Image log management system and image log management program

Abstract

To suppress reduction of an addition frequency of transaction information in relative to a case where a resolution of an image log included in the transaction information is fixed when managing the image log by means of a block chain.SOLUTION: Based on an addition frequency of a plurality of latest blocks 40 added to a block chain 32, a transaction information creation section 54 determines a resolution of an image log to be included in new transaction information 44. An image log of the determined resolution is generated and included in the new transaction information 44 by the transaction information creation section 54. The transaction information creation section 54 simultaneously transmits the created new transaction information 44 to other image processing devices 12 included in an image log management system 10.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an image log management system and an image log management program. [Background technology]

[0002] Conventionally, when processing target data is performed, image data representing the processing target data is left as an image log.

[0003] For example, Patent Document 1 discloses an image forming device that has a first memory provided within the device and a second memory externally connected to the device, and stores log information including image data indicating a job (e.g., a print job or a copy job) executed by the device in the first memory and the second memory. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-28606 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, if the image log is tampered with, it may not be able to perform its intended function. Therefore, it is advisable to manage the image log so that it is not tampered with.

[0006] Here, a technology called blockchain is known. Blockchain has a structure in which data units called blocks, each having transaction information including information to be recorded, are linked like a chain. Blockchains are stored in multiple devices (also called nodes) that are connected to each other so that they can communicate directly with each other. This mechanism prevents tampering with the data to be recorded. By managing the image log with the blockchain, in other words, by including the image log in the transaction information held by each block that constitutes the blockchain, it is possible to prevent tampering with the image log.

[0007] When managing image logs with a blockchain, the low frequency at which transaction information including image logs (more specifically, blocks that have the information) is added to the blockchain (referred to as the frequency of transaction information addition in this specification) can be a problem. For example, if the speed at which transaction information is added to the blockchain is low, a problem occurs in that unprocessed transaction information accumulates.

[0008] In particular, image data such as image logs has a larger data volume than data generally managed by blockchains (e.g., cryptocurrency transaction information), so the reduced frequency of adding transaction information can easily become a problem.

[0009] The object of the present invention is to suppress a decrease in the frequency of adding transaction information when image logs are managed using a blockchain, compared to when the resolution of the image logs included in the transaction information is fixed. [Means for solving the problem]

[0010] The invention of claim 1 is an image log management system comprising a plurality of devices connected to each other so as to be able to communicate with each other, each storing a blockchain composed of blocks having transaction information including an image log, which is image data indicating the data to be processed, and a processor, wherein the processor generates new transaction information including an image log with a resolution determined based on the addition frequency of a plurality of most recent blocks already added to the blockchain, transmits the new transaction information to the plurality of devices, and adds a block having the new transaction information to the blockchain. The invention of claim 2 is the image log management system described in claim 1, characterized in that when the addition frequency of the most recent blocks already added to the blockchain is lower than a predetermined appropriate frequency value, the processor generates new transaction information including an image log with a resolution lower than the most recent resolution, which is the resolution of the image log included in the transaction information held by the most recent blocks. The invention of claim 3 is the image log management system described in claim 2, characterized in that the processor sets the current resolution, which is the resolution of the image log to be included in the new transaction information, to a value calculated based on the most recent resolution. The invention of claim 4 is the image log management system described in claim 3, characterized in that if the calculated current resolution is smaller than a predetermined minimum resolution, the processor does not send the new transaction information to the multiple devices and interrupts processing of the data to be processed. The invention of claim 5 is an image log management system as described in any one of claims 1 to 4, characterized in that the header information of each block of the blockchain includes information indicating the resolution of the image log included in the transaction information held by the block. The invention of claim 6 is an image log management system described in any one of claims 2 to 4, characterized in that the header information of each block of the blockchain includes information indicating the appropriate frequency value. The invention of claim 7 is an image log management system described in any one of claims 2 to 4, characterized in that the processor changes the appropriate frequency value for the entire blockchain in response to instructions from a user. The invention of claim 8 is an image log management program that causes a computer capable of accessing a blockchain composed of blocks having transaction information including image logs, which are image data indicating data to be processed, stored in a plurality of devices connected to each other so as to be able to communicate with each other, to generate new transaction information including image logs of a resolution determined based on the addition frequency of a plurality of most recent blocks already added to the blockchain and a most recent resolution, which is the resolution of the image logs included in the transaction information held by the most recent blocks, and transmits the new transaction information to the plurality of devices to add a block having the new transaction information to the blockchain. Effect of the Invention

