 is supplied to the adder 13 and the output of the adder 15 is supplied to the syndrome calculator 7.

  According to such a modified example, the same effect as that of the encryption key sharing system shown in FIG. 2 can be obtained, and the vector signal N′1 changes every time key sharing is performed, and is sent to the decoder 11. And the input to the adder 13 can be changed.

  Therefore, according to the present system, it is difficult to apply a side channel attack, and high tamper resistance can be made unnecessary.

  Instead of the adder 15 and the syndrome calculator 7 described above, the syndrome calculator that converts the vector signal N′1 into a syndrome, and the syndrome output from the syndrome calculator and the syndrome calculator 7 are read. The same effect as that of the encryption key sharing system shown in FIG. 3 can be obtained by adding the syndromes and providing an adder connected to the subtracter 9.

FIG. 4 is a block diagram showing a second modification of the encryption key sharing system shown in FIG.
The encryption key sharing system shown in FIG. 4 has the same configuration as that of the encryption key sharing system shown in FIG. 2, but the configuration is different in the following points.

  That is, the first device DV1a is provided with a converter 17 including an adder 16 instead of the syndrome calculator 5 shown in FIG. 2, and the second device DV2b is provided with a syndrome calculator shown in FIG. 7 is provided with a subtractor 19 connected between the adder 16 and the syndrome calculator 21 instead of the subtracter 9 connected between the decoder 7 and the decoder 11. However, if the result obtained by inputting the signal D1 to the syndrome calculator 21 is stored in the second device DV2b in advance, the subtracter 19 is not calculated between the adder 16 and the syndrome calculator 21, but the syndrome is calculated. The result stored in the second device DV2b in advance may be subtracted from the result obtained by inputting the signal Y′1 to the syndrome calculator 21.

  A random codeword signal M1 of an error correction code to be used is input to the adder 16 and added to the signal output from the adder 3. Here, the code word signal means a signal in which the syndrome becomes zero (the same applies hereinafter).

  The subtracter 19 subtracts the signal D1 from the signal Y′1 output from the adder 16, and the syndrome calculator 21 calculates a syndrome for the output signal from the subtractor 19. The decoder 11 generates a signal E1 by decoding the syndrome calculated by the syndrome calculator 21 and correcting the error.

  According to the modification as described above, the same effect as that of the encryption key sharing system shown in FIG. 2 can be obtained, and the addition value of the vector signal R′1 and the vector signal N1 becomes the same as the previous value. Even in such a case, by concealing the error correction code to be used and its parameters, it is possible to obtain the effect that the fact can be concealed.

  FIG. 5 is a block diagram showing a third modification of the encryption key sharing system shown in FIG. The encryption key sharing system shown in FIG. 5 has a configuration similar to that of the encryption key sharing system shown in FIG. 4, but the second device DV2c further includes two adders 14 and 15 shown in FIG. It is different in the point provided.

  According to the third modified example, in addition to the same effect as that of the second modified example, the effect of the first modified example can be obtained, and the vector signal R′1 and the vector signal N1 can be obtained. Even when the added value is the same as the previous value, the fact that the fact can be concealed can be obtained by concealing the error correction code to be used and its parameters.

[Embodiment 2]
FIG. 6 is a block diagram showing a configuration of an encryption key sharing system according to Embodiment 2 of the present invention. As shown in FIG. 6, the encryption key sharing system according to the second embodiment is different from the first device DV1b and the second device in that the functions of the encryption key sharing system according to the first embodiment shown in FIG. It is configured to be executed bi-directionally with DV2d.

  That is, the first device DV1b shown in FIG. 6 includes the components included in the second device DV2 shown in FIG. 2 in addition to the components of the first device DV1 shown in FIG. The second device DV2d shown in FIG. 6 includes the components included in the first device DV1 shown in FIG. 2 in addition to the components of the second device DV2 shown in FIG. Includes elements.

Specifically, the configuration differs from the encryption key sharing system shown in FIG. 2 in the following points.
The first device DV1b further includes a syndrome calculator 23, a subtracter 25, a decoder 27, an adder 29, and a combiner 31. Here, the subtractor 25 is connected to the two syndrome calculators 5 and 23, the decoder 27 is connected to the subtractor 25, the adder 29 is connected to the decoder 27, and the combiner 31 is connected to the syndrome calculator 5 and Connected to the adder 29.

  On the other hand, the second device DV2d further includes a device specific information generation device 2, an adder 3, a syndrome calculator 5, and a combiner 31. Here, the adder 3 is connected to the device specific information generating apparatus 2, the syndrome calculator 5 is connected to the adder 3 and the subtracter 25, and the combiner 31 is connected to the two adders 3 and 13.

