DATA CARE SYSTEM, DATA CARE PROCEDURES, DATA CARE PROGRAM, DATA REGISTRATION DEVICE AND DATA VERIFICATION DEVICE

Abstract

A data registration device (200) processes original data stored in a data source and registers the processed data. A data verification device (300) calculates a digest value from combined reference data, generated based on a digest value of the original data and a digest value of the processed data as the reference digest value. The data verification device calculates a digest value of the registered processed data as a preliminary digest value, retrieves a digest value stored in the data source as a preliminary digest value, calculates a digest value from combined verification data, generated based on the preliminary digest values ​​of the original data and the preliminary digest values ​​of the processed data, as the verification digest value, and compares the verification digest value with the reference digest value.

Description

Technical area

[0001] The present disclosure relates to data maintenance techniques. State of the art

[0002] Data backup systems using magnetic tapes are traditionally used for the cost-effective storage of large amounts of data.

[0003] However, current data recording systems do not offer sufficient security, reliability, and scalability. For example, data compression and error correction are inadequate.

[0004] Patent Literature 1 discloses an archival data recording system.

[0005] The system solves the above problems by optimizing work planning, detecting data corruption at a data level, and detecting errors at a metadata level.

[0006] Specifically, the data is divided into a series of subsections, and a root digest (a collection of digest values) is maintained. This guarantees the authenticity of the data. Reference listPatent literature

[0007] Patent Literature 1: JP 6463796 Summary of the inventionTechnical problem

[0008] A traditional data maintenance system calculates a digest value of data and compares the calculated digest value with a digest value from a data source to ensure data authenticity. This verifies that the data maintenance system has the same data as the data from the data source.

[0009] However, in cases where part of the data is backed up or processed data is backed up, a traditional data maintenance system cannot guarantee that the backed up data is data derived from the data source.

[0010] The objective of the present disclosure is to enable verification of whether the registered data is data derived from data in a data source when processing and registering data from the data source. Solution to the problem

[0011] A data maintenance system according to the present disclosure comprises: a data processing unit for retrieving original data stored in a data source, processing the retrieved original data, and registering the received processed data; a reference digest value calculation unit for calculating, during registration of the processed data, a digest value of the retrieved original data and a digest value of the processed data, for generating combined reference data by combining the calculated digest values, and for calculating a digest value of the combined reference data as a reference digest value; a preliminary digest value calculation unit for calculating a digest value of the registered processed data as a preliminary digest value during the verification of the processed data; and a data verification unit to retrieve the digest value saved in the data source as the digest value of the original data as a preliminary digest value, generate combined verification data by combining the preliminary digest value of the original data and the preliminary digest value of the processed data, calculate a digest value of the combined verification data as a verification digest value, compare the verification digest value with the reference digest value, and determine whether the registered processed data is data derived from the original data in the data source. Advantageous effects of the invention

[0012] According to the present disclosure, it can be verified whether the registered data is data derived from data in a data source when data from the data source is processed and registered. Short description of the drawings Fig. 1 shows a configuration of a data management system 100 in Embodiment 1. Fig. 2 shows a configuration of a data registration device 200 in Embodiment 1. Fig. 3 shows a configuration of a data verification device 300 in Embodiment 1. Fig. 4 shows a configuration of a data source device 400 in Embodiment 1. Fig. 5 is a flowchart of a data registration process in Embodiment 1. Fig. 6 is a flowchart of a consistency verification process in Embodiment 1. Fig. 7 schematically shows a data maintenance method in Embodiment 1. Fig. 8 schematically shows a data maintenance method according to a conventional technique. Fig. Figure 9 shows problems of the data maintenance procedure according to the conventional technique. Fig. 10 shows a configuration of the data management system 100 in Embodiment 2. Fig. 11 shows a configuration of a signature device 500 in Embodiment 2. Fig. 12 is a flowchart of a data registration process in Embodiment 2. Fig. 13 is a flowchart of a consistency verification process in Embodiment 2. Fig. 14 schematically shows a data maintenance method in Embodiment 2. Fig. 15 is a flowchart of a data registration process in Embodiment 3. Fig. 16 is a flowchart of a consistency verification process in Embodiment 3. Fig. 17 schematically shows a data maintenance method in Embodiment 3. Fig. 18 is a flowchart of a data registration process in Embodiment 4. Fig. 19 is a flowchart of a consistency verification process in Embodiment 4. Fig. 20 schematically shows a data maintenance method in Embodiment 4. Fig. 21 is a flowchart of a data registration process in Embodiment 5. Fig. 22 is a flowchart of a consistency verification process in Embodiment 5. Fig. 23 schematically shows a data maintenance method in Embodiment 5. Fig. 24 is a flowchart of a data registration process in Embodiment 6. Fig. 25 is a flowchart of a consistency verification process in Embodiment 6. Fig. Figure 26 is the flowchart of the consistency verification process in Embodiment 6. Fig. 27 schematically shows a data maintenance method in Embodiment 6. Fig. 28 schematically shows the data maintenance method in Embodiment 6. Fig. 29 shows a hardware configuration of the data registration device 200 in one embodiment. Fig. 30 shows a hardware configuration of the data verification device 300 in one embodiment. Fig. 31 shows a hardware configuration of the data source device 400 in one embodiment. Fig. 32 shows a hardware configuration of the signature device 500 in one embodiment. Description of embodiments

[0013] In the embodiments and drawings, identical or corresponding elements are designated by the same reference numerals. Descriptions of elements with the same reference numerals as previously described elements are omitted or simplified where appropriate. Arrows in the drawings primarily indicate a data flow or a processing flow. Embodiment 1.

[0014] A data management system 100 is based on the Fig. 1 to 9 described. ***Configuration Descriptions***

[0015] With reference to Fig. 1 describes a configuration of the data management system 100.

[0016] The data management system 100 includes a data maintenance system 101 and a data source device 400.

[0017] The data maintenance system 101 includes a data registration device 200 and a data verification device 300.

[0018] The data registration device 200, the data verification device 300, and the data source device 400 communicate with each other via a network.

[0019] Based on Fig. 2, a configuration of the data registration device 200 is described.

[0020] The data registration device 200 is a computer having hardware parts such as a processor 201, a memory 202, an auxiliary storage device 203, a communication device 204, and an input / output interface 205. These hardware parts are connected to each other via signal lines.

[0021] Processor 201 is an integrated circuit that performs arithmetic processing and controls other hardware components. Processor 201 is, for example, a CPU.

[0022] IC is an abbreviation for Integrated Circuit.

[0023] CPU is an abbreviation for Central Processing Unit.

[0024] The working memory 202 is a volatile or non-volatile storage device. The working memory 202 is also referred to as a main storage device or main memory. For example, the working memory 202 is a RAM. Data stored in the working memory 202 is backed up to the auxiliary storage device 203 as needed.

[0025] RAM is an abbreviation for Random Access Memory.

[0026] Auxiliary storage device 203 is a non-volatile memory device. Auxiliary storage device 203 is, for example, a ROM, an HDD, a flash memory, or a combination thereof. Data stored in auxiliary storage device 203 is loaded into main memory 202 as needed.

