Information processing apparatus, authentication system, method, computer program, and image forming apparatus

Abstract

To eliminate the need of access to a server at the time of reproduction while securing the reliability of a reproduced device.SOLUTION: An information processing apparatus for remanufacturing a device attachable to and detachable from an image forming apparatus is provided. The device includes a memory having a rewritable storage area, and a component involved in an image forming operation performed by the image forming apparatus. The information processing apparatus includes a storage unit configured to store in advance a first private key for signature generation, a first public key corresponding to the first private key, and an electronic certificate certifying the reliability of the first public key, a connection unit configured to connect the information processing apparatus to the device, an acquisition unit configured to acquire characteristic information representing characteristics of the component after remanufacture, a signature generation unit configured to generate a digital signature of the characteristic information using the first private key, and a writing unit configured to write the characteristic information, the digital signature, the first public key, and the electronic certificate in the storage area of the memory of the device.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an information processing device, an authentication system, a method, a computer program, and an image forming device. [Background technology]

[0002] Image forming devices such as copiers, printers, facsimile receivers, and multifunction devices form images on sheets using developers such as toner or ink, and consumable components such as photosensitive drums. These consumable components are often housed in devices that are detachable from the image forming device. When the developer runs out or the remaining life of the components expires, a user installs a new device in the image forming device. Patent Document 1 discloses a cartridge-type device (e.g., a process cartridge) that is permanently installed in the image forming device, and a replenishment-type device (e.g., a replenishment pack) that is temporarily installed in the image forming device when replenishing the developer.

[0003] In recent years, with growing environmental awareness, efforts are being made to design used devices in advance so that they can be reused in image forming devices rather than being discarded. For example, a company that remanufactures devices for reuse collects used devices and performs tasks such as replenishing developers and replacing worn parts. Patent Document 2 discloses a technology in which a device authenticated by a cloud service writes data related to a remanufactured device into the device's memory in order to ensure proper operation of the image forming device when it is reused. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-106130 [Patent Document 2] International Publication No. 2022 / 173444 Summary of the Invention [Problem to be solved by the invention]

[0005] However, with the technology of Patent Document 2, every time data is written to the memory of a remanufactured device, the remanufacturer's equipment must communicate with a server in a cloud environment via a network, which incurs excessive communication and computational costs.On the other hand, if data is allowed to be freely written to the device's memory, the reliability of the remanufactured device cannot be ensured.

[0006] In view of the above, the present invention aims to provide a mechanism that eliminates the need to access a server during remanufacturing while ensuring the reliability of the remanufactured device. [Means for solving the problem]

[0007] According to one aspect, there is provided an information processing apparatus for remanufacturing a device detachable from an image forming apparatus, the device having a memory with a rewritable storage area and components involved in image formation operations by the image forming apparatus, the information processing apparatus including: storage means for pre-storing a first private key for signature generation, a first public key corresponding to the first private key, and a digital certificate certifying the reliability of the first public key; connection means for connecting the information processing apparatus to the device; acquisition means for acquiring characteristic information representing characteristics of the components after remanufacturing; signature generation means for generating a digital signature for the characteristic information using the first private key; and writing means for writing the characteristic information, the digital signature, the first public key, and the digital certificate to the storage area of ​​the memory of the device. Corresponding authentication systems, methods, computer programs, and image forming apparatuses are also provided. [Effects of the Invention]

[0008] According to the present invention, it is possible to ensure the reliability of the remanufactured device while eliminating the need to access the server during remanufacturing. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram illustrating a schematic configuration of an authentication system according to an embodiment. [Figure 2] FIG. 2 is a schematic cross-sectional view showing an example of the internal physical configuration of the cartridge. [Figure 3] FIG. 2 is a schematic cross-sectional view showing an example of the internal physical configuration of a printer in which a cartridge is installed. [Figure 4] FIG. 10 is a schematic perspective view showing an example of the appearance of a connection interface of a remanufacturing device. [Figure 5] FIG. 2 is a block diagram showing an example of the configuration of a certificate authority according to an embodiment. [Figure 6] FIG. 1 is a block diagram showing an example of the configuration of a remanufacturing device according to an embodiment. [Figure 7] FIG. 2 is a block diagram showing an example of the configuration of a cartridge according to an embodiment. [Figure 8] FIG. 3 is an explanatory diagram illustrating an example of the configuration of a storage area of ​​a cartridge memory. [Figure 9] FIG. 2 is a block diagram showing an example of the configuration of a control function of a printer according to an embodiment. [Figure 10] FIG. 10 is a sequence diagram showing an example of the flow of a certificate preparation process executed prior to remanufacturing. [Figure 11] FIG. 10 is a sequence diagram showing an example of the flow of a writing process executed when a cartridge is remanufactured. [Figure 12] FIG. 10 is a sequence diagram showing an example of the flow of cartridge authentication processing executed by the printer. [Figure 13] 10 is a flowchart showing an example of the flow of a certificate validation process according to the first embodiment. [Figure 14] 10 is a flowchart showing an example of the flow of a certificate validation process according to the second embodiment. [Figure 15] 11 is a flowchart showing an example of the flow of a certificate validation process according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0011] <1. System Overview> <1-1. Overall structure> 1 is a schematic diagram showing a general configuration of an authentication system 1 according to an embodiment. Referring to FIG. 1, the authentication system 1 includes a cartridge 10, a printer 100, a remanufacturing device 200, and an authentication authority 50.

[0012] The cartridge 10 is a device that can be attached to and detached from the printer 100. The printer 100 operates with the cartridge 10 attached. In this embodiment, an example in which the cartridge 10 is a process cartridge will be mainly described. In other embodiments, the cartridge 10 may be another type of cartridge, such as a toner cartridge or an ink cartridge. Note that the technology disclosed herein can also be applied to other types of devices, such as a refill pack that is temporarily attached to an image forming apparatus to replenish developer.

[0013] The printer 100 is an image forming device installed in the user environment E1. In this embodiment, an example will be mainly described in which the printer 100 is a laser printer that forms an image on a sheet using an electrophotographic method. In other embodiments, the printer 100 may be another type of printer, such as an inkjet printer. The printer 100 may be a monochrome printer or a color printer. Note that the technology disclosed herein can also be applied to other types of image forming devices, such as a copier or a multifunction peripheral.

[0014] The remanufacturing device 200 is an information processing device for remanufacturing the cartridge 10. The remanufacturing device 200 is typically used by a remanufacturer that remanufactures the cartridge 10. In this embodiment, the remanufacturer is a company different from the manufacturer that manufactures the printer 100. In other embodiments, the remanufacturer may be the same manufacturer that manufactures the printer 100. The remanufacturing device 200 may be a general-purpose information processing device such as a PC (Personal Computer), or may be a device dedicated to writing information to the cartridge 10. The remanufacturing device 200 has a connection interface 201 (described below) for connecting to the cartridge 10. In addition, the remanufacturing device 200 is connected to a network N1.

[0015] The network N1 may be the Internet, a cloud network, or a private network, or any combination thereof.

