JP2003316652A - Data file storage service system and operation control method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the contents of a data file from being recognized by a third person by packet monitoring or the like in the case of transmitting and receiving the data file with a server from a user terminal through a network. <P>SOLUTION: The user terminal adds an error correction code to the data file B1 storing various kinds of information and divides the data file B2 to which the error correction code is added into a plurality of the data files B3. The divided data files are ciphered, the ciphered data files B4 are transmitted to the servers provided in different places, and the data files are stored in the respective servers. In response to a data file take-out request from the user terminal, the respective servers return the stored data files to the user terminal. The user terminal deciphers the returned data files, connects the deciphered data files, and performs the error correction of the data file and the confirmation of normality from the connected data file and the error correction code. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data file storage service system and its operation control method,
In particular, the present invention relates to a data file storage service system in which a data file is transmitted from a user terminal to a server via a communication network and the data file is stored in the server.

There is a data file storage service system for storing a data file in a user terminal via a communication network such as the Internet in a server installed at a remote place away from the user terminal. The schematic block diagram is shown. Referring to FIG. 4, the user terminal 200 and the server 400 are connected to each other via the network 300. When the data file of the user terminal 200 is stored in the remote server 400, the data file is encrypted by the user terminal 200 and transmitted to the server 400 via the network 300. Server 4 that received this data file
In 00, by storing this data file,
It is designed to provide a large-capacity storage area that cannot be provided in the user terminal.

[0003]

In such an online storage service system, it is possible for a third party to obtain an encrypted data file by monitoring the communication line. There is a possibility that the contents of the data file may be acquired by the device.
Therefore, techniques for preventing such a data file from being obtained by a third party are disclosed in JP-A-10-070531 (Prior Art 2), JP-A-11-103290 (Prior Art 2), and JP-A-2000. No. 059355 (Prior Art 3) and the like.

In the prior art 1, although data is divided into a plurality of pieces and transmitted using a plurality of communication paths, it is made difficult to leak the data due to interception of the communication paths. Since the data is combined in the server, if the data in the print server is acquired by a third party, there is a problem that the data is leaked.

In prior art 2, when transmitting data from a first correspondent to a second correspondent, the data is divided in the same manner as in prior art 1, and these divided data are encrypted,
By transmitting using a plurality of communication paths, it is difficult to leak data due to interception of the communication paths. However, since the second correspondent performs the decoding and combining of the data, When the communication information output from the correspondent is acquired, there is a drawback that data can be leaked.

In the prior art 3, the data hiding property is improved by transmitting the data after dividing the file and adding the dummy data. However, the output of the decoding device or the data of the receiving terminal device is acquired. Then, there is a problem that data leakage occurs. Furthermore, in any of the above-mentioned prior arts, there is a drawback that data can be acquired if the receiving side device is used illegally.

An object of the present invention is to provide a data file storage service system and its operation control method that prevent the contents of a data file transmitted from a user terminal to a server from leaking to a third party.

Another object of the present invention is to provide a data file storage service system and its operation control method in which the original data cannot be known even if a third party acquires the data stored in the server body. Is to provide.

Still another object of the present invention is to provide a data storage service system and an operation control method thereof in which data acquisition by spoofing a user terminal is impossible.

[0010]

A data file storage service system according to the present invention is a data file storage in which a data file is transmitted from a user terminal to a server via a communication network and the data file is stored in the server. A service system,
The user terminal adds an error correction code to the data file, and a unit that divides the data file to which the error correction code is added into a plurality of parts to encrypt the data file.
And transmitting means for transmitting the divided data files to different servers, each of the servers storing the transmitted data files, and responding to a data file retrieval request from the user terminal. And a return means for returning the stored data file to the user terminal.

Then, the user terminal further combines the means for decoding the data files returned from each of the servers with the decoded data files and uses the error correction code to check the normality of the data. And means for confirming. Further, the transmitting means is characterized in that when transmitting the divided data file, the transmission interval is randomly changed.

Further, the user terminal has means for adding meaningless dummy data to the data file, and the data file is divided after the dummy data is added. . Further, each of the servers is connected via a different communication path and is installed at a geographically different place.

Furthermore, the user terminal has means for adding position information of the terminal itself when transmitting the divided data file and transmitting a data file retrieval request, and each of the servers The returning means compares the position information added to the stored data file with the position information added to the retrieval request, and returns the stored data file to the user terminal only when they match. It is characterized by doing so.

