JP6719789B2 - Cryptographic processing system, cryptographic processing method, and cryptographic processing program - Google Patents

Description

The present invention relates to a technique for encrypting and decrypting data.

In an image processing device used in a gaming machine such as a pachinko machine or a slot, encrypted data obtained by encrypting image data, program data, etc. (hereinafter, also referred to as data) is stored in a storage device, and is stored as a game progresses. Then, a technique for decrypting and using encrypted data is known.

In a gaming machine such as a pachinko machine or a slot, a technology of decrypting and using encrypted data is an important technology for preventing so-called goto action, in which the data is falsified and a payout is obtained by an illegal method.

As another related technology, a plurality of pieces of fragment image data are compressed and encoded in a data ROM, and the whole is encrypted image data encrypted by a common key KC based on a common key method. The EPD and the encrypted common key EKC obtained by encrypting the common key KC with the public key KP are stored. The RSA decryption unit reads the encrypted common key EKC from the data ROM, and decrypts the encrypted common key EKC with the secret key KS corresponding to the public key KP based on the RSA public key system to obtain the common key KC. , And sends it to the common key decryption unit. The data bus control unit instructs the common key method decryption unit to read the encrypted image data EPD from the data ROM and to decrypt the decrypted image data EPD, and sends the decrypted image data PD to the decoder (for example, Patent Document 1). 1).

JP, 2013-223599, A

In the above-described encryption technology, for example, when a third party obtains a development environment for data including the public key KP, it is possible to completely rewrite the data ROM by newly setting the common key KC. Therefore, it may not be possible to prevent fraudulent acts due to falsification of data.
The present invention, as one aspect, provides a technique for preventing fraudulent acts due to falsification of data.

One of the cryptographic processing systems disclosed in this specification is a cryptographic processing system including a first information processing device, a second information processing device, and a third information processing device. The first information processing apparatus used by the designer who provides the data creation program and the third information processing apparatus includes a first generation unit, a first creation unit, and a first processing unit. The first generation unit generates the first secret key using the developer identifier that identifies the developer set by the designer. The first creation unit creates a first public key using the first secret key. The first processing unit executes a process of adding the first public key to the data creation program.
The second information processing device used by the developer, which operates by executing the data creation program provided by the designer, includes an acquisition unit, a second creation unit, an encryption unit, and a second processing unit. Prepare The acquisition unit acquires the first public key given to the data creation program and the second secret key set by the developer. The second creation unit creates a common key using the first public key and the second secret key, and creates a second public key using the second secret key. The encryption unit encrypts the data created by the data creation program using the common key. The second processing unit executes a process of storing the second public key created by the second creating unit and the encrypted data encrypted by the encryption unit in a storage device connected to the third information processing device. To do.
The third information processing device provided to the customer includes a storage unit, a connection unit, a second generation unit, a third creation unit, and a decryption unit. The storage unit stores the developer identifier set by the designer. The connection unit is connected to the storage device. The second generation unit generates the first secret key using the developer identifier stored in the storage unit. The third creation unit creates a common key using the second public key stored in the storage device and the first secret key generated by the generation unit. The decryption unit decrypts the encrypted data stored in the storage device using the common key.

According to one embodiment, it is possible to prevent fraudulent acts due to falsification of data.

It is a figure which shows one Example of a cryptographic processing system. It is a figure which shows one Example of the encryption processing system using a developer identifier. It is a figure which shows the production|generation process of the private key P. It is explanatory drawing of the correspondence of public key A and developer ID. It is a block diagram which shows one Example of a cryptographic processing system. It is a flowchart which shows the process in a 1st information processing apparatus. 7 is a flowchart showing a process of creating a secret key P. It is a flowchart which shows the process in a 2nd information processing apparatus. It is a flowchart which shows the process in a 3rd information processing apparatus. FIG. 3 is a block diagram showing an example of a computer device.

[Embodiment]
The cryptographic processing system of the embodiment will be described.
FIG. 1 is a diagram showing an embodiment of a cryptographic processing system 300.
The cryptographic processing system 300 includes a fourth information processing device 4, a fifth information processing device 5, and a sixth information processing device 6.

The fourth information processing device 4 is, for example, a computer device used in a company that designs and manufactures the sixth information processing device 6 (hereinafter, also referred to as a designer). The fifth information processing device 5 uses, for example, a data creation program (hereinafter, also referred to as a development environment) provided by a designer to develop image data, program data, etc. (hereinafter, also referred to as a developer). Is a computer device used in. The sixth information processing device 6 is, for example, an image processing device used in a gaming machine such as a pachinko machine, a slot, and a game machine. In the following description, the process performed by the designer is performed using the fourth information processing device 4. The processing of the developer is processed by using the fifth information processing device 5. The sixth information processing device 6 may be an image processing device used in a game machine or the like, and may be various information processing devices used in, for example, a personal computer, a transportation device, a game machine, a VR (Virtual Reality) device, or the like.

In an image processing device used in a game machine such as a pachinko machine or a slot, a technique of using Diffie-Hellman (hereinafter, also referred to as DH) key exchange in encryption processing is known in order to prevent fraudulent acts by falsifying data. There is. The encryption process includes a key creation process, an encryption process, and a decryption process. In the following description, as an example, the sixth information processing device 6 will be described as an image processing device used in a gaming machine.

Specifically, the designer sets the generator g for performing the DH key exchange and the prime number n, and shares it with the developer. In addition, the design source stores the set prime number n in the sixth information processing device 6 by hard wiring (hereinafter, also referred to as connection logic). Furthermore, the design source generates the secret key p using an arbitrary random number or the like, and stores the secret key p in the sixth information processing device 6 by hard wiring.