[0016] The certificate authority 50 is a certificate authority associated with the manufacturer of the cartridge 10 (and the printer 100) that has the function of issuing so-called public key certificates. The certificate authority 50 may be a private certificate authority introduced for the authentication system 1. The certificate authority 50 may be operated, for example, by the manufacturer of the cartridge 10, or by a third-party organization commissioned by the manufacturer. The certificate authority 50 is connected to the network N1. The remanufacturing device 200 can communicate with the certificate authority 50 via the network N1.

[0017] <1-2. Cartridge Overview> FIG. 2 is a schematic cross-sectional view showing an example of the internal physical configuration of the cartridge 10. Referring to FIG. 2, the cartridge 10 includes components involved in the image forming operation, such as a photoconductor 2, a charging roller 3, a toner container 5, a developing roller 6, a cleaning blade 7, and a cartridge memory 20. The photoconductor 2, the charging roller 3, the developing roller 6, and the cleaning blade 7 are components driven by the printer 100 during the printer's image forming operation. The toner container 5 contains toner T as a developer. The toner T is supplied to the printer 100 when the printer 100 forms a toner image. The cartridge memory 20 is a storage device that stores identification information for the cartridge 10, characteristic information representing the characteristics of the components involved in the image forming operation, and information for verifying the reliability of the cartridge 10, which will be described later. The cartridge memory 20 includes a pair of connection terminals 22. When the cartridge 10 is installed in the printer 100, the cartridge memory 20 is electrically connected to the printer 100 via the connection terminals 22.

[0018] <1-3. Printer Overview> 3 is a schematic cross-sectional view showing an example of the internal physical configuration of a printer 100 equipped with a cartridge 10. Referring to FIG. 3, the printer 100 includes an exposure unit 4, a transfer roller 8, a fixing unit 9, a cassette 11, a conveying path 12, a top sensor 13, an ejection tray 15, a connection terminal 101, and a controller 110.

[0019] The photoreceptor 2 is an image carrier, and is driven to rotate in the direction of arrow A during image formation. A charging voltage is applied to the charging roller 3, which uniformly charges the surface of the photoreceptor 2. The exposure device 4 exposes the surface of the photoreceptor 2 to laser light in accordance with image data input from the controller 110, thereby forming an electrostatic latent image on the surface of the photoreceptor 2. A developing voltage is applied to the developing roller 6, which develops the electrostatic latent image by supplying toner T contained in a toner container 5 to the photoreceptor 2, thereby forming a toner image on the surface of the photoreceptor 2.

[0020] The cassette 11 contains a stack of sheets. During image formation, sheets P are fed one by one from the stack of sheets in the cassette 11 to the conveying path 12. The sheets P are conveyed along the conveying path 12 by multiple conveying rollers. A top sensor 13 detects the leading and trailing edges of the sheets P. Based on the detection signal from the top sensor 13, the controller 110 controls the timing of feeding the sheets P to the transfer position where the transfer roller 8 is disposed, and the timing of feeding the subsequent sheets. A transfer voltage is applied to the transfer roller 8, which transfers the toner image formed on the surface of the photoreceptor 2 to the sheets P. A cleaning blade 7 removes toner remaining on the surface of the photoreceptor 2. The fixing device 9 heats and presses the sheets P to fix the toner image to the sheets P. After passing through the fixing device 9, the sheets P are discharged to an output tray 15.

[0021] The controller 110 is connected to the cartridge 10 installed in the printer 100 via a connection terminal 101, and controls the image forming operation of the printer 100 based on the characteristics represented by the characteristic information read from the cartridge 10. For example, image forming conditions such as charging voltage, developing voltage, transfer voltage, laser light amount, and process speed may be determined based on member characteristic information described below. Furthermore, the remaining amount of toner may be determined based on toner characteristic information described below. A more detailed configuration of the controller 110 will be described later.

[0022] Although the present embodiment will mainly describe an example in which the cartridge 10 is connected to the controller 110 via a connection terminal in a wired manner, in other embodiments, the cartridge 10 may be connected to the controller 110 wirelessly, for example, via an antenna. The same applies to the connection between the cartridge 10 and the remanufacturing apparatus 200.

[0023] <1-4. Remanufacturing of cartridges> For example, a user purchases a new cartridge 10 from a manufacturer (typically the same manufacturer as the printer 100) that produces the cartridge 10, installs the cartridge 10 in the printer 100, and uses the printer 100. As the printer 100 repeatedly performs image formation operations, the toner in the cartridge 10 eventually runs out, or the components of the cartridge 10 wear out and reach the end of their remaining life (for example, the rollers wear out). The user removes the cartridge 10 from the printer 100 and installs a newly purchased cartridge in the printer 100. As shown in FIG. 1, used cartridges 10 are collected by a remanufacturer.

[0024] The remanufacturer performs tasks for remanufacturing the cartridge 10, such as cleaning the toner container 5 of the recovered cartridge 10, refilling the toner container 5 with toner T, and cleaning or replacing (if necessary) components such as rollers and blades. The remanufacturer also connects a connection interface 201 of a remanufacturing device 200 to the cartridge 10. FIG. 4 is a schematic perspective view showing an example of the appearance of the connection interface 201. Referring to FIG. 4, the connection interface 201 has a pair of connection terminals 202 disposed in a recess 203 capable of receiving the cartridge memory 20. When the cartridge memory 20 is set in the recess 203, the connection terminals 202 come into electrical contact with the connection terminals 22 of the cartridge memory 20, enabling communication between the remanufacturing device 200 and the cartridge memory 20.

[0025] Prior to remanufacturing each cartridge, the remanufacturing device 200 generates a first key pair, i.e., a first secret key K, for digitally signing information to be written to the cartridge memory. S1 and the first public key K P1 is generated in advance and the first key pair is stored internally.

[0026] When remanufacturing the cartridge 10, the remanufacturing device 200 acquires characteristic information representing the characteristics of the components of the remanufactured cartridge 10 based on, for example, an input by the remanufacturer, and digitally signs the acquired characteristic information using the first secret key K. S1Then, the remanufacturing device 200 stores the generated digital signature and the first public key K together with the characteristic information in the cartridge memory 20 of the cartridge 10. P1 Write.

[0027] A user purchases the remanufactured cartridge 10 in this manner and reuses it by installing it in the printer 100. Naturally, the printer into which the remanufactured cartridge 10 is installed may actually be different from the printer in which the cartridge 10 was installed before being remanufactured. Before using the characteristic information read from the cartridge memory 20 to control the image forming operation, the printer 100 verifies the characteristic information based on the digital signature read together with the characteristic information. To verify the characteristic information, the first public key K read from the cartridge memory 20 is used. P1 is used, but this first public key K P1 Unless the signature is trustworthy, the characteristic information cannot be used safely even if verification based on the digital signature is successful.