  The encryption key sharing system shown in FIG. 6 having the above-described configuration performs bidirectional operations of the encryption key sharing system shown in FIG. 2 between the first device DV1b and the second device DV2d. To run. The adder 3 included in the second device DV2d is supplied with the vector signal N2. The vector signal N2, like the vector signal N1, is fixed by being registered in the second device DV2d. The Further, the vector signal R′1 or the vector signal N1 of the first device DV1b or the result of the addition of the vector signal R′1 and the vector signal N1 can be corrected by the second device DV2d and every time. A variable error may be added, and the first device DV1b can correct the result of the addition of the vector signal R′2 or the vector signal N2 of the second device DV2d or the vector signal R′2 and the vector signal N2. It is also possible to add an error that varies within a certain range and every time.

  Each coupler 31 included in the first device DV1b and the second device DV2d includes an encryption key generation signal KM1 generated according to the signal output from the device specific information generation apparatus 1, and device specific information. An encryption key generation signal KM is generated from the encryption key generation signal KM2 generated according to the signal output from the generation device 2.

  Here, the encryption key generation signal KM reproduces the same key by using, for example, a hash value obtained by connecting the encryption key generation signal KM1 and the encryption key generation signal KM2 and applying a hash function. Attack (same key replay attack) can be avoided.

  That is, even if an attacker gives a deliberate input each time to the first device DV1b or the second device DV2d, it is difficult to generate the same encryption key generation signal KM.

  The two input signals C1 and C2 shown in FIG. 6 may use the same value.

  According to the encryption key sharing system according to the second embodiment as described above, the pair of the vector signal N1 and the signal D1 is changed, or the added value of the vector signal R′1 and the vector signal N1 is so diverse that the exhaustive search is difficult If the error is added, the value of the encryption key generation signal KM1 changes drastically, or the pair of the vector signal N2 and the signal D2 is changed or the exhaustive search is difficult for the added value of the vector signal R′2 and the vector signal N2 Since the value of the encryption key generation signal KM2 changes drastically by adding various errors, the device specific information generation apparatus 1 and the device specific information generation apparatus 2 even if the encryption key generation signals KM1 and KM2 leak Use a new challenge-response pair for, ie, consume a pre-stored challenge-response pair in the database Ku easily by restoring the confidentiality of the encryption key generation signal KM1, KM2, can share the encryption key kept confidential between the first device DV1b and a second device DV2d.

  As described above, in the encryption key sharing system according to Embodiment 2, the two encryption key sharing systems shown in FIG. 2 are symmetrically combined in the first device DV1b and the second device DV2d. Although having a configuration, an encryption key sharing system in which two encryption key sharing systems shown in FIGS. 2 to 5 are arbitrarily combined is also conceivable.

[Embodiment 3]
FIG. 7 is a block diagram showing a configuration of an encryption key sharing system according to Embodiment 3 of the present invention. As shown in FIG. 7, the encryption key sharing system according to Embodiment 3 has the same configuration as that of the encryption key sharing system according to Embodiment 1 shown in FIG. The configuration of the device DV2e is different.

  That is, the second device DV2e further includes a device specific information generating device 2 and a subtracter 19, and further includes an adder 33 instead of the subtracter 9, and a subtractor 35 instead of the adder 13, respectively.

  Here, the device specific information generating apparatus 2 is connected to the two subtractors 19 and 35, and the subtractor is further connected to the syndrome calculator 7.

  In the second device DV2e having such a configuration, the signal D corresponding to the signal D1 shown in FIG. 2 is input to the subtractor 19, and the subtractor 19 receives the vector input from the device specific information generation apparatus 2. The result obtained by subtracting the signal D from the signal R ′ 2 is supplied to the syndrome calculator 7.

  The signal D includes a signal R1 output from the device specific information generation apparatus 1 in advance according to the input signal C1, a signal R2 output from the device specific signal generation apparatus 2 in advance according to the input signal C2, and a vector signal N1. It is assumed that it was obtained by adding.

  Also, the decoder 11 decodes the signal obtained by the adder 33 and corrects the error to generate a signal E12. The subtractor 35 subtracts the signal S′1 output from the syndrome calculator 5 and the vector signal R′2 output from the device specific information generation apparatus 2 from the signal E12 to generate the encryption key generation signal KM.

  As described above, the encryption key sharing system according to Embodiment 3 includes the device-specific information generation apparatuses 1 and 2 in both the first device DV1 and the second device DV2e, and only in the second device DV2e. That is, error correction is performed by the decoder 11.

  As described above, also in the encryption key sharing system according to the third embodiment, the vector signal N1 and the signal D are changed or various errors are added to the added value of the vector signal R′1 and the vector signal N1 so that exhaustive search is difficult. As a result, the encryption key generation signal KM can be significantly changed. Therefore, even if the encryption key generation signal KM leaks, a new challenge / response for the device specific information generation apparatus 1 and the device specific information generation apparatus 2 By using the pair, that is, by easily recovering the confidentiality of the encryption key generation signal KM without consuming the challenge-response pair stored in advance in the database, the first device DV1 and the second device It is possible to share a secret encryption key with the DV 2e.