[0027] ROM is an abbreviation for Read Only Memory.

[0028] HDD is an abbreviation for Hard Disk Drive.

[0029] The communication device 204 includes a receiver and a transmitter. For example, the communication device 204 is a communication chip or NIC. Communications of the data registration device 200 are performed through the communication device 204. NIC is an abbreviation for Network Interface Card.

[0030] The input / output interface 205 consists of ports for connecting input devices and output devices. The input / output interface 205 includes, for example, USB ports, the input device includes a keyboard and mouse, and the output device includes a display. The input and output of the data recording device 200 are performed via the input / output interface 205.

[0031] USB is an abbreviation for Universal Serial Bus.

[0032] The data registration device 200 includes elements referred to as a data processing unit 210 and a data management unit 220. These elements are implemented in software.

[0033] A data registration program is stored in the auxiliary storage device 203, which causes a computer to operate as a data processing unit 210 and a data management unit 220. The data registration program is loaded into the main memory 202 and executed by the processor 201.

[0034] Furthermore, the auxiliary storage device 203 stores an operating system therein. At least a portion of the operating system is loaded into the main memory 202 and executed by the processor 201.

[0035] The processor 201 executes the data registration program while the OS is running.

[0036] OS is an abbreviation for Operating System.

[0037] Input and output data for the data registration program are stored in a storage unit 290.

[0038] The auxiliary storage device 203 functions as the storage unit 290. However, instead of or in conjunction with the auxiliary storage device 203, a storage device such as the main memory 202, a register in the processor 201, and a cache memory in the processor 201 may also function as the storage unit 290.

[0039] The storage unit 290 functions as a data storage 291.

[0040] The data registration device 200 may also include multiple processors that replace the processor 201.

[0041] The data registration program may be recorded (stored) in computer-readable form on a non-volatile recording medium such as an optical disk or flash memory.

[0042] Based on Fig. 3, a configuration of the data registration device 300 is described.

[0043] The data verification device 300 is a computer with hardware parts such as a processor 301, a memory 302, an auxiliary storage device 303, a communication device 304, and an input / output interface 305. These hardware parts are connected to each other via signal lines.

[0044] Processor 301 is an integrated circuit that performs arithmetic processing and controls other hardware components. Processor 301 is, for example, a CPU.

[0045] The working memory 302 is a volatile or non-volatile storage device. The working memory 302 is also referred to as the main storage device or main working memory. For example, the working memory 302 is a RAM. The data stored in the working memory 302 is backed up to the auxiliary storage device 303 when needed.

[0046] Auxiliary storage device 303 is a non-volatile memory device. Auxiliary storage device 303 is, for example, a ROM, an HDD, a flash memory, or a combination thereof. Data stored in auxiliary storage device 303 is loaded into main memory 302 as needed.

[0047] The communication device 304 includes a receiver and a transmitter. For example, the communication device 304 is a communication chip or a network interface (NIC). Communications of the data verification device 300 are performed by the communication device 304.

[0048] The input / output interface 305 consists of ports for connecting input devices and output devices. The input / output interface 305 may be, for example, USB ports, the input device may be a keyboard and mouse, and the output device may be a display. The input and output of the data verification device 300 are performed via the input / output interface 305.

[0049] The data verification device 300 includes elements such as a digest value calculation unit 310 and a data verification unit 320. These elements are implemented in software.

[0050] The digest value calculation unit 310 includes a reference digest value calculation unit 311 and a preliminary digest value calculation unit 312.

[0051] A data verification program is stored in the auxiliary storage device 303, which causes a computer to operate as the digest value calculation unit 310 and the data verification unit 320. The data verification program is loaded into the main memory 302 and executed by the processor 301.

[0052] Furthermore, the auxiliary storage device 303 stores an operating system therein. At least a portion of the operating system is loaded into the main memory 302 and executed by the processor 301.

[0053] The processor 301 executes the data verification program while the OS is running.

[0054] Input and output data for the data verification program are stored in a storage unit 390.

[0055] The auxiliary storage device 303 functions as the storage unit 390. However, instead of or in conjunction with the auxiliary storage device 303, a storage device such as the main memory 302, a register in the processor 301, and a cache memory in the processor 301 may also function as the storage unit 390.

[0056] The storage unit 390 functions as a data storage 391.

[0057] The data verification device 300 may also include multiple processors that replace the processor 301.

[0058] The data verification program may be recorded (stored) in computer-readable form on a non-volatile recording medium such as an optical disk or flash memory.

[0059] With reference to Fig. 4, a configuration of the data source device 400 is described.

[0060] The data source device 400 is a computer with hardware parts such as a processor 401, a memory 402, an auxiliary storage device 403, a communication device 404, and an input / output interface 405. These hardware parts are connected to each other via signal lines.

[0061] Processor 401 is an integrated circuit that performs arithmetic processing and controls other hardware components. Processor 401 is, for example, a CPU.

[0062] The working memory 402 is a volatile or non-volatile storage device. The working memory 402 is also referred to as the main storage device or main memory. The working memory 402 is, for example, a RAM. Data stored in the working memory 402 is backed up to the auxiliary storage device 403 as needed.

[0063] Auxiliary storage device 403 is a non-volatile memory device. Auxiliary storage device 403 is, for example, a ROM, an HDD, a flash memory, or a combination thereof. Data stored in auxiliary storage device 403 is loaded into main memory 402 as needed.

[0064] The communication device 404 includes a receiver and a transmitter. For example, the communication device 404 is a communication chip or a network interface (NIC). Communications of the data source device 400 are performed by the communication device 404.

[0065] The input / output interface 405 consists of ports for connecting input devices and output devices. The input / output interface 405 may be, for example, USB ports, the input device may be a keyboard and mouse, and the output device may be a display. The input and output of the data source device 400 are performed via the input / output interface 405.

[0066] The data source device 400 includes elements such as a data management unit 410 and a digest value calculation unit 420. These elements are implemented in software.

[0067] A data source program is stored in the auxiliary storage device 403, which causes a computer to operate as the data management unit 410 and the digest value calculation unit 420. The data source program is loaded into the main memory 402 and executed by the processor 401.

[0068] Furthermore, the auxiliary storage device 403 stores an operating system therein. At least a portion of the operating system is loaded into the main memory 402 and executed by the processor 401.

[0069] The processor 401 executes the data source program while the operating system is running.

[0070] Input and output data for the data source program are stored in a storage unit 490.

[0071] The auxiliary storage device 403 functions as the storage unit 490. However, instead of or in conjunction with the auxiliary storage device 403, a storage device such as the main memory 402, a register in the processor 401, and a cache memory in the processor 401 may also function as the storage unit 490.

[0072] The storage unit 490 acts as data source 491.

[0073] The data source device 400 may also include multiple processors that replace the processor 401.

[0074] The data source program may be recorded (stored) in computer-readable form on a non-volatile recording medium such as an optical disk or flash memory. ***Description of how it works***

[0075] A functional sequence of the data management system 100 corresponds to a data management method. A functional sequence of the data management system 100 also corresponds to a processing sequence by a data management program.