[0028] Therefore, in this embodiment, the digital certificate issued by the above-mentioned certificate authority 50 is incorporated into the authentication mechanism of the cartridge 10. The certificate authority 50 issues the digital certificate C X A second key pair, i.e., a second private key K S2 and the second public key K P2 is generated in advance, and the second secret key K S2 The manufacturer of the printer 100 manages the second public key K generated by the certificate authority 50 in secret when manufacturing the printer 100. P2 In response to a request from the remanufacturing device 200, the certificate authority 50 stores the first public key K P1 Digital certificate C certifying the authenticity of P1 The remanufacturing device 200 issues this digital certificate C P1 When the cartridge 10 is remanufactured, the first public key K P1 In this way, the printer 100 uses the first public key KP1 is trusted, and the digital certificate C P1 and the second public key K P2 The remanufacturer can use the digital certificate C to determine whether the cartridge is genuine, even if a large number of cartridges are collected and remanufactured. P1 As long as the certificate is valid, you can access the certification authority 50 only once in advance to obtain the digital certificate C. P1 This means that the remanufacturing device 200 does not need to access the certificate authority 50 every time a cartridge is remanufactured.

[0029] In this embodiment, the remanufacturer may typically be a company authorized by the manufacturer of the new device. By having the certificate authority 50 operated for the manufacturer issue the above-mentioned digital certificate only to legitimately authorized remanufacturers, users can purchase and use remanufactured products with peace of mind without worrying about the risk of malfunction or deterioration in quality. This promotes the reuse of detachable devices and reduces the environmental impact associated with image forming apparatuses.

[0030] The configuration of each device for realizing the above-described authentication system 1 will be explained in more detail in the next section.

[0031] <2. Configuration of each device> <2-1. Certification Authority Configuration> 5 is a block diagram showing an example of the configuration of the certificate authority 50. The certificate authority 50 includes a central processing unit (CPU) 51, a memory 52, a communication unit 53, and a key management unit .

[0032] The CPU 51 is a control means that executes computer programs to control the overall operation of the certification authority 50. The memory 52 may include volatile and non-volatile storage media, and stores the computer programs executed by the CPU 51 and various data. The communication unit 53 is a communication interface that enables the certification authority 50 to communicate with other devices via the network N1. The key management unit 54 is a unit that manages encryption keys required to issue digital certificates.

[0033] In this embodiment, the CPU 51 functions as a key pair generation unit 61 and a certificate issuing unit 62. The key pair generation unit 61 generates the second secret key K S2 and the second public key K P2 and generate a second key pair consisting of a second private key K S2 is stored in a storage medium of the tamper-resistant key management unit 54. In FIG. 5, the key management unit 54 stores one second secret key K S2 However, the key management unit 54 may store different second secret keys for each of the printers that may be under the control of the system. P2 is stored in the encryption processing unit 113 of the printer 100, which will be described later. The certificate issuing unit 62 receives the first public key K from the remanufacturing device 200. P1 In response to the certificate issuance request received together with the first public key K P1 An example of the flow of a certificate preparation process involving the certification authority 50 will be described in more detail later.

[0034] <2-2. Configuration of remanufacturing equipment> 6 is a block diagram showing an example of the configuration of the remanufacturing device 200. The remanufacturing device 200 includes a connection terminal 202, a CPU 211, a memory 212, a communication unit 213, an input unit 214, a display unit 215, and a data management unit 216. The connection terminal 202 functions as a connection means for connecting the remanufacturing device 200 to the cartridge 10.

[0035] The CPU 211 is a control means that executes computer programs to control the overall operation of the remanufacturing apparatus 200. The memory 212 may include volatile and non-volatile storage media, and stores computer programs executed by the CPU 211 and various data. The communication unit 213 is a communication interface that enables the remanufacturing apparatus 200 to communicate with the certificate authority 50 via the network N1. The input unit 214 is an input device that enables the remanufacturing apparatus 200 to accept user input. The display unit 215 is a display that displays information to the user of the remanufacturing apparatus. The data management unit 216 manages security-related data for writing information to the cartridge 10.

[0036] In this embodiment, the CPU 211 functions as a key generation unit 221, a certificate acquisition unit 222, an information acquisition unit 223, a signature generation unit 224, and a writing unit 225. Prior to the remanufacturing of the cartridge 10, the key generation unit 221 generates the above-mentioned first secret key K S1 and the first public key K P1 The key generation unit 221 may generate the first key pair in accordance with any public key cryptography algorithm, such as the Edwards Curve Digital Signature Algorithm (EdDSA) or RSA. The certificate acquisition unit 222 generates the first key pair in accordance with the first public key K P1 A certificate issuance request including the above is sent to the certification authority 50, and the digital certificate C is issued by the certification authority 50 in response to the certificate issuance request. P1 This is a method of obtaining a certificate. P1 is the first public key K P1 The data management unit 216 verifies the authenticity of the first secret key K for signature generation generated by the key generation unit 221. S1 and the corresponding first public key K P1 , and the electronic certificate C acquired by the certificate acquisition unit 222 P1 is stored in advance.

[0037] The information acquisition unit 223 is an information acquisition means for acquiring remanufacturing information specific to the remanufactured cartridge 10 when the cartridge 10 is remanufactured. For example, the remanufacturing information acquired by the information acquisition unit 223 may include identification information for identifying the remanufactured cartridge 10 and characteristic information representing the characteristics of the components of the remanufactured cartridge 10. The signature generation unit 224 generates a first secret key K S1 The writing unit 225 is a signature generating means for generating a digital signature for the remanufacturing information using the remanufacturing information acquired by the information acquiring unit 223, the digital signature generated by the signature generating unit 224, and the first public key K stored in the data management unit 216. P1 and Electronic Certificate C P1 This is a writing means for writing the above information to the cartridge memory 20. An example of the flow of the writing process executed when remanufacturing a cartridge will be further explained later.

[0038] <2-3. Cartridge configuration> 7 is a block diagram showing an example of the configuration of the cartridge 10. The cartridge 10 comprises a cartridge memory 20, a connection terminal 22, an access control unit 24, and an authentication calculation unit 26. The cartridge memory 20 has a read-only storage area and a rewritable storage area. The connection terminal 22 functions as a connection means for connecting the cartridge 10 to a remanufacturing device 200 when the cartridge 10 is remanufactured.

[0039] The access control unit 24 is a control means that controls the reading and writing of information from and to the cartridge memory 20 based on commands received from an external device. For example, when the access control unit 24 receives a read command from an external device specifying a specific address in the cartridge memory 20, it reads the information stored at the specified address and transmits the read information to the external device via the connection terminal 22. When the access control unit 24 receives a write command from an external device specifying a specific address, it performs different processing depending on whether the specified address belongs to a rewritable storage area. If the specified address belongs to a read-only storage area, the access control unit 24 refuses to write information to that address. If the specified address belongs to a rewritable storage area, the access control unit 24 writes the information included in the write command to that address.

[0040] The authentication calculation unit 26 is a calculation means that performs authentication calculations related to the use and remanufacturing of the cartridge 10. For example, when the cartridge 10 is installed in the printer 100, challenge-response authentication may be performed to verify the authenticity of the cartridge 10. In this case, the authentication calculation unit 26 generates a challenge to be sent to the printer 100 and calculates a response based on the challenge.

[0041] 8 is an explanatory diagram showing an example of the configuration of the storage areas of the cartridge memory 20. Referring to FIG. 8, the cartridge memory 20 has a first storage area 31, a second storage area 32, a third storage area 33, and a fourth storage area 34.