The design source creates the public key a by substituting the generator g, the secret key p, and the prime number n into the following equation (1). Then, the designer provides the created public key a to the developer (S501). Specifically, the designer provides the public key a to the developer by including the public key a in the data creation program provided to the developer.
Public key a=g ^{^p} mod n (1)

Further, the developer generates a secret key s by using a random number or the like, and substitutes the generator g, the secret key s, and the prime number n into the following equation (2) to generate the public key b. Then, the developer stores the created public key b in the storage device included in the sixth information processing device 6 (S502).
Public key b=g ^{^s} mod n (2)
Further, the developer substitutes the public key a, the secret key s, and the prime number n into the following formula (3) to create the common key dh (S503).
Common key dh=a ^{^s} mod n (3)

The developer uses the common key dh to encrypt image data, program data, etc. created by the developer. Then, the developer stores the encrypted data that has been encrypted in the storage device of the sixth information processing device 6 (S504).

At startup, the sixth information processing device 6 reads the public key b from the storage device included in the sixth information processing device 6, and further reads the secret key p and the prime number n stored by hardwired, Substituting into (4), the common key dh is created (S505).
Common key dh=b ^{^p} mod n (4)
The sixth information processing device 6 reads the encrypted data from the storage device according to the progress of the game and decrypts the encrypted data using the generated common key dh (S506).
As described above, in the cryptographic processing system 300, the developer can prevent fraudulent acts due to falsification of data by keeping the secret key s secret.

However, in the cryptographic processing system 300, since there is only one type of public key a, the designer provides each developer with a common development environment including the public key a. Therefore, in the cryptographic processing system 300, when a development environment including the public key a is obtained by a third party, it may not be possible to prevent data tampering by the third party.

In other words, a third party obtains the development environment including the public key a, the third party arbitrarily sets the secret key sa, and the public key ba and the common key sa are used by using the arbitrary secret key sa. Create dha and. Further, the third party creates unauthorized encrypted data by encrypting the data created for falsification using the common key dha. Further, the third party creates an unauthorized storage device that stores the created unauthorized public key ba and the unauthorized encrypted data. Then, the third party replaces the storage device included in the sixth information processing device 6 with the created unauthorized storage device. Then, the sixth information processing device 6 decodes the falsified data and executes the process according to the data. Therefore, the cryptographic processing system 300 may not be able to prevent fraudulent acts due to falsification of data.

FIG. 2 is a diagram showing an embodiment of a cryptographic processing system using a developer identifier.
An embodiment of the cryptographic processing system 100 using a developer identifier (hereinafter, also referred to as a developer ID) for identifying a developer who creates data will be described with reference to FIG. Specifically, in order to prevent fraudulent acts due to falsification of data, each developer includes a public key A (first public key) created using a developer ID that identifies each developer. It is to provide the environment.

The cryptographic processing system 100 includes a first information processing device 1 (hereinafter also referred to as a key generation device), a second information processing device 2 (hereinafter also referred to as an encryption device), and a third information processing device 3 (hereinafter referred to as a “information processing device”). , And decoding device).

The first information processing device 1 is a computer device used by the designer. The second information processing device 2 is a computer device used by the developer. The third information processing device 3 is, for example, an image processing device including a decoding device. In the following description, the design source process is performed using the first information processing device 1. Further, the processing of the developer is processed by using the second information processing device 2. The third information processing device 3 may be, for example, an image processing device used for a game machine or the like, and various information processing devices used for a personal computer, a transportation device, a game machine, a VR device, or the like, including a decoding device. ..

The designer sets a generator G (first set value) for performing DH key exchange and a prime number N (second set value) and shares it with the developer. Further, the designer sets the master key (third setting value) and the developer ID, and stores the master key set in the third information processing device 3, the developer ID, and the prime number N by hardwired. To do.

More specifically, the master key and the prime number N are the first connection logic (hereinafter, also referred to as the first numerical value storage unit) using the wiring and the fuse on the integrated circuit included in the third information processing device 3. Is stored using. The developer ID is stored using the second connection logic (hereinafter, also referred to as the second numerical value storage unit) on the board on which the integrated circuit included in the third information processing device 3 is mounted.

In the integrated circuit included in the third information processing device 3, for example, a pull-up resistor and a fuse are connected in series between the power supply and the ground, and an output line is connected between the pull-up resistor and the fuse. A first connection logic having one or more select circuits described above. At this time, the pull-up resistor is connected to the power supply side and the fuse is connected to the ground side.

Before designing the integrated circuit, the designer makes a selection such that a high voltage is applied to the fuse portion of each selection circuit included in the first connection logic to blow out the fuse, or the fuse is left as it is. As a result, the design source switches the H level and L level of the output from each output line included in the first connection logic and stores the values of the master key and the prime number N in the first connection logic.

The third information processing device 3 detects the output from the first connection logic on the integrated circuit and reads the master key and the prime number N. The above configuration of the first connection logic is an example, and other configurations such as a configuration using a pull-down resistor and a configuration using an antifuse may be used. The master key and the prime number N may be stored using an EPROM (Erasable Programmable Read Only Memory) or an electronic fuse (eFuse).

The substrate on which the integrated circuit included in the third information processing device 3 is mounted is, for example, two pins that switch connection and opening between a power supply and a ground, and a pull-down connected between a ground-side pin and the ground. Included is second wire logic having one or more select circuits with a resistor and an output line connected between a pin on the ground side and a pull-down resistor.

The designing source arranges the pin header on the board and selects whether or not to insert the jumper into or out of the two pins of each selection circuit included in the second connection logic. As a result, the designer switches the output from each output line included in the second connection logic between the H level and the L level and stores the value of the developer ID in the second connection logic.

The third information processing device 3 detects the output from the second connection logic on the board and reads the developer ID. The above-described configuration of the second connection logic is an example, and for example, a configuration in which two pins of a selection circuit included in the second connection logic are connected by wiring, a configuration using a DIP switch, a power supply or a ground directly to an output line is used. Other configurations such as a connection configuration may be used.
The master key, the developer ID, and the prime number N may be stored by appropriately selecting one or both of the first connection logic and the second connection logic.
In the following description, the first connection logic and the second connection logic are also simply referred to as a storage unit or a storage device.

