JP2008010952A - Authentication of mounter by plurality of times of challenges and responses - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve reliability in the authentication between a body and a mounter while restraining the amount of increase in data transfer. <P>SOLUTION: An electronic control device includes: a random number generator for generating a random number; a transmission section for transmitting (challenging) the generated random number to the mounter; a secret key used for authenticating whether the mounter has been authorized; an encoder for encrypting the generated random number; a RAM for holding encrypted data encrypted by the encoder; a reception section for receiving data transmission (response) from the mounter; and an authentication device for comparing the received data with the encrypted data held by the RAM for authentication. The encoder encrypts input data for a plurality of times. The authentication device compares a plurality of corresponding data. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to authentication between an electronic control device and a mounting device that can be mounted on the device.

  In a multifunction printer having a printer and a copy function, consumables and periodic replacement parts are service-exchanged in units. For example, the fixing device is an essential function for an electrophotographic printer. Since the fixing device is used in a high-temperature environment, its lifetime is shorter than that of the printer body, and is therefore often designed as a unit that can be easily replaced. In many cases, an expansion function is provided so that an optional feeder or an optional paper discharge device can be attached to the printer. In such a mounting device connected to the printer body, illegal counterfeit products are often on the market. If such a counterfeit product is installed in the printer, the printer may not operate, and the worst printer body may be destroyed. It is important to identify whether or not a regular unit is used, particularly for a unit that requires very high reliability such as a fixing device. When it is recognized that a non-regular unit is attached, it is necessary to alert the user. In order to determine whether or not the mounting device is a legitimate unit, an authentication technique, which is a kind of cryptographic technique, has already been used. As one of the authentication methods, there is a challenge response authentication method using a common key encryption. Details of the challenge response method are described below.

  It is assumed that the printer main body and the mounting device have the same key (common key). The main body creates a random number (this is a random number) and sends it to the wearer (challenge). The main body uses the key to the created random number to create encrypted data. In addition, the wearer that has received the random number uses the key in the same manner as the main body to create encrypted data. The wearer that created the encrypted data sends it back to the main unit (response). The main body compares the created encrypted data with the data sent back from the mounting device. At this time, if the keys used between the main body and the mounting device are the same, the compared data match. As described above, authentication between the main body mounting devices can be performed.

  In addition, a challenge response may be executed several times in order to increase the authenticity of authentication.

For example, Patent Document 1 and Patent Document 2 can be cited as conventional examples.
Japanese Patent Laid-Open No. 2004-126889 Japanese Patent Laid-Open No. 2003-163661

  However, in the above conventional example, the data transfer amount between the main body and the mounting device is doubled the number of challenge responses in order to increase the reliability of authentication, so the processing time is increased and the error generation amount at the time of data transmission is increased. This will cause harmful effects such as

  An object of the first, second and third inventions related to the present application is to suppress an increase in the amount of data transfer while increasing the reliability of authentication.

  In order to achieve the above object, a first invention according to the present application includes a random number generator for generating a random number, a transmission means 1 for transmitting (challenge) the random number to a mounting device to which the random number is mounted, and the mounting device A secret key 1 used for authenticating whether or not it is authentic, an encryptor 1 for encrypting the random number with the secret key 1, and encrypted data encrypted by the encryptor 1 A storage device 1 for holding, a receiving means 1 for receiving data transmission (response) from the wearer, a storage device 2 for holding received data obtained by the receiving means 1, and the storage An electronic control device comprising: comparing means for comparing the encrypted data held in the device 1 and the received data held in the storage device 2.

  The mounting device has the same secret key 2 as the electronic control device, receiving means 2 for receiving transmission data transmitted from the electronic control device, and encrypting the data received by the secret key 2 It is provided with the encryption device 2 and the transmission means 2 for transmitting the encryption data which performed encryption to the said electronic control apparatus, It is characterized by the above-mentioned.

  The encryptor 1 encrypts the random number data a plurality of times using the secret key 1.

  The encryptor 2 encrypts data received using the secret key 2 a plurality of times.

  The storage device 1 holds a plurality of encrypted data encrypted by the encryptor 1.

  The comparing means compares a plurality of encrypted data held in the storage device 1 and a plurality of received data held in the storage device 2 with corresponding data.

  Thereby, when something different from the expected one is attached to the electronic control device, it can be determined that the attached one is not a regular one.