[0076] A functional sequence of the data maintenance system 101 corresponds to a data maintenance procedure. The functional sequence of the data maintenance system 101 also corresponds to a processing sequence by a data maintenance program.

[0077] The data maintenance procedure is part of the data management procedure.

[0078] With reference to Fig. 5 to 7 describe the data management procedure.

[0079] Original data and a digest value of the original data were saved in data source 491. The digest value of the original data is calculated by digest value calculation unit 420.

[0080] With reference to Fig. 5 describes a data registration process.

[0081] The data registration process is a process carried out in the data management procedure.

[0082] In step S101, the data processing unit 210 retrieves the original data saved in the data source 491.

[0083] Thus, the data management unit 410 reads the original data from the data source 491 and transmits the original data to the data registration device 200. The data processing unit 210 then receives the original data.

[0084] In Fig. 7, data A is the original data saved in data source 491.

[0085] The data processing unit 210 retrieves the data A stored in the data source 491.

[0086] Referring again to Fig. 5, step S102 and the following steps are described.

[0087] In step S102, the data processing unit 210 processes the retrieved original data.

[0088] Specifically, the data processing unit 210 executes a data processing program on the original data as input.

[0089] This provides processed data. The processed data is the original data after processing.

[0090] In step S103, the data processing unit 210 registers the processed data in the data memory 291.

[0091] In Fig. 7, the data A' is the processed data for data A and is saved in the data memory 291.

[0092] Referring again to Fig. 5, step S111 and the following step are described.

[0093] In step S111, the reference digest value calculation unit 311 retrieves the original data and the processed data.

[0094] For example, the data management unit 220 transmits the original data and the processed data to the data verification device 300. The reference digest value calculation unit 311 then retrieves the original data and the processed data.

[0095] The reference digest value calculation unit 311 then calculates a reference digest value using the original data and the processed data.

[0096] The reference digest value is calculated as follows.

[0097] The reference digest value calculation unit 311 first calculates a digest value of the original data.

[0098] The reference digest value calculation unit 311 also calculates a digest value of the processed data.

[0099] Subsequently, the reference digest value calculation unit 311 combines the digest value of the original data with the digest value of the processed data to generate combined data. The thus generated combined data is referred to as combined reference data.

[0100] The combined reference data can also be calculated in a manner other than that described above. For example, the original data and the processed data can be combined to generate combined data, and a digest value of the combined data can be calculated as the combined reference data. Instead of combining, four arithmetic operations can also be used.

[0101] The combined reference data can be calculated in any way, as long as the uniqueness of the combined reference data is guaranteed. The method of calculation is irrelevant, as long as the combined reference data is a digest value calculated using the original data and the processed data.

[0102] The reference digest value calculation unit 311 then calculates a digest value of the combined reference data. The calculated digest value is the reference digest value.

[0103] In step S112, the reference digest value calculation unit 311 saves the reference digest value in the data memory 391.

[0104] In Fig. 7, D(D(Data A) + D(Data A')) is the reference digest value stored in data memory 391. D(Data A) + D(Data A') represents the combined reference data. D(Data A) is the digest value of Data A, and D(Data A') is the digest value of Data A'.

[0105] With reference to Fig. 6 describes a consistency verification process.

[0106] The consistency verification process is a process performed in the data management procedure.

[0107] In step S121, the preliminary digest value calculation unit 312 retrieves the processed data registered in the data storage 291.

[0108] The preliminary digest value calculation unit 312 transmits, for example, a data request to the data registration device 200. The data management unit 220 receives the data request, reads the processed data from the data storage 291, and sends the processed data to the data verification device 300. The preliminary digest value calculation unit 312 then receives the processed data.

[0109] The preliminary digest value calculation unit 312 then calculates a digest value of the processed data. The calculated digest value is referred to as a preliminary digest value.

[0110] In Fig. 7, D(Data A') is the preliminary digest value of the processed data.

[0111] Referring again to Fig. 6, step S122 and the following steps are described.

[0112] In step S122, the data verification unit 320 retrieves the digest value of the original data, which is the digest value saved in the data source 491.

[0113] For example, the data verification unit 320 sends a digest value request to the data source device 400. The data management unit 410 receives the digest value request, reads the digest value of the original data from the data source 491, and transmits the digest value of the original data to the data verification device 300. The data verification unit 320 then receives the digest value of the original data.

[0114] The retrieved digest value is called the preliminary digest value.

[0115] In Fig. 7, D(Data A) is the digest value of Data A, saved in data source 491.

[0116] The data verification unit 320 retrieves the D(Data A) saved in the data source 491.

[0117] In Fig. 7, D(Data A) is stored in the data source 491. However, only Data A may be present in the data source 491. In this case, the data verification unit 320 would retrieve the Data A and calculate D(Data A) using the retrieved Data A.

[0118] Referring again to Fig. 6, step S123 and the following steps are described.

[0119] In step S123, the data verification unit 320 combines the preliminary digest value of the original data with the preliminary digest value of the processed data to generate combined data.

[0120] The combined data generated is called combined verification data.

[0121] In step S124, the data verification unit 320 calculates a digest value of the combined verification data.

[0122] The calculated digest value is called the verification digest value.

[0123] In step S125, the data verification unit 320 retrieves the reference digest value stored in the data storage 391.

[0124] In particular, the data verification unit 320 reads the reference digest value from the data memory 391.

[0125] In Fig. 7, D(D(Data A) + D(Data A')) is the reference digest value stored in data memory 391.

[0126] The data verification unit 320 retrieves the reference digest value stored in the data memory 391.

[0127] Referring again to Fig. 6, step S131 and the following steps are described.

[0128] In step S131, the data verification unit 320 compares the verification digest value with the reference digest value.

[0129] If the verification digest value matches the reference digest value, processing proceeds to step S132.

[0130] If the verification digest value does not match the reference digest value, processing proceeds to step S133.

[0131] In step S132, the data verification unit 320 determines “consistent.”

[0132] “Consistent” means that the processed data registered in the data store 291 is derived from the original data of the data source 491.

[0133] The data verification unit 320 then outputs a determination result indicating "consistent." The data verification unit 320 displays the determination result on a display, for example.

[0134] In step S133, the data verification unit 320 determines “inconsistent.”

[0135] "Inconsistent" means that the processed data registered in the data store 291 is not derived from the original data of the data source 491. For example, "inconsistent" indicates that the processed data registered in the data store 291 is manipulated data.

[0136] The data verification unit 320 then outputs a determination result indicating "inconsistent." The data verification unit 320 displays the determination result on a display, for example. ***Effects of Embodiment 1***

[0137] With reference to the Fig. 7 to 9 describe the effects of Embodiment 1.

[0138] Fig. 8 and Fig. 9 show a conventional data maintenance system. The conventional data maintenance system verifies the consistency of the registered data A with the data A in the data source by comparing the digest values ​​D of the data A (see Fig. 8). However, if part of the data A or converted data A is registered, the traditional data maintenance system cannot verify that the registered data A' is data derived from data A in the data source.

