JP2009038736A - Electronic control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable an electronic control device which can attach and detach a plurality of mounting devices to authenticate which mounting device is attached to the electronic control device and to detect an illegal mounting device when it is attached. <P>SOLUTION: An electronic control device has n pieces of keys, a random number generator 14, and a cipher device 15. A mounting device which can be attached to the electronic control device has the cipher device identical to that of the electronic control device and any one or more keys which the electronic control device holds. The electronic control device authenticates the mounting device by using a challenge response authentication method. Because of n pieces of keys, the electronic control device can authenticate different mounting devices of the number of combinations of n pieces of keys. <P>COPYRIGHT: (C)2009,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 life 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 mounting devices connected to the printer main body, not only regular mounting devices (including mounting devices that are not genuine but not illegal) as well as 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. In addition, even with a regular wearer, there are differences depending on the manufacturer. Therefore, it is conceivable to change the control of the printer main body according to each mounting device. From these, it is necessary to call attention to the user when recognizing that a non-regular unit is installed, and the difference in the control method (regarding which manufacturer made it) even with a regular wearer ) Is necessary. 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.
JP-A-11-008618

  However, in the above conventional example, it was possible to authenticate whether the mounting device is regular or not, but it was not possible to determine what type of mounting device it was in the regular mounting device.

  The first invention according to the present application makes it possible to determine the type of the mounting device.

  Further, the second invention according to the present application can perform optimum body control depending on the type of the mounting device.

  Further, the third invention according to the present application can prevent erroneous authentication of the mounting device.

  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 ROM 1 for holding a plurality of secret keys used for authenticating whether or not they are authentic, an encryptor 1 for encrypting the random number with the secret key, and encryption by the encryptor 1 RAM 1 for holding the encrypted data, receiving means 1 for receiving the data (response) from the mounting device, RAM 2 for holding the received data obtained by the receiving means 1, An electronic control device comprising: comparing means for comparing the encrypted data held in the RAM1 and the received data held in the RAM2.

  The mounting device has a ROM 2 that holds one or more of the plurality of secret keys, a receiving means 2 for receiving transmission data transmitted from the electronic control unit, and the ROM 2 that holds the ROM 2 It is characterized by comprising an encryptor 2 for encrypting data received with a key, and a transmission means 2 for transmitting encrypted data subjected to encryption to the electronic control unit.

  The encryptor 1 encrypts the random number data using each of the plurality of secret keys stored in the ROM 1 to create a plurality of encrypted data.

  The encryptor 2 encrypts the received data using each of the one or more secret keys stored in the ROM 2 to create one or more encrypted data.

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

  The RAM 2 holds one or more data received by the receiving means 1.

  The comparison means compares the data held in the RAM 1 and the RAM 2 with each other.

  As a result, even if a plurality of mounting devices are mounted on the electronic control device, it is possible to authenticate whether the mounting device is genuine and to determine what type the mounting device belongs to. be able to.

  In order to achieve the above object, the second invention according to the present application is characterized in that the electronic control device according to claim 1 changes the control of the electronic control device according to the type of key held by the mounting device. And

  Accordingly, when any mounting device is mounted on the electronic control device, it is possible to perform control suitable for the mounting device.

  In order to achieve the above object, according to a third invention of the present application, in the electronic control device according to claim 1, the comparison unit is held in the RAM 1 among transmission data held in the RAM 2. If there is even one that does not match the encrypted data, it is determined that the mounting device is not a regular mounting device.

  Thus, when the mounting device is not authorized, even if the mounting device has a large number of keys and one or more of them happen to be the same key as the electronic control device, the mounting device If it is not a proper mounting device, correct authentication can be performed.

  As described above, according to the first invention of the present application, when a plurality of mounting devices can be mounted on the control device, it is possible to determine what mounting device the mounting device is. Here, if the control device holds n keys, the number of key combinations

The type of the wearer can be authenticated. Furthermore, even when the wearing device is not a proper one, it can be detected.

  Further, according to the second invention relating to the present application, it is possible to perform optimum control for each different mounting device mounted on the electronic control device.

  Further, according to the third invention relating to the present application, when the mounting device mounted on the electronic control device is not a regular one and has a large amount of keys, the electronic control device happens to be held. Even if the key and one or more keys held by the mounting device match, it can be determined that the mounting device is not genuine if there is even one key that does not match.

  Next, details of the present invention will be described in accordance with the description of the embodiments.