FIG. 3 is a diagram showing a process of generating the secret key P.
The process of generating the secret key P (first secret key) will be described with reference to FIG.
The designer generates a combination value C by combining each of the specified number of count values output from the counter and the set master key. In addition, the designer uses the developer ID as an encryption key to encrypt each of the generated combination values C. Further, the designer creates the secret key P by concatenating the specified number of encrypted combination values CC that have been encrypted (S601).

This will be described with reference to FIG.
The design source creates the public key A by substituting the generator G, the secret key P, and the prime number N into the following equation (5). Then, the designer provides the development environment including the created public key A to the developer (S602).
Public key A=G ^{^P} mod N (5)

In addition, the developer creates a secret key S using a random number or the like, and substitutes the generator G, the secret key S, and the prime number N into the following formula (6) to create the public key B. Then, the developer stores the created public key B in the storage device included in the third information processing device 3 (S603).
Public key B=G ^{^S} mod N (6)
Furthermore, the developer substitutes the public key A, the secret key S, and the prime number N into the following equation (7) to create a common key DH (common key) (S604).
Common key DH=A ^{^S} mod N (7)

Then, the developer uses the common key DH to encrypt the image data, program data, etc. created by the developer. Then, the developer stores the encrypted data that has been encrypted in the storage device of the third information processing device 3 (S605).

This will be described with reference to FIG.
The third information processing device 3 generates a combination value C, which is a combination of the specified number of count values output from the counter and the set master key, when activated. In addition, the third information processing device 3 uses the developer ID as an encryption key to encrypt each of the generated combination values C. Further, the third information processing device 3 creates the secret key P by concatenating the designated number of encrypted combination values CC that have been encrypted (S606).

This will be described with reference to FIG.
Then, the third information processing device 3 reads the public key B and the prime number N from the storage device, and substitutes the read public key B, the prime number N, and the created secret key P into the following formula (8). Then, the common key DH is created (S607).
Common key DH=B ^{^P} mod N (8)
The third information processing device 3 reads the encrypted data from the storage device according to the progress of the game, and decrypts the encrypted data using the generated common key DH (S608).
As described above, in the cryptographic processing system 100, the developer can prevent the fraudulent act due to the falsification of the data by keeping the secret key S secret.

FIG. 4 is an explanatory diagram of a correspondence relationship between the public key A and the customer ID.
The correspondence relationship between the public key A and the customer ID will be described with reference to FIG.
In the cryptographic processing system 100, when the secret key P is generated by the first information processing apparatus 1 and the third information processing apparatus 3, the developer IDs are used by each other, so that the corresponding relationship between the developer ID and the public key A. Occurs. As a result, the third information processing device 3 decrypts the encrypted data with the common key created using another public key other than the public key A corresponding to the developer ID stored in the second connection logic. At this time, damaged image data or program data that cannot be started will be output. At this time, the third information processing device 3 does not operate properly.

In addition, in the cryptographic processing system 100, the designer provides the developer with a development environment including the public key A corresponding to the developer ID and the third information processing device 3 that stores the developer ID. Therefore, it is difficult for a third party to obtain a development environment including the public key A corresponding to the third information processing device 3. Therefore, even if the third party falsifies the data and replaces the unauthorized storage device storing the falsified data with the storage device of the third information processing device 3, the third information processing device 3 outputs the data properly. I can't. As described above, the third information processing device 3 can prevent fraudulent acts due to falsification of data.

FIG. 5 is a block diagram showing an embodiment of the cryptographic processing system.
With reference to FIG. 5, an encryption system 100 including a first information processing device 1 (key generation device), a second information processing device 2 (encryption device), and a third information processing device 3 (decryption device). Will be further described. The first information processing device 1, the second information processing device 2, and the third information processing device 3 are, for example, a computer device 200 described later.

The first information processing device is, for example, a computer device used by the designer. The second information processing device is, for example, a computer device used by a developer and executes a data creation program including a public key A corresponding to a developer ID for identifying the developer, which is provided by the designer. To do. The third information processing device 3 is a computer device designed and manufactured by a designer and provided to a developer, and is, for example, an image processing device used for a game machine such as a pachinko machine or a slot. The data creation program is a program for creating data to be stored in the storage device of the third information processing device 3.

The encryption system 100 uses DH key exchange. The designer sets a generator G for performing DH key exchange and a prime number N. Then, the generator G and the prime number N are shared in advance between the design source and the development source. Further, the designer stores the developer ID of the developer who is the destination of the third information processing device 3, the prime number N, and the master key in the second storage unit 50 of the third information processing device.

The first information processing device 1 includes a first control unit 10. The first control unit 10 includes a first acquisition unit 11, a first counting unit 12, a first generation unit 13, and a first creation unit 14.

The first acquisition unit 11 acquires a generator G, a prime number N, a master key, and a developer ID. The first acquisition unit 11 acquires the generator G, the prime number N, the master key, and the developer ID by receiving an input from the designer, for example. The generator G, the prime number N, the master key, and the developer ID are, for example, values arbitrarily set by the designer. The generator G and the prime number N are values used in DH key exchange. The master key is, for example, a value that is set by a designer and kept secret. The developer ID is, for example, an identifier arbitrarily assigned by the designer to each developer who provides the third information processing device 3.

Then, the first acquisition unit 11 outputs the master key and the developer ID to the first generation unit 13. Further, the first acquisition unit 11 outputs the generator G and the prime number N to the first creation unit 14.
The first count unit 12 counts the values and outputs the count value of the designated number D to the first generation unit 13. The designated number D is designated by the developer, for example.