[0139] Fig. 7 shows the data maintenance system 101. The data maintenance system 101 saves a digest value D(D(Data A) + D(Data A')) (hereinafter referred to as DD) of combined data generated with the digest value D of Data A and the digest value D of Data A'. When verifying the data, the data maintenance system 101 retrieves the digest value D of Data A from the data source 491, calculates the digest value D of the registered Data A', and calculates the digest value DD of the combined data. The data maintenance system 101 then compares the calculated digest value DD with the saved digest value DD, thus verifying that the registered Data A' is data derived from Data A in the data source 491.

[0140] If the data A' is tampered with, the digest value D of the data A' changes, so that the digest value DD does not match during verification.

[0141] This means that by saving the digest value DD, the data maintenance system 101 can verify that the registered data A' is data derived from data A in the data source 491.

[0142] It is desirable to secure the digest value DD in an area where tampering is difficult, since tampering with the secured digest value DD makes it impossible to detect tampering with the data A'. Embodiment 2.

[0143] An arrangement for the secure management of a reference digest value is made with reference to the Fig. 10 to 14 are described especially with regard to the differences to embodiment 1. *** Configuration description ***

[0144] With reference to Fig. 10 describes the configuration of the data management system 100.

[0145] The data management system 100 also includes a signature device 500.

[0146] With reference to Fig. 11, a configuration of the signature device 500 is described.

[0147] The signature device 500 is a computer with hardware components such as a processor 501, a memory 502, an auxiliary storage device 503, a communication device 504, and an input / output interface 505. These hardware components are interconnected via signal lines.

[0148] Processor 501 is an integrated circuit that performs arithmetic processing and controls other hardware components. Processor 501 is, for example, a CPU.

[0149] The working memory 502 is a volatile or non-volatile storage device. The working memory 502 is also referred to as the main storage device or main memory. For example, the working memory 502 is a RAM. Data stored in the working memory 502 is backed up to the auxiliary storage device 503 as needed.

[0150] Auxiliary storage device 503 is a non-volatile memory device. Auxiliary storage device 503 is, for example, a ROM, an HDD, a flash memory, or a combination thereof. Data stored in auxiliary storage device 503 is loaded into main memory 502 as needed.

[0151] The communication device 504 includes a receiver and a transmitter. For example, the communication device 504 is a communication chip or a network interface (NIC). Communications of the signature device 500 are performed by the communication device 504.

[0152] The input / output interface 505 consists of ports for connecting input devices and output devices. For example, the input / output interface 505 includes USB ports, the input device includes a keyboard and mouse, and the output device includes a display. The input and output of the signature device 500 are performed via the input / output interface 505.

[0153] The signature device 500 includes elements such as a key management unit 510 and a signature unit 520. These elements are implemented in software.

[0154] A signature program is stored in the auxiliary storage device 503, which causes a computer to operate as the key management unit 510 and the signature unit 520. The signature program is loaded into the main memory 502 and executed by the processor 501.

[0155] Furthermore, the auxiliary storage device 503 stores an operating system therein. At least a portion of the operating system is loaded into the main memory 502 and executed by the processor 501.

[0156] The processor 501 executes the data source program while the operating system is running.

[0157] Input and output data for the signature program are stored in a storage unit 590.

[0158] The auxiliary storage device 503 functions as the storage unit 590. However, instead of or in conjunction with the auxiliary storage device 503, a storage device such as the main memory 502, a register in the processor 501, and a cache memory in the processor 501 may also function as the storage unit 590.

[0159] The signature device 500 may also include multiple processors that replace the processor 501.

[0160] The signature program may be recorded (stored) in computer-readable form on a non-volatile recording medium such as an optical disk or flash memory. ***Description of how it works***

[0161] With reference to the Fig. 12 and Fig. 13 describes the data management procedure.

[0162] In the signature device 500, the key management unit 510 generates a pair of a secret key and a public key. The secret key is stored in the storage unit 590 of the signature device 500. The public key is stored in the storage unit 390 of the data verification device 300.

[0163] With reference to Fig. 12 describes a data registration process.

[0164] Steps S201 to S203 are the same as steps S101 to S103 in Embodiment 1.

[0165] In step S211, the reference digest value calculation unit 311 calculates a reference digest value using the original data and processed data.

[0166] Step S211 is the same as step S111 in Embodiment 1.

[0167] In step S212, the signature unit 520 generates a signature for the reference digest value (hereinafter referred to as digest signature).

[0168] A digest signature is a value obtained by encrypting the reference digest value with a secret key. A digest signature is generated in the following way.

[0169] The reference digest value calculation unit 311 transmits the reference digest value to the signature device 500. The reference digest value calculation unit 311 also temporarily records the reference digest value.

[0170] The signature unit 520 receives the reference digest value and generates a digital signature for the reference digest value using the secret key.

[0171] The signature unit 520 transmits the digest signature to the data verification device 300.

[0172] The reference digest value calculation unit 311 receives the digest signature.

[0173] In step S213, the data verification unit 320 saves the digest signature in the data storage 391.

[0174] The digest signature is secured in the following process.

[0175] The data verification unit 320 decrypts the digest signature with the public key to obtain the reference digest value.

[0176] The data verification unit 320 compares the temporarily recorded reference digest value with the reference digest value resulting from the decryption.

[0177] If the comparison shows that the temporarily recorded reference digest value and the reference digest value resulting from the decryption match, the data verification unit 320 stores the digest signature in the data memory 391.

[0178] If the comparison reveals that the temporarily recorded reference digest value and the reference digest value resulting from the decryption are different, the processing proceeds to step S212.

[0179] With reference to Fig. 13 describes a consistency verification process.

[0180] Steps S221 to S224 are the same as steps S121 to S124 in Embodiment 1.

[0181] In step S225, the data verification unit 320 retrieves the digest signature from the data storage 391 and decrypts the reference digest value from the digest signature using the public key.

[0182] Steps S231 to S233 are the same as steps S131 to S133 in Embodiment 1. ***Effects of Embodiment 2***

[0183] With reference to Fig. 14 describes the effects of Embodiment 2.

[0184] It is desirable that the reference digest value DD is managed securely, since manipulation of the reference digest value DD makes it impossible to detect manipulation of the data A'.

[0185] In this way, the signature device 500 is provided, and a digest signature S(D(D(Data A) + D(Data A'))) (hereinafter referred to as SDD) is generated using a secret key. The reference digest value DD can be obtained by decrypting the digest signature SDD with the public key. It is difficult to easily tamper with the digest signature SDD if the secret key is not obtained.

[0186] Embodiment 2 can accordingly securely manage the reference digest value DD. Embodiment 3.

[0187] An arrangement for managing a reference digest value in the data source 491 is described with reference to the Fig. 15 to 17 are described especially with regard to the differences to embodiment 1. *** Configuration description ***

[0188] The configuration of the data management system 100 is the same as the configuration in Embodiment 1. ***Description of how it works***

[0189] With reference to Fig. 15 describes a data registration process.

[0190] Steps S301 to S303 are the same as steps S101 to S103 in Embodiment 1.