[0011] According to the invention of claim 1 or 8, when image logs are managed by a blockchain, it is possible to suppress a decrease in the frequency of adding transaction information compared to when the resolution of the image logs included in the transaction information is fixed. According to the invention of claim 2, the resolution of the image log included in the new transaction information can be reduced based on a comparison between the addition frequency of the most recent block and the appropriate frequency value. According to the invention as defined in claim 3, the current resolution can be set to a value corresponding to the most recent resolution. According to the invention as defined in claim 4, it is possible to prevent the current resolution from becoming an inappropriate resolution for an image log. According to the invention of claim 5, the processor can obtain the previous resolution from the header information of the block, without analyzing the transaction information held by the block. According to the invention as defined in claim 6, the processor can obtain the appropriate frequency value from the header information of the block. According to the invention as defined in claim 7, the user can determine the appropriate frequency value. [Brief description of the drawings]

[0012] [Figure 1] 1 is a schematic diagram illustrating the configuration of an image log management system according to an embodiment of the present invention. [Diagram 2] 1 is a schematic diagram illustrating the configuration of an image processing device according to an embodiment of the present invention. [Diagram 3] 1 is a conceptual diagram showing the structure of a blockchain. [Figure 4] FIG. 2 is a conceptual diagram showing the contents of a block header. [Diagram 5] FIG. 2 is a conceptual diagram showing the contents of transaction information. [Figure 6] 5 is a flowchart showing a flow of processing of the image processing apparatus according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] FIG. 1 is a schematic diagram of the configuration of an image log management system 10 according to this embodiment. The image log management system 10 is configured to include a plurality of devices that are a plurality of nodes of a blockchain. In this embodiment, the image log management system 10 is configured from a plurality of image processing devices 12 as a plurality of nodes of the blockchain. In this specification, the image processing device 12 included in the image log management system 10 is simply called the image processing device 12. The image processing device 12 is a device having a print function, a copy function, a scan function, a FAX function, etc., such as a multifunction device. Note that while FIG. 1 shows only three image processing devices 12 that constitute the image log management system 10, the image log management system 10 may include more than three image processing devices 12.

[0014] The image processing devices 12 are connected to each other via a communication line such as a LAN (Local Area Network) or a WAN (Wide Area Network) so that they can communicate with each other by P2P (Peer to Peer). P2P is a communication method in which devices communicate directly with each other without going through a server.

[0015] In the image log management system 10 according to the present embodiment, the image logs formed in each image processing device 12 are managed by a blockchain to prevent the image logs from being lost or tampered with. An image log is image data representing data to be processed in the image processing device 12. For example, when the image processing device 12 performs a print process, the image data to be printed becomes the image log. Note that the data to be processed is not limited to the image data to be printed. The image log is used, for example, to prevent and track information leaks and to effectively utilize the information in business. Specifically, for example, the image log is used to manage, monitor, and track when, who, and which image processing device 12 performed what processing.

[0016] As mentioned above, image logs tend to have a larger data volume than data that is generally managed by blockchains, such as cryptocurrency transaction information. Also, since image logs are image data, the higher the resolution, the larger the data volume, and vice versa.

[0017] Although the details will be described later, a blockchain is a form of a distributed database that is configured by linking multiple blocks. The distributed database here means that the same content of the blockchain is stored in each image processing device 12. Each block that configures the blockchain contains one or multiple pieces of transaction information to be managed. In this embodiment, each piece of transaction information is an image log. In addition, each block contains a hash value (hereinafter, for convenience, referred to as the hash value of the block) of the block information of the immediately previous block that was previously added to the blockchain. The block information is information that contains transaction information and the like contained in the block. The hash value is a value obtained by irreversibly converting the target data (here, the block information of the immediately previous block). Therefore, if the transaction information included in a certain block is lost or tampered with, the hash values ​​included in all subsequent blocks will be different from the regular ones. With this mechanism, loss or tampering of transaction information (in this embodiment, the image log) is suppressed.

[0018] If it were possible to easily add blocks to a blockchain, a malicious user could easily add fraudulent blocks (for example, blocks containing falsified transaction information) to the blockchain. Therefore, in a blockchain, restrictions are generally imposed for adding new blocks. An algorithm called PoW (Proof of Work) has been proposed as one of such restrictions. PoW is a mechanism in which a processor of a blockchain node (the image processing device 12 in this embodiment) is made to repeat calculations, and when the calculation results satisfy a predetermined condition, a new block is permitted to be added to the blockchain. In the blockchain of this embodiment, PoW is also used as a restriction for adding a new block.

