JPH08249238A - Security maintaining method for attachable and detachable storage medium - Google Patents

Abstract

PURPOSE: To surely maintain the security of an external storage medium without damaging efficiency at the time of a normal operation by storing information without ciphering it at the time of normal use and ciphering the information at the time of ejecting an attachable and detachable storage medium to store the information. CONSTITUTION: At the time of taking out an attachable and detachable hard disk (HD) 6, a CPU 1 checks whether or not a security folder is present in the HD 6. When the security folder is present, the presence of the data which are not ciphered in it is checked. When the data which are not ciphered are present, the CPU 1 instructs an HD controller 5 to read them. The data read from the attachable and detachable HD 6 are ciphered by the CPU 1 and stored in a main memory 3. Thereafter, the CPU 1 instructs the HD controller 5 and a DMA controller 4 to store the ciphered data to the attachable and detachable HD 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a confidentiality holding method for an information processing apparatus that handles removable storage media.

[0002]

2. Description of the Related Art A removable storage medium such as a floppy disk or an optical disk is portable and can be easily duplicated. Then, the information stored in the duplicated medium is read by another reading device, so that confidentiality cannot be maintained.

For this reason, as a method of maintaining the confidentiality of a removable storage medium, as shown in Japanese Patent Laid-Open No. 64-64713, a plaintext data input from an external device is encrypted by an encryption circuit and then removable. A magnetic disk system has been proposed in which, when writing to and reading from a removable medium, the encrypted data read from the removable removable medium is flat-cultured by a flat-culture circuit and sent to an external device.

[0004]

However, in the above-mentioned prior art, the data must be encrypted and recorded, and must be decrypted when read. Therefore, when data is created with a storage medium installed, even if recording and reproduction are repeated, encryption processing is required for recording and decryption processing is required for reproduction, and data recording operation Playback has slowed down.

Therefore, the present invention is a method of encrypting information stored in a removable storage medium to maintain confidentiality, by storing the encrypted information in the storage medium without impairing the efficiency during normal work. , For the purpose of achieving confidentiality.

[0006]

According to the present invention, there is provided a confidentiality storing method for storing encrypted information in a storage medium detachable from a device body, wherein the information is stored in the storage medium without being encrypted. In association with the ejecting operation of the storage medium, the information stored without being encrypted in the storage medium is encrypted and stored again in the storage medium, and the storage medium is ejected.

Further, in accordance with the present invention, in synchronism with the operation of ejecting the storage medium, after the encryption of the information stored in the storage medium without being encrypted and the storage in the storage medium are all completed, The feature is that the storage medium is ejected. Furthermore, the invention is characterized in that a part of the information is encrypted. Further, the present invention is characterized in that, when the information composed of a plurality of pieces of section information is encrypted, each piece of section information to be stored is used as a unit for selective encryption.

[0008]

In the present invention, the information is stored in the storage medium without being encrypted, and the information stored in the storage medium without being encrypted is encrypted in association with the discharging operation of the storage medium. It is re-stored in the storage medium and the storage medium is ejected.

Further, according to the present invention, in synchronism with the discharge operation of the storage medium, after the encryption of the information stored in the storage medium without being encrypted and the storage in the storage medium are all finished, Eject the storage medium. Further, in the present invention, a part of the information is encrypted. Further, according to the present invention, the information composed of a plurality of section information is selectively encrypted with each section information to be stored as a unit.

[0010]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an embodiment of an information processing apparatus using the confidentiality holding method of the present invention. In FIG. 1, the removable hard disk 6 (hereinafter referred to as removable HD)
Normal data, encrypted data, a program (application software) for editing the data, and the like are stored. Hard disk controller 5 (hereinafter H
The D controller) controls the input / output of data to / from the detachable HD 6. The CPU 1 controls the entire device and also encrypts / decrypts data. The encryption method includes a method of taking exclusive OR of data, DES type encryption, and the like, but an encryption method according to confidentiality may be adopted. The ROM 2 stores a program for the CPU 1 to control the device and an encryption / decryption program. encryption/
The decryption program may be stored in the removable HD 6. The main memory 3 is a memory used by the CPU 1 for processing, and the DMA controller 4 performs high-speed data transfer between the main memory 3 and the HD controller 5. The CRT 8 is a display device and displays the data stored in the video memory 7. The mouse 9 conveys an instruction from the operator to the CPU 1, and may be composed of another pointing device such as a joystick.

Next, the data structure stored in the removable HD 6 will be described. As shown in FIG. 2, the detachable HD6
There are folders with different names. Among them, the folder 2 is marked with a "secret", which means that the folder 2 is a folder for storing confidential data. In the data of this confidential folder,
The unencrypted data is encrypted and re-stored when the removable HD 6 is ejected. FIG. 3 shows an example of the contents of the folder 2. In the icon indicating each data, the data marked with "encryption" indicates that the data is encrypted.

In the information processing apparatus having the above structure,
How to specify the confidential folder is explained. FIG. 4 shows an example of a screen displayed on the CRT 8. At the top of the screen, there is a menu for selecting a process, and an icon indicating a folder is arranged below it. Also, a mouse cursor that moves in response to the movement of the mouse 9 is displayed as an arrow. For example, to specify the folder 1 as a confidential folder, first move the mouse cursor over the icon of the folder 1 and click. As shown in FIG. 5, the designated folder icon is displayed in black. In this state, the mouse cursor is moved to the "secret" which is the confidential designation command in the menu and clicked, and the "secret" mark is displayed on the icon as shown in FIG. As a result, when the removable HD 6 is ejected, the data in the folder 1 (corresponding to “classification information” in claim 4) is encrypted and re-stored. The operator stores, in this folder, data that he wants to encrypt when the removable HD 6 is ejected.