[0191] Step S311 is the same as step S111 in Embodiment 1.

[0192] In step S312, the reference digest value calculation unit 311 transmits the reference digest value to the data source device 400.

[0193] The data management unit 410 receives the reference digest value.

[0194] In step S313, the data management unit 410 saves the reference digest value in the data source 491.

[0195] With reference to Fig. 16 describes a consistency verification process.

[0196] In step S321, the preliminary digest value calculation unit 312 calculates a digest value of the processed data. The calculated digest value is referred to as a preliminary digest value.

[0197] Step S321 is the same as step S121 in Embodiment 1.

[0198] In step S322, the data verification unit 320 retrieves the digest value of the original data, which is the digest value saved in the data source 491. The retrieved digest value is referred to as a preliminary digest value.

[0199] The data verification unit 320 also retrieves the reference digest value stored in the data source 491.

[0200] For example, the data verification unit 320 transmits a digest value request to the data source device 400. The data management unit 410 receives the digest value request, reads the digest value of the original data and the reference digest value from the data source 491, and transmits the digest value of the original data and the reference digest value to the data verification device 300. The data verification unit 320 then receives the digest value of the original data and the reference digest value.

[0201] In step S323, the data verification unit 320 generates combined verification data.

[0202] Step S323 corresponds to step S123 in Embodiment 1.

[0203] In step S324, the data verification unit 320 calculates a verification digest value.

[0204] Step S324 is the same as step S124 in Embodiment 1.

[0205] Steps S331 to S333 are the same as steps S131 to S133 in Embodiment 1. ***Effects of Embodiment 3***

[0206] With reference to Fig. 17 describes the effects of Embodiment 3.

[0207] It is desirable that the reference digest value DD is managed securely, since manipulation of the reference digest value DD makes it impossible to detect manipulation of the data A'.

[0208] Thus, the reference digest value DD is managed in the data source 491 in such a way that manipulation of the reference digest value DD is difficult. It is desirable that the data source 491 be a system that is difficult to manipulate, such as a blockchain.

[0209] In embodiment 3, this allows the reference digest value DD to be managed securely. Embodiment 4.

[0210] An arrangement for increasing the verification accuracy is described with reference to the Fig. 18 to 20 are described especially with regard to the differences to embodiment 1. *** Configuration description ***

[0211] The configuration of the data management system 100 is the same as the configuration in Embodiment 1. ***Description of how it works***

[0212] With reference to Fig. 18 describes a data registration process.

[0213] In step S401, the data processing unit 210 retrieves the original data saved in the data source 491.

[0214] Step S401 is the same as step S101 in Embodiment 1.

[0215] In step S402, the data processing unit 210 executes a data processing program on the original data as input. This provides processed data.

[0216] Step S402 is the same as step S102 in Embodiment 1.

[0217] In step S403, the data processing unit 210 registers the data processing program in the data memory 291 with the processed data.

[0218] In step S411, the reference digest value calculation unit 311 retrieves the data processing program including the original data and the processed data.

[0219] The reference digest value calculation unit 311 then calculates a reference digest value using the original data, the processed data, and the data processing program.

[0220] Specifically, the reference digest value calculation unit 311 calculates the respective digest values ​​of the original data, the processed data, and the data processing program, and combines the calculated digest values ​​to generate combined reference data. The reference digest value calculation unit 311 then calculates a digest value of the combined reference data (a reference digest value).

[0221] In step S412, the reference digest value calculation unit 311 saves the reference digest value in the data memory 391.

[0222] Step S412 is the same as step S112 in Embodiment 1.

[0223] With reference to Fig. 19 describes a consistency verification process.

[0224] In step S421, the preliminary digest value calculation unit 312 calculates a digest value of the processed data. The calculated digest value is referred to as a preliminary digest value.

[0225] Step S421 is the same as step S121 in Embodiment 1.

[0226] In step S422, the preliminary digest value calculation unit 312 retrieves the data processing program registered in the data storage 291.

[0227] The preliminary digest value calculation unit 312 then calculates a digest value of the data processing program. The calculated digest value is referred to as a preliminary digest value.

[0228] In step S423, the data verification unit 320 retrieves the digest value of the original data, which is the digest value saved in the data source 491. The retrieved digest value is referred to as a preliminary digest value.

[0229] Step S423 is the same as step S122 in Embodiment 1.

[0230] In step S424, the data verification unit 320 combines the preliminary digest value of the original data, the preliminary digest value of the processed data, and the preliminary digest value of the data processing program to generate combined data. The generated combined data is referred to as combined verification data.

[0231] In step S425, the data verification unit 320 calculates a digest value of the combined verification data. The calculated digest value is referred to as the verification digest value.

[0232] Step S425 is the same as step S124 in Embodiment 1.

[0233] In step S426, the data verification unit 320 retrieves the reference digest value stored in the data storage 391.

[0234] Step S426 is the same as step S125 in Embodiment 1.

[0235] Steps S431 to S433 are the same as steps S131 to S133 in Embodiment 1. ***Effects of Embodiment 4***

[0236] With reference to Fig. 20 describes the effects of embodiment 4.

[0237] The data processing program is registered with data A'. Then, the digest value D of data A, the digest value D of data A', and the digest value D of the data processing program are combined, and the digest value of the combined data is saved as the reference digest value D(D(Data A) + D(Data A') + D(Data processing program)) (hereinafter referred to as DD).

[0238] By also backing up the data processing program along with an associated reference digest value, it can be ensured that data A' is generated by converting data A using the data processing program, which provides a stronger guarantee that data A' was derived from data A. To manipulate data A' in a consistent manner, not only the digest value D of data A' and the reference digest value DD must be manipulated, but also the data processing program. This achieves greater robustness. Embodiment 5.

[0239] An arrangement for increasing the verification accuracy by managing several data processing programs is described with reference to the Fig. 21 to 23 are described especially with regard to the differences from embodiment 1. *** Configuration description ***

[0240] The configuration of the data management system 100 is the same as the configuration in Embodiment 1.

[0241] However, a plurality of data processing programs are stored in the storage unit 290 of the data registration device 200. ***Description of how it works***

[0242] With reference to Fig. 18 describes a data registration process.

[0243] In step S501, the data processing unit 210 retrieves the original data saved in the data source 491.

[0244] Step S501 is the same as step S101 in Embodiment 1.

[0245] In step S502, the data processing unit 210 selects a data processing program for processing the original data from among the plurality of data processing programs.

[0246] The data processing program is determined, for example, by the user of the data registration device 200. Alternatively, the data processing program is determined by the type of original data.

[0247] The data processing unit 210 then executes the selected data processing program on the original data as input. This provides processed data.

[0248] In step S503, the data processing unit 210 registers a program identifier of the data processing program that was used in the data storage 291 together with the processed data.

[0249] In step S511, the reference digest value calculation unit 311 retrieves the data processing program used together with the original data and the processed data.

[0250] The reference digest value calculation unit 311 then calculates a reference digest value using the original data, the processed data, and the data processing program.