The designated number D is the number of bits of the secret key P divided by the number of bits of the encrypted combination value CC. That is, the designated number D is a value obtained by, for example, substituting the bit number L of the encrypted combination value CC obtained by combining the count value and the master key and the bit number M of the secret key P into the following formula (9). Is.
Designated number D=M/L (9)

Specifically, for example, when the encryption combination value CC is 128 bits and the number of bits of the secret key P is 2048 bits, the first counting unit 12 counts from 0 to 15 because the designated number D=16. Then, 16 count values are output. The first counting unit 12 may output the count value of the specified number D different values. When the designated number is 16, the first counting unit 12 may output 16 different count values.
The first generator 13 uses the developer ID to generate the secret key P.

As an example, the first generation unit 13 generates a specified number of combination values C by combining each count value counted by the first counting unit 12 and the master key, as shown in FIG. Then, the first generation unit 13 uses the developer ID as an encryption key to perform encryption processing on each generated combination value C, concatenates the specified number of encrypted combination values CC that have been subjected to the encryption processing, and concatenates the secret key. Generate P. The first generation unit 13 outputs the generated secret key P to the first generation unit 14.

The combination value C may be, for example, the logical sum of the master key and the count value. Further, the combination value C may be, for example, an addition or a logical product of the master key and the count value, or may be a connection.

Further, the encryption process may use an arbitrary block cipher process such as DES (Data ENcryptionN StaNard), AES (AdvaNced ENcryptionN StaNard), or the like.

The first preparation unit 14 prepares a public key A which is a remainder obtained by dividing a value obtained by raising the generator G by the secret key P to the power of N. More specifically, the first creation unit 14 substitutes the generator G and the prime number N input from the first acquisition unit 11 and the secret key P input from the first generation unit 13 into the equation (5). Then, the public key A is created. Then, the first creating unit 14 provides the public key A to the developer. The first creation unit 14 may incorporate the public key A into the data creation program, for example. Thereby, the public key A is provided to the developer when the data creation program is executed by the second information processing device 2. That is, the first creating unit 14 creates a private key P that is created by using a different developer ID at each developer, creates a public key A by using the created private key P, and publishes differently to each developer. Provide key A.

The second information processing device 2 includes a second control unit 20 and a first storage unit 30. The second control unit 20 includes a second acquisition unit 21, a second creation unit 22, and an encryption unit 23. The first storage unit 30 stores the first setting information 31 and the first key information 32.
The first setting information 31 includes a generator G shared with the developer and a prime number N. The first key information 32 includes the public key A.

The second acquisition unit 21 acquires the public key A and the secret key S (second secret key) arbitrarily set by the developer. Then, the second acquisition unit 21 outputs the secret key S to the second creation unit 22. Further, the second acquisition unit 21 may store the secret key S in the first key information 32.

The second acquisition unit 21 acquires, for example, the public key A incorporated in the data creation program executed by the second information processing device 2. Then, the second acquisition unit 21 stores the public key A in the first key information 32.

The second creation unit 22 creates a public key B (second public key) that is a remainder that is obtained by dividing the value of the generator G raised to the power of the secret key S by the prime number N. Specifically, the second creation unit 22 substitutes the generator G and the prime number N read from the first storage unit 30 and the secret key S input from the second acquisition unit 21 into the equation (6). , Public key B is created. Then, the second creation unit 22 stores the created public key B in the storage device connected to the third information processing device 3. When the third information processing device 3 is an image processing device, the public key B may be stored in the top area of the CGROM, for example.

The second creating unit 22 creates a common key DH that is a remainder obtained by dividing a value obtained by raising the public key A by the secret key S by the prime number N. Specifically, the second creation unit 22 substitutes the prime number N and the public key A read from the first storage unit 30 and the secret key S input from the second acquisition unit 21 into the equation (7). , Create a common key DH.

The encryption unit 23 uses the common key DH created by the second creation unit 22 to encrypt the data created by the developer executing the data creation program in the second information processing device 2. Then, the encryption unit 23 stores the encrypted data in the second storage unit 50 of the third information processing device 3. Further, the encryption process may be a process corresponding to the decryption process of the decryption unit 44, and for example, an arbitrary encryption process such as DES (Data Encryption Standard) or AES (Advanced Encryption Standard) may be used.

The third information processing device 3 includes a third control unit 40 and a second storage unit 50. The third control unit 40 includes a second counting unit 41, a second generating unit 42, a third creating unit 43, and a decoding unit 44. The second storage unit 50 stores the second setting information 51, the second key information 52, the identification information 53, and the data information 54.

The second setting information 51 includes a master key and a prime number N. The second key information 52 includes the public key B. The identification information 53 includes a developer ID. The data information 54 includes encrypted data.

The second storage unit 50 includes, for example, a first numerical value storage unit that stores numerical values using the first connection logic on the integrated circuit. Further, the second storage unit 50 includes, for example, a second numerical value storage unit that stores a numerical value by using the second connection circuit on the board on which the integrated circuit is mounted. Then, the master key and the prime number N may be stored in the first numerical value storage unit. The developer ID may be stored in the second numerical value storage unit. The master key, the developer ID, and the prime number N may be stored by appropriately selecting one or both of the first numerical value storage unit and the second numerical value storage unit.

The second counting unit 41 counts the values and outputs the count value of the designated number D to the second generating unit 42. The counting process of the second counting unit 41 is the same counting process as that of the first counting unit 12, and outputs the same count value as that of the first counting unit 12.
The second generation unit 42 uses the developer ID to generate the secret key P.

As an example, the second generation unit 42 generates a specified number of combination values C by combining each count value counted by the second count unit 41 and the master key, as shown in FIG. Then, the second generation unit 42 uses the developer ID as an encryption key to encrypt each combination value C that has been generated, concatenates the specified number of encrypted combination values CC that have been encrypted, and concatenates the secret key. Generate P. The second generation unit 42 outputs the generated secret key P to the second generation unit 22. The generation process of the second generation unit 42 is the same as the generation process of the first generation unit 13, and outputs the same secret key P as that of the first generation unit 13.