  FIG. 8 is a block diagram showing a modification of the encryption key sharing system shown in FIG. The encryption key sharing system shown in FIG. 8 has the same configuration as the encryption key sharing system shown in FIG. 7, but differs in the following points.

  The encryption key sharing system shown in FIG. 8 includes a converter 17 including the adder 16 shown in FIG. 4 in place of the syndrome calculator 5 shown in FIG. 7, and the addition shown in FIG. Instead of the unit 33, an adder 37 connected between the subtractor 19 and the syndrome calculator 21 is provided.

  The same effect as the encryption key sharing system shown in FIG. 7 can be obtained by the encryption key sharing system shown in FIG. 8, and the addition value of the vector signal R′1 and the vector signal N1 is the previous value. Even in the case of the same, it is possible to obtain an effect that the fact can be concealed by concealing the error correction code to be used and its parameter.

[Embodiment 4]
FIG. 9 is a block diagram showing a configuration of an encryption key sharing system according to Embodiment 4 of the present invention. As shown in FIG. 9, the encryption key sharing system according to the fourth embodiment has the same configuration as the encryption key sharing system according to the second embodiment shown in FIG. 6, but differs in the following points. Is.

  The first device DV1c has a configuration in which the adder 3, the syndrome calculator 23, and the combiner 31 are excluded from the first device DV1b shown in FIG. Further, the second device DV2g has a configuration in which the adder 3, the syndrome calculator 7, and the combiner 31 are excluded from the second device DV2d illustrated in FIG.

  In the encryption key sharing system having such a configuration, in the first device DV1c, the vector signal R′2 output in advance from the device specific information generation apparatus 2 in response to the input signal C2 and the random error correction code to be used The signal D1 obtained by adding the codeword signal N to the adder 3 is supplied to the subtractor 39 and the adder 3, and the vector signal R′1 output from the device specific information generating apparatus 1 is supplied to the adder 3. Supplied. In addition, an error that changes within the range correctable by the second device DV2g and every time may be added to the vector signal R′1 of the first device DV1c, and the first signal is added to the vector signal R′2 of the second device DV2g. In the device DV1c, an error that is within a correctable range and changes every time may be added.

  In the second device DV2g, the signal R′2 output from the device specific information generation apparatus 2 is supplied to the syndrome calculator 5 and the adder 43. Further, the signal D2 obtained by adding the signal R1 output from the device specific information generating apparatus 1 in advance according to the input signal C1 and the signal N is supplied to the subtracter 41 and the adder 43.

  As described above, the encryption key sharing system according to Embodiment 4 includes the device-specific information generation apparatuses 1 and 2 in both the first device DV1c and the second device DV2g, respectively, and the first device DV1c and the second device DV1g Error correction is performed in both of the two devices DV2g, that is, both the decoder 27 and the decoder 11.

  As described above, according to the encryption key sharing system according to the fourth embodiment, the signals D1 and D2 are changed, or various errors are added to the vector signal R′1 and the vector signal R′2 so that exhaustive search is difficult. As a result, the encryption key generation signal KM can be significantly changed. Therefore, even if the encryption key generation signal KM leaks, a new challenge / response for the device specific information generation apparatus 1 and the device specific information generation apparatus 2 The first device DV1c and the second device can be recovered by using the pair, that is, by easily recovering the confidentiality of the encryption key generation signal KM without consuming the challenge-response pair stored in advance in the database. It is possible to share an encryption key with confidentiality secured with the DV 2g.

  FIG. 10 is a block diagram showing a modification of the encryption key sharing system shown in FIG. The encryption key sharing system shown in FIG. 10 has the same configuration as the encryption key sharing system shown in FIG. 9, but differs in the following points.

  The encryption key sharing system shown in FIG. 10 includes a converter 17 including an adder 16 shown in FIG. 4 in place of the syndrome calculator 5 shown in FIG. 9 in the first device DV1d. A syndrome calculator 45 is connected between the subtractor 39 and the decoder 27.

  Similarly, in the second device DV2h, instead of the syndrome calculator 5 shown in FIG. 9, a converter 47 including an adder 46 is provided, and syndrome calculation is performed between the subtractor 19 and the decoder 11. A device 21 is connected.

  The adder 46 is supplied with a random codeword signal M2 of an error correction code to be used.

  The encryption key sharing system shown in FIG. 10 can achieve the same effect as the encryption key sharing system shown in FIG. 9, and the error correction code to be used and its parameters are concealed. Even when the vector signal R′1 of the current vector has the same value as the previous vector signal R′1, or when the current vector signal R′2 has the same value as the previous vector signal R′2, The effect that it can conceal can be acquired.

  In the above, for example, an adder that adds the vector signal A and the vector signal B can be replaced with a subtracter that subtracts the vector signal (−B) from the vector signal A, and a subtraction that subtracts the vector signal B from the vector signal A. The unit can be replaced with an adder that adds the vector signal A and the vector signal (-B). Here, since addition and subtraction are the same processing in a Galois field composed of a prime number 2 remainder system, it goes without saying that an adder and a subtracter are replaced with each other.