[0251] Specifically, the reference digest value calculation unit 311 calculates the respective digest values ​​of the original data, the processed data, and the data processing program, and combines the calculated digest values ​​to generate combined reference data. The reference digest value calculation unit 311 then calculates a digest value of the combined reference data (a reference digest value).

[0252] In step S512, the reference digest value calculation unit 311 saves the reference digest value in the data memory 391.

[0253] Step S512 is the same as step S112 in Embodiment 1.

[0254] With reference to Fig. 19 describes a consistency verification process.

[0255] In step S521, the preliminary digest value calculation unit 312 calculates a digest value of the processed data. The calculated digest value is referred to as a preliminary digest value.

[0256] Step S521 is the same as step S121 in Embodiment 1.

[0257] In step S522, the preliminary digest value calculation unit 312 retrieves the program identifier registered in the data memory 291.

[0258] The preliminary digest value calculation unit 312 further retrieves the data processing program identified by the retrieved program identifier.

[0259] The preliminary digest value calculation unit 312 then calculates a digest value of the data processing program. The calculated digest value is referred to as a preliminary digest value.

[0260] In step S523, the data verification unit 320 retrieves the digest value of the original data, which is the digest value saved in the data source 491. The retrieved digest value is referred to as a preliminary digest value.

[0261] Step S523 is the same as step S122 in Embodiment 1.

[0262] In step S524, the data verification unit 320 combines the preliminary digest value of the original data, the preliminary digest value of the processed data, and the preliminary digest value of the data processing program to generate combined data. The generated combined data is referred to as combined verification data.

[0263] In step S525, the data verification unit 320 calculates a digest value of the combined verification data. The calculated digest value is referred to as the verification digest value.

[0264] Step S525 is the same as step S124 in Embodiment 1.

[0265] In step S526, the data verification unit 320 retrieves the reference digest value stored in the data storage 391.

[0266] Step S526 is the same as step S125 in Embodiment 1.

[0267] Steps S531 to S533 are the same as steps S131 to S133 in Embodiment 1. ***Effects of Embodiment 5***

[0268] With reference to Fig. 23 describes the effects of embodiment 5.

[0269] The program identifier of the data processing program is registered with data A'. Then, the digest value D of data A, the digest value D of data A', and the digest value D of the data processing program are combined, and a digest value of the combined data is saved as the reference digest value DD. During verification, the digest value D of the data processing program identified by the program identifier is calculated.

[0270] It can therefore be verified with a high degree of certainty that data A' was derived from data A. For example, it is possible to detect the manipulation of data A' by an unauthorized data processing program.

[0271] In addition, space in the data memory 291 can be saved by registering the program identifier in the data memory 291 instead of the data processing program.

[0272] In addition, limiting the data processing program prevents the execution of arbitrary data processing programs and makes it less likely that fraud will be introduced into the generation process of data A'. Embodiment 6.

[0273] An arrangement in case data in the data source 491 is updated is made with reference to the Fig. 24 to 28 are described especially with regard to the differences from embodiment 1. *** Configuration description ***

[0274] The configuration of the data management system 100 is the same as the configuration in Embodiment 1.

[0275] However, the original data stored in data source 491 will be updated. The original data before the update is referred to as old data.

[0276] At least the original data and the digest value of the original data are saved in data source 491. ***Description of how it works***

[0277] With reference to Fig. The data management procedure is described in sections 24 to 26.

[0278] Before updating the old data, the data processing unit 210 retrieved the old data saved in the data source 491, processed the retrieved old data to obtain processed old data, and registered the processed old data in the data storage 291.

[0279] With reference to Fig. 24 describes a data registration process.

[0280] In step S601, the data processing unit 210 retrieves the original data saved in the data source 491.

[0281] Step S601 is the same as step S101 in Embodiment 1.

[0282] In step S602, the data processing unit 210 processes the retrieved original data.

[0283] Specifically, the data processing unit 210 executes a data processing program on the original data as input.

[0284] This provides processed original data. The processed original data is the original data after processing.

[0285] In step S603, the data processing unit 210 registers processed data in the data memory 291.

[0286] The processed data is a set of the processed original data and the digest value of the processed old data.

[0287] The digest value of the processed old data is calculated, for example, by the digest value calculation unit 310.

[0288] Steps S611 and S612 are the same as steps S111 and S112 in Embodiment 1.

[0289] With reference to Fig. 25 and Fig. 26 describes a consistency verification process.

[0290] Steps S621 to S625 are the same as steps S121 to S125 in Embodiment 1.

[0291] In step S631, the data verification unit 320 compares the verification digest value with the reference digest value.

[0292] If the verification digest value matches the reference digest value, processing proceeds to step S641.

[0293] If the verification digest value does not match the reference digest value, processing proceeds to step S632.

[0294] In step S632, the data verification unit 320 determines “inconsistent.”

[0295] Step S632 is the same as step S133 in Embodiment 1.

[0296] In step S641, the data verification unit 320 retrieves the old data processed and registered in the data storage 291.

[0297] The data verification unit 320 then calculates a digest value of the processed old data.

[0298] In step S642, the data verification unit 320 compares the digest value of the processed old data with the digest value in the registered processed data.

[0299] If the digest values ​​match, the data verification unit 320 determines whether a digest value exists in the processed old data.

[0300] If a digest value exists in the processed old data, the processed old data becomes the processed data and processing proceeds to step S641.

[0301] If there is no digest value in the processed old data, processing proceeds to step S651.

[0302] If the digest values ​​do not match, processing proceeds to step S652.

[0303] In step S651, the data verification unit 320 determines “consistent.”

[0304] The data verification unit 320 then outputs a determination result indicating "consistent." The data verification unit 320 displays the determination result on a display, for example.

[0305] In step S652, the data verification unit 320 determines “inconsistent.”

[0306] The data verification unit 320 then outputs a determination result indicating "inconsistent." The data verification unit 320 displays the determination result on a display, for example. ***Effects of Embodiment 6***

[0307] With reference to Fig. 27 and Fig. 28 describes the effects of Embodiment 6.

[0308] In Fig. 27, the data in the data source 491 is updated and its update history is managed. To respond to the data update and update history management, the data maintenance system 101 incorporates the digest value D of the processed old data A' into the processed data B' and saves the digest value D(D(Data B) + D(Data B')) of the processed data B' (hereinafter referred to as DD).

[0309] The data maintenance system 101 can detect tampering with the data history by performing a verification and tracking the digest values ​​D, starting with the digest value DD. Only one digest value DD needs to be saved.

[0310] In Fig. Section 28 explains how tampering can be detected if only one digest value DD is secured. For example, if data A' has been tampered with, D(Data A') for data B' must be tampered with to maintain consistency. Similarly, consistency can only be maintained by tampering with D(Data B') for data C' and D(Data C') for data D', and finally with the digest value DD. As long as the digest value DD is robustly secured, tampering with all data could be detected. ***Additional description of the embodiments***

[0311] The data maintenance system 101 may consist of a single device. That is, the data maintenance system 101 may be a data maintenance device.

[0312] Based on Fig. 29, a hardware configuration of the data registration device 200 is described.