  According to a second aspect of the present invention, a random number generator for generating a random number, a secret key 1 used for authenticating whether or not the mounted device to be mounted is authentic, and the secret key 1 Is attached to the encryption device 1 for encrypting the random number data generated by the random number generator, the storage device 1 for holding the random number data and the encryption data encrypted by the encryption device 1, and the encryption data. Transmitting means 1 for transmitting (challenge) to the wearer to be received, receiving means 1 for receiving data transmission (response) from the wearer, and for holding received data obtained by the receiving means 1 A storage device 2; and comparison means for comparing the random number data and the encrypted data held in the storage device 1 with the received data held in the storage device 2. Electronic control unit.

  The mounting device has the same secret key 2 as that of the electronic control device, receiving means 2 for receiving transmission data transmitted from the electronic control device, and encrypts (decrypts) the data received by the secret key 2. ), And a transmission means 2 for transmitting the encrypted data subjected to encryption to the electronic control unit.

  The encryptor 1 encrypts the random number data a plurality of times using the secret key 1.

  The encryptor 2 encrypts (decrypts) data received using the secret key 2 a plurality of times.

  The storage device 1 holds the random number data and a plurality of encrypted data encrypted by the encryptor 1.

  The transmission means 1 transmits the last data encrypted a plurality of times by the encryptor.

  The comparison means compares the random number data and a plurality of encrypted data held in the storage device 1 with a plurality of received data held in the storage device 2, respectively.

  Thereby, when something different from the expected one is attached to the electronic control device, it can be determined that the attached one is not a regular one.

  A third aspect of the invention relates to a random number generator for generating a random number, a transmission means 1 for transmitting (challenge) the random number to a mounting device to which the random number is mounted, and the mounting device being a regular one. A secret key 1 used for authenticating whether or not there exists, an encryptor 1 for encrypting input data with the secret key 1, and a storage device for holding and updating data encrypted by the encryptor 1 1, a receiving means 1 for receiving data transmission (response) from the mounting device, a storage device 2 for holding received data obtained by the receiving means 1, and a storage device 1 An electronic control device comprising: comparing means for comparing the encrypted data stored in the storage device 2 with the received data.

  The mounting device has the same secret key 2 as the electronic control device, receiving means 2 for receiving transmission data transmitted from the electronic control device, and encrypting the data received by the secret key 2 It is provided with the encryption device 2 and the transmission means 2 for transmitting the encryption data which performed encryption to the said electronic control apparatus, It is characterized by the above-mentioned.

  The encryptor 1 encrypts data held in the storage device 1 by using the secret key 1 every time the receiving unit 1 receives data.

  The storage device 1 holds the random number as an initial value, and updates the data with data encrypted by the encryptor 1.

  The encryptor 2 encrypts data received using the secret key 2 a plurality of times.

  The transmission means 2 transmits encrypted data to the electronic control device every time encryption is performed.

  The comparison means compares the data stored in the storage device 2 with the data updated by the encryption device 1 held in the storage device 1, and performs authentication.

  As a result, data processing (from random number generation to authentication) can be performed smoothly, and the capacity of the storage device can be reduced.

  As described above, according to the first aspect of the present application, authentication can be performed a plurality of times, so that the reliability can be improved. Further, since data transfer from the electronic control unit to the mounting device is only required once, the amount of transfer data can be reduced and transfer errors due to data errors during transfer can be reduced.

  In addition, according to the second invention of the present application, since the authentication can be performed a plurality of times, the reliability can be improved. Further, since data transfer from the electronic control unit to the mounting device is only required once, the amount of transfer data can be reduced and transfer errors due to data errors during transfer can be reduced.

  In addition, according to the third invention of the present application, the capacity of the storage device is reduced because it is not necessary to store a plurality of data (data encrypted a plurality of times) necessary for authentication while having the first feature. can do.

(Example 1)
FIG. 1 is a drawing that best represents the features of the present invention, in which 11 is a printer device, 12 is a mounting device that can be mounted on the printer device, 13 is a random number generator that generates random numbers, and 14 is input. 15 is a ROM that can read data (here, key 1 used for authentication is stored in advance), and 16 is a RAM that can read and write data (here: 17 is used to store comparison data 1, 2 and 3 used for authentication), 17 is a data transmission unit for transmitting input data (random number data) to the mounting device 12, and 18 is transmitted from the mounting device 12. A data receiving unit 19 that receives the received data, 19 is an authentication device that compares two input data and determines whether or not they match.