[0042] The first storage area 31 is a read-only storage area (the label "RO" indicates read-only). The first storage area 31 stores initial information 35 specific to a new cartridge 10 (i.e., before remanufacturing). In the example of FIG. 8, the initial information 35 includes cartridge identification information (ID), toner characteristic information, and component characteristic information. The cartridge ID is information that identifies a new cartridge 10. The cartridge ID may be in any format, such as a combination of the manufacturing date and a serial number (which is reset each time the date changes). The toner characteristic information is information that represents the characteristics of the toner contained in the cartridge 10. For example, the toner characteristic information may include a parameter (e.g., "Black") that represents the color component of the toner contained in the cartridge 10. The toner characteristic information may also include a parameter that represents the amount of toner refilled into the cartridge 10 at the time of manufacturing (e.g., in units of sheets, such as "1000 sheets"). The component characteristic information is information that represents the characteristics of the components that make up the cartridge 10. For example, the component characteristic information may include parameters that represent one or more of an optimal charging voltage, a developing voltage, a transfer voltage, a laser light amount, and a process speed. Note that a part of the cartridge ID may represent a toner characteristic or a component characteristic (for example, an alphabet at a specific position may represent the color of the toner), and in that case, the cartridge ID may be treated as characteristic information.

[0043] The second memory area 32 is a rewritable memory area (the label "RW" means rewritable). The second memory area 32 stores history information 36 indicating the usage history of the cartridge 10. In the example of FIG. 8, the history information 36 includes two parameters: the number of printed sheets and the amount of remaining toner. The number of printed sheets represents the cumulative number of sheets printed as a result of the execution of an image forming job. The value of the number of printed sheets is initialized to zero upon initial manufacture and remanufacturing, and may be counted up each time the printer 100 executes an image forming job. The amount of remaining toner represents an estimated amount of toner remaining in the cartridge 10, for example, as a percentage of a maximum value.

[0044] The third storage area 33 is a rewritable storage area. The third storage area 33 stores remanufacturing information 37 specific to the remanufactured cartridge 10, and a digital signature 38. In the example of FIG. 8, the remanufacturing information 37 has the same format as the initial information, and includes a cartridge ID, toner characteristic information, and component characteristic information. The cartridge ID may be, for example, a combination of the date on which the cartridge 10 was remanufactured and a serial number that is unique within the range of that date. The digital signature 38 is generated by the signature generation unit 224 of the remanufacturing device 200 using the first secret key K S1 The digital signature 38 is used to verify the authenticity of the characteristic information when the printer 100 reads out the characteristic information of the remanufactured cartridge 10 from the cartridge memory 20 and uses it.

[0045] In the initial state, a copy of the initial information 35 may be written to the third storage area 33. In this case, the digital signature 38 may be generated based on the initial information 35.

[0046] The fourth storage area 34 is a rewritable storage area. The fourth storage area 34 stores the first public key K used to verify the digital signature 38. P1 As shown in FIG. 8, the public key certificate 39 is stored for the first public key K P1 , and Electronic Certificate C P1 Includes electronic certificate C P1 may have any known certificate format, such as X.509, and includes a digital signature generated based on the first public key and the certificate information, along with a certificate number and other certificate information.

[0047] <2-4. Printer configuration> 9 is a block diagram showing an example of the configuration of the control functions of a printer 100 equipped with a cartridge 10. In the example of FIG. 9, the printer 100 includes, in addition to the cartridge 10, a connection terminal 101, an image forming unit 102, a communication unit 103, an operation unit 104, and a controller 110. The connection terminal 101 functions as a connection means for connecting the cartridge 10 to the printer 100.

[0048] The image forming unit 102 is an image forming means that cooperates with components included in the cartridge 10 to form an image on a sheet. The image forming operation performed by the image forming unit 102 is as described with reference to FIG. 3. The communication unit 103 is a communication interface that enables the printer 100 to communicate with other devices via the network N1. The operation unit 104 provides a user interface to the user of the printer 100. The operation unit 104 may include, for example, input devices such as a touch panel, buttons, and switches, and output devices such as a display and speaker.

[0049] The controller 110 includes a CPU 111, a memory 112, and a cryptographic processing unit 113. The CPU 111 executes computer programs to control the overall operation of the printer 100. The memory 112 may include volatile and non-volatile storage media, and stores computer programs executed by the CPU 111 and various data.

[0050] The cryptographic processing unit 113 includes a processor for performing cryptographic processing related to authentication of the cartridge 10, and a memory for storing a cryptographic key used for authentication. In this embodiment, the memory of the cryptographic processing unit 113 stores a second public key K P2 The second public key K P2 The certificate authority 50 issues the digital certificate C to the remanufacturer who remanufactures the cartridge 10. P1 The second secret key K used to issue S2The cryptographic processing unit 113 can calculate a hash value from a message and decrypt a digital signature received along with the message. If the hash value obtained as a result of decrypting the digital signature is equal to the hash value calculated from the message, the message is determined to have not been tampered with. This cryptographic processing can be performed in both certificate verification and signature verification, which will be described later. In addition, the cryptographic processing unit 113 may generate a challenge to be sent to the cartridge 10 and calculate a response based on the challenge, for challenge-response authentication when the cartridge 10 is installed in the printer 100.

[0051] In this embodiment, the CPU 111 functions as a signature verification unit 121 and a print control unit 122. The signature verification unit 121 is a verification means that, when the cartridge 10 is mounted in the printer 100, reads the above-mentioned remanufacturing information 37 and digital signature 38 from the third storage area 33 of the cartridge memory 20, and verifies the authenticity of the remanufacturing information 37 based on the digital signature 38. The first public key K to be used for this signature verification is P1 is included in the public key certificate 39 read from the fourth storage area 34 of the cartridge memory 20. The signature verification unit 121 P1 In order to determine whether the public key certificate 39 is trustworthy, the digital certificate C P1 and the second public key K stored in the cryptographic processing unit 113 P2 Then, the signature verification unit 121 performs a verification process using the first public key K P1 If it is determined that the first public key K is reliable, P1 is used to verify the remanufacturing information (for example, characteristic information) based on the above-mentioned digital signature 38. Some examples of the flow of such a verification process will be further described later.

[0052] The print control unit 122 controls the execution of a print job. The execution of a print job is instructed, for example, from an external host computer (not shown) via the communication unit 103, or by a user via the operation unit 104. When the print control unit 132 is instructed to execute a job, it controls the image forming unit 102 to form an image on a sheet under image formation conditions determined based on the characteristic information read from the cartridge memory 20. The characteristic information read from the cartridge memory 20 of the remanufactured cartridge 10 can be used if the signature verification unit 121 has successfully verified the information.

[0053] <3. Processing flow> In this section, some example processing flows that can be executed in the authentication system 1 described above will be described in detail.

[0054] <3-1. Certificate preparation process> Fig. 10 is a sequence diagram showing an example of the flow of the certificate preparation process executed prior to remanufacturing. The certificate preparation process shown in Fig. 10 mainly involves the certificate authority 50, printer 100, and remanufacturing device 200. In the following explanation, processing steps will be abbreviated as 'S'.