[0313] The data registration device 200 includes a processing circuit 209.

[0314] The processing circuit 209 is hardware that implements the data processing unit 210 and the data management unit 220.

[0315] The processing circuit 209 may be dedicated hardware or may be the processor 201 executing programs stored in the memory 202.

[0316] When the processing circuit 209 is dedicated hardware, the processing circuit 209 may be, for example, a single circuit, a compound circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof.

[0317] ASIC is an abbreviation for Application Specific Integrated Circuit.

[0318] FPGA is an abbreviation for Field Programmable Gate Array.

[0319] The data registration device 200 may include multiple processing circuits to replace the processing circuit 209.

[0320] In the processing circuit 209, some functions may be implemented in special hardware and the remaining functions in software or firmware.

[0321] The functions of the data registration device 200 can therefore be implemented in hardware, software, firmware, or a combination thereof.

[0322] Based on Fig. 30, a hardware configuration of the data verification device 300 is described.

[0323] The data verification device 300 includes a processing circuit 309.

[0324] The processing circuit 309 is a hardware that implements the digest value calculation unit 310 and the data verification unit 320.

[0325] The processing circuit 309 may be dedicated hardware or may be the processor 301 that executes programs stored in the memory 302.

[0326] When the processing circuit 309 is dedicated hardware, the processing circuit 309 may be, for example, a single circuit, a compound circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof.

[0327] The data verification device 300 may include multiple processing circuits to replace the processing circuit 309.

[0328] In the processing circuit 309, some functions may be implemented in special hardware and the remaining functions in software or firmware.

[0329] The functions of the data verification device 300 can therefore be implemented in hardware, software, firmware, or a combination thereof.

[0330] Based on Fig. 31, a hardware configuration of the data source device 400 is described.

[0331] The data source device 400 includes a processing circuit 409.

[0332] The processing circuit 409 is a hardware that implements the data management unit 410 and the digest value calculation unit 420.

[0333] The processing circuit 409 may be dedicated hardware or may be the processor 401 that executes programs stored in the memory 402.

[0334] When the processing circuit 409 is dedicated hardware, the processing circuit 409 may be, for example, a single circuit, a compound circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof.

[0335] The data source device 400 may include multiple processing circuits to replace the processing circuit 409.

[0336] In the processing circuit 409, some functions may be implemented in special hardware and the remaining functions in software or firmware.

[0337] The functions of the data source device 400 may therefore be implemented in hardware, software, firmware, or a combination thereof.

[0338] With reference to Fig. 32, a hardware configuration of the signature device 500 is described.

[0339] The signature device 500 includes a processing circuit 509.

[0340] The processing circuit 509 is a hardware that implements the key management unit 510 and the signature unit 520.

[0341] The processing circuit 509 may be dedicated hardware or may be the processor 501 that executes programs stored in the memory 502.

[0342] When the processing circuit 509 is dedicated hardware, the processing circuit 509 may be, for example, a single circuit, a compound circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof.

[0343] The signature device 500 may include multiple processing circuits to replace the processing circuit 509.

[0344] In the processing circuit 509, some functions may be implemented in special hardware and the remaining functions in software or firmware.

[0345] The functions of the signature device 500 can therefore be implemented in hardware, software, firmware, or a combination thereof.

[0346] The above embodiments are examples of preferred embodiments and are not intended to limit the technical scope of the present disclosure. The embodiments may be practiced partially or in combination with other embodiments. The methods discussed with flowcharts and the like may be modified as needed.

[0347] For the data management system 100, the “unit” of each element of each device may be read as a “process,” “step,” “circuit,” or “circuit.” List of reference symbols

[0348] 100: Data management system; 101: Data maintenance system; 200: Data registration device; 201: Processor; 202: Working memory; 203: Auxiliary storage device; 204: Communication device; 205: Input / output interface; 209: Processing circuit; 210: Data processing unit; 220: Data management unit; 290: Storage unit; 291: Data storage; 300: Data verification device; 301: Processor; 302: Working memory; 303: Auxiliary storage device; 304: Communication device; 305: Input / output interface; 309: Processing circuit; 310: Digest value calculation unit; 311: Reference digest value calculation unit; 312: Preliminary digest value calculation unit; 320: Data verification unit; 390: Storage unit; 391: Data storage; 400: Data source device; 401: Processor; 402: Random access memory; 403: Auxiliary storage device; 404: Communication device; 405: Input / output interface; 409: Processing circuit;410: Data management unit; 420: Digest value calculation unit; 490: Storage unit; 491: Data source; 500: Signature device; 501: Processor; 502: Memory; 503: Auxiliary storage device; 504: Communication device; 505: Input / output interface; 5090: Processing circuit; 510: Key management unit; 520: Signature unit; 590: Storage unit; QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 6463796

[0007]

