JP3554499B2 - Document management apparatus and method using physical random numbers - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a document management apparatus such as a personal computer for managing management information associated with document data in association with a physical random number and a method thereof.
[0002]
[Background Art]
Conventional computers and word processors have a function of automatically adding the creation date and time to a document file using an internal clock.
However, the internal clock is likely to be out of order due to the low accuracy, and the date and time of creation of the document is generally unreliable because the user can easily adjust it. Therefore, when proof of a document creation date is required, such as a patent document, the creation date and time attached to such a document may lack credibility as legal evidence.
[0003]
[Object of the invention]
In view of the above problems, an object of the present invention is to provide a document management apparatus and a method thereof that have high credibility of document management information such as creation date and time and copyright information of a created document and that can easily verify document management information. To provide.
[0004]
Summary of the Invention
A document management device according to a first aspect of the present invention is a document management device that manages document management information attached to document data. The document management device includes: a random number generator that generates a physical random number; A storage unit for embedding a physical random number fetched from the random number generator into the document data and outputting the document, and storing the physical random number in a recording medium in correspondence with the document management information of the document data. Reading means for detecting a physical random number and reading document management information corresponding to the physical random number that matches the physical random number obtained by searching the detected physical random number in the recording medium. .
[0005]
10. The document management method according to claim 9, wherein the document management method manages document management information attached to the document data, wherein an embedding process of embedding a physical random number in the document data and the physical random number are stored in the document data. And a storage step of storing the document management information in a recording medium in correspondence with the document management information.
According to a twelfth aspect of the present invention, there is provided a document management method for document data in which a physical random number corresponding to accompanying document management information is embedded and the physical random number is recorded on a recording medium together with the document management information. A method for verifying the document management information, comprising: a detection step of detecting a physical random number from document data; a search step of searching for the detected physical random number in the recording medium; and a physical random number obtained in the search step. Reading out document management information corresponding to the matching physical random number from the recording medium when there is a matching physical random number.
[0006]
15. The document management method according to claim 14, wherein the document management method manages document management information attached to the document data, wherein an embedding process of embedding a physical random number in the document data and the physical random number are stored in the document data. A storage step of storing the physical random number from the document data in accordance with the document management information, a search step of searching the detected storage medium for the detected physical random number, Reading out the document management information corresponding to the obtained physical random number from the recording medium when there is a physical random number that matches the obtained physical random number.
[0007]
[Action]
According to the present invention, the physical random number is embedded in the document data by associating the physical random number with the document management information attached to the document data, and the physical random number and the document management information are stored in the recording medium. The document management information can be verified at any time by searching the storage medium for the physical random number detected from.
[0008]
【Example】
Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram showing a document management apparatus according to the present invention. In FIG. 1, the document management apparatus includes a system 10, which includes a CPU (Central Processing Unit) 11, a hard disk device 12, a main memory 13, an input device 14, a display 15, a printer 16 , A data input / output device 17, a random number generator 18, an internal clock 19, a recording medium writing / reading device 20, and a CPU bus 21 for connecting the above devices to the CPU 11.
[0009]
The CPU 11 inputs / outputs and edits document data, displays images on the display 15, prints on the printer 16, data communication for communication with communication satellites and information networks, generation of physical random numbers, determination of time, recording medium It controls writing and reading of the embedding / reading device, and embedding and decoding of data.
The input device 14 includes, for example, a keyboard, a mouse, a card reader, an image input device, and a voice recognition device. Commands and various information are input to the system 10 by a user.
[0010]
Software for controlling various operations of the system 10 is installed in the hard disk device 12.
The data input / output device 17 includes a floppy disk drive, an optical disk (CD) reading drive, or a communication line such as the Internet or an information network, and transmits various data including document data to the system 10 via the input / output device 17. Input and output.
[0011]
The random number generator 18 generates, for example, a 64-bit binary physical random number in response to a random number generation command from the CPU 11. However, the random number generated by the random number generator 18 is not limited to the above configuration, and can generate a physical random number having an appropriate configuration.
The internal clock 19 is connected via a communication line to a time server 23 existing outside the system 10, such as an NTP (Network Time Protocol) server or an SNTP (Simple Network Time Protocol) server on the Internet. Therefore, the clock fetches accurate time information from the time server 23 constantly or at predetermined intervals to synchronize its own time with the standard time. In this way, it is guaranteed by the third party that the clock 22 always displays the standard time in synchronization with the standard time. The clock 19 is not limited to the time server, and may be connected to an appropriate device or institution that guarantees the credibility of the time display of the clock 19.
[0012]
The recording medium writing / reading device 20 converts data supplied via the CPU bus 21 in response to a write command from the CPU 11 to a write-once optical disk (hereinafter, referred to as a CD-R) as a recording medium. 22 and save it.
Thus, the system 10 of the present invention is configured.
Next, the operation of the above embodiment will be described.
[0013]
First, embedding of document management information will be described based on the flowchart shown in FIG. In the present invention, the document management information includes at least the document name and creation date and time of the original document data, and may further include copyright information such as the name of the creator. When a command for embedding document management information is input from the input device 14, the CPU 11 loads the target original document data into the system 10 via the input / output device 17 (step S10). Next, the CPU 11 sends a random number generation command to the random number generator 18, captures a physical random number generated in response to the command (step S11), and determines the capture date and time of the physical random number by the clock 19 (step S11). S12). Next, the acquired physical random numbers are embedded as electronic watermarks in the original document data, and the created watermarked document data is temporarily stored in, for example, the main memory 13 (step S13). In this way, the physical random number is made to correspond to the acquired original document data, and thereafter, the physical random number is attached to the document data as a digital watermark.
[0014]
Next, the CPU 11 stores an ID (Identification) file including, as a data set, the physical random numbers, the capture date and time, and the document management information of the original document managed by the random numbers as shown in FIG. 4, for example. (Step S14). In this ID file, the date and time of generation of the random number determined by the standard time indicated by the clock is treated as corresponding to the date and time of creation of the original document, and thereafter proves the date and time of creation of the original document. Next, the CPU 11 sends the ID file to the writing device 20, and the writing device 20 writes and stores the ID file in the CD-R 22 in response to a write command from the CPU 11 (step S15). When the writing of the ID file to the CD-R 22 is completed, the CPU 11 next outputs the watermarked document data temporarily stored in the memory to the data input / output device 17 (step S16).
[0015]
In this way, a physical random number is embedded as an electronic watermark in the original document and output, and the CD-R 22 is created as a recording medium necessary for decoding the physical random number.
Next, verification of the document management information will be described with reference to the flowchart shown in FIG.
[0016]
When an output command of document management information is input from the input device 14, the CPU 11 captures target watermarked document data via the data input / output device 17 (step S20), and decodes a digital watermark from the watermarked document. The embedded physical random number is detected (step S21). Next, the CPU 11 loads the ID file from the CD-R 22 (step S22), and searches the ID file for a physical random number that matches the detected physical random number (step S23). In step S24, if a physical random number that matches the detected physical random number exists in the ID file, in step S25, the document management information such as the document name and the document creation date and time corresponding to the matched physical random number is read from the ID file. It is displayed on the display 15 or printed out by the printer 16 for output. In step S24, if there is no physical random number that matches the detected physical random number in the ID file, "not applicable" is output by display or printing (step S26).
[0017]
In this manner, by comparing the physical random number detected from the watermarked document data with the ID file, the document management information of the watermarked document data can be read and verified.
As described above, the document management apparatus of the present invention employs a configuration in which a physical random number is associated with document management information and the original document management information is verified from the physical random number as necessary.
[0018]
Since it is stochastically difficult to generate the same physical random number twice, the same random number does not actually exist and is unique. Therefore, while storing the random number in the storage medium in association with the document management information of the document data, if the random number is embedded in the document data, the document management information of the document data corresponding to the random number is verified based on the unique random number. can do. Further, since the document management information is managed through the intermediation of random numbers, the management information of the document data can be protected from fraud such as erasure and tampering. Further, since the random number is embedded in the document data as a digital watermark, the embedded random number itself can be protected from fraud such as erasure or tampering.
[0019]
In addition, since the collation between the random number and the document management information requires a recording medium different from the document data, even if the physical random number can be decrypted from the document data, the document obtained from the document data by the random number alone is used. The credibility of the management information is not guaranteed. On the other hand, the essential document data cannot be obtained by using only the recording medium. Therefore, according to the present invention, the credibility of the document management information can be guaranteed.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a document management device according to the present invention.
FIG. 2 is a diagram showing an operation flow at the time of embedding a random number by the document management apparatus of the present invention.
FIG. 3 is a diagram showing an operation flow when document management information is read by the document management apparatus of the present invention.
FIG. 4 is a diagram showing information stored on a recording medium of the present invention.
[Description of Signs of Main Parts]
10 System 11 CPU
18 random number generator 22 recording medium

