JP2011186631A - File transfer system and file transfer method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a file transfer system, selecting a transfer destination server after confirming resource states. <P>SOLUTION: In the file transfer system in which a sender terminal 1 and a receiver terminal 4 transfer files via a network 5 constituted of a management server 2 and a plurality of transfer servers 3, the sender terminal 1 asks the management server 2 for the resource state of an adjacent transfer server 3, selects the transfer server 3 having a margin in the resource state as a transfer destination, and transmits a file to the selected transfer server 3. The transfer server 3 confirms the resource state of an adjacent transfer server 3, and selects the transfer server 3 having a margin in the resource state or selects the receiver terminal 4 as a transfer destination so long as the receiver terminal 4 is an adjacent one. The transfer server 3 transfers the file to the selected transfer server 3 or the receiver terminal 4. The receiver terminal 4 then receives the file. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a file transfer system for transferring a large capacity file.

  Conventionally, when trying to transfer a large-capacity file via a network, the network is occupied, which sometimes hinders other network users. Further, since there is one communication path, there is a risk that file data may be acquired by a malicious third party by eavesdropping on one communication path. As a method for solving these problems, Patent Documents 1 and 2 below disclose a technique for dividing a large-capacity data file, encrypting it, and transmitting it.

Japanese Patent Laid-Open No. 2003-316652 JP 2003-337803 A

  However, according to the above-described conventional technique, when a divided file is transferred, if there is a transfer server or the like in the network that does not have a sufficient resource state, it takes time to transfer some of the divided files. . For this reason, there is a problem in that the divided file cannot be prepared on the file receiving side, and the original file cannot be decrypted or it takes time to decrypt.

  The present invention has been made in view of the above, and in the case of transferring a file, to obtain a file transfer system capable of selecting a transfer destination after confirming a resource state of a transfer destination server. Objective.

  In order to solve the above-described problems and achieve the object, the present invention provides a file transfer system in which terminals transfer files via a network including a management server