JPH0498552A - Electronic filing device - Google Patents

Abstract

PURPOSE:To improve the secret holing performance by ciphering the data themselves that are recorded into an external storage. CONSTITUTION:A data processor DP 11 produces the digital data including the image data, etc., which are stored in an external storage EM 12. A ciphering means MD 13 ciphers these digital data with a due command. The DP 11 records the digital data ciphered by the MD 13 into the EM 12. Thus the digital data can be automatically ciphered and recorded into the EM 12 by the DP 11 and the MD 13 respectively with no consciousness of ciphering required to a user. Thus it is impossible to understand the contents of the EM 12 unless the deciphering method is unknown even though the contents of the EM 12 are illicitly drawn out as long as the data themselves to be recorded into the EM 12 are ciphered.

Description

[Detailed Description of the Invention] [Summary] This invention relates to an electronic filing device that records digital data such as image data in an external storage device so that it can be searched at any time without complicating recording and reading operations for the electronic filing device. , an electronic filing device that records digital data created by a data processing means in an external storage device so that it can be retrieved at any time, with the purpose of ensuring the confidentiality of digital data recorded in the electronic filing device. , an encryption means for encrypting digital data recorded on an external storage device, a decryption means for decoding the encrypted digital data retrieved from the external storage device into the original digital data, and operations of the encryption means and the decryption means. , and the data processing means for controlling recording and reading operations of encrypted digital data to and from an external storage device.

(Industrial Field of Application) The present invention relates to an electronic filing device that records digital data such as image data of documents and drawings on an external storage device such as an optical disk so that it can be searched at any time.

[Conventional technology]

In recent years, electronic filing devices that use large-capacity storage media such as optical disks as recording media for external storage devices have been put into practical use, making it possible to store vast amounts of information in external storage devices. It's here.

If an external storage medium such as an optical disk is illegally accessed by an outsider, a large amount of data will be illegally extracted, which is extremely inconvenient. This is especially important when there is confidential information in it.

In order to prevent such unauthorized access by outsiders to electronic filing devices, conventional electronic filing devices have been designed to identify users using passwords to maintain confidentiality.

That is, when a user first starts using an information recording medium such as an optical disk, he or she sets a password on the storage medium. Thereafter, the electronic filing device requires the user to enter the password manually when the user attempts to use the recording medium for which the password has been set.

If the user enters the correct password, the user is permitted to use the recording medium; if the password is not entered or the entered password is incorrect, the user is denied access to the recording medium.

By providing such a password, it is possible to prevent an outsider who does not know the correct password from illegally extracting the contents from the electronic filing device, and to maintain the confidentiality of the contents.

[Problem to be solved by the invention]

Conventional electronic filing devices are provided with a password as described above to prevent unauthorized withdrawals by outsiders and to maintain confidentiality.

However, in this conventional system, once the password is known, anyone can access the electronic filing device and retrieve its contents, which poses a problem in terms of maintaining the confidentiality of the electronic filing device. Moreover, this password check restricts the right to use the electronic filing device, and the information (data) itself written on a recording medium such as an optical disk is not protected against confidentiality.

Therefore, if you know the structure and format of the information (data) recorded on a recording medium, you can read the recording medium using another device and read the recorded information (data) without knowing the password. There was a problem that it became possible to extract data).

The present invention allows an outsider to illegally extract the contents even if he or she knows the password or the structure and format of the information (data) recorded on the recording medium, without complicating the recording and reading operations for the electronic filing device. The purpose of the present invention is to provide an electronic filing device that is improved so that it is not possible to do so.

[Means to solve the problem]

The means adopted by the present invention to solve the above-mentioned problems are as follows:
This will be explained with reference to FIG. FIG. 1 is a block diagram showing the basic configuration of the present invention.

In FIG. 1, reference numeral 11 denotes a data processing means, in addition to processing for creating digital data such as image data of documents and drawings to be recorded in an external storage device, the operation of the encrypting means and decrypting means described below, and Controls recording (writing) and reading of encrypted data to and from an external storage device.

Reference numeral 12 denotes an external storage device, which includes a recording medium such as an optical disk (not shown), and records digital data such as image data of documents and drawings.

Reference numeral 13 denotes an encryption means, which performs a process of encrypting the digital data created by the data processing means 11.

14 is a decryption means, which performs a process of decrypting the encrypted digital data retrieved from the external storage device I2 into the original digital data.

Note that since the encryption means 13 and the decryption means 14 have many common circuit parts, they may be integrated.