Claims (12)

A document management device attached to document data and managing document identification information including creation time information of the document data ,
A random number generator that generates a physical random number in response to input of document data ;
A random number embedding means for embedding the physical random number generated by the previous SL-random number generator in the document data,
A clock that determines standard time corresponding to the generation time of the physical random number and generates standard time data;
A document management device, comprising: identification information generation means for generating, as creation time information of the document data, a piece of data that uniquely associates the standard time data with the physical random number. A storage unit for storing the document identification information in a recording medium; detecting a physical random number from the document data; searching the recording medium; and reading out the document identification information corresponding to the detected physical random number. 2. The document management apparatus according to claim 1, further comprising: a reading unit. 2. The document management device according to claim 1, wherein the clock is connected to an external device and synchronized with a standard time. 2. The document management apparatus according to claim 1, wherein the clock is connected to a time server via a communication line and synchronized with a standard time. 2. The document management apparatus according to claim 1, wherein the document identification information includes copyright information of the document data. 3. The document management apparatus according to claim 2 , wherein the embedding unit embeds the physical random number in document data as a digital watermark. 7. The document management apparatus according to claim 6, wherein the reading unit detects a physical random number by decoding a digital watermark from the input document data. 3. The document management apparatus according to claim 2, wherein the storage medium is a write-once optical disk. A document management method for managing document identification information that is attached to document data and includes creation time information of the document data ,
A random number generation step of generating a physical random number in response to input of document data ;
A random number embedded stroke embed physical random number generated in the previous SL random number generation process in the document data,
A standard time generation step of determining standard time corresponding to the generation time of the physical random number and generating standard time data;
An identification information generating step of generating, as creation time information of the document data, a piece of the standard time data uniquely associated with the physical random number. Storing the document identification information in a recording medium;
A step of detecting a physical random number from the document data;
10. The document management method according to claim 9, further comprising a step of searching the recording medium for document identification information corresponding to a physical random number that matches the detected physical random number. 10. The document management method according to claim 9, wherein the random number embedding step embeds the physical random number as an electronic watermark in the document data. A step of determining whether a physical random number corresponding to the physical random number detected from the recording medium is present in the document identification information,
When it is determined that a physical random number corresponding to the detected physical random number exists in the stored document identification information, a step of determining that the document identification information corresponding to the physical random number is genuine; The document management method according to claim 10, further comprising:

Images