The operation control method according to the present invention is an operation control method in a data file storage service system in which a data file is transmitted from a user terminal to a server via a communication network and the data file is stored in the server. Then, in the user terminal,
Adding an error correction code to the data file, dividing the data file to which the error correction code is added into a plurality of pieces, and encrypting the data file; and transmitting the divided data files to different servers. In each of the servers, storing the transmitted data file, and returning the stored data file to the user terminal in response to a data file retrieval request from the user terminal. Characterize.

The operation of the present invention will be described. When sending a data file from a user terminal to a server, the user terminal divides the data file, encrypts it, and sends it to multiple servers in a distributed manner, and the multiple servers store only a part of the data file. The configuration. Therefore, even if the communication line is monitored or the data is acquired from the server, only part of the data file can be acquired, and acquisition of all data files becomes difficult.

Further, by adding the error correction code to the data file, even if the data file is damaged in a part of the server, the original data file can be reconstructed from the remaining data by the error correction code. By adding meaningless dummy data, it becomes difficult for a third party to know the true contents of the data file even if the data file is decrypted.

Further, by installing the servers at different geographically different places, a disaster or the like becomes strong, and it becomes difficult for a third party to obtain all the data files. Further, by transmitting the divided data files in different communication paths or changing the transmission intervals randomly, it becomes extremely difficult to leak all the data files.

Furthermore, the position information of the user terminal is also added to the data file and transmitted to the server, and when the user terminal requests the server to take out the data file,
By transmitting the position information of the user terminal at the same time, the server side compares the position information added to the data file with the position information added to the data file retrieval request, and only when they match, the user terminal By sending the data file back to, it is possible to completely prevent the file acquisition by a spoofed person.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the online storage service of the present invention will be described in detail with reference to the drawings. With reference to FIG. 1, an embodiment of an online storage service of the present invention includes a user terminal 10, a server a10, a server b20, a server c30, and a communication network 1 such as the Internet for mutually connecting these.
00 and 00.

The user terminal 10 is an information processing device such as a personal computer. The user terminal 10 has a data file creation and storage function. The data file is, for example, a document, an image, a sound or the like.
The user terminal 10 further uses the software provided by the online storage service provider to transfer the data file to the server a1 via the network 100.
0, the server b20 and the server c30 have a function of transmitting and receiving.

Server a10, server b20 and server c
Reference numeral 30 is used by a provider of online storage service, and is composed of information processing devices such as workstations and servers, installed in geographically different places, and has a different connection route (communication route) with the network 100. It is assumed that The server a10, the server b20, and the server c30 receive the data file transmitted from the user terminal 10 and store it in a storage device (not shown).
And a function of transmitting a specified data file to the user terminal 10 in accordance with a data file extraction request from the user terminal 10.

Next, the operation of this embodiment will be described with reference to the operation sequence diagram of FIG. In the following description, the network 100 is the Internet. Referring to FIG. 2, when the data file created by the user terminal 10 is transmitted to the server, an error correction code for the data file is generated and added (step A).
1). Next, add dummy data (step A)
2). Up to this point, the original data file has been converted from the format of B1 in FIG. 3 to the format of B2.

Next, the data file is divided according to the number of destination servers (step A3). In the embodiment of the present invention, the data is divided into three and converted into the format of B3 in FIG. Next, each data file is encrypted and GPS
Positioning and position information from a base station such as a mobile phone are added (step A4) and converted into the format of B4 in FIG. 3 to be transmitted to the server. Next, copy the first data file 1x to server a
10 (step A5), after the randomly set time T1 has passed, the second data file 2x is sent to the server b20 (step A6), and after the randomly set time T2 has passed , The third data file 3x is transmitted to the server c30 (step A
7). In this way, when all the data files can be transmitted normally, the correspondence between the original data file name, the divided data file name, the position information, and the destination server is stored (step A8).

The server a10, the server b20, and the server c30 which have received the data files from the user terminal respectively store the data file 1x, the data file 2x, and the data file 3x (step A9, step A).
10, step A11).

When the user terminal retrieves the data from the server, the original data file name stored in step A8, the divided data file name, the positional information, and the correspondence of the destination server are retrieved (step A20). ,
The server a10 is requested to transmit the first data file 1x with the position information added (step A2).
1). It may be possible to encrypt the transmission request in this case.

Next, after the randomly set time T3 has elapsed, the server b20 is requested to transmit the second data file 2x to which the same position information as the first one is added (step A22). Further, after the randomly set time T4 has elapsed, the server c is requested to transmit the third data file 3x to which the same position information as the first is added (step A23).