  In addition, the combination of the adder and the subtracter is the same result or effect even if the order of processing is changed so that, for example, C− (A + B) = (C−A) −B is established and the combination of inputs is changed. Needless to say, the order of processing is changed so that, for example, (A + B) × H = A × H + B × H is established in the combination of the adder or subtractor and the syndrome calculator. It goes without saying that the same results and effects can be obtained even if the combination is changed.

  Hereinafter, the encryption key sharing method according to the embodiment of the present invention will be described with reference to the flowcharts of FIGS. Although this method will be specifically described using the encryption key sharing system according to Embodiments 1 to 4, the method is not limited to those using these encryption key sharing systems.

  FIG. 11 is a flowchart showing a basic procedure of the encryption key sharing method according to the embodiment of the present invention. Hereinafter, this procedure will be described using the encryption key sharing system shown in FIG.

  The encryption key sharing method according to the present embodiment includes an encryption key between the first device DV10 including the unique signal generation unit 10 that outputs a device-specific signal in response to the input signal C and the second device DV20. In step S1, the first device DV10 generates an encryption key from the signal output from the unique signal generation unit 10 and the predetermined first fixed vector signal NA. An encryption key generation signal K is generated for this purpose.

  Next, in step S2, the first device DV10 calculates key sharing information such as a syndrome for the encryption key generation signal K.

  In step S3, in the second device DV20, the second fixed vector signal NB generated from the signal output from the eigensignal generation unit 10 in advance according to the input signal C and the first fixed vector signal NA. And the difference signal between the encryption key generation signal K and the second fixed vector signal NB in accordance with the key sharing information.

  Next, in step S4, the second device DV20 creates an encryption key generation signal from the signal obtained in step S3 and the second fixed vector signal NB.

  According to the encryption key sharing method shown in FIG. 11 as described above, the same key is transferred between the first device DV10 and the second device DV20 without performing public key encryption processing with a large calculation amount. Can be generated.

  Also, according to the present encryption key sharing method, the encryption key generation signal K can be changed by changing the first fixed vector signal NA and the second fixed vector signal NB. Even if K leaks, the encryption key can be shared between the first device DV10 and the second device DV20 by easily recovering the confidentiality of the encryption key generation signal K.

  Therefore, according to such an encryption key sharing method, it is difficult to apply the side channel attack and high tamper resistance can be made unnecessary.

  FIG. 12 is a flowchart showing a specific example of the encryption key sharing method shown in FIG. In the following, this method will be described using the encryption key sharing system shown in FIG.

  In the method shown in FIG. 12, the encryption key is shared between the first device DV1 including the device specific information generation apparatus 1 that outputs a device specific signal in response to the input signal C1 and the second device DV2. In step S1, in the first device DV1, the signal R′1 output from the device specific information generation apparatus 1 and a predetermined fixed vector signal N1 are added. An encryption key generation signal KM for generating an encryption key is created.

  Next, in step S2, the syndrome for the encryption key generation signal KM is calculated in the first device DV1.

  In step S3, the second device DV2 fixes the vector signal obtained by adding the signal R1 output from the device specific information generating apparatus 1 in advance according to the input signal C1 and the vector signal N1. A syndrome is calculated for D1.

  Next, in step S4, the syndrome calculated in step S3 is subtracted from the syndrome calculated in step S2 in the second device DV2.

  In step S5, the signal generated in step S4 is decoded in the second device DV2.

  Next, in step S6, the second device DV2 generates the encryption key generation signal KM by adding the signal E1 generated in step S5 and the vector signal D1.

  According to the encryption key sharing method shown in FIG. 12 as described above, the same key is transferred between the first device DV1 and the second device DV2 without performing public key encryption processing with a large calculation amount. Can be generated.

  In addition, according to the present encryption key sharing method, the encryption key generation signal KM can be changed by changing the vector signal N1 and the vector signal D1, so that even if the encryption key generation signal KM leaks, it is easy. In addition, by restoring the confidentiality of the encryption key generation signal KM, the encryption key can be shared between the first device DV1 and the second device DV2.

  FIG. 13 is a flowchart showing a modification of the encryption key sharing method shown in FIG. In the following, the method will be described using the encryption key sharing system shown in FIG.

  In the method shown in FIG. 13, the encryption key is shared between the first device DV1a including the device specific information generation apparatus 1 that outputs a device specific signal in response to the input signal C1 and the second device DV2b. In step S1, in the first device DV1a, the signal R′1 output from the device specific information generating apparatus 1 and a predetermined fixed vector signal N1 are added. Then, an encryption key generation signal KM for generating an encryption key is created.

  Next, in step S2, the first device DV1a adds the codeword signal M1 to the encryption key generation signal KM.