[0019] The process for adding a new block to the blockchain is called mining. In mining by PoW, the node processor calculates the hash value of the latest block added to the blockchain by inputting a composite value obtained by combining block information of the latest block added to the blockchain, i.e., one or more pieces of transaction information included in the block, the hash value of the block immediately preceding the block, and a value called a nonce, into a hash function. For example, a function such as SHA-256 is used as the hash function. If the calculated hash value is less than a predetermined threshold (called a difficulty target), the mining process is successful and a new block is permitted to be added to the blockchain. The hash value that is less than the threshold is called a correct hash value. If the calculated hash value is equal to or greater than the threshold, the processor changes the nonce value and calculates the hash value again. Note that, due to the characteristics of the hash function, if the input data (here, the nonce value) is slightly different, the output hash value changes significantly. In this way, the processor repeats the calculation of the hash value while changing the nonce value until the hash value becomes less than the threshold (in other words, until the correct hash value is obtained). Generally, the amount of calculation required to obtain a correct hash value is enormous.

[0020] As described above, a huge amount of calculation is required to make the mining process successful. Therefore, it has been proposed that a plurality of nodes work together to perform the mining process. A group of nodes that work together to perform the mining process is called a mining pool. In this embodiment, a plurality of image processing devices 12 may also form a mining pool, and the plurality of image processing devices 12 (specifically, their processors) may work together to perform the mining process.

[0021] 2 is a schematic diagram of the configuration of the image processing device 12. The image processing device 12 executes printing, scanning, copying, faxing, and other processes that are inherent to the image processing device 12. In this specification, such inherent processes of the image processing device 12 are referred to as normal processes. In addition to normal processes, the image processing device 12 in this embodiment executes mining processes. Since the image processing devices 12 included in the image log management system 10 have similar configurations, one image processing device 12 will be described here.

[0022] The communication IF (Interface) 20 is composed of, for example, a network adapter. The communication IF 20 performs a function of communicating with other devices via a communication line. In particular, in this embodiment, the communication IF 20 performs a function of communicating with other image processing devices 12 by P2P.

[0023] The input IF 22 is configured with, for example, a button, a touch panel, etc. The input IF 22 is used when the user inputs instructions to the image processing device 12.

[0024] The display 24 is configured by, for example, a liquid crystal display, an organic EL (Electro Luminescence) display, etc. Various screens are displayed on the display 24 in response to instructions from a processor 50, which will be described later.

[0025] The printer 26 is, for example, a laser printer or an inkjet printer, and is a mechanism that performs a print process to form an image on a print medium such as paper based on an input print job. If the printer 26 is a laser printer, the printer 26 is composed of, for example, a photosensitive drum, a charging roller, a transfer roller, a fixing roller, toner, etc. If the printer 26 is an inkjet printer, the printer 26 is composed of a nozzle, a charging electrode plate, a deflection electrode plate, ink, etc.

[0026] The scanner 28 includes a light source, and an image sensor such as a charge-coupled device (CCD), etc. The scanner 28 is a mechanism that performs a scan process to optically read a paper medium and acquire image data.

[0027] The memory 30 includes a hard disk drive (HDD), an embedded multi media card (eMMC), a read only memory (ROM), or a random access memory (RAM). The memory 30 stores an image log management program for operating each unit of the image processing device 12. The image log management program can also be stored in a computer-readable non-transitory storage medium such as a universal serial bus (USB) memory or an SD card. The image processing device 12 can read and execute the image log management program from such a storage medium. In addition, as shown in FIG. 2, the memory 30 stores a blockchain 32.

[0028] 3 is a conceptual diagram showing the structure of the blockchain 32. As described above, the blockchain 32 has a structure in which a plurality of blocks 40 are linked together. Each block 40 includes a header 42 and transaction information 44.

[0029] FIG. 4 is a conceptual diagram showing the contents of the header 42 included in each block 40. As shown in FIG. 4, in this embodiment, the header 42 includes version information, a hash value of the immediately preceding block 40, a timestamp, an average resolution of the image log, and an appropriate frequency value. The version information is information indicating the version of the software or protocol related to the blockchain 32. The hash value of the immediately preceding block 40 is a correct hash value calculated when the immediately preceding block 40 is added to the blockchain 32. The timestamp is information indicating the time when the block 40 is added to the blockchain 32. The average resolution of the image log is the average resolution of one or more image logs included in one or more transaction information 44 held by the block 40. The appropriate frequency value is information indicating an appropriate value for the frequency of addition of the block 40 to the blockchain 32. A method for generating the header 42 and a method for using each piece of information included in the header 42 will be described later.