[0055] First, when the printer 100 is manufactured, in step S11, the key pair generation unit 61 of the certificate authority 50 generates a second secret key K S2 and the second public key K P2 The key management unit 54 generates a second key pair consisting of the generated second secret key K S2 In S12, the second public key K P2 In step S13, the second public key K is stored in the memory of the cryptographic processor 113 of the controller 110 of the printer 100. P2 is stored.

[0056] In S21, the key generation unit 221 of the remanufacturing device 200 generates a first secret key K S1 and the first public key K P1 The data management unit 216 generates a first key pair consisting of the generated first secret key K S1In S22, the certificate acquisition unit 222 stores the first public key K P1 In S23, the certificate issuing unit 62 of the certificate authority 50 sends a certificate issuance request including the first public key K in response to the certificate issuance request from the remanufacturing device 200. P1 Digital certificate C certifying the authenticity of P1 In S24, the first public key K P1 and the digital certificate C generated by the certificate issuing unit 62 P1 The public key certificate including the above is delivered to the remanufacturing apparatus 200. In S25, the certificate acquisition unit 222 stores the public key certificate in the data management unit 216.

[0057] In addition, the second public key K in S12 P2 The transfer of the public key certificate in S24 may be carried out via a secure communication path established on the network N1, or may be carried out by storing the data on a storage medium and physically delivering it.

[0058] <3-2. Write process> 11 is a sequence diagram showing an example of the flow of a write process executed when a cartridge is remanufactured. The write process shown in FIG.

[0059] Prior to the writing process, in S101, the remanufacturer performs remanufacturing operations such as refilling toner into the cartridge 10 and replacing worn components. Once the operations are completed, in S102, the remanufacturer connects the cartridge 10 to the connection interface 201 of the remanufacturing device 200. Thereafter, the CPU 211 of the remanufacturing device 200 starts a computer program for writing remanufacturing information, thereby starting the writing process.

[0060] In S111, the information acquisition unit 223 transmits to the cartridge 10 a read command for reading the initial information and history information stored in the first memory area 31 and the second memory area 32 of the cartridge memory 20. In S112, the access control unit 24 of the cartridge 10 transmits the initial information and history information read from the cartridge memory 20 to the remanufacturing apparatus 200.

[0061] The initial information and history information may be read before the remanufacturing operation in S101. In this case, the remanufacturer may determine how much toner to replenish and which components to replace based on the remaining toner amount and the degree of wear of other components indicated by the history information.

[0062] In S113, the information acquisition unit 223 acquires remanufacturing information unique to the remanufactured cartridge 10. The remanufacturing information may be received, for example, via a user interface provided by the input unit 214 and display unit 215 of the remanufacturing apparatus 200, or may be received (for example, in data file format) from some external device via the communication unit 213. As described above, the remanufacturing information may include identification information that identifies the remanufactured cartridge 10 and characteristic information that represents the characteristics of the components of the remanufactured cartridge 10.

[0063] In S114, the signature generation unit 224 generates the first secret key K stored in the data management unit 216. S1 The signature generation unit 224 generates a digital signature for the remanufacturing information acquired in S113 using the above. The digital signature may be generated according to any known signature generation method, such as the DSA (Digital Signature Algorithm) method or the Elliptic Curve DSA (ECDSA) method. The signature generation unit 224 may generate a digital signature for an information set that includes the remanufacturing information as well as the initial information acquired in S112. This ensures that the signature value of the digital signature will be different between different cartridges, making it possible to prevent fraudulent reuse of remanufacturing information and digital signatures.

[0064] In S115, the writing unit 225 sends a write command to the cartridge 10 to write the remanufacturing information and the digital signature to the third memory area 33. In S116, in response to receiving the write command, the access control unit 24 of the cartridge 10 writes the remanufacturing information and the digital signature to the third memory area 33 of the cartridge memory 20. In S117, the access control unit 24 notifies the remanufacturing device 200 of the completion of writing.

[0065] Furthermore, in S118, the writing unit 225 writes the first public key K P1 and Electronic Certificate C P1 In S119, the access control unit 24 of the cartridge 10 writes the public key certificate to the fourth memory area 34 of the cartridge memory 20 in response to receiving the write command. In S120, the access control unit 24 notifies the remanufacturing device 200 of the completion of writing.

[0066] <3-3. Cartridge authentication process> 12 is a sequence diagram showing an example of the flow of cartridge authentication processing executed by the printer 100. The cartridge 10 and the printer 100 are mainly involved in the cartridge authentication processing shown in FIG.

[0067] First, in S201, the signature verification unit 121 of the printer 100 detects that the cartridge 10 has been installed and performs challenge-response authentication with the access control unit 24 of the cartridge 10. The challenge-response authentication here may be performed according to any known method, and a detailed description of the flow will be omitted here. In S202, the signature verification unit 121 determines whether the challenge-response authentication has been successful. If the challenge-response authentication has failed, the subsequent processing steps in FIG. 12 are skipped. If the challenge-response authentication has been successful, the processing proceeds to S203.

[0068] In S203, the signature verification unit 121 sends a read command to the cartridge 10 to read the initial information and history information stored in the first memory area 31 and the second memory area 32 of the cartridge memory 20. In S204, the access control unit 24 of the cartridge 10 sends the initial information and history information read from the cartridge memory 20 to the printer 100.

[0069] In S205, the signature verification unit 121 sends a read command to the cartridge 10 to read the public key certificate stored in the fourth memory area 34 of the cartridge memory 20. In S206, the access control unit 24 of the cartridge 10 sends the public key certificate read from the cartridge memory 20 to the printer 100.

[0070] In S210, the signature verification unit 121 verifies the first public key K included in the public key certificate. P1 In the certificate verification process, a certificate verification process is performed to determine the reliability of the first public key K. Several examples of the detailed flow of the certificate verification process will be described later. The subsequent process branches in S220 depending on the result of the certificate verification process. P1 If the first public key K is not determined to be trustworthy, the subsequent processing steps in Figure 12 are skipped. P1 If it is determined that the value is reliable, the process proceeds to S221.

[0071] In S221, the signature verification unit 121 sends a read command to the cartridge 10 to read the remanufacturing information stored in the third memory area 33 of the cartridge memory 20. In S221, the access control unit 24 of the cartridge 10 sends the remanufacturing information and digital signature read from the cartridge memory 20 to the printer 100.

[0072] In S223, the signature verification unit 121 verifies the authenticity of the remanufacturing information (particularly the characteristic information) read from the cartridge memory 20, based on the digital signature read together with the remanufacturing information. Specifically, the signature verification unit 121 causes the cryptographic processing unit 113 to calculate a hash value of the remanufacturing information, and also uses the second public key K P2 In S224, the signature verification unit 121 determines whether the hash value obtained as a result of the decryption of the digital signature matches the hash value of the remanufacturing information.

[0073] If the two hash values ​​match in S224, the signature verification is successful. Then, in S225, the signature verification unit 121 permits the print control unit 122 to control the image formation operation using the characteristic information included in the remanufacturing information. The signature verification unit 121 displays the results of authentication and verification on the screen of the operation unit 104 and stores them in the memory 112.