[For production]

When the data processing means 11 creates digital data such as image data to be stored in the external storage device 12, it instructs the encryption means 13 to perform encryption processing.

Upon receiving this instruction, the encryption means 13 encrypts the digital data using various known encryption methods.

The data processing section 11 performs a process of recording the digital data encrypted by the encryption means 13 into the external storage bag W12.

The encryption process of this digital data and the process of recording it in the external storage device 12 are automatically performed by the data processing section 11 and the encryption means 12 without the user being aware of the encryption.

In this way, by encrypting the data itself recorded in the external storage device 12, even if the contents are illegally retrieved from the external storage device 12, the contents cannot be known unless one knows how to decode the encryption. becomes impossible, so
It is possible to realize an electronic filing device with extremely high confidentiality performance compared to conventional methods.

When reading digital data from the external storage device I2, the data processing means 11 reads the encrypted digital data from the external storage device 12, and then decrypts the encrypted digital data from the external storage device 12.
to instruct the decryption process.

Upon receiving this instruction, the decryption means 14 performs a decryption process on the encrypted digital data, which is the reverse of the encryption process, to decode the encrypted digital data into the original digital data.

This decryption process of the encrypted digital data is automatically performed by the data processing unit 11 and the decryption means 14 without the user being aware of it.

In this way, since the data itself recorded in the external storage device 12 is encrypted, even if the external storage device 12
Even if the contents are illegally retrieved from 2, it will be impossible to know the contents unless you know how to decode the code.This makes it possible to realize an electronic filing device with extremely high confidentiality performance compared to conventional methods. be able to.

Furthermore, since the data encryption and decryption processing for the external storage device 12 is automatically performed, the user can perform normal data storage without being aware that the data stored in the external storage device 12 is encrypted. It can be used as an external storage device.

Further, as explained in the second embodiment section below, at least one processing part or information part essential for the decoding process in the decoding means 14 is configured to be removable, and the component part is electronically filed. If it is stored in a separate location from the device, even if an outsider tries to decrypt the data that has been illegally retrieved, the decryption means 14 cannot be used, so the contents of the data cannot be known, and the data cannot be stored electronically. The security of the device can be further ensured.

[First Embodiment] The first embodiment of the present invention will be explained with reference to FIG. 2, taking as an example the case where image data such as documents and drawings read by an image scanner is encrypted and decrypted. . FIG. 2 is an explanatory diagram of the configuration of the first embodiment.

(A) Configuration of the first embodiment In FIG. 2, data processing means 11, external storage device 1
2. Regarding the encryption means 13 and decryption means 14,
As explained in the figure.

In the data processing means 11, 111 is an image scanner that reads image information such as documents and drawings,
Performs processing to convert to image data.

A memory 112 stores image data and various instructions and data for data processing.

A display 113 displays documents, drawings, etc. read from the external storage device 12.

A printer 114 prints out documents, drawings, etc. read from the external storage device 12.

Reference numeral 115 denotes an operation panel through which various commands and control signals necessary for operating the electronic filing device are manually input, and the operating status of the device is displayed.

116 is a processor which controls the operations of each of the above-mentioned parts, stores a control program in a memory (not shown), performs compression and decompression processing on image data, and controls the operations of the encryption means 13 and decryption means 14 as well as encryption. It controls writing and reading of data into and from the external storage device 12.

Encryption processing performed by the encryption means 13 and decryption means 14
The decoding process performed in will be explained in the following section regarding the operation of the first embodiment. Further, since the encryption means 13 and the decryption means 14 have many common circuit parts, they may be integrated.

(B) Operation of First Embodiment The operation of the first embodiment of the present invention is divided into a recording (write) operation and a read operation, and the write operation will first be explained in the order of processing. It is assumed that the user has been checked to see if he or she is an authorized user using a password or the like. Further, each of the following processes is performed under the control of the processor 116, but this will not be mentioned unless it is particularly necessary.

(1) Recording (writing) operation ■ The image scanner 111 reads image information such as documents and drawings to be stored and converts it into digital image data.

(2) The generated image data is temporarily stored in the memory 112 and displayed on the display 113.

(2) After confirming the image data displayed on the display 113, the operator instructs recording to the external storage device 12 from the operation panel 115.

- When the processor 116 receives a recording instruction from the operation panel 115, the processor 116 reads out the image data in the memory 112, performs data compression processing, and then sends the image data to the encryption means 13.
send to Note that the data compression process is for reducing the amount of data to be recorded, and in some cases, the encryption process is performed without performing the data compression process.