[0030] FIG. 5 is a conceptual diagram showing the contents of the transaction information 44 included in each block 40. As shown in FIG. 5, in this embodiment, the transaction information 44 includes an image log, information indicating the resolution of the image log, a job log related to the job related to the image log, and a device ID. As described above, the image log is image data representing data to be processed in the image processing device 12. The job log includes, for example, a job ID that uniquely identifies the job, a user ID that uniquely identifies the user who executed the job, information indicating the type of job (e.g., print, scan, copy, FAX, etc.), and the date and time of receipt of the job. The device ID is an identifier that uniquely identifies the image processing device 12 that executed the process related to the image log.

[0031] 2, the processor 50 is composed of, for example, a CPU (Central Processing Unit) etc. The processor 50 is communicably connected to the communication IF 20, the input IF 22, the display 24, the printer 26, the scanner 28, and the memory 30 via a data bus. The processor 50 performs the functions of a normal processing unit 52, a transaction information creating unit 54, and a mining processing unit 56 by an image log management program stored in the memory 30.

[0032] The normal processing unit 52 and the transaction information creation unit 54 are primarily responsible for creating and transmitting the transaction information 44 to be included in the block 40 .

[0033] The normal processing unit 52 performs control for executing normal processing based on a job as a processing command input by a user to the image processing device 12. For example, when the normal processing unit 52 receives a print job from a user, it causes the printer 26 to execute a printer process. Also, for example, when the normal processing unit 52 receives a scan job from a user, it causes the scanner 28 to execute a scan process. Specifically, after receiving a job from a user via the communication IF 20, the normal processing unit 52 authenticates the user, and when an instruction is given by the authenticated user, it executes processing related to the job.

[0034] When normal processing under the control of the normal processing unit 52 starts, the transaction information creation unit 54 creates transaction information 44 (see FIG. 5) related to the normal processing. Specifically, the transaction information creation unit 54 sets the resolution of the image log related to the job related to the normal processing and then generates an image log. The transaction information creation unit 54 also acquires the job log of the job and its own device ID (which may be stored in advance in the memory 30), and includes these in the transaction information 44. Details of the process of setting the resolution of the image log by the transaction information creation unit 54 will be described later. In this specification, the transaction information 44 before being added to the block chain 32 is referred to as new transaction information 44. The transaction information creation unit 54 transmits the created new transaction information 44 to the other image processing devices 12 included in the image log management system 10 all at once.

[0035] In this way, when normal processing is executed in each image processing device 12 included in the image log management system 10, new transaction information 44 is simultaneously transmitted from the image processing device 12 that executed the normal processing to the other image processing devices 12. Each image processing device 12 accumulates and stores in memory 30 transaction information 44 acquired from any of the multiple image processing devices 12 included in the image log management system 10 (including its own device).

[0036] As will be described in detail later, there are cases where the transaction information creation unit 54 is unable to generate an image log with an appropriate resolution. In this embodiment, the generation of an image log with an appropriate resolution is a condition for completing the processing of a job. Therefore, if an image log with an appropriate resolution cannot be generated, the normal processing unit 52 stops the execution of the job, and the transaction information creation unit 54 stops generating new transaction information 44 related to the job, and does not transmit the new transaction information 44 to other image processing devices 12.

[0037] The mining processing unit 56 is a function related to mining processing of the block 40 including the new transaction information 44 transmitted from the image processing device 12 itself or from another image processing device 12 .

[0038] The mining processing unit 56 executes mining processing on a new block 40, which is a block 40 including new transaction information 44, at a predetermined timing (for example, when a predetermined number of new transaction information 44 has been accumulated in the memory 30, or at a predetermined time interval). As described above, in this embodiment, the mining processing unit 56 executes mining processing in cooperation with the mining processing units 56 of other image processing devices 12, but the mining processing may be executed by the mining processing unit 56 of one image processing device 12 alone.

[0039] The mining process performed by the mining processing unit 56 is as described above. That is, the mining processing unit 56 calculates a hash value of one or more pieces of new transaction information 44, the hash value of the immediately preceding block 40, and a composite value of the nonce. If the hash value resulting from the mining process meets the condition that it is less than a threshold value set by the difficulty setting unit 58, which will be described later, the mining process is successful. The mining processing unit 56 repeats the calculation of the hash value while changing the nonce until it obtains the correct hash value.