Claims

[1] Data maintenance system, comprising: a data processing unit for retrieving original data stored in a data source, processing the retrieved original data, and registering the received processed data; a reference digest value calculation unit for calculating, during registration of the processed data, a digest value of the retrieved original data and a digest value of the processed data, for generating combined reference data based on the calculated digest values, and for calculating a digest value of the combined reference data as a reference digest value; a preliminary digest value calculation unit for calculating a digest value of the registered processed data as a preliminary digest value during the verification of the processed data; and a data verification unit to retrieve the digest value of the original data saved in the data source as a preliminary digest value, to generate combined verification data based on the preliminary digest value of the original data and the preliminary digest value of the processed data, to calculate a digest value of the combined verification data as a verification digest value, to compare the verification digest value with the reference digest value, and to determine whether the registered processed data is data derived from the original data in the data source. [2] Data maintenance system according to claim 1, wherein the reference digest value is stored in a data store, and the data verification unit retrieves the reference digest value stored in the data store. [3] Data maintenance system according to claim 1, wherein an encrypted digest value is stored in a data store, where the encrypted digest value is the reference digest value encrypted with a secret key, and the data verification unit retrieves the encrypted digest value stored in the data store and decrypts the reference digest value from the encrypted digest value using a public key corresponding to the secret key. [4] Data maintenance system according to claim 1, wherein the reference digest value is saved in the data source, and the data verification unit retrieves the reference digest value stored in the data store. [5] Data maintenance system according to claim 1, wherein the data processing unit processes the original data by executing a data processing program, the reference digest value calculation unit calculates a digest value of the data processing program in addition to the digest value of the original data and the digest value of the processed data, and generates the combined reference data based on the digest value of the original data, the digest value of the processed data, and the digest value of the data processing program, the preliminary digest value calculation unit calculates a digest value of a registered data processing program as a preliminary digest value in addition to the preliminary digest value of the registered processed data, and the data verification unit generates the combined verification data based on the preliminary digest value of the original data, the preliminary digest value of the processed data, and the preliminary digest value of the data processing program. [6] Data maintenance system according to claim 5, wherein the data processing program is registered with the processed data, and the preliminary digest value calculation unit retrieves the data processing program registered with the processed data and calculates a digest value of the retrieved data processing program as a preliminary digest value of the data processing program. [7] Data maintenance system according to claim 5, wherein a program identifier that identifies the data processing program registered with the processed data, and the preliminary digest value calculation unit retrieves the program identifier registered with the processed data, retrieves the data processing program identified by the retrieved program identifier, and calculates a digest value of the retrieved data processing program as the preliminary digest value of the data processing program. [8] The data maintenance system according to any one of claims 1 to 7, wherein the reference digest value calculation unit generates the combined reference data by combining the calculated digest values. [9] Data maintenance procedures, including: Retrieving original data stored in a data source, processing the retrieved original data, and registering the received processed data; during registration of the processed data, calculating a digest value of the retrieved original data and a digest value of the processed data, generating combined reference data based on the calculated digest values, and calculating a digest value of the combined reference data as a reference digest value; Calculating a digest value of the registered processed data as a preliminary digest value during the verification of the processed data; and Retrieving the digest value saved in the data source as the digest value of the original data as a preliminary digest value, generating combined verification data based on the preliminary digest value of the original data and the preliminary digest value of the processed data, calculating a digest value of the combined verification data as a verification digest value, comparing the verification digest value with the reference digest value, and determining whether the registered processed data is data derived from the original data in the data source. [10] Data maintenance program that causes a computer to execute: a data process of retrieving original data stored in a data source, processing the retrieved original data, and registering the obtained processed data; during registration of the processed data, a reference digest value calculation process of calculating a digest value of the retrieved original data and a digest value of the processed data, generating combined reference data based on the calculated digest values, and calculating a digest value of the combined reference data as a reference digest value; a preliminary digest value calculation process of calculating a digest value of the registered processed data as a preliminary digest value during the verification of the processed data; and a data verification process of retrieving the digest value saved in the data source as the digest value of the original data as a preliminary digest value, generating combined verification data based on the preliminary digest value of the original data and the preliminary digest value of the processed data, calculating a digest value of the combined verification data as a verification digest value, comparing the verification digest value with the reference digest value, and determining whether the registered processed data is data derived from the original data in the data source. [11] Data recording device comprising: a data processing unit for retrieving original data stored in a data source, processing the retrieved original data, and registering the received processed data. [12] Data verification device for verifying processed data, wherein the processed data is obtained by processing original data secured and registered in a data source, wherein the data verification device comprises: a reference digest value calculation unit for calculating, during registration of the processed data, a digest value of retrieved original data and a digest value of the processed data, for generating combined reference data based on the calculated digest values, and for calculating a digest value of the generated combined reference data as a reference digest value; a preliminary digest value calculation unit for calculating a digest value of the registered processed data as a preliminary digest value during the verification of the processed data; and a data verification unit for retrieving the digest value saved in the data source as the digest value of the original data as a preliminary digest value, generating combined verification data based on the preliminary digest value of the original data and the preliminary digest value of the processed data, calculating a digest value of the generated combined verification data as a verification digest value, comparing the calculated verification digest value with the reference digest value, and determining whether the registered processed data is data derived from the original data in the data source. [13] Data maintenance system, comprising: a data processing unit for retrieving original data obtained by updating old data and saved in a data source, processing the retrieved original data to obtain processed original data, and registering a set of the obtained processed original data and a digest value of the processed old data as processed data, the processed old data being obtained by processing the old data; a reference digest value calculation unit for calculating, during registration of the processed data, a digest value of the retrieved original data and a digest value of the processed data, for generating combined reference data based on the calculated digest values, and for calculating a digest value of the combined reference data as a reference digest value; a preliminary digest value calculation unit for calculating a digest value of the registered processed data as a preliminary digest value during the verification of the processed data; and a data verification unit for retrieving the digest value saved in the data source as the digest value of the original data as a preliminary digest value, generating combined verification data based on the preliminary digest value of the original data and the preliminary digest value of the processed data, calculating a digest value of the combined verification data as a verification digest value, comparing the verification digest value with the reference digest value, and determining whether the registered processed data is data derived from the original data in the data source. [14] Data maintenance system according to claim 13, wherein the old data stored in the data source is retrieved, the retrieved old data is processed to obtain the processed old data, and the obtained processed old data is registered, and the data verification unit calculates a digest value of the registered processed old data and compares the calculated digest value with a digest value in the registered processed data. [15] Data maintenance procedures, including: Retrieving original data obtained by updating old data and saving it in a data source, processing the retrieved original data to obtain processed original data, and registering a set of the obtained processed original data and a digest value of the processed old data as processed data, the processed old data being obtained by processing the old data; during registration of the processed data, calculating a digest value of the retrieved original data and a digest value of the processed data, generating combined reference data based on the calculated digest values, and calculating a digest value of the generated combined reference data as a reference digest value; Calculating a digest value of the registered processed data as a preliminary digest value during the verification of the processed data; and Retrieving the digest value stored in the data source as the digest value of the original data as a preliminary digest value, generating combined verification data based on the preliminary digest value of the original data and the preliminary digest value of the processed data, calculating a digest value of the generated combined verification data as a verification digest value, and comparing the calculated verification digest value with the reference digest value. [16] Data maintenance program that causes a computer to perform: a data process: a process of retrieving original data obtained by updating old data and saved in a data source, processing the retrieved original data to obtain processed original data, and registering a set of the obtained processed original data and a digest value of the processed old data as processed data, the processed old data being obtained by processing the old data; during registration of the processed data, a reference digest value calculation process of calculating a digest value of the retrieved original data and a digest value of the processed data, generating combined reference data based on the calculated digest values, and calculating a digest value of the generated combined reference data as a reference digest value; a preliminary digest value calculation process of calculating a digest value of the registered processed data as a preliminary digest value during the verification of the processed data; and a data verification process of retrieving the digest value stored in the data source as the digest value of the original data as a preliminary digest value, generating combined verification data based on the preliminary digest value of the original data and the preliminary digest value of the processed data, calculating a digest value of the generated combined verification data as a verification digest value, and comparing the calculated verification digest value with the reference digest value. [17] Data recording device comprising: a data processing unit for retrieving original data obtained by updating old data and saved in a data source, processing the retrieved original data to obtain processed original data, and registering a set of the obtained processed original data and a digest value of the processed old data as processed data, the processed old data being obtained by processing the old data. [18] Data verification device for verifying processed data, wherein the processed data is a set of processed original data and a digest value of processed old data, the processed original data is obtained by processing original data obtained by updating old data and saved in a data source, the processed old data is obtained by processing the old data, wherein the data verification device comprises: a reference digest value calculation unit for calculating, during registration of the processed data, a digest value of retrieved original data and a digest value of the processed data, for generating combined reference data based on the calculated digest values, and for calculating a digest value of the generated combined reference data as a reference digest value; a preliminary digest value calculation unit for calculating a digest value of the registered processed data as a preliminary digest value during the verification of the processed data; and a data verification unit for retrieving the digest value saved in the data source as the digest value of the original data as a preliminary digest value, generating combined verification data based on the preliminary digest value of the original data and the preliminary digest value of the processed data, calculating a digest value of the generated combined verification data as a verification digest value, and comparing the calculated verification digest value with the reference digest value.

Images