(2) The encryption unit 13 performs encryption processing on image data that has been subjected to data compression processing (or not subjected to data compression processing).

Encryption processing can be performed using various known encryption methods, but hereafter, it is a type of public key encryption (Rehess).
(Rivest), Shamir,
R3 invented by Adleman
A-cipher will be briefly explained.

The R3A cipher is based on the fact that it is very difficult to factorize large numbers.

Now, assume that the three encryption keys of the R3A encryption are E, D, and N.

For the encryption key N, choose large prime numbers P and Q, N=PXQ Calculate and find.

Letting L be the least common multiple of the encryption keys EH1 (P-1) and (Q-1), it is determined as an integer E that is coprime to L.

The encryption key D is EXD=1 (MOD L) It is found as an integer that satisfies .

Next, let the plaintext M be M (0≦M≦N-1), and the ciphertext is C
Then, the encryption is performed using the encryption keys ~E and N as follows: C= M Em o d N −−−−−−−−−−−
---------------- (1) is carried out.

Decryption is performed using encryption keys D and N as follows: M = C' m o d N
−−−−−−−−−−−−−−−(2).

In the above explanation, if plaintext M corresponds to digital data and ciphertext C corresponds to encrypted digital data, then
Digital data can be encrypted.

In other words, since M is a value O≦M≦N-1, if 1 and O of the digital data are treated as a numerical value by corresponding to a binary number, the plaintext M is the numerical value indicated by the input digital data of continuous Z bits. become.

Further, in the ciphertext C, if the number of digits when N-1 is expressed as a binary number is Y, then the ciphertext, that is, the encrypted digital data, is output as Y-bit digital data.

Note that if the input digital data is greater than or equal to Z pinto, encryption may be performed for each Z bit.

In the R3A encryption described above, if the encryption keys E and N used during encryption are made public and only the encryption key D is made public, plaintext M cannot be decrypted from ciphertext C.

The encryption means 13 compresses (or does not compress) the data.
By fetching data from the image data in units of Z bits and performing the calculation shown in equation (1) above, encrypted digital data of Y bits is created.

(2) The processor 116 sends the image data encrypted by the encryption means 13 to the external storage device 12 and records it on a recording medium such as an optical disk (not shown).

As described above, the user can encrypt the image data and store it in the external storage device 12 by encrypting it using the same operations as when recording normal image data, without being aware that the image data recorded in the external storage device 12 will be encrypted. It can be recorded in the storage device 12.

(2) Reading operation The operation of reading image data from the external storage device 12 is performed as follows.

(2) The processor 116 reads the encrypted image data from the external storage device I2 and sends it to the decryption means 14.

(2) The decryption means 14 decrypts the encrypted image data into the original image data by performing the operation shown in equation (2) above.

(2) When the decoded image data is compressed, the processor 116 performs decompression processing to restore the original image data before compression.

(2) The restored image data is temporarily stored in the memory 113 and further displayed on the display 113.

■ After confirming that the image data displayed on the display has been correctly restored, the operator instructs printout from the operation panel 115 and prints it out to the printer 1.
14 to print out the restored image data.

As described above, the user can decrypt the image data written to the external storage device 12 by performing the same operation as reading normal image data without being aware that the image data written to the external storage device 12 is encrypted. image data can be read out.

[Second Embodiment] According to the first embodiment described above, it is possible to reliably prevent an outsider who has accessed the external storage device 12 from illegally taking out recorded contents from the recording medium. However, if it is possible to use the decryption means 14, it is possible to decrypt the encrypted image data and easily read out the recorded contents.

The second embodiment is designed to solve this problem in the first embodiment. The second embodiment will be described below with reference to FIG.

FIG. 3 is a block diagram showing the configuration of a second embodiment of the present invention.

(A) Structure of the second embodiment In the structure of the second embodiment shown in FIG. 3, parts common to the structure of the first embodiment shown in FIG. 2 are given the same reference numerals and explained. do. Also, the second embodiment uses the same R3A encryption as the first embodiment, but the encryption means and decryption means have many common circuit parts, so they are not integrated. ing.

In FIG. 3, data processing means 11, external storage device 1
2. The image scanner 111, memory 112, display 113, printer 114, operation panel 115, and professional sensor 116 are as described in FIG.

Reference numeral 15 denotes an encryption cart, in which at least one processing part or information part essential for encryption and decryption processing is recorded, and it is configured to be detachable from the encryption card reader I6, which will be described next. There is. In this embodiment, in which R3A encryption is used as the encryption method, an IC card type card is used as the encryption card I5, and the encryption key E described above is contained inside.