  FIG. 1 is a drawing that best represents the features of the present invention, in which 11 is a printer device, 12 is a detachable mounting device that provides additional functions to the printer device 11, and 13 is a plurality of keys used for authentication. Pre-stored ROM, 14 is a random number generator that generates random numbers, 15 is an encryptor that encrypts input data using multiple keys in ROM 13, and 16 is encrypted by the encryptor 15 RAM that holds a plurality of encrypted data, 17 is a data transmission unit that transmits input data as it is or some processing, 18 is a data reception unit that receives data and performs some processing as it is, 19 is This is a data comparison unit that compares which data stored in the RAM 16 corresponds to the data received by the data reception unit 18. The authentication data 1, 2, 3, 4 in the RAM 16 is encrypted data obtained by encrypting random numbers with the encryptor 15 using the keys 1, 2, 3, 4 in the ROM 13.

  FIG. 2 is a diagram illustrating the mounting device 12 of FIG. 1 in detail. In the figure, 21 is a data receiving unit for receiving received data as it is or performing some processing, 22 is a ROM (in this case, key 2) that holds one or more of the keys held in ROM 13 in FIG. , 23 encrypts the input data using the key stored in the ROM 22, and 24 encrypts the input data as it is or performs some processing. It is a data transmission part to transmit.

  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.

  In the printer apparatus 11 of FIG. 1, when a mounting device 12 is mounted, a random number is generated by a random number generator 14. The random number is input to the encryptor 15 and the data transmitter 17. The encryption device 15 to which the random number has been input encrypts the random number with a key stored in the ROM 13 in advance. Here, the encryption data corresponding to the key 1 is the authentication data 1, the encryption data corresponding to the key 2 is the authentication data 2, the encryption data corresponding to the key 3 is the authentication data 3, and the encryption data corresponding to the key 4 is the authentication data 4. And Authentication data 1 to 4 is held in the RAM 16. The data transmission unit 17 to which the random number is input transmits the data to the data reception unit 21 in the mounting device 12. The data receiving unit 21 that has received the data inputs the data to the encryptor 23. The encryption device to which data has been input performs encryption using a key stored in advance in the ROM 24. Here, the key 2 and the key 4 in the ROM 24 are the same as the key 2 and the key 4 in the ROM 13 of the printer 11. In addition, the encrypted data corresponding to the key 2 is referred to as encrypted data 2, and the encrypted data corresponding to the key 4 is referred to as encrypted data 4. The encrypted data is sequentially input to the data transmission unit 25. The data transmitting unit 25 to which the data has been input transmits the encrypted data to the data receiving unit 18 in the printer device 11. The data receiving unit 18 that has received the data inputs the encrypted data to the data comparing unit 19. The data comparison unit 19 that has input the data confirms which of the authentication data stored in the RAM 16 matches the input data (in this example, the wearer 12 holds the key 2 and the key 4) Encryption data 2 and authentication data 2 and encryption data 4 and authentication data 4 match.) When the data input from the data receiving unit 18 does not match any of the authentication data in the RAM 16, the data comparison unit 19 determines that the mounting device 12 is not a proper mounting device, and is input from the data receiving unit 18. If there is a match in the authentication data in the RAM 16 for all the data, the mounting device 12 is determined to be a regular mounting device. Further, the type of the mounting device is determined by the combination of keys held by the mounting device, and the control of the printer 11 is determined accordingly.

  FIG. 3 is a drawing showing the features of the present invention. In FIG. 3, 31 is a printer device, 32 is a detachable mounting device that gives an additional function to the printer device 31, and 33 has a plurality of keys used for authentication in advance. ROM, 34 is a random number generator that generates random numbers, 35 is an encryptor that encrypts input data using multiple keys in ROM33, and 36 is encrypted data that is encrypted by the encryptor 35 , 37 is a data transmitting unit that transmits the input data as it is or after performing some processing, 38 is a data receiving unit that receives the data and performs some processing, 39 is a data receiving unit 38 This is a data comparison unit that compares whether the data received in step 3 matches the data held in the RAM 36.

  FIG. 2 is a diagram illustrating the mounting device 32 of FIG. 3 in detail. In the figure, 21 is a data receiving unit that receives the received data as it is or some processing, 22 is a ROM that holds one or more of the keys held in the ROM 33 in FIG. , 23 encrypts the input data using the key stored in the ROM 22, and 24 encrypts the input data as it is or performs some processing. It is the data transmission part which transmits from.