[0040] When the mining process is successful, the mining process unit 56 generates a header 42 (see FIG. 4). Specifically, the mining process unit 56 acquires the version of the software or protocol related to the blockchain 32, and uses this as version information. The mining process unit 56 also acquires a hash value of the immediately preceding block 40, and includes this in the header 42. The mining process unit 56 also acquires the time when the new block 40 was added to the blockchain 32, and uses this as a timestamp. The mining process unit 56 also calculates the average resolution of one or more image logs included in one or more pieces of transaction information 44 held by the new block 40, and includes this in the header 42. The appropriate frequency value is determined in advance, and is stored in the memory 30, for example. The mining process unit 56 acquires the appropriate frequency value, and includes this in the header 42.

[0041] As described above, the appropriate frequency value is information that represents an appropriate value for the frequency of adding blocks 40 to the blockchain 32. If the frequency of adding blocks 40 to the blockchain 32 is too high or too low, inconveniences may occur. For example, if the frequency of adding blocks 40 to the blockchain 32 is too low, new transaction information 44 that has not been added to the blockchain 32 will accumulate. Conversely, if the frequency of adding blocks 40 to the blockchain 32 is too high, the difficulty of the mining process will be low, and the possibility that the blocks 40 of the blockchain 32 will be tampered with will increase. Therefore, in this embodiment, an appropriate frequency value is determined in advance, and the mining processing unit 56 includes the appropriate frequency value in the header of each block 40. Note that the same appropriate frequency value is used for the entire blockchain 32, and does not differ for each block 40.

[0042] The processor 50 of each image processing device 12 may change the appropriate frequency value in response to an instruction from a user. That is, the user may be able to change the appropriate frequency value. As described above, the same value is used as the appropriate frequency value for the entire blockchain 32, so when the appropriate frequency value is changed by the user, the appropriate frequency value for the entire blockchain 32 is changed. It is preferable that the upper and lower limits of the appropriate frequency value that the user can set are determined in advance so that an inappropriate appropriate frequency value is not set by the user.

[0043] In this embodiment, the appropriate frequency value is included in the header 42 of each block 40, but information indicating the appropriate frequency value may be stored in a device (e.g., a server) accessible from each image processing device 12 without being included in the header 42. However, as described below, the appropriate frequency value is referred to by each image processing device 12 when determining the resolution of the image log, and by including the appropriate frequency value in the header 42 of the block 40, each image processing device 12 can obtain the appropriate frequency value within the framework of the blockchain 32 without the need to separately prepare a device for storing the appropriate frequency value.

[0044] The mining processing unit 56 forms a new block 40 including the generated header 42 and the new transaction information 44 (see FIG. 5 ). Then, the new block 40 is added to the blockchain 32.

[0045] The details of the process of determining the resolution of the image log by the transaction information creation unit 54 will be described below. The transaction information creation unit 54 determines the resolution of the image log to be included in the new transaction information 44 based on the addition frequency of the most recent blocks 40 that have already been added to the blockchain 32. As described above, in this specification, the block 40 previously added to the blockchain 32 is called the immediately previous block 40, and the multiple blocks 40 recently added to the blockchain 32, including the immediately previous block 40, are called the most recent blocks 40. In addition, in this specification, the resolution of the image log to be included in the new transaction information 44 is called the current resolution.

[0046] The transaction information creation unit 54 acquires a timestamp from the header 42 of each of the most recent blocks 40. Then, the addition frequency of the most recent blocks 40 is calculated from the time intervals indicated by the timestamps of the most recent blocks 40. For example, when the most recent blocks 40 are composed of the first to third blocks 40, the transaction information creation unit 54 determines the addition frequency of the most recent blocks 40 to be the average value of the difference between the time indicated by the timestamp included in the header 42 of the first block 40 and the time indicated by the timestamp included in the header 42 of the second block 40, and the difference between the time indicated by the timestamp included in the header 42 of the second block 40 and the time indicated by the timestamp included in the header 42 of the third block 40.

[0047] The transaction information creation unit 54 sets the current resolution to be smaller than a predetermined default resolution if the most recent blocks 40 are added less frequently, and sets the current resolution to the default resolution if the most recent blocks 40 are added more frequently. If the most recent blocks 40 are added more frequently, the current resolution may be set to be larger than the default resolution.

[0048] The smaller the resolution of the image log, the smaller the data capacity of the image log. Therefore, the amount of calculation required to calculate a hash value for a new block 40 that includes the image log as new transaction information 44 is reduced, and as a result, the amount of calculation required to obtain a correct hash value for the new block 40 is also reduced. In other words, the mining time required for the mining process of the new block 40 is reduced. This improves the frequency at which new blocks 40 are added to the blockchain 32, that is, the decrease in the frequency at which new blocks 40 (i.e., new transaction information 44) are added to the blockchain 32 is suppressed.