  In step S3, the second device DV2b is fixed by adding the signal R1 output from the device specific information generating apparatus 1 in advance according to the input signal C1 and the fixed vector signal N1. The vector signal D1 is subtracted from the signal generated in step S2.

  Next, in step S4, the syndrome for the signal generated in step S3 is calculated in the second device DV2b.

  In step S5, the syndrome calculated in step S4 is decoded in the second device DV2b.

  Next, in step S6, the second device DV2b creates the encryption key generation signal KM by adding the signal generated in step S5 and the vector signal D1.

  Also by the encryption key sharing method shown in FIG. 13 as described above, the same effect as the encryption key sharing method shown in FIG. 12 can be obtained.

  FIG. 14 is a flowchart showing an encryption key sharing method according to another embodiment of the present invention. Hereinafter, this method will be described using the encryption key sharing system shown in FIG.

  The method shown in FIG. 14 outputs a device-specific signal according to the first device DV1 including the device-specific information generating apparatus 1 that outputs a device-specific signal in response to the input signal C1, and the input signal C2. An encryption key sharing method for sharing an encryption key with the second device DV2e including the device specific information generation apparatus 2, and is output from the device specific information generation apparatus 1 at the first device DV1 in step S1. The signal R′1 and a predetermined fixed vector signal N1 are added to create an encryption key generation signal KM for generating an encryption key.

  Next, in step S2, the syndrome for the encryption key generation signal KM is calculated in the first device DV1.

  In step S3, in the second device DV2e, the signal R1 output from the device specific information generation device 1 in advance according to the input signal C1 and the device specific information generation device 2 in advance according to the input signal C2. The fixed signal D obtained by adding the received signal and the vector signal N1 is subtracted from the device-specific signal R′2 output from the device-specific information generation device 2 according to the input signal C2.

  Next, in step S4, the syndrome for the signal generated in step S3 is calculated in the second device DV2e.

  In step S5, the syndrome calculated in step S2 and the syndrome calculated in step S4 are added to the second device DV2e.

  Next, in step S6, the second device DV2e decodes the signal generated in step S5.

  In step S7, in the second device DV2e, the device-specific signal R′2 output from the device-specific information generation apparatus 2 according to the input signal C2 is generated from the signal generated in step S6 and the signal D. An encryption key generation signal KM is created by subtraction.

  According to the encryption key sharing method shown in FIG. 14 as described above, the encryption key generation signal KM can be changed by changing the vector signal N1 and the signal D. Even if leaked, the confidentiality of the encryption key generation signal KM can be easily recovered without using a new challenge / response pair for the device specific information generation apparatus 1 and the device specific information generation apparatus 2. The encryption key can be shared between the DV1 and the second device DV2e.

  FIG. 15 is a flowchart showing an encryption key sharing method according to still another embodiment of the present invention. Hereinafter, this method will be described using the encryption key sharing system shown in FIG.

  The method shown in FIG. 15 outputs a device-specific signal according to the first device DV1c including the device-specific information generating apparatus 1 that outputs a device-specific signal in response to the input signal C1, and the input signal C2. An encryption key sharing method for sharing an encryption key with the second device DV2g including the device specific information generation apparatus 2, and is output from the device specific information generation apparatus 1 at the first device DV1c in step S1. The syndrome for the received signal R′1 is calculated.

  Next, in step S2, the second device DV2g is obtained by adding the signal R1 output from the device specific information generating apparatus 1 in advance according to the input signal C1 and a predetermined codeword signal. The fixed signal D2 is subtracted from the syndrome calculated in step S1.

  In step S3, the second device DV2g decodes the signal generated in step S2.

  Next, in step S4, the second device DV2g generates an encryption key by adding the signal and signal D2 generated in step S3 and the signal output from the device specific information generation apparatus 2. An encryption key generation signal KM is created.

  In step S5, the second device DV2g calculates a syndrome for the signal output from the device specific information generation apparatus 2.

  Next, in step S6, in the first device DV1c, a fixed signal obtained by adding the signal output from the device specific information generating apparatus 2 in advance according to the input signal C2 and the codeword signal. D1 is subtracted from the syndrome calculated in step S5.

  In step S7, the first device DV1c decodes the signal generated in step S6.

  Next, in step S8, the first device DV1c adds the signal and signal D1 obtained in step S7 and the signal R′1 output from the device specific information generation apparatus 1 to add an encryption key generation signal. Create a KM.

  According to the encryption key sharing method shown in FIG. 15 as described above, since the encryption key generation signal KM can be changed by changing the signal D1 and the signal D2, the encryption key generation signal KM leaks. Even so, the first device DV1c can be recovered by easily recovering the confidentiality of the encryption key generation signal KM without using a new challenge-response pair for the device specific information generation device 1 and the device specific information generation device 2. And the second device DV2g can share an encryption key.