The third creating unit 43 creates a common key DH that is a remainder obtained by dividing a value obtained by raising the public key B by the secret key P input from the second generating unit 42 by a prime number N. Specifically, the third generation unit 43 substitutes the secret key P, the public key B, and the prime number N into the equation (8) to create the common key DH.

The decryption unit 44 uses the common key DH to decrypt the encrypted data stored in the second storage unit 50. Further, the decryption process may be any process corresponding to the encryption process of the encryption unit 23, and for example, an arbitrary encryption process such as DES or AES may be used.

In the above description, the first generation unit 13 and the second generation unit 42 respectively perform the encryption process using the combination ID C generated using the master key and the counter value, using the developer ID as the encryption key. do. The first generation unit 13 and the second generation unit 42 have been described as generating the secret key P by concatenating the plurality of encrypted combination values CC generated by encrypting the plurality of combination values C. , But is not limited to this.

The first generation unit 13 and the second generation unit 42 may generate the secret key P by any method using the developer ID. Specifically, the first generation unit 13 and the second generation unit 42 may generate the secret key P by performing an encryption process using, for example, the developer ID and the master key as an encryption key. .. In addition, the first generation unit 13 and the second generation unit 42 generate a plurality of combination values C2 using, for example, the developer ID and the counter value, and perform encryption processing using the master key as an encryption key. A plurality of encrypted combination values CC2 may be generated. Then, the first generation unit 13 and the second generation unit 42 may concatenate the plurality of encrypted combination values CC2 to generate the secret key P.

The first generation unit 13 and the second generation unit 42 may include a pseudo random number generator, and the developer ID may be input to the pseudo random number generator to generate the secret key P. That is, the secret key P may be generated using a pseudo random number generator. The pseudo-random number generator may be a cryptographical pseudo-random number generator (CSPRNG).

Note that CSPRNG is an abbreviation for Cryptographically Secure Pseudo RaNdom Number GeNerator, and is a cryptographic pseudo-random number generator having characteristics suitable for use in cryptography.

FIG. 6 is a flowchart showing a process in the first information processing device.
Processing in the first information processing apparatus will be described with reference to FIG.
The first acquisition unit 11 determines whether the master key and the developer ID have been acquired (S101). Then, when the master key and the developer ID are not acquired (No in S101), the first acquisition unit 11 repeatedly executes the process of S101.
When the first acquisition unit 11 acquires the master key and the developer ID (Yes in S101), the first acquisition unit 11 outputs the master key and the developer ID to the first generator 13.

Upon acquiring the master key input from the first acquisition unit 11 and the developer ID, the first generation unit 13 generates the private key P (S102). Then, the first generation unit 13 outputs the secret key P to the first creation unit 14.

FIG. 7 is a flowchart showing the process of creating the secret key P.
The process of creating the secret key P in S102 will be described with reference to FIG.
The first generation unit 13 determines whether the count value is input from the first counting unit 12 (S201). When the count value is not input from the first counting unit 12 (No in S201), the first generating unit 13 repeatedly executes the process of S201.

When the count value is input from the first count unit 12 (Yes in S201), the first generation unit 13 combines the count value counted by the first count unit 12 and the master key to obtain the combination value C. It is generated (S202).
The first generation unit 13 uses the developer ID as an encryption key to encrypt the generated combination value C and generates an encrypted combination value CC (S203).

The first generation unit 13 determines whether the number of input count values (hereinafter, also referred to as a count number) is the designated number D (S204). When the count number is not the designated number D (No in S204), the first generation unit 13 executes the process of S201. In the subsequent processing, in S201, the first generation unit 13 determines whether or not a count value different from the count value input so far is input. Then, when the count value different from the count value acquired up to the previous time is input, the first generation unit 13 executes the process of S202. For example, when the count value is incremented by the first counting unit 12, the first generating unit 13 determines that the designated number D of different count values is 0, 1, 2, 3,... In this order in S201. The processes of S201 to S204 are repeatedly executed until input.

When the count number is the designated number D (Yes in S204), the first generation unit 13 concatenates the designated number of encrypted combination values CC generated in S203 to generate the secret key P (S205).

Then, the first generation unit 13 resets the count value of the first counting unit 12 (S206). For example, when the count value is incremented by the first count unit 12, the first generation unit 13 sets the count value of the count unit (the first count unit 12 or the second count unit 41) to 0 in S206. To

This will be described with reference to FIG.
The first acquisition unit 11 determines whether the generator G and the prime number N have been acquired (S103). When the generator G and the prime number N are not acquired (No in S103), the first acquisition unit 11 repeatedly executes the process of S103.
When acquiring the generator G and the prime number N (Yes in S103), the first acquisition unit 11 outputs the generator G and the prime number N to the first creation unit 14.

The first creation unit 14 substitutes the generator G and the prime number N input from the first acquisition unit 11 and the secret key P input from the first generation unit 13 into the equation (5) to obtain the public key A. Create (S104).
Then, the first creation unit 14 incorporates the public key A into the data creation program (S105).

In the above description, in S102, the plurality of combination values C generated using the master key and the counter value are encrypted using the developer ID as an encryption key, and the encrypted combination value CC is concatenated to keep the secret. Although the process of creating the key P has been described, the present invention is not limited to this. In S102, the developer ID may be used to generate the secret key P by an arbitrary method. Further, in S102, the developer ID may be input to the pseudo random number generator to generate the secret key P. That is, the secret key P may be generated using a pseudo random number generator.

FIG. 8 is a flowchart showing the processing in the second information processing device.
Processing in the second information processing apparatus will be described with reference to FIG.
In the following description, the data creation program is installed in the second information processing device 2, and the public key A incorporated in the data creation program is acquired by the second acquisition unit 21 and stored in the first storage unit 30. Be present.

The second acquisition unit 21 determines whether or not the secret key S has been acquired (S301). Then, when the secret key S has not been acquired (No in S301), the second acquisition unit 21 repeatedly executes the process of S301.
When acquiring the private key S (Yes in S301), the second acquisition unit 21 outputs the private key S to the second creation unit 22.