[0049] In this embodiment, the transaction information creation unit 54 compares the addition frequency of the most recent blocks 40 with the above-mentioned appropriate frequency value. Then, when the addition frequency of the most recent blocks 40 is lower than the appropriate frequency value, the transaction information creation unit 54 sets the current resolution to be smaller than a predetermined default resolution. In particular, when the addition frequency of the most recent blocks 40 is lower than the appropriate frequency value, the transaction information creation unit 54 may set the current resolution to be smaller than the most recent resolution, which is the resolution of the image included in the transaction information 44 of the most recent blocks 40.

[0050] The transaction information creation unit 54 acquires the resolution of the image log included in the transaction information 44 of the most recent blocks 40 based on the average resolution of the image logs included in the headers 42 of the most recent blocks 40. For example, if the most recent blocks 40 are composed of the first to third blocks 40, the transaction information creation unit 54 calculates the average of the average resolution of the image log indicated by the header 42 of the first block 40, the average resolution of the image log indicated by the header 42 of the second block 40, and the average resolution of the image log indicated by the header 42 of the third block 40, and sets this as the resolution of the image log included in the transaction information 44 of the most recent blocks 40.

[0051] In this embodiment, the header 42 of each block 40 includes the average resolution of the image log, but the header 42 does not have to include the average resolution of the image log. In this case, the transaction information creation unit 54 can acquire the resolution of each image log included in the most recent blocks 40 by referring to the multiple pieces of transaction information 44 included in each of the most recent blocks 40. However, by including the average resolution of the image log in the header 42 of each block 40, the transaction information creation unit 54 can acquire the resolution of the image included in the transaction information 44 held by the most recent blocks 40 by referring to the header 42 without having to refer to the transaction information 44 of each block 40.

[0052] If the addition frequency of the most recent blocks 40 thus acquired is lower than the appropriate frequency value, the transaction information creation unit 54 sets the current resolution to be smaller than the most recent resolution.

[0053] Furthermore, the transaction information creation unit 54 may set the current resolution to a value calculated based on the most recent resolution. In particular, the transaction information creation unit 54 may determine the current resolution based on the most recent resolution and the relationship between the addition frequency of the most recent plurality of blocks 40 and the appropriate frequency value.

[0054] For example, it is assumed that the appropriate frequency value is once every 10 minutes (i.e., a new block 40 is added to the blockchain 32 once every 10 minutes). Here, if the addition frequency of the most recent blocks 40 is once every 40 minutes, the addition frequency of the most recent blocks 40 is lower than the appropriate frequency value, which is 1 / 4 of the appropriate frequency value. In this case, the transaction information creation unit 54 sets the current resolution to 1 / 2 of the most recent resolution (because the data size of the image log is proportional to the square of the resolution) so that the addition frequency of the new blocks 40 approaches the appropriate frequency value (to be four times) and the data size of the image log included in the new transaction information 44 becomes 1 / 4. On the other hand, if the addition frequency of the most recent blocks 40 is once every 5 minutes, the addition frequency of the most recent blocks 40 is equal to or higher than the appropriate frequency value. In this case, as described above, the transaction information creation unit 54 sets the current resolution to the default resolution (does not lower the current resolution).

[0055] It is possible that the current resolution determined as described above will be a considerably small value. For example, in the above example, if the current resolution is set to 1 / 2 of the most recent resolution, and the most recent resolution is, for example, 20 dpi, the current resolution will be 10 dpi. An image log with such a low resolution cannot be used as an image log. Therefore, in this embodiment, a minimum resolution is determined in advance, and the transaction information creation unit 54 does not generate an image log when the calculated current resolution is smaller than the minimum resolution. As a result, the transaction information creation unit 54 does not transmit new transaction information 44. Also, as described above, in each image processing device 12 according to this embodiment, since the generation of an image log with an appropriate resolution is a condition for completing the processing of a job, the normal processing unit 52 interrupts the processing of the job related to the image log when the current resolution is smaller than the minimum resolution.

[0056] The image log management system 10 according to this embodiment has been outlined above. The flow of processing by the image processing device 12 will now be described with reference to the flowchart shown in FIG.

[0057] In step S10, the normal processing section 52 starts normal processing, which is processing related to a job input by a user, in accordance with the job.

[0058] In step S12, the transaction information creation unit 54 calculates the addition frequency of the most recent blocks 40 based on the timestamps included in the headers 42 of the most recent blocks 40.