The server a10 which has received the data file transmission request from the user terminal 10 retrieves the stored data file 1x (step A24), and sends it to the user terminal 10 only when the position information matches. It is transmitted (step 25). Similarly, the server b20 takes out the data file 2x (step A26), sends it to the user terminal 10 only when the position information matches (step A27), and the server c30 takes out the data file 3x (step A28). , And only when the position information matches, the data is transmitted to the user terminal 10 (step A2).
9).

The user terminal 10 decrypts the data file 1x, the data file 2x, and the data file 3x received from each server (step A30), and FIG.
The B4 format is converted to the B3 format. Next, the data files are combined (step A31) and converted from the format B3 in FIG. 3 to the format B2. Furthermore, the dummy data is deleted (step A32), the error correction code is used,
It is confirmed that the data file is not damaged or tampered with, and the error correction code is removed (step A33).
The B2 format is converted to the B1 format, that is, the original data file.

When the data file is divided in the user terminal, a random data file name that is not associated with the data file before the division is generated, so that the divided data file is Since they do not seem to be related to each other, they are effective in terms of confidentiality.

[0030]

The first effect of the present invention is that the contents of the data file transmitted from the user terminal to the server are not leaked to a third party. The reason is that the data file is divided, encrypted, and distributed to multiple servers for transmission, and only a part of the data file is stored on multiple servers, so even if the communication line is monitored, part of the data file will be stored. Even if all data files are acquired, decrypt all data files, eliminate meaningless data files, and reconstruct the correct dependency of each data file. Because it is difficult. Further, even if a third party acquires the data of the server body, it is impossible to know the original data from a part of the data, as in the above case.

The second effect is that even if a part of the data file stored in the server is damaged, the data file can be restored. The reason is that since the error correction code is added when the data file is divided, even if the data file is damaged in a part of the server, the error correction code is used to restore the original data from the remaining data files. This is because the data file can be reconstructed. Further, since the servers are installed at geographically distant places, even in the event of a disaster or the like, only some of the data will be damaged and the data can be recovered as described above.

The third effect is that it is impossible to obtain data by impersonating the user terminal. The reason is,
This is because a third party cannot know the position information of the user terminal when the data is transmitted to the server.

The fourth effect is that it becomes difficult to obtain data by illegally using the user terminal. The reason is that the position information added to the data acquisition request from the user terminal is
By using GPS positioning at the time of request and position information from a base station such as a mobile phone, unless a user's position at the time of data registration is accurately known, even if a regular user terminal is used,
This is because data acquisition is impossible.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing an operation of the embodiment of the present invention.

FIG. 3 is a diagram showing an example of a data file division method and a data file reconstruction method in the user terminal of the present invention.

FIG. 4 is a diagram showing an example of a conventional online storage service system.

[Explanation of symbols]

10 user terminals 20 server a 30 server b 40 server c 100 communication network

Claims (7)

[Claims] 1. A data file storage service system for transmitting a data file from a user terminal to a server via a communication network and storing the data file in the server, wherein the user terminal is the data file. A means for adding an error-correcting code to the server, a means for dividing the data file to which the error-correcting code is added into a plurality of pieces for encryption, and a means for transmitting the divided data files to different servers. However, each of the servers includes means for storing the transmitted data file, and return means for returning the stored data file to the user terminal in response to a data file extraction request from the user terminal. Data file storage service system. 2. The user terminal further comprises means for decoding the data files returned from each of the servers, and combining these decoded data files with each other to normalize the data by using the error correction code. The data file storage service system according to claim 1, further comprising: 3. The data file storage service system according to claim 1, wherein said transmitting means randomly changes the transmission interval when transmitting said divided data file. . 4. The user terminal further comprises means for adding meaningless dummy data to the data file, and the data file is divided after the dummy data is added. Claims 1-3
Any one of the data file storage service system described. 5. The data file storage service system according to claim 1, wherein each of the servers is connected via different communication paths and installed in different geographical locations. 6. The user terminal further includes means for adding position information of the terminal itself when transmitting the divided data file and transmitting a data file retrieval request, each of the servers The return means compares the position information added to the stored data file with the position information added to the retrieval request, and returns the stored data file to the user terminal only when they match. The data file storage service system according to claim 5, characterized in that. 7. An operation control method in a data file storage service system, wherein a data file is transmitted from a user terminal to a server via a communication network and the data file is stored in the server. A step of adding an error correction code to the data file, a step of dividing the data file to which the error correction code is added into a plurality of pieces and encrypting the data file, and a step of transmitting the divided data file to different servers Each of the servers includes a step of storing the transmitted data file, and a step of returning the stored data file to the user terminal in response to a data file retrieval request from the user terminal. And a motion control method.