When the secret key S is input, the second creating unit 22 substitutes the secret key S, the generator G stored in the first storage unit 30, and the prime number N into the equation (6) to obtain the public key. B is created (S302).

Further, when the secret key S is input from the second acquisition unit 21, the second creation unit 22 calculates the secret key S, the prime number N, and the public key A stored in the first storage unit 30 using the formula ( 7), and the common key DH is created (S303).
Then, the second creation unit 22 stores the public key B in the second storage unit 50 of the third information processing device 3 (S304).
The encryption unit 23 uses the common key DH created by the second creation unit 22 to encrypt the data created by the developer (S305).
Then, the encryption unit 23 stores the encrypted data in the second storage unit 50 of the third information processing device 3 (S306).

FIG. 9 is a flowchart showing processing in the third information processing device.
Processing in the third information processing device 3 will be described with reference to FIG. 9.
In the following description, the public key B created by the second information processing device 2 is assumed to be stored in the second storage unit 50.
For example, when the third information processing device 3 is activated, the second generation unit 42 stores the master key stored in the second storage unit 50, the developer ID, and the count value of the second count unit 41. The private key P is created by using it (S401). The process of creating the secret key P of the second generator 42 is the same as the process of creating the secret key P of the first generator 13 described with reference to FIG.

The third creation unit 43 substitutes the secret key P created by the second generation unit 42, the prime number N stored in the second storage unit 50, and the public key B into the equation (8) to obtain the common value. The key DH is created (S402).
The decryption unit 44 decrypts the encrypted data stored in the second storage unit 50 using the common key DH (S403).

In the above description, in S401, a plurality of combination values C generated using the master key and the counter value are encrypted by using the developer ID as an encryption key, and the encrypted combination value CC is concatenated to keep secret. Although the process of creating the key P has been described, the present invention is not limited to this. In S401, the developer ID may be used to generate the secret key P by an arbitrary method. Further, in S401, the developer ID may be input to the pseudo random number generator to generate the secret key P. That is, the secret key P may be generated using a pseudo random number generator.

FIG. 10 is a block diagram showing an embodiment of a computer device.
The configuration of the computer device 200 will be described with reference to FIG.
In FIG. 10, the computer device 200 includes a control circuit 201, a storage device 202, a reading device 203, a recording medium 204, a communication interface 205, an input/output interface 206, an input device 207, a display device 208, And connection logic 209. The communication interface 205 is also connected to the network 210. Then, each component is connected by a bus 211. The first information processing device 1, the second information processing device 2, and the third information processing device 3 can be configured by appropriately selecting some or all of the components described in the computer device 200.

The control circuit 201 controls the entire computer device 200. The control circuit 201 is, for example, a processor such as a CPU (Central Processing Unit), a multi-core CPU, an FPGA (Field Programmable Gate Array), and a PLD (Programmable Logic Device). Then, the control circuit 201 functions as the first control unit 10, the second control unit 20, and the third control unit 40 in FIG. 5, for example.

The storage device 202 stores various data. The storage device 202 is, for example, a memory such as a ROM (Read Only Memory) and a RAM (Random Access Memory) or an HD (Hard Disk). The storage device 202 functions as the first storage unit 30 and the second storage unit 50 in FIG. 5, for example. When the storage device 202 functions as the first storage unit 30, the storage device 202 may store the first setting information 31 and the first key information 32 shown in FIG. Further, when the storage device 202 functions as the second storage unit 50, it may store the second setting information 51, the second key information 52, the identification information 53, and the data information 54 shown in FIG. good.

Further, the ROM stores a program such as a boot program. The RAM is used as a work area for the control circuit 201. The HD stores an OS, application programs, programs such as firmware, and various data.

The storage device 202 of the first information processing device 1 stores a key generation program that causes the control circuit 201 to function as the first acquisition unit 11, the first counting unit 12, the first generation unit 13, and the first generation unit 14. May be stored. Further, the storage device 202 of the second information processing device 2 may store the second acquisition unit 21, the second creation unit 22, the encryption program that functions as the encryption unit 23, and the data creation program. .. Furthermore, the storage device 202 of the third information processing device 3 may store a second count unit 41, a second generation unit 42, a third creation unit 43, and a decoding program that functions as the decoding unit 44. The storage device 202 of each of the first to third information processing devices 1 to 3 causes the control circuit 201 to function as the first control unit 10, the second control unit 20, and the third control unit 40. The program may be stored.

When performing the encryption process, the information processing device 1 to the information processing device 3 read the program stored in the storage device 202 into the RAM. By executing the program read in the RAM by the control circuit 201, each of the information processing device 1 to the information processing device 3 has an acquisition process, a count process, a generation process, a creation process, an encryption process, and An encryption process including one or more of the decryption process is executed.

Each program described above may be stored in a storage device included in a server on the network 210 as long as the control circuit 201 can access the communication interface 205.

The reading device 203 is controlled by the control circuit 201 and reads/writes data from/in the removable recording medium 204. The reading device 203 includes, for example, an FDD (Floppy Disk Drive), a CDD (Compact Disc Drive), a DVDD (Digital Versatile Disk Drive), a BDD (Blu-ray (registered trademark) Disk Diver Usive (USB), and a USB (USB)). And so on.

The recording medium 204 stores various data. The recording medium 204 stores, for example, one or more of a key creation program, an encryption program, a decryption program, and an encryption processing program. Further, the recording medium 204 includes the first setting information 31, the first key information 32, the second setting information 51, the second key information 52, the identification information 53, and the data information 54 shown in FIG. You may remember.

Then, the recording medium 204 is connected to the bus 211 via the reading device 203, and the control circuit 201 controls the reading device 203 to read/write data. The recording medium 204 is, for example, an SD memory card (SD Memory Card), an FD (Floppy Disk), a CD (Compact Disc), a DVD (Digital Versatile Disk), a BD (Blu-ray (registered trademark) Disk), and It is a non-transitory recording medium such as a flash memory.