1, 2 Device specific information generator 3, 13, 14, 15, 16, 29, 33, 37, 43, 46 Adder 5, 7, 21, 23, 45 Syndrome calculator 9, 19, 25, 35, 39 , 41 Subtractor 10 Unique signal generator 11, 27 Decoder 30 First encryption key generator 31 Combiner 50 First key share information calculator 60 Difference decryptor 70 Second key share information calculator 110 Decoder 130 Second encryption key creation unit

DV1, DV1a, DV1b, DV1c, DV1d, DV10 First device

DV2, DV2a, DV2b, DV2c, DV2d, DV2e, DV2f, DV2g, DV2h, DV20 Second device

Claims (13)

An encryption key sharing system for sharing an encryption key between a first device and a second device,
The first device is:
Unique signal generation means for outputting a device-specific signal in response to an input signal;
First encryption key generation means for generating an encryption key generation signal for generating the encryption key from the signal output from the unique signal generation means and a predetermined first fixed signal;
First key sharing information calculating means for calculating key sharing information for the encryption key generation signal generated by the first encryption key generating means,
The second device is:
A signal output in advance from the unique signal generation means in response to the input signal, a second fixed signal generated from the first fixed signal, and the key calculated from the first key sharing information calculation means Differential decryption means for decrypting a differential signal between the encryption key generation signal created by the first encryption key creation means and the second fixed signal according to shared information;
An encryption key sharing system comprising: a second encryption key generation unit that generates the encryption key generation signal from the signal obtained by the differential decryption unit and the second fixed signal. An encryption key sharing system for sharing an encryption key between a first device and a second device,
The first device is:
Unique signal generation means for outputting a device-specific signal in response to an input signal;
First addition means for adding a signal output from the unique signal generation means and a predetermined first fixed signal to create an encryption key generation signal for generating the encryption key;
First syndrome calculation means for calculating a syndrome for the encryption key generation signal,
The second device is:
The syndrome for the second fixed signal obtained by adding the signal output from the specific signal generating means in advance according to the input signal and the first fixed signal, or the calculated syndrome Second syndrome calculating means for storing in advance,
Subtracting means for subtracting the syndrome calculated or read by the second syndrome calculating means from the syndrome calculated by the first syndrome calculating means;
Decoding means for decoding the signal generated by the subtracting means;
An encryption key sharing system comprising: a second addition unit that creates the encryption key generation signal by adding the signal generated by the decryption unit and the second fixed signal. The second device is:
A third addition means connected to the second syndrome calculation means, or the encryption key, which adds an error-correctable weight signal that changes every time the encryption key generation signal is created, to the second fixed signal A third syndrome calculating means for converting an error-correctable weight signal that changes every time a generated signal is generated into a syndrome, a syndrome output from the third syndrome calculating means, and a read from the second syndrome calculating means. And adding the syndrome, and a third addition means connected to the subtraction means,
Adding the weight signal to the second fixed signal, and further comprising a fourth addition means connected to the second addition means,
The encryption according to claim 2, wherein the second adding means creates the encryption key generation signal by adding the signal generated by the decrypting means and the signal generated by the fourth adding means. Key sharing system. An encryption key sharing system for sharing an encryption key between a first device and a second device,
The first device is:
Unique signal generation means for outputting a device-specific signal in response to an input signal;
First addition means for adding a signal output from the unique signal generation means and a predetermined first fixed signal to create an encryption key generation signal for generating the encryption key;
Second addition means for adding a codeword signal to the encryption key generation signal,
The second device is:
A second fixed signal obtained by adding the signal output from the specific signal generating means in advance according to the input signal and the first fixed signal is generated by the second adding means. A first subtracting means for subtracting from the signal and a first syndrome calculating means for calculating a syndrome for the signal generated by the first subtracting means; or a syndrome for the signal generated by the second adding means And a second syndrome calculation means for storing a syndrome for the second fixed signal calculated in advance,
Second subtracting means for subtracting a syndrome for the second fixed signal stored in the syndrome calculating means from a syndrome for the signal generated by the second adding means, and further comprising: the first syndrome calculating means Or decoding means for decoding the syndrome calculated by the second subtracting means;
An encryption key sharing system comprising: a third addition unit that creates the encryption key generation signal by adding the signal generated by the decryption unit and the second fixed signal. The second device is:
Adding a weight signal capable of error correction that changes every time the encryption key generation signal is created to the second fixed signal, and a fourth adding means connected to the subtracting means;
Adding the weight signal to the second fixed signal, and further comprising a fifth adding means connected to the third adding means,
The subtracting means subtracts the signal generated by the fourth adding means from the signal generated by the second adding means;
5. The encryption according to claim 4, wherein the third addition unit creates the encryption key generation signal by adding the signal generated by the decryption unit and the signal generated by the fifth addition unit. Key sharing system. The second device is:
Second specific signal generating means for outputting a device specific signal in response to the second input signal;
A second encryption key generation signal for generating the encryption key is created by adding the signal output from the second unique signal generation means and a predetermined third fixed signal. Adding means;
Third syndrome calculation means for calculating a syndrome for the second encryption key generation signal, or codeword addition means for adding a codeword signal to the second encryption key generation signal;