  FIG. 2 is a diagram illustrating details of the mounting device. In FIG. 2, reference numeral 21 denotes a data receiving unit that receives data transmitted from the printer device 11, and 22 transmits input data to the printer device 11. A data transmitting unit 23 is a ROM from which data can be read (a key 2 used for authentication is stored in advance), and 24 is an encryptor that encrypts the input data using the key 2.

  When the mounting device is mounted on the printer device, authentication is performed to determine whether or not the mounting device is a mounting device (a regular mounting device) that can be expected by the printer device. The operation is described below.

  1 generates random number data by a random number generator 13 when the mounting device 12 is mounted. The random number data is input to the encryptor 14 and the data transmission unit 17. When the random number data is inputted, the encryptor 14 encrypts the random number data by using the key 1 in the ROM 15. The encrypted data thus obtained is stored as comparison data 1 in the RAM 16. The encrypted data is again input to the encryptor 14 and further encrypted. This process is performed a plurality of times (three pieces of encrypted data are obtained in FIG. 1). The encrypted data obtained by this processing is stored in the RAM 16 as comparison data 2 and 3. The random number data input unit 17 transmits the input data to the mounting device 12. The mounting device 12 to which the data has been transmitted is received by the data receiving unit 21 in FIG. The random number data received by the data receiving unit 21 is input to the encryptor 24. The encryptor 24 creates encrypted data by using the key 2 in the ROM 23 for the input random number data (if the key 2 is the same as the key 1 stored in the ROM 15 in the printer 11), the encryptor 24 The encrypted data created in 24 matches the comparison data 1 stored in the RAM 16 in the printer 11). The created encrypted data is input again to the data transmission unit 22 and the encryptor 24. The encrypted data input to the data transmission unit is transmitted to the printer apparatus of FIG. In addition, the encryptor to which the data is input uses the key 2 in the ROM 23 to perform encryption again. This process is performed a plurality of times (three encrypted data are created to match the number of comparison data in FIG. 1). The encrypted data is input to the data transmission unit 22 every time it is created. The printer apparatus 11 of FIG. 1 to which the data has been transmitted receives the data at the data receiving unit 18. Data received by the data receiving unit 18 is input to the authentication device 19. The authentication device 19 to which the data has been input receives corresponding comparison data (comparison data having the same number as the order received from the data receiving unit 18) from the RAM 16, and checks whether the data match each other. If all of the comparison data matches, authentication OK is output, and if even one does not match, authentication NG is output.

(Example 2)
FIG. 3 is a drawing showing the features of the present invention, in which 31 is a printer device, 32 is a mounting device that can be mounted on the printer device, 33 is a random number generator for generating random numbers, and 34 is input data. An encryption device 35 for encrypting data, a ROM 35 for reading data (the key 1 used for authentication is stored in advance here), and a RAM 36 for reading and writing data (here for authentication) Used to store comparison data 1, 2 and 3 to be used), 37 is a data transmission unit for transmitting input data (random number data) to the mounting device 32, and 38 is data sent from the mounting device 32 Is a data receiving unit 39 for comparing two input data and determining whether or not they match.

  FIG. 4 is a diagram illustrating the details of the mounting device. In FIG. 4, reference numeral 41 denotes a data receiving unit that receives data transmitted from the printer device 31, and 42 transmits input data to the printer device 31. A data transmitting unit 43 for reading data is a ROM from which data can be read (key 2 used for authentication is stored in advance), and 44 is a decoder for decrypting input data using the key 2.

  When the mounting device is mounted on the printer device, authentication is performed to determine whether or not the mounting device is a mounting device (a regular mounting device) that can be expected by the printer device. The operation is described below.