The communication interface 205 communicatively connects the computer device 200 and another device via the network 210. The communication interface 205 may include an interface having a wireless LAN function and an interface having a short-range wireless communication function. The wireless LAN interface may support Wi-Fi (registered trademark) as a wireless LAN standard, for example. The short-range wireless interface may support, for example, Bluetooth (registered trademark) as a short-range wireless communication standard. LAN is an abbreviation for Local Area Network.

The input/output interface 206 is connected to, for example, an input device 207 such as a keyboard, a mouse, and a touch panel. When a signal indicating various types of information is input from the connected input device 207, a signal input via the bus 211. Is output to the control circuit 201. Further, when the signal indicating various information output from the control circuit 201 is input via the bus 211, the input/output interface 206 outputs the signal to various connected devices. The input/output interface 206 may receive, for example, the input of the generator G, the prime number N, the master key, the developer ID, and the secret key S by the user. The input/output interface 206 functions as the first acquisition unit 11 and the second acquisition unit 21 in FIG. 5, for example, by operating together with the control circuit 201.
The display device 208 displays various information. The display device 208 may display information for accepting an input on the touch panel.

The connection logic 209 is, for example, a hard-wired logic memory. The connection logic 209 is provided in, for example, the third information processing device 3, and stores the prime number N, the master key, and the developer ID. The connection logic 209 functions, for example, in FIG. 5 as a first numerical value storage section and a second numerical value storage section included in the second storage section 50. The prime number N and the master key are stored in, for example, the first numerical value storage unit. The developer ID is stored in, for example, the second numerical value storage unit.
The network 210 is, for example, a LAN, wireless communication, or the Internet, and communicatively connects the computer device 200 and another device.

As described above, the key generation device (first information processing device 1) and the decryption device (third information processing device 3) generate the private key P using the developer ID in the DH key exchange. The key creation device also creates a public key A using the generated private key P. As a result, when the decryption device decrypts the encrypted data with the common key created using another public key, which is not the public key A corresponding to the developer ID stored in the decryption device as hardwired, Damaged image data and program data that cannot be started will be output. At this time, the decoding device cannot display and execute the image data and the program data properly. In the cryptographic processing system 100, the designer provides each developer with a development environment including the public key A corresponding to the developer ID, and a decryption device that stores the developer ID. Therefore, it is difficult for a third party to obtain a development environment including the public key A corresponding to the decryption device. Therefore, even if the third party falsifies the data and replaces the unauthorized storage device storing the falsified data with the storage device of the decryption device, the third party cannot cause the decryption device to properly output the data. As described above, the key generation device and the decryption device can prevent fraudulent acts due to falsification of data.

The key generation device and the decryption device according to the embodiment generate the secret key P using the developer ID and the master key. By this, if the third party does not know the master key and the developer ID, the secret is generated even if the third party knows the encryption algorithm used for generating the secret key P in the key generation device and the decryption device. The key P cannot be generated. Therefore, the key generation device and the decryption device can prevent fraudulent acts due to falsification of data.

The key generation device and the decryption device of the embodiment include a cryptographic pseudo-random number generator (CSPRNG), and generate the secret key P using the cryptographic pseudo-random number generator. Therefore, the key generation device and the decryption device can generate the secret key P that is cryptographically suitable.

The key creation device and the decryption device, for example, concatenate the specified number of combination values C obtained by combining the master key and the specified number of count values with each other, and concatenate the encrypted combination value CC to obtain the secret key P. Creating. Further, in the CTR mode using a secure block cipher algorithm, it is known that the data before XORing with plaintext has a property called CSPRNG. Therefore, the key generation device and the decryption device can generate the secret key P that is cryptographically suitable.

In the key generation device and the decryption device of the embodiment, the counter counts a designated number D obtained by dividing the number of bits of the secret key P by the number of bits of the encrypted combination value CC, and designates a combination of the count value and the master key. The encrypted combination value CC is generated using the combination value C of the number D. Then, the key generation device and the decryption device generate the secret key P by concatenating the specified number of encrypted combination values CC. As a result, the decryption apparatus may store the master key, the developer ID, and the prime number N, which are short bit numbers, in a hard wired manner, instead of the secret key P having a long bit number, which is difficult to store in a hard wired manner. Since it is good, the manufacturing cost can be reduced.

The decryption device of the embodiment stores the master key and the prime number N by using the first connection logic on the integrated circuit included in the decryption device. Since the integrated circuit is packaged after storing the master key and the prime number N, it is difficult for a third party to obtain the master key. Therefore, the decryption device can prevent fraudulent acts due to falsification of data.

The decoding device of the embodiment stores the numerical value by using the second connection logic on the board on which the integrated circuit included in the decoding device is mounted. Since the board is fixed inside the housing, it is necessary to open the housing to check the wiring of the board to obtain the developer ID. As a result, the decryption device makes it difficult for a third party to obtain the developer ID. Therefore, the decryption device can prevent unauthorized rewriting of the developer ID.

The decryption device according to the embodiment stores the master key and the prime number N in the first connection logic, and stores the developer ID in the second connection logic. The master key and prime number N are low cost because they are stored in the first wire logic in the integrated circuit. Further, since the developer ID does not need to have a large number of bits, low cost can be realized even if it is stored in the second connection logic on the board. As a result, the decryption device sets the master key having a large number of bits and the prime number N by hard-wiring by wiring in the integrated circuit, and sets the developer ID having a small number of bits by a fuse or pin on a board having a large mounting area. The mounting area can be reduced.

The decoding device of the embodiment stores the developer ID in the second connection logic on the board. The second connection logic can be configured to set the developer ID, for example, by selecting shorting and opening of the pin on the board. Thereby, the decoding device can easily set the developer ID when the board is provided from the designer to the developer.