A first combining unit that combines the encryption key generation signal and the second encryption key generation signal to generate a third encryption key generation signal;
The first device is:
A signal output in advance from the second specific signal generating means in response to the second input signal;
Calculating a syndrome for a fourth fixed signal obtained by adding the third fixed signal, or a signal output in advance from the second specific signal generating means in accordance with the second input signal; , Fourth syndrome calculating means for storing a syndrome for the fourth fixed signal obtained by adding the third fixed signal, and the fourth syndrome from the syndrome calculated by the third syndrome calculating means. A second subtracting unit that subtracts the syndrome calculated by the syndrome calculating unit, or a third addition that adds an error-correctable weight signal that changes each time the encryption key generation signal is generated to the fourth fixed signal. Means for adding the weight signal to the fourth fixed signal, and a signal for the signal obtained by the third addition means. Fourth syndrome calculating means for calculating a syndrome, and second subtracting means for subtracting the syndrome calculated by the fourth syndrome calculating means from the syndrome calculated by the third syndrome calculating means, or A second subtracting means for subtracting a fourth fixed signal from the signal generated by the codeword adding means; a fourth syndrome calculating means for calculating a syndrome for the signal obtained by the second subtracting means; Or a fourth addition means for adding an error-correctable weight signal that changes each time the encryption key generation signal is generated to the fourth fixed signal, and the fourth addition from the signal generated by the codeword addition means. Second subtracting means for subtracting the signal obtained by the means, and syndrome for the signal obtained by the second subtracting means A fourth syndrome calculating means for calculating,
Second decoding means for decoding the signal generated by the second subtracting means;
Encryption key generating means for generating the second encryption key generation signal by adding the signal generated by the second decryption means and the fourth fixed signal;
The encryption key sharing according to claim 2, further comprising: a second combining unit that combines the encryption key generation signal and the second encryption key generation signal to generate the third encryption key generation signal. system. An encryption key sharing system for sharing an encryption key between a first device and a second device,
The first device is:
First unique signal generating means for outputting a device specific signal in response to the first input signal;
First addition means for creating an encryption key generation signal for generating the encryption key by adding the signal output from the first unique signal generation means and a predetermined first fixed signal; ,
First syndrome calculation means for calculating a syndrome for the encryption key generation signal,
The second device is:
Second specific signal generating means for outputting a device specific signal in response to the second input signal;
A signal output from the first specific signal generation unit in advance according to the first input signal, a signal output from the second specific signal generation unit in advance according to the second input signal, and A second fixed signal obtained by adding the first fixed signal is subtracted from the device specific signal output from the second specific signal generating means according to the second input signal. 1 subtraction means,
Second syndrome calculating means for calculating a syndrome for the signal output from the first subtracting means;
Second adding means for adding the syndrome calculated by the first syndrome calculating means and the syndrome calculated by the second syndrome calculating means;
Decoding means for decoding the signal generated by the adding means;
The cipher is obtained by subtracting the device-specific signal output from the second specific signal generation unit according to the second input signal from the signal generated by the decryption unit and the second fixed signal. An encryption key sharing system comprising: a second subtracting unit that creates a key generation signal. An encryption key sharing system for sharing an encryption key between a first device and a second device,
The first device is:
First unique signal generating means for outputting a device specific signal in response to the first input signal;
First syndrome calculation means for calculating a syndrome for the signal output from the first unique signal generation means;
The second device is:
A second fixed signal obtained by adding a signal output in advance from the first specific signal generating means in accordance with the first input signal and a predetermined codeword signal is used as the first fixed signal. Subtracting means for subtracting from the syndrome calculated by the syndrome calculating means,
Decoding means for decoding the signal generated by the subtracting means;
Second specific signal generating means for outputting a device specific signal in response to the second input signal;
An encryption key generation signal for generating an encryption key is created by adding the signal generated by the decryption unit and the second fixed signal and the signal output from the second unique signal generation unit. Adding means;
Second syndrome calculating means for calculating a syndrome for the signal output from the second unique signal generating means,
The first device is:
The second syndrome calculation is performed on the first fixed signal obtained by adding the signal output in advance from the second specific signal generation means in accordance with the second input signal and the codeword signal. Second subtracting means for subtracting from the syndrome calculated by the means;
Second decoding means for decoding the signal generated by the second subtracting means;
The encryption key generation signal is created by adding the signal generated by the second decryption means and the first fixed signal and the signal output from the first unique signal generation means. An encryption key sharing system further comprising an adding means. An encryption key sharing method for sharing an encryption key between a second device and a first device including unique signal generation means for outputting a device-specific signal in response to an input signal,
In the first device, a first step of creating an encryption key generation signal for generating the encryption key from a signal output from the unique signal generation means and a predetermined first fixed signal;
A second step of calculating key sharing information for the encryption key generation signal in the first device;