[0074] If any of the challenge-response authentication, certificate verification, and signature verification fails, the signature verification unit 121 does not permit use of the characteristic information included in the remanufacturing information. In this case, the signature verification unit 121 may display a warning about use of the cartridge 10 on the screen of the operation unit 104. The signature verification unit 121 may prohibit use of the cartridge 10, or may permit use of the cartridge 10 if the user who received the warning chooses to continue use.

[0075] <3-4. Certificate verification process> 8, the digital certificate written to the cartridge memory 20 together with the first public key includes certificate information and a digital signature in a predetermined format. The certificate information may include, for example, the following items: 'Certificate Number' 'Signature Algorithm' 'Publisher' 'Validity Period' 'subject' 'Certificate number' is a number (serial number) that uniquely identifies each digital certificate issued by the certification authority 50. 'Signature algorithm' indicates the algorithm used to generate the digital signature included in the digital certificate. 'Issuer' indicates the name of the company or institution that operates the certification authority 50. 'Validity period' indicates the start and end dates of the validity period of each digital certificate. 'Subject' indicates the name of the company that owns the private key corresponding to each digital certificate.

[0076] In the certificate verification process executed in S210 of Fig. 12, in addition to verification of the hash value based on the digital signature of the electronic certificate, various verifications based on the certificate information described above may be performed. Here, three examples of the certificate verification process will be described.

[0077] (1) First Example FIG. 13 is a flowchart showing an example of the flow of the certificate validation process according to the first embodiment.

[0078] First, in S211, the signature verification unit 121 transmits the first public key K P1 In S212, the signature verification unit 121 causes the encryption processing unit 113 to calculate the hash value of the second public key K P2 Next, in S213, the signature verification unit 121 decrypts the digital signature of the public key certificate using the first public key K. P1 It is determined whether the hash value of the certificate information matches the hash value obtained as a result of decrypting the digital signature. If the two hash values ​​match, the process proceeds to S214. On the other hand, if the two hash values ​​do not match, the process proceeds to S219.

[0079] In S214, the signature verification unit 121 obtains certificate information from the public key certificate. The certificate information includes the name of the issuer of the public key certificate. In S215, the signature verification unit 121 determines whether the issuer indicated by the certificate information is a legitimate issuer by comparing the issuer name with a predetermined name (predefined as the name of a legitimate issuer). The legitimate issuer here may be, for example, the manufacturer of the cartridge 10 or a third-party organization commissioned by the manufacturer, which operates the certification authority 50. If it is determined that the issuer of the public key certificate is a legitimate issuer, the process proceeds to S218. On the other hand, if it is determined that the issuer of the public key certificate is not a legitimate issuer, the process proceeds to S219.

[0080] In S218, the signature verification unit 121 determines that the certificate verification was successful and the first public key K P1 On the other hand, in S219, the signature verification unit 121 determines that the certificate verification has failed and the first public key K P1 is judged to be unreliable.

[0081] In the first embodiment, if an electronic certificate issued by an issuer that is not a legitimate issuer is written to the cartridge 10, the use of the cartridge 10 can be prohibited or the user can be warned about the risks of using it.

[0082] (2) Second Example Fig. 14 is a flowchart showing an example of the flow of certificate verification processing according to the second embodiment. Steps S211 to S215 in Fig. 14 are the same as steps S211 to S215 in Fig. 13, and therefore a repeated description thereof will be omitted here. If it is determined in S215 that the issuer of the public key certificate is a legitimate issuer, the processing proceeds to S216.

[0083] In S216, the signature verification unit 121 acquires the current time by referring to the internal clock of the printer 100 or by receiving time information from an external time server. In S217, the signature verification unit 121 determines whether the acquired current time is within the validity period of the electronic certificate indicated by the certificate information. If the current time is within the validity period of the electronic certificate, the process proceeds to S218. On the other hand, if the current time is not within the validity period of the electronic certificate and the validity period has already passed, the process proceeds to S219.

[0084] In S218, the signature verification unit 121 determines that the certificate verification was successful and the first public key K P1 On the other hand, in S219, the signature verification unit 121 determines that the certificate verification has failed and the first public key K P1 is judged to be unreliable.

[0085] As a modification of the second embodiment, the signature verification unit 121 may determine whether the time when the electronic certificate was written to the cartridge 10 is within the validity period, rather than the current time when cartridge authentication is performed. In this case, the writing time of the electronic certificate is additionally included in the certificate information.

[0086] In the second embodiment, the company or organization operating the certificate authority 50 can limit the period during which a remanufacturer can validly remanufacture and sell devices, or the period during which a remanufactured device can be used, by setting a validity period for the digital certificate. For example, a manufacturer can monitor the quality of remanufactured products released on the market after issuing a digital certificate, and take measures such as not issuing the next digital certificate to a remanufacturer selling low-quality remanufactured products.

[0087] (3) Third Example 15 is a flowchart showing an example of the flow of certificate verification processing according to the third embodiment. In the third embodiment, the printer 100 is assumed to be able to access, via the network N1, a certificate database in which identification information (e.g., certificate numbers) of invalid electronic certificates are registered. This certificate database is provided, for example, by the manufacturer of the cartridge 10 or the organization that operates the certification authority 50, and registers numbers of electronic certificates suspected of fraud.

[0088] Since S211 to S215 in Fig. 15 are the same processing steps as S211 to S215 in Fig. 13, a repeated description thereof will be omitted here. If it is determined in S215 that the issuer of the public key certificate is a legitimate issuer, the processing proceeds to S226.

[0089] In S226, the signature verification unit 121 obtains an invalid number list that lists the certificate numbers of invalid electronic certificates from the database described above. In S227, the signature verification unit 121 compares the certificate number indicated by the certificate information obtained in S214 with the invalid number list obtained in S226. If the certificate number indicated by the certificate information is not on the invalid number list, the process proceeds to S218. On the other hand, if the certificate number indicated by the certificate information is on the invalid number list, the process proceeds to S219.

[0090] In S218, the signature verification unit 121 determines that the certificate verification was successful and the first public key K P1 On the other hand, in S219, the signature verification unit 121 determines that the certificate verification has failed and the first public key K P1 is judged to be unreliable.

[0091] In the third embodiment, by registering in advance in a database the identification information of electronic certificates suspected of fraudulent activity, it is possible to prevent the reuse of devices that use those electronic certificates.

[0092] As a modification of the third embodiment, the expiration date of each digital certificate may be registered in the certificate database in association with the certificate number of the digital certificate. In this case, the signature verification unit 121 may determine that a digital certificate whose expiration date registered in the certificate database has already arrived is invalid.

[0093] The embodiments and variations described in this section may be combined in any manner. For example, in the certificate validation process, both the determination of the validity period in the second embodiment and the comparison of the certificate number with the invalid number list in the third embodiment may be performed.