The encryption device of the embodiment acquires the public key A and the secret key S created by using the secret key P generated by using the developer ID. Then, the encryption device creates the common key DH using the public key A and the secret key S, and stores the encrypted data obtained by encrypting the data with the created common key DH in the storage device of the decryption device. As a result, the encryption device can cause only the decryption device that stores the developer ID corresponding to the public key A to decrypt the original data from the encrypted data. Therefore, the encryption device can prevent fraudulent acts due to falsification of data.

It should be noted that the present embodiment is not limited to the above-described embodiments, and various configurations or embodiments can be adopted without departing from the gist of the present embodiment.

1 1st information processing apparatus 2 2nd information processing apparatus 3 3rd information processing apparatus 10 1st control part 20 2nd control part 30 1st storage part 40 3rd control part 50 2nd storage part 100,300 Cryptographic processing system 200 Computer device 201 Control circuit 202 Storage device 203 Reading device 204 Recording medium 205 Communication I/F
206 Input/output I/F
207 Input device 208 Display device 209 Connection logic 210 Network 211 Bus

Claims (9)

A cryptographic processing system including a first information processing device, a second information processing device, and a third information processing device,
The first information processing device used by the designer who provides the data creation program and the third information processing device,
A first generator for generating a first secret key using a developer identifier identifying the open Hatsumoto said design source is set,
A first creating unit that creates a first public key using the first secret key;
A first processing unit that executes a process of adding the first public key to the data creation program;
Equipped with
The second information processing device used by the developer, which executes the data creation program provided by the designer,
An acquisition unit that acquires the first public key given to the data creation program and the second secret key set by the developer.
A second creating unit that creates a common key using the first public key and the second secret key and a second public key using the second secret key;
An encryption unit that encrypts the data created by the data creation program using the common key;
Executing a process of storing the second public key created by the second creating unit and the encrypted data encrypted by the encrypting unit in a storage device connected to the third information processing device; 2 processing units,
Equipped with
Wherein is provided to customers third information processing apparatus,
A storage unit that stores the developer identifier set by the designer,
A connection unit connected to the storage device;
A second generation unit that generates the first secret key using the developer identifier stored in the storage unit;
A third creating unit that creates the common key using the second public key stored in the storage device and the first secret key generated by the generating unit;
A decryption unit that decrypts the encrypted data stored in the storage device using the common key;
A cryptographic processing system comprising: The third information processing device,
An information processing apparatus that is provided from the design source to the developer together with the data creation program to which the first public key is added, and is provided to the customer from the developer together with the storage device. The cryptographic processing system according to claim 1. The first generation unit,
Generating the first secret key using the master key set by the designer and the developer identifier;
The storage unit further includes
Memorize the master key set in the design source,
The second generator is
The cryptographic processing system according to claim 1, wherein the first secret key is generated using the master key stored in the storage unit and the developer identifier. The first generation unit,
Generating the first secret key by encrypting a value including the master key using the developer identifier as an encryption key,
The second generator is
The cryptographic processing system according to claim 3, wherein the first secret key is generated using the same encryption processing as that of the first generation unit. The storage unit is
It has a memory area with tamper resistance,
The first processing unit,
The encryption processing system according to any one of claims 1 to 4, wherein the developer identifier is stored in the storage area having tamper resistance. The storage unit is
It has a memory area with tamper resistance,
The first processing unit,
The cryptographic processing system according to claim 3, wherein the master key and the developer identifier are stored in the tamper-resistant storage area. The third information processing device,
An image processing device used in the game machine owned by the customer,
The first information processing device,
A computer device used in the design source for designing the image processing device,
The second information processing device,
The encryption processing system according to claim 1, wherein the encryption processing system is a computer device that generates encrypted data to be stored in the storage device used by the developer. A cryptographic processing method executed by a cryptographic processing system including a first information processing device, a second information processing device, and a third information processing device,
The first information processing device used by the designer who provides the data creation program and the third information processing device,
It generates the first secret key using the developer identifier identifying the open Hatsumoto said design source is set,
Creating a first public key using the first private key,
Assigning the first public key to the data creation program,
The second information processing device used by the developer, which executes the data creation program provided by the designer,
Obtaining a first public key given to the data creation program and a second secret key set by the developer,
Creating a common key using the first public key and the second secret key and creating a second public key using the second secret key;
The data created by the data creation program is encrypted using the common key,
Storing the created second public key and the encrypted encrypted data in a storage device connected to the third information processing device;
A storage unit that stores the developer identifier set by the design source and a connection portion connected to the storage device, the third information processing apparatus to be provided to customers is
Generating the first secret key using the developer identifier stored in the storage unit,
Creating the common key using the second public key stored in the storage device and the generated first secret key;
An encryption processing method, comprising: decrypting the encrypted data stored in the storage device using the common key. A cryptographic processing program executed by the processor of the first information processing device, the processor of the second information processing device, and the processor of the third information processing device,
In the processor of the first information processing device used by the designer who provides the data creation program and the third information processing device,
It generates the first secret key using the developer identifier identifying the open Hatsumoto said design source is set,
Creating a first public key using the first private key,
Execute a process of assigning the first public key to the data creation program,
A processor of the second information processing device used by the developer, which executes the data creation program provided by the designer,
Obtaining a first public key given to the data creation program and a second secret key set by the developer,
Creating a common key using the first public key and the second secret key, and creating a second public key using the second secret key,
The data created by the data creation program is encrypted using the common key,
A process of storing the created second public key and the encrypted data in a storage device connected to the third information processing device,
A storage unit that stores the developer identifier set by the design source and a connection portion connected to the storage device, the processor of the third information processing apparatus that is provided to the customer,
Generating the first secret key using the developer identifier stored in the storage unit,
Creating the common key using the second public key stored in the storage device and the generated first secret key;
A cryptographic processing program for executing a process of decrypting the encrypted data stored in the storage device using the common key.