[0059] In step S14, the transaction information creation unit 54 determines whether the addition frequency of the most recent blocks 40 calculated in step S12 is lower than an appropriate frequency value. If the addition frequency of the most recent blocks 40 is equal to or higher than the appropriate frequency value ("No" in step S14), the process proceeds to step S16. In step S16, the transaction information creation unit 54 sets the current resolution to the default resolution. As described above, in step S16, the transaction information creation unit 54 may set the current resolution to be higher than the default resolution. After step S16, the process proceeds to step S28, which will be described later.

[0060] In step S14, if the addition frequency of the most recent blocks 40 is lower than the appropriate frequency value (step S14: Yes), the process proceeds to step S18. In step S18, the transaction information creation unit 54 acquires the resolution of the image log included in the transaction information 44 of the most recent blocks 40 based on the average resolution of the image log included in the headers 42 of the most recent blocks 40.

[0061] In step S20, the transaction information creation unit 54 judges whether the resolution of the image log included in the most recent blocks 40 acquired in step S18 is equal to or higher than the minimum resolution. The image processing devices 12 included in the image log management system 10 may have different minimum resolutions. In such a case, when the image log included in the most recent block 40 is generated by another image processing device 12, the resolution of the image log included in the most recent block 40 may be lower than the minimum resolution of the device itself. If the resolution of the image log included in the most recent blocks 40 is lower than the minimum resolution ("No" in step S20), the process proceeds to step S22. In step S22, the normal processing unit 52 interrupts the processing of the job that started in step S10. The normal processing unit 52 then notifies the user that the job has been interrupted.

[0062] If the resolution of the image log included in the most recent blocks 40 is equal to or higher than the minimum resolution (YES in step S20), the process proceeds to step S24. In step S24, the transaction information creation unit 54 determines the current resolution based on the relationship between the addition frequency of the most recent blocks 40 and the appropriate frequency value, and the most recent resolution.

[0063] In step S26, the transaction information creation unit 54 determines whether the current resolution determined in step S24 is equal to or greater than the minimum resolution. If the current resolution is smaller than the minimum resolution, the process proceeds to step S22. If the current resolution is equal to or greater than the minimum resolution, the process proceeds to step S28.

[0064] In step S28, the transaction information creation unit 54 generates an image log for the job whose processing was started in step S10, the image log having the current resolution determined in step S24.

[0065] In step S30, the transaction information creation unit 54 generates new transaction information 44 including the image log generated in step S28.

[0066] In step S32, the transaction information creation unit 54 broadcasts the new transaction information 44 generated in step S30 to the other image processing devices 12 included in the image log management system 10. In this embodiment, the broadcasting of the new transaction information 44 including the image log determines that the image log has been generated. Therefore, when the new transaction information 44 is broadcasted in step S30, the normal processing unit 52 proceeds with the processing of the job that was started in step S10, and completes the processing. After completing the processing of the job, the normal processing unit 52 notifies the user that the processing of the job has been completed.

[0067] Thereafter, the mining processing unit 56 of each image processing device 12 included in the image log management system 10 performs mining processing of the new block 40 including the new transaction information 44 that was simultaneously transmitted in step S32, and if the mining processing is successful, the new block 40 is added to the blockchain 32.

[0068] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention.

[0069] In the above embodiment, the processor refers to a processing device in a broad sense, and includes at least one of a general-purpose processing device (e.g., a CPU (Central Processing Unit)) and a dedicated processing device (e.g., a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a programmable logic device). The processor may not be a single processing device, but may be a device formed by the cooperation of multiple processing devices located at physically separate locations.