Next, the operation of ejecting the removable HD 6 will be described with reference to the flowchart of FIG. First, when the mouse cursor is moved to "Eject" in the menu and clicked (step S1), the CPU 1 checks whether or not there is a confidential folder in the removable HD 6 (step S2). If there is a confidential folder, it is checked whether or not there is unencrypted data in it (step S3). If there is unencrypted data, CP
U1 instructs the HD controller 5 to read this. The data read from the removable HD 6 by the HD controller 5 is encrypted by the CPU 1 (step S4) and stored in the main memory 3. Then the CPU
1 stores encrypted data in the removable HD 6,
Instruct the HD controller 5 and the DMA controller 4. The HD controller 5 writes the encrypted data read from the main memory 3 by the DMA controller 4 into the removable HD 6 and replaces it with the original data. CPU
1 checks whether there is any other unencrypted data (step S5) and encrypts all the data in the folder. Then, all the confidential folders are checked by the same method (step S6), and when there is no unencrypted data, the removable HD 6 is ejected (step S6).
7).

Next, a description will be given of a case where the removable HD 6 is taken out by high-speed encryption by a simple encryption process. When the data is stored in the detachable HD 6, the data is generally stored separately in the data main body and the data management unit (corresponding to “a part of information” in claim 3). By encrypting only this data management unit, the contents of data can be kept confidential. When the operator specifies "high-speed retrieval" in the menu instead of "retrieval", the CPU 1 encrypts only the data management portion of each data and stores it again in the removable HD 6. By this method,
The encryption process can be performed faster than when all data is encrypted.

Further, there is a case where the operator gives an instruction to take out the removable HD 6 and wants to take out the removable HD 6 urgently during the process of encryption or the like. At this time, the operator clicks "forced ejection" in the menu. CP
U1 interrupts the encryption process for the data currently being encrypted, and ejects the removable HD6. Further, after the "forced removal" instruction, the above-mentioned simple encryption process may be performed without interrupting the process.

Next, the operation when reading the encrypted data will be described. When the operator changes the data using the application software, first the removable HD
The encrypted data is read from 6, and the CPU 1 decrypts it. After changing the contents, the changed data is stored in the removable HD 6 without being encrypted and replaced with the original data. In addition, the data decrypted by the CPU 1 is removable H
Correction may be performed after replacing with the original data of D6. After that, even when the operator corrects or adds data, the decrypted data is stored as it is,
It is not encrypted until the removable HD 6 is ejected.

In the embodiment, the removable HD 6 is taken as an example of the removable storage medium, but another removable storage medium such as an optical disk, a magnetic tape or a floppy disk may be used. Further, in the embodiment, the data to be encrypted is designated in the folder unit, but it may be designated in the data unit, or all the data may be encrypted.

Further, although the encryption / decryption processing is performed by the CPU 1, it goes without saying that this may be performed by a dedicated circuit.

[0019]

As is apparent from the above description, according to the present invention, at the time of normal use, the information is stored without being encrypted, and the removable storage medium for storing the information is ejected. Encrypt and store information. Therefore, it is not necessary to perform encryption / decryption when reading or writing information during normal use, and it is possible to work efficiently. In addition, encrypted information is stored in the ejected storage medium, and confidentiality can be maintained.

Further, according to the present invention, since the storage medium is ejected after the encryption and the re-restore of the information stored in the storage medium without being encrypted, the storage medium is ejected to other users. It is possible to prevent the information from being read from. Further, according to the present invention, the encryption process can be performed at high speed by encrypting a part of the information.

Further, according to the present invention, since the classification information to be encrypted can be selected, only the classification information having high confidentiality is encrypted and stored, and the other classification information is stored as it is. The time can be shortened.

[Brief description of drawings]

FIG. 1 is a functional block diagram of an information processing device according to an embodiment of the present invention.

FIG. 2 is an image diagram of an example of a data structure of a removable HD according to an embodiment of the present invention.

FIG. 3 is an image diagram of an example of a data structure in a folder of a removable HD according to an embodiment of the present invention.

FIG. 4 is a display example of a screen when a folder is designated according to an embodiment of the present invention.

FIG. 5 is a display example of a screen after a folder is designated according to an embodiment of the present invention.

FIG. 6 is a display example of a screen after designation of a confidential folder in one embodiment of the present invention.

FIG. 7 is a flowchart showing a flow of operations in the embodiment of the present invention.

[Explanation of symbols]

 1 CPU 2 ROM 3 Main Memory 4 DMA Controller 5 HD Controller 6 Detachable HD 7 Video Memory 8 CRT 9 Mouse

Claims (4)

[Claims] 1. A confidentiality holding method for storing encrypted information in a storage medium detachable from a device body, wherein information is stored in the storage medium without being encrypted,
Removable, characterized in that, in synchronization with the operation of ejecting the storage medium, information stored in the storage medium without being encrypted is encrypted and stored again in the storage medium, and the storage medium is ejected. Security method for secure storage media. 2. After the encryption of the information stored in the storage medium that is not encrypted and the storage in the storage medium are all completed in association with the operation of ejecting the storage medium, the storage medium is removed. The method for maintaining confidentiality of a removable storage medium according to claim 1, wherein the confidentiality is retained. 3. The security method for a removable storage medium according to claim 1, wherein the encryption is performed on a part of the information. 4. The confidentiality of the removable storage medium according to claim 1, wherein the information is composed of a plurality of pieces of division information, and the encryption is selectively performed in units of each piece of division information. Method.