In the second device, in accordance with the input signal, a signal output in advance from the specific signal generation means, a second fixed signal generated from the first fixed signal, and a calculation in the second step A third step of decrypting a difference signal between the encryption key generation signal generated in the first step and the second fixed signal according to the key sharing information;
An encryption key sharing method comprising: a fourth step of creating the encryption key generation signal from the signal obtained in the third step and the second fixed signal in the second device. An encryption key sharing method for sharing an encryption key between a second device and a first device including unique signal generation means for outputting a device-specific signal in response to an input signal,
The first device adds a signal output from the unique signal generation means and a predetermined first fixed signal to generate an encryption key generation signal for generating the encryption key. And the steps
A second step of calculating a syndrome for the encryption key generation signal in the first device;
In the second device, a syndrome for the second fixed signal obtained by adding the signal output from the specific signal generating means in advance according to the input signal and the first fixed signal is calculated. Or a third step of previously storing a syndrome for the second fixed signal obtained by adding the signal output from the specific signal generating means in advance according to the input signal and the first fixed signal. When,
A fourth step of subtracting the syndrome calculated or stored in the third step from the syndrome calculated in the second step in the second device;
A fifth step of decoding the signal generated in the fourth step in the second device;
An encryption key sharing method comprising: a sixth step of creating the encryption key generation signal by adding the signal generated in the fifth step and the second fixed signal in the second device. An encryption key sharing method for sharing an encryption key between a second device and a first device including unique signal generation means for outputting a device-specific signal in response to an input signal,
The first device adds a signal output from the unique signal generation means and a predetermined first fixed signal to generate an encryption key generation signal for generating the encryption key. And the steps
A second step of adding a codeword signal to the encryption key generation signal in the first device;
In the second device, a second fixed signal obtained by adding a signal output in advance from the specific signal generating means in accordance with the input signal and the first fixed signal is obtained as the second fixed signal. A third step of subtracting from the signal generated in step
The second device calculates a syndrome for the signal generated in the third step, or calculates a syndrome for the signal generated in the second step, and stores the second stored in advance. A fourth step of subtracting the syndrome for the fixed signal;
A fifth step of decoding the syndrome calculated in the fourth step in the second device;
An encryption key sharing method comprising: a sixth step of creating the encryption key generation signal by adding the signal generated in the fifth step and the second fixed signal in the second device. A first device including first unique signal generating means for outputting a device-specific signal in response to the first input signal; and a second specific signal for outputting a device-specific signal in response to the second input signal An encryption key sharing method for sharing an encryption key with a second device including a generation means,
In the first device, an encryption key generation signal for generating the encryption key is created by adding the signal output from the first unique signal generation means and a predetermined first fixed signal. A first step to:
A second step of calculating a syndrome for the encryption key generation signal in the first device;
In the second device, a signal output from the first specific signal generation unit in advance according to the first input signal, and a second specific signal generation unit in advance according to the second input signal. The second fixed signal obtained by adding the signal output from the second fixed signal and the first fixed signal is output from the second specific signal generating means according to the second input signal. A third step of subtracting from the unique signal;
A fourth step of calculating a syndrome for the signal generated in the third step in the second device;
A fifth step of adding, in the second device, the syndrome calculated in the second step and the syndrome calculated in the fourth step;
A sixth step of decoding the signal generated in the fifth step in the second device;
In the second device, the device specific output from the second specific signal generating means according to the second input signal from the signal generated in the sixth step and the second fixed signal And a seventh step of creating the encryption key generation signal by subtracting the above signal. A first device including first unique signal generating means for outputting a device-specific signal in response to the first input signal; and a second specific signal for outputting a device-specific signal in response to the second input signal An encryption key sharing method for sharing an encryption key with a second device including a generation means,
A first step of calculating a syndrome for the signal output from the first specific signal generating means in the first device;
In the second device, a second signal obtained by adding a signal output in advance from the first unique signal generating means in accordance with the first input signal and a predetermined codeword signal. A second step of subtracting a fixed signal from the syndrome calculated in the first step;
A third step of decoding the signal generated in the second step in the second device;
In the second device, an encryption key is generated by adding the signal generated in the third step, the second fixed signal, and the signal output from the second unique signal generating means. A fourth step of creating an encryption key generation signal for
A fifth step of calculating a syndrome for the signal output from the second specific signal generation means in the second device;
In the first device, a first fixed signal obtained by adding a signal output in advance from the second specific signal generating means in accordance with the second input signal and the codeword signal is obtained. A sixth step of subtracting from the syndrome calculated in the fifth step;
A seventh step of decoding the signal generated in the sixth step in the first device;
In the first device, the encryption key generation signal is obtained by adding the signal obtained in the seventh step, the first fixed signal, and the signal output from the first unique signal generation means. And an eighth step of creating the encryption key sharing method.

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