N and D are recorded.

The cryptographic cart reader 16 reads the cryptographic key from the inserted cryptographic card 15 and performs predetermined R3A3 quantification or decryption processing.

(B) Operation of Second Embodiment The operation of the second embodiment of the present invention is divided into a write operation and a read operation, and the write operation will first be explained in the order of processing. It is assumed that the user has been checked to see if he or she is an authorized user using a password or the like. Further, each of the following processes is performed under the control of the processor 116, but this will not be mentioned unless it is particularly necessary.

(]) Recording (writing) operation ■ Following the instructions displayed on the operation panel 115 or display 113, the user inserts the encryption card 15 into the encryption card reader 16.

(2) The encryption card reader 16 reads the encryption keys E and N from the encryption card 5 and stores them in an internal register (not shown).

(2) In the same manner as in the first embodiment described above, image information such as documents and drawings is read by the image scanner 111, and the image data is compressed (or not compressed in some cases).

(2) The cipher card reader I6 uses the cipher keys E and N read from the cipher card 15 to quantize the image data into R3A3 according to the formula (1) as in the first embodiment.

The encrypted image data is recorded in the external storage device 12.

(2) Reading operation ■ The user inserts the encryption card 15 into the encryption card reader 16 according to the instructions displayed on the operation panel 115 or the display 113.

(2) The encryption card reader 16 reads the encryption keys D and N from the encryption card 5 and stores them in an internal register (not shown).

(2) Thereafter, encrypted image data is read out from the external storage device 12 and sent to the encryption card reader 16 in the same manner as in the first embodiment.

(2) The cryptographic card reader 16 uses the cryptographic keys D and N read from the cryptographic card 15 to decode the image data encrypted by the formula (2) in the same way as in the first embodiment.

(2) When the decoded image data is compressed, it is restored to the original image data before compression by decompression processing and displayed on the display 113.

■ After confirming that the image data displayed on the display has been correctly restored, the operator instructs printout from the operation panel 115 and prints it out to the printer 1.
14 to print out the restored image data.

Although each embodiment of the present invention has been described above, the present invention is not limited to each of these embodiments, and various modifications can be made in accordance with the gist of the invention.

For example, if the encryption process is performed not only on the image data part but also on the data management information part that indicates the data storage location, etc., the confidentiality can be further improved.

As the recording medium of the external storage device 12, various known digital recording media such as an optical disk, a magnetic disk, and a magnetic tape can be used.

As for the encryption method, in addition to R3A encryption, various encryption methods such as DBS, FEAL, and Parnam can be used.

The encryption means and the decryption means may be provided in the electronic filing device as in the embodiment, or may be provided in the external storage device. Moreover, as already mentioned, the encryption means and the decryption means may be provided separately or may be integrated.

〔Effect of the invention〕

As explained above, according to the present invention, the following effects can be obtained.

(1) Since the data recorded on the external storage device itself is encrypted, even if the contents are illegally retrieved from the external storage device, it is impossible to know the contents unless you know how to decipher the encryption. Since this is impossible, it is possible to realize an electronic filing device with extremely high security performance compared to conventional methods.

(2) Since data encryption and decryption processing for external storage devices is performed automatically, users can use normal external storage devices without being aware that the data stored in the external storage device is encrypted. It can be used as a storage device.

(3) If at least one of the processing parts or information parts essential for the decryption process in the decryption means is removable, and the component is stored in a separate location from the electronic filing device, Even if an outsider attempts to decrypt data that has been illegally retrieved, the content of the data cannot be known because the decryption means cannot be used, and the confidentiality of the electronic filing device can be further ensured.

3... Encryption means, 14... Decryption means, 15...
Encryption card, 16... Encryption card reader.

Claims (3)

[Claims] (1) In an electronic filing device in which digital data created by a data processing means (11) is recorded in an external storage device (12) and can be searched at any time, (a) Digital data recorded in the external storage device (12) (b) a decoding means (14) for decoding the encrypted digital data retrieved from the external storage device (12) into the original digital data;
); and (c) the data processing means (11) for controlling the operations of the encryption means (13) and the decryption means (14), as well as the recording and reading operations of encrypted digital data to and from the external storage device (12). An electronic filing device comprising: (2) The electronic filing device according to claim (1), wherein at least one of the processing portion or information portion essential for the encryption process in the encryption means (13) is configured to be removable. . (3) The electronic filing device according to claim (1), wherein at least one of the processing portion or information portion essential for decoding processing in the decoding means (11) is configured to be removable.