  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.

  In the printer device 31 of FIG. 3, when a mounting device 32 is mounted, a random number is generated by a random number generator. The random number is input to the encryptor 35 and the data transmitter 37. The data transmission unit 37 to which the random number is input transmits the data to the data reception unit 21 in the mounting device 32 (challenge). The data receiving unit 21 that has received the data inputs the data to the encryptor 23. The encryption device to which data has been input performs encryption using a key stored in advance in the ROM 24. Here, the key 2 and the key 4 in the ROM 24 are the same as the key 2 and the key 4 in the ROM 33 of the printer device 31. In addition, the encrypted data corresponding to the key 2 is referred to as encrypted data 2, and the encrypted data corresponding to the key 4 is referred to as encrypted data 4. The encrypted data is sequentially input to the data transmission unit 25 for each encryption. The data transmitting unit 25 to which the data has been input transmits the data to the data receiving unit 38 in the printer device 31 (response). The data receiving unit 38 that has received the data inputs the received data to the data comparing unit 39. The data comparison unit 39, which has received the received data, issues an encryption command to the encryptor 35. Receiving the command, the encryptor 35 encrypts the input random number using the key 1 in the ROM 33. The encrypted data is input to the RAM 36 as authentication data. The authentication data input to the RAM 36 is input to the data comparison unit 39. The data comparison unit 39 compares the input authentication data with the previously received data, and if they match, the wearer 32 holds the key 1 and waits for the next received data to be input. . If they do not match, an encryption command is issued to the encryptor 35. At this time, the encryptor 35 encrypts the random number using the next key (key 2). This process is performed for the number of keys held in the ROM 33, and if there is no match by the last key, it is determined that the mounting device is not a regular mounting device. The above processing of the data comparison unit is repeated until the received data is completed. Further, the type of the mounting device is determined based on the combination of keys that can be confirmed to be held by the mounting device, and the control of the printer device 31 is determined accordingly.

1 is a diagram illustrating a configuration of a printer device according to a first embodiment of the present invention. FIG. FIG. 6 is a diagram illustrating the configuration of a mounting device according to first and second embodiments of the present invention. FIG. 6 is a diagram illustrating a configuration of a printer device according to a second embodiment of the present invention.

Explanation of symbols

11 Printer device
12 Wearer
13 ROM
14 Random number generator
15 Encryptor
16 RAM
17 Data transmitter
18 Data receiver
19 Data comparison part
21 Data receiver
22 ROM
23 Encryption
24 Data transmitter

Claims (9)

  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 authentic ROM 1 for holding a plurality of keys, an encryption device 1 for encrypting the random number with the secret key, a RAM 1 for storing encrypted data encrypted by the encryption device 1, and the mounting Receiving means 1 for receiving data (response) from the device, RAM 2 for holding the received data obtained by the receiving means 1, the encrypted data held in the RAM 1, and the RAM 2 Comparing means for comparing the received data with the received data.   The mounting device has a ROM 2 that holds one or more of the plurality of secret keys, a receiving means 2 for receiving transmission data transmitted from the electronic control unit, and the ROM 2 that holds the ROM 2 2. The encryption device 2 for encrypting data received with a key, and transmission means 2 for transmitting encrypted data subjected to encryption to the electronic control unit. Electronic control unit.   3. The encryption device 1 encrypts the random number data using each of the plurality of secret keys stored in the ROM 1 to create a plurality of encrypted data. The electronic control device described.   The encryption device (2) encrypts the received data using each of the one or more secret keys stored in the ROM (2) to create one or more encrypted data. Item 4. The electronic control device according to Item 3.   5. The electronic control device according to claim 1, wherein the RAM 1 holds a plurality of encrypted data encrypted by the encryptor 1.   The electronic control apparatus according to claim 1, wherein the RAM 2 holds one or more data received by the receiving unit 1.   The electronic control apparatus according to claim 1, wherein the comparison unit compares which data is the same among the data held by the RAM 1 and the RAM 2.   The electronic control device according to claim 1, wherein the control of the electronic control device is changed according to a type of a key held by the mounting device.   The comparing means determines that the mounting device is not a regular mounting device if at least one of the transmission data stored in the RAM 2 does not match the encrypted data stored in the RAM 1 The electronic control device according to claim 1, wherein:

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