  The printer device 31 of FIG. 3 creates random number data by a random number generator 33 when the mounting device 32 is mounted. The random number data is input to the encryptor 34. The encryptor 34 to which the random number data has been input encrypts the random number data using the key 1 in the ROM 35. The encrypted data thus obtained is stored as comparison data 1 in the RAM 36. The encrypted data is again input to the encryptor 34 and further encrypted. This process is performed a plurality of times (three pieces of encrypted data are obtained in FIG. 3). The encrypted data obtained by this processing is stored in the RAM 36 as comparison data 2 and 3. Further, another encrypted data (data obtained by further encrypting the data stored in the RAM 36 as the comparison data 3) is input to the data transmission unit 37. The data transmission unit 37 to which the encrypted data is input transmits the input data to the mounting device 32. The mounting device 32 to which the data has been transmitted is received by the data receiving unit 41 in FIG. The encrypted data received by the data receiving unit 41 is input to the decryptor 44. The decryptor 44 creates decrypted data using the key 2 in the ROM 43 for the input encrypted data (if the key 2 is the same as the key 1 stored in the ROM 35 in the printer 31) The decrypted data created in 44 matches the comparison data 1 stored in the RAM 36 in the printer 31.) The generated decoded data is input again to the data transmission unit 42 and the decoder 44. The decoded data input to the data transmission unit is transmitted to the printer apparatus of FIG. In addition, the decoder to which the data has been input performs decryption again using the key 2 in the ROM 43. This process is performed a plurality of times (three decoded data numbers are created to match the number of comparison data in FIG. 3). The decrypted data is input to the data transmission unit 42 every time it is created. The printer device 31 in FIG. 3 to which the data has been transmitted receives the data at the data receiving unit 38. Data received by the data receiving unit 38 is input to the authentication device 39. The authentication device 39 to which the data is input receives corresponding comparison data (comparison data having a number opposite to the order received from the data receiving unit 38) from the RAM 36, and checks whether the data match each other. If all of the comparison data matches, authentication OK is output, and if even one does not match, authentication NG is output.

(Example 3)
FIG. 5 is a drawing showing the features of the present invention, in which 51 is a printer device, 12 is a mounting device that can be mounted on the printer device, 53 is a random number generator for generating random numbers, and 54 is input data. 55 is a ROM that can read data (here, key 1 used for authentication is stored in advance), and 56 is a RAM that can read and write data (this is used for authentication). Used for storing comparison data to be used), 57 is a data transmission unit for transmitting input data (random number data) to the mounting device 52, and 58 is a data receiving unit for receiving data sent from the mounting device 52 Reference numeral 59 denotes an authentication device that compares two input data and determines whether or not they match.

  FIG. 2 is a diagram illustrating details of the mounting device. In FIG. 2, reference numeral 21 denotes a data receiving unit that receives data transmitted from the printer device 51, and 22 transmits input data to the printer device 51. A data transmitting unit 23 is a ROM from which data can be read (a key 2 used for authentication is stored in advance), and 24 is an encryptor that encrypts the input data using the key 2.

  When the mounting device is mounted on the printer device, authentication is performed to determine whether or not the mounting device is a mounting device (a regular mounting device) that can be expected by the printer device. The operation is described below.

  5 generates random number data by a random number generator 53 when the mounting device 12 is mounted. The random number data is input to the RAM 56 and the data transmission unit 57. The data transmitting unit 57 to which the random number data is input transmits the input data to the mounting device 12. The mounting device 12 to which the data has been transmitted is received by the data receiving unit 21 in FIG. The random number data received by the data receiving unit 21 is input to the encryptor 24. The encryptor 24 creates encrypted data using the key 2 in the ROM 23 for the input random number data. The created encrypted data is input again to the data transmission unit 22 and the encryptor 24. The encrypted data input to the data transmission unit is transmitted to the printer apparatus of FIG. In addition, the encryptor to which the data is input uses the key 2 in the ROM 23 to perform encryption again. This process is performed a plurality of times (three encrypted data numbers are created to match the number of comparison data in FIG. 5). The encrypted data is input to the data transmission unit 22 every time it is created. The printer 51 of FIG. 5 to which the data has been transmitted receives the data at the data receiving unit 58. Data received by the data receiving unit 58 is input to the authentication device 59. The authentication device 59 to which the data has been input issues an encryption command to the encryptor 54. In response to the encryption command, the encryptor 54 reads the data from the RAM 56 and encrypts it using the key 1 in the ROM 23. The encrypted encryption data is stored in the RAM 56 as comparison data and input to the authentication device 59. The authentication device 59 to which the data has been input performs comparison with the received data that has been input previously. If they do not match, output authentication NG and end. If they match, it waits for the next received data to be input to the authentication device 59. The authentication device 59 performs the same process until all received data is input. If the last received data matches the comparison data, an authentication OK is output and the process ends.

1 is a diagram illustrating a configuration of a printer device according to a first embodiment of the present invention. FIG. It is a figure explaining the structure of the mounting device which concerns on 1st Example of this invention. It is a figure explaining the structure of the printer apparatus which concerns on 2nd Example of this invention. It is a figure explaining the structure of the mounting device which concerns on the 2nd Example of this invention. It is a figure explaining the structure of the printer apparatus which concerns on 3rd Example of this invention.