[0094] <4. Summary> Various embodiments, examples, and modifications of the technology according to the present disclosure have been described in detail above using FIGS. 1 to 15. According to the above-described embodiments, an information processing device for remanufacturing a device detachably attached to an image forming apparatus is provided. The device includes a memory having a rewritable storage area and components involved in image forming operations. The information processing device includes a storage unit that pre-stores a first private key for signature generation, a first public key corresponding to the first private key, and a digital certificate verifying the reliability of the first public key, and a connection unit that connects the information processing device to the device. The information processing device acquires characteristic information representing characteristics of the components after remanufacturing, generates a digital signature for the characteristic information using the first private key, and writes the acquired characteristic information, the generated digital signature, the first public key, and the digital certificate to the storage area of ​​the memory. This configuration eliminates the need to communicate with an external server to ensure the reliability of information to be written to the device's memory each time the device is remanufactured. This reduces communication and computational costs for remanufacturing while ensuring the reliability of the remanufactured product.

[0095] In the above-described embodiment, the information processing device generates a first key pair consisting of a first private key and a first public key prior to remanufacturing the device and stores the first private key and the first public key in the storage unit in advance. The information processing device also transmits a certificate issuance request including the first public key to a certificate authority associated with the device manufacturer, and stores the digital certificate issued by the certificate authority in response to the certificate issuance request in the storage unit. Therefore, even if a large number of devices are collected and remanufactured by a remanufacturer, the information processing device does not need to access a certificate authority or another external server each time a device is remanufactured, as long as the remanufacturer possesses a valid digital certificate. Even if the device manufacturer is different from the remanufacturer, a private PKI (public key infrastructure) mechanism can be utilized to guarantee the reliability of the remanufactured products, thereby promoting flexible cooperation between businesses to reduce environmental impact.

[0096] In the above-described embodiment, the image forming apparatus equipped with a remanufactured device reads the first public key and digital certificate from the device's storage area and determines whether the read first public key is trustworthy using the read digital certificate and a second public key previously stored in the image forming apparatus's storage. If the image forming apparatus determines that the first public key is trustworthy, it uses the first public key to verify the characteristic information read from the device based on the digital signature read together with the characteristic information. This configuration ensures that the reliability of the first public key used to verify the digital signature accompanying the characteristic information read from the remanufactured device to the image forming apparatus is guaranteed by the digital certificate issued in advance for the remanufacturer. This eliminates the need for the remanufacturer's apparatus to communicate with an external server each time a device is remanufactured.

[0097] <5. Other embodiments> The above-described embodiment can also be realized in the form of a process in which a program for realizing one or more functions is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program, or by a circuit (e.g., ASIC) that realizes one or more functions.

[0098] The disclosure of this specification includes at least the following information processing device, authentication system, method, computer program, and image forming device. (Item 1) An information processing apparatus for remanufacturing a device detachable from an image forming apparatus, the device has a memory having a rewritable storage area and components involved in an image forming operation by the image forming apparatus, The information processing device includes: a storage means for storing in advance a first private key for signature generation, a first public key corresponding to the first private key, and a digital certificate certifying the reliability of the first public key; a connection means for connecting the information processing device to the device; an acquisition means for acquiring characteristic information representing characteristics of the component after remanufacturing; a signature generating means for generating a digital signature of the characteristic information using the first private key; a writing means for writing the characteristic information, the digital signature, the first public key, and the electronic certificate into the storage area of ​​the memory of the device; An information processing device comprising: (Item 2) The information processing device includes: a key generation means for generating a first key pair consisting of the first private key and the first public key; Furthermore, the storage means pre-stores the first private key and the first public key generated by the key generation means; Item 1. An information processing device according to item 1. (Item 3) The information processing device includes: a certificate obtaining means for transmitting a certificate issuance request including the first public key to a certificate authority associated with a manufacturer of the device, and obtaining the digital certificate issued by the certificate authority in response to the certificate issuance request; Item 3. The information processing device according to item 2, further comprising: (Item 4) 4. The information processing device of item 3, wherein the manufacturer of the device is different from a remanufacturer that remanufactures the device. (Item 5) 5. The information processing device according to item 3 or 4, wherein the certificate authority is a private certificate authority. (Item 6) the components involved in the image forming operation include a developer supplied from the device to the image forming apparatus; said remanufacturing of said device includes replenishing said device with said developer; 6. The information processing device according to any one of items 1 to 5. (Item 7) the components involved in the image forming operation include a member driven in the image forming operation; said remanufacturing of said device includes replacing said component; 7. The information processing device according to any one of items 1 to 6. (Item 8) An information processing device according to any one of items 1 to 7, a certificate authority associated with the manufacturer of the device; An authentication system comprising: the certification authority issues the digital certificate certifying authenticity of the first public key in response to a certificate issuance request received from the information processing device together with the first public key; the storage means of the information processing device stores the digital certificate issued by the certificate authority prior to the remanufacturing of the device; Authentication system. (Item 9) 1. A method for remanufacturing a device detachable from an image forming apparatus, the method being performed using an information processing device connected to the device, the method comprising: the device has a memory having a rewritable storage area and components involved in an image forming operation by the image forming apparatus, the information processing device pre-stores a first private key for signature generation, a first public key corresponding to the first private key, and a digital certificate certifying the reliability of the first public key; The method comprises: obtaining characteristic information representative of characteristics of the component after remanufacturing of the device; generating a digital signature of the characteristic information using the first private key; writing the characteristic information, the digital signature, the first public key, and the electronic certificate from the information processing device to the storage area of ​​the memory of the device; A method comprising: (Item 10) A computer program that, when executed by a processor of an information processing apparatus connected to a device detachably attached to an image forming apparatus, causes the information processing apparatus to perform an operation for remanufacturing the device, the device has a memory having a rewritable storage area and components involved in an image forming operation by the image forming apparatus, the information processing device pre-stores a first private key for signature generation, a first public key corresponding to the first private key, and a digital certificate certifying the reliability of the first public key; The operation is obtaining characteristic information representative of characteristics of the component after remanufacturing of the device; generating a digital signature of the characteristic information using the first private key; writing the characteristic information, the digital signature, the first public key, and the electronic certificate from the information processing device to the storage area of ​​the memory of the device; a computer program comprising: (Item 11) An image forming apparatus, an image forming means; a connecting means for connecting a device detachable from the image forming apparatus to the image forming apparatus; a verification means for verifying characteristic information, which is read from a rewritable storage area of ​​the device and indicates characteristics of components of the device involved in the image forming operation by the image forming means, based on a digital signature read from the storage area together with the characteristic information; a control unit that controls the image forming operation of the image forming unit based on the characteristic information when the verification unit has successfully verified the characteristic information; a storage means for storing in advance a second public key corresponding to an electronic certificate that certifies the reliability of the first public key for verifying the digital signature; Equipped with The verification means reading the first public key and the digital certificate from the storage area of ​​the device; determining whether the first public key is trustworthy using the digital certificate and the second public key stored in the storage means; If it is determined that the first public key is trustworthy, verifying the characteristic information based on the digital signature using the first public key. Image forming device. (Item 12) Item 12. The image forming device described in Item 11, wherein the digital signature is generated using a first private key corresponding to the first public key and written to the memory area of ​​the device by an information processing device of a remanufacturer that remanufactures the device. (Item 13) Item 13. An image forming apparatus according to item 11 or 12, wherein the second public key corresponds to a second private key used by a certification authority associated with the device manufacturer when issuing the electronic certificate to a remanufacturer who remanufactures the device. (Item 14) Item 14. The image forming apparatus according to item 13, wherein the certificate authority is a private certificate authority. (Item 15) 15. The image forming apparatus according to item 13 or 14, wherein the verification means determines that the first public key is not trustworthy if certificate information included in the electronic certificate does not indicate a predetermined issuer. (Item 16) 16. The image forming apparatus according to any one of items 11 to 15, wherein the verification unit determines that the first public key is not trustworthy if the validity period of the electronic certificate has already expired. (Item 17) the image forming device is capable of accessing a database in which identification information of invalid electronic certificates is registered; The verification means determines that the first public key is not trustworthy if the identification information of the electronic certificate is registered in the database. 17. The image forming apparatus according to any one of items 11 to 16.