[0070] (Additional Note) (((1))) A plurality of devices each storing a blockchain composed of blocks having transaction information including an image log, which is image data showing data to be processed, and connected to each other in a manner capable of communicating with each other; A processor; Equipped with The processor, generating new transaction information including an image log having a resolution determined based on an addition frequency of the most recent blocks added to the blockchain; transmitting the new transaction information to the plurality of devices to add a block having the new transaction information to the blockchain; 1. An image log management system comprising: (((2))) The processor, When the frequency of addition of the most recent blocks that have been added to the blockchain is lower than a predetermined optimum frequency value, new transaction information is generated that includes an image log with a resolution lower than the most recent resolution, which is the resolution of an image log included in the transaction information of the most recent blocks. 4. The image log management system according to claim 1, wherein: (((3))) The processor, A current resolution, which is a resolution of the image log to be included in the new transaction information, is set to a value calculated based on the most recent resolution. 2. An image log management system according to claim 1, wherein the image log management system comprises: (((4))) The processor, if the calculated current resolution is smaller than a predetermined minimum resolution, the new transaction information is not transmitted to the plurality of devices, and processing of the data to be processed is interrupted. 4. The image log management system according to claim 3, wherein: (((5))) The header information of each block of the blockchain includes information indicating the resolution of the image log included in the transaction information of the block. 2. An image log management system according to claim 1, wherein the image log management system comprises: (((6))) The header information of each block of the blockchain includes information indicating the appropriate frequency value. 2. An image log management system according to claim 1, wherein the image log management system comprises: (((7))) The processor, Changing the appropriate frequency value for the entire blockchain in response to an instruction from a user. 2. An image log management system according to claim 1, wherein the image log management system comprises: (((8))) A computer that can access a blockchain composed of blocks having transaction information including an image log, which is image data showing data to be processed, stored in a plurality of devices that are communicatively connected to each other, is provided. Generate new transaction information including an image log with a resolution determined based on the addition frequency of the most recent blocks added to the blockchain and a most recent resolution, which is the resolution of an image log included in the transaction information of the most recent blocks; transmitting the new transaction information to the plurality of devices to add a block having the new transaction information to the blockchain; 2. An image log management program comprising:

[0071] According to the invention relating to (((1))) or (((8))), when image logs are managed using a blockchain, it is possible to suppress a decrease in the frequency of addition of transaction information compared to a case in which the resolution of the image logs included in the transaction information is fixed. According to the invention related to (((2))), the resolution of the image log included in the new transaction information can be reduced based on a comparison between the addition frequency of the most recent block and the appropriate frequency value. According to the invention related to (((3))), the current resolution can be set to a value corresponding to the most recent resolution. According to the invention related to (((4))), it is possible to prevent the current resolution from becoming an inappropriate resolution for an image log. According to the invention related to (((5))), the processor can obtain the previous resolution from the header information of the block, without analyzing the transaction information contained in the block. According to the invention pertaining to (((6))), the processor can obtain the appropriate frequency value from the header information of the block. According to the invention pertaining to (((7))), the user can determine the appropriate frequency value. [Explanation of symbols]

[0072] 10 Blockchain control system, 12 Image processing device, 20 Communication IF, 22 Input IF, 24 Display, 26 Printer, 28 Scanner, 30 Memory, 32 Blockchain, 40 Block, 42 ​​Header, 44 Transaction information, 50 Processor, 52 Normal processing unit, 54 Transaction information creation unit, 56 Mining processing unit.

Claims

1. A plurality of devices each storing a blockchain composed of blocks having transaction information including an image log, which is image data showing data to be processed, and connected to each other in a manner capable of communicating with each other; A processor; Equipped with The processor, generating new transaction information including an image log having a resolution determined based on an addition frequency of the most recent blocks added to the blockchain; transmitting the new transaction information to the plurality of devices to add a block having the new transaction information to the blockchain; 1. An image log management system comprising:

2. The processor, When the frequency of addition of the most recent blocks that have been added to the blockchain is lower than a predetermined optimum frequency value, new transaction information is generated that includes an image log with a resolution lower than the most recent resolution, which is the resolution of an image log included in the transaction information of the most recent blocks.

2. The image log management system according to claim 1,

3. The processor, A current resolution, which is a resolution of the image log to be included in the new transaction information, is set to a value calculated based on the most recent resolution.

3. The image log management system according to claim 2.

4. The processor, if the calculated current resolution is smaller than a predetermined minimum resolution, the new transaction information is not transmitted to the plurality of devices, and processing of the data to be processed is interrupted.

4. The image log management system according to claim 3.

5. The header information of each block of the blockchain includes information indicating the resolution of the image log included in the transaction information of the block.

5. The image log management system according to claim 1, wherein the image log management system is a system for managing an image of a plurality of objects.

6. The header information of each block of the blockchain includes information indicating the appropriate frequency value.

5. The image log management system according to claim 2, wherein the image log management system is a system for managing an image of a plurality of objects.

7. The processor, Changing the appropriate frequency value for the entire blockchain in response to an instruction from a user.

5. The image log management system according to claim 2, wherein the image log management system is a system for managing an image of a plurality of objects.

8. A computer that can access a blockchain composed of blocks having transaction information including an image log, which is image data showing data to be processed, stored in a plurality of devices that are communicatively connected to each other, is provided. Generate new transaction information including an image log with a resolution determined based on the addition frequency of the most recent blocks added to the blockchain and a most recent resolution, which is the resolution of an image log included in the transaction information of the most recent blocks; transmitting the new transaction information to the plurality of devices to add a block having the new transaction information to the blockchain; 2. An image log management program comprising:

Images