Explanation of symbols

11 Printer device 12 Mounting device 13 Random number generator 14 Cryptographic device 15 ROM
16 RAM
17 Data Transmitter 18 Data Receiver 19 Authentication Device 21 Data Receiver 22 Data Transmitter 23 ROM
24 Cryptographic device 31 Printer device 32 Mounting device 33 Random number generator 34 Cryptographic device 35 ROM
36 RAM
37 Data transmission unit 38 Data reception unit 39 Authentication device 41 Data reception unit 42 Data transmission unit 43 ROM
44 Decoder 51 Printer Device 53 Random Number Generator 54 Encryptor 55 ROM
56 RAM
57 data transmission unit 58 data reception unit 59 authentication device

Claims (3)

A random number generator for generating a random number, a transmission means 1 for transmitting (challenge) the random number to a mounting device to which the random number is mounted, and a secret used for authenticating whether or not the mounting device is genuine A key 1, an encryption device 1 for encrypting the random number with the secret key 1, a storage device 1 for holding encrypted data encrypted by the encryption device 1, and data transmission from the mounting device (Response) for receiving means 1, a storage device 2 for holding received data obtained by the receiving means 1, the encrypted data held in the storage device 1, and the storage device 2 Comparing means for comparing the received data to be held, the electronic control device characterized in that
The mounting device has the same secret key 2 as the electronic control device, receiving means 2 for receiving transmission data transmitted from the electronic control device, and encrypting the data received by the secret key 2 An encryption device 2 and transmission means 2 for transmitting encrypted data subjected to encryption to the electronic control unit;
The encryptor 1 encrypts the random number data a plurality of times using the secret key 1;
The encryptor 2 encrypts data received using the secret key 2 a plurality of times,
The storage device 1 holds a plurality of encrypted data encrypted by the encryptor 1;
The comparison means compares the plurality of encrypted data held in the storage device 1 and the plurality of received data held in the storage device 2 with corresponding data, respectively. A random number generator for generating a random number, a secret key 1 used to authenticate whether or not the mounted device to be attached is authentic, and random number data generated from the random number generator by the secret key 1 The encryption device 1 for encryption, the storage device 1 for holding the random number data and the encryption data encrypted by the encryption device 1, and for transmitting (challenge) the encryption data to a mounting device to which the encryption data is attached. Transmitting means 1, receiving means 1 for receiving data transmission (response) from the wearer, storage device 2 for holding received data obtained by the receiving means 1, and holding in the storage device 1 An electronic control device comprising: comparing means for comparing the received random number data and the encrypted data with the received data held in the storage device 2;
The mounting device has the same secret key 2 as that of the electronic control device, receiving means 2 for receiving transmission data transmitted from the electronic control device, and encrypts (decrypts) the data received by the secret key 2. ), And a transmission means 2 for transmitting the encrypted encrypted data to the electronic control unit,
The encryptor 1 encrypts the random number data a plurality of times using the secret key 1;
The encryptor 2 encrypts (decrypts) data received using the secret key 2 a plurality of times, and the storage device 1 stores a plurality of data encrypted by the random number data and the encryptor 1. It holds the encryption data of
The transmitting means 1 transmits the last data encrypted a plurality of times by the encryptor 1,
The comparison means compares the random number data and a plurality of encrypted data held in the storage device 1 with a plurality of received data held in the storage device 2, respectively. apparatus. A random number generator for generating a random number, a transmission means 1 for transmitting (challenge) the random number to a mounting device to which the random number is mounted, and a secret used for authenticating whether or not the mounting device is genuine A key 1, an encryption device 1 for encrypting the input data with the secret key 1, a storage device 1 for holding and updating data encrypted by the encryption device 1, and data transmission (response) ), A storage device 2 for holding the reception data obtained by the reception unit 1, the encrypted data held in the storage device 1, and the storage device 2 Comparing means for comparing the received data with the electronic control device, comprising:
The mounting device has the same secret key 2 as the electronic control device, receiving means 2 for receiving transmission data transmitted from the electronic control device, and encrypting the data received by the secret key 2 An encryption device 2 and transmission means 2 for transmitting encrypted data subjected to encryption to the electronic control unit;
The encryptor 1 encrypts data held in the storage device 1 using the secret key 1 each time the receiving means 1 receives data,
The storage device 1 holds the random number as an initial value, and updates the data with the data encrypted by the encryptor 1,
The encryptor 2 encrypts data received using the secret key 2 a plurality of times,
The transmission means 2 transmits encrypted data to the reception means 1 for each encryption,
The electronic control device characterized in that the comparison means compares the data updated by the encryptor 1 with the data stored in the storage device 2 for authentication.

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