[0099] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0100] 1: authentication system, 10: device (cartridge), 20: memory, 32, 33, 34: storage area, 37: remanufacturing information, 38: digital signature, 39: public key certificate, 50: certification authority, 100: image forming apparatus, 101: connection terminal (connection means), 102: image forming unit (image forming means), 121: signature verification unit (verification means), 122: print control unit (control means), 113: encryption processing unit (storage means), 200: remanufacturing apparatus (information processing apparatus), 202: connection terminal (connection means), 216: data management unit (storage means), 221: key generation unit (key generation means), 222: certificate acquisition unit (certificate acquisition means), 223: information acquisition unit (acquisition means), 224: signature generation unit (signature generation means), 225: writing unit (writing means), K S1 :1st private key, K P1 :1st public key, C P1 :Electronic certificate, K S2 :Second private key, K P2 :Second public key

Claims

1. An information processing apparatus for remanufacturing a device detachable from an image forming apparatus, the device has a memory having a rewritable storage area and components involved in an image forming operation by the image forming apparatus; The information processing device includes: a storage means for storing in advance a first private key for signature generation, a first public key corresponding to the first private key, and a digital certificate certifying the reliability of the first public key; a connection means for connecting the information processing device to the device; an acquisition means for acquiring characteristic information representing characteristics of the component after remanufacturing; a signature generating means for generating a digital signature of the characteristic information using the first private key; a writing means for writing the characteristic information, the digital signature, the first public key, and the electronic certificate into the storage area of ​​the memory of the device; An information processing device comprising:

2. The information processing device includes: a key generation means for generating a first key pair consisting of the first private key and the first public key; Furthermore, the storage means pre-stores the first private key and the first public key generated by the key generation means; The information processing device according to claim 1 .

3. The information processing device includes: a certificate obtaining means for transmitting a certificate issuance request including the first public key to a certificate authority associated with a manufacturer of the device, and obtaining the digital certificate issued by the certificate authority in response to the certificate issuance request; The information processing device according to claim 2 , further comprising:

4. The information processing apparatus according to claim 3 , wherein the manufacturer of the device is different from a remanufacturer that remanufactures the device.

5. The information processing device according to claim 3 , wherein the certificate authority is a private certificate authority.

6. the components involved in the image forming operation include a developer supplied from the device to the image forming apparatus; said remanufacturing of said device includes replenishing said device with said developer; The information processing device according to claim 1 .

7. the components involved in the image forming operation include a member driven in the image forming operation; said remanufacturing of said device includes replacing said component; The information processing device according to claim 1 .

8. An information processing device according to any one of claims 1 to 7; a certificate authority associated with the manufacturer of the device; An authentication system comprising: the certification authority issues the digital certificate certifying the reliability of the first public key in response to a certificate issuance request received from the information processing device together with the first public key; the storage means of the information processing device stores the digital certificate issued by the certificate authority prior to the remanufacturing of the device; Authentication system.

9. 1. A method for remanufacturing a device detachable from an image forming apparatus, the method being performed using an information processing device connected to the device, the method comprising: the device has a memory having a rewritable storage area and components involved in an image forming operation by the image forming apparatus; the information processing device pre-stores a first private key for signature generation, a first public key corresponding to the first private key, and a digital certificate certifying the reliability of the first public key; The method comprises: obtaining characteristic information representative of characteristics of the component after remanufacturing of the device; generating a digital signature of the characteristic information using the first private key; writing the characteristic information, the digital signature, the first public key, and the electronic certificate from the information processing device to the storage area of ​​the memory of the device; A method comprising:

10. A computer program that, when executed by a processor of an information processing apparatus connected to a device detachably attached to an image forming apparatus, causes the information processing apparatus to perform an operation for remanufacturing the device, the device has a memory having a rewritable storage area and components involved in an image forming operation by the image forming apparatus; the information processing device pre-stores a first private key for signature generation, a first public key corresponding to the first private key, and a digital certificate certifying the reliability of the first public key; The operation is obtaining characteristic information representative of characteristics of the component after remanufacturing of the device; generating a digital signature of the characteristic information using the first private key; writing the characteristic information, the digital signature, the first public key, and the electronic certificate from the information processing device to the storage area of ​​the memory of the device; a computer program comprising:

11. An image forming apparatus, an image forming means; a connecting means for connecting a device detachable from the image forming apparatus to the image forming apparatus; a verification means for verifying characteristic information, which is read from a rewritable storage area of ​​the device and indicates characteristics of components of the device involved in the image forming operation by the image forming means, based on a digital signature read from the storage area together with the characteristic information; a control unit that controls the image forming operation of the image forming unit based on the characteristic information when the verification unit has successfully verified the characteristic information; a storage means for storing in advance a second public key corresponding to an electronic certificate that certifies the reliability of the first public key for verifying the digital signature; Equipped with The verification means reading the first public key and the digital certificate from the storage area of ​​the device; determining whether the first public key is trustworthy using the digital certificate and the second public key stored in the storage means; If it is determined that the first public key is trustworthy, verifying the characteristic information based on the digital signature using the first public key. Image forming device.

12. 12. The image forming apparatus according to claim 11, wherein the digital signature is generated using a first private key corresponding to the first public key, and written to the storage area of ​​the device by an information processing device of a remanufacturer that remanufactures the device.

13. The image forming apparatus according to claim 11 , wherein the second public key corresponds to a second private key used by a certificate authority associated with the device manufacturer when issuing the electronic certificate to a remanufacturer who remanufactures the device.

14. The image forming apparatus according to claim 13 , wherein the certificate authority is a private certificate authority.

15. 14. The image forming apparatus according to claim 13, wherein the verification unit determines that the first public key is not trustworthy when certificate information included in the digital certificate does not indicate a predetermined issuer.

16. 12. The image forming apparatus according to claim 11, wherein the verification unit determines that the first public key is not trustworthy if the validity period of the electronic certificate has already expired.

17. the image forming device is capable of accessing a database in which identification information of invalid electronic certificates is registered; The verification means determines that the first public key is not trustworthy if the identification information of the electronic certificate is registered in the database. The image forming apparatus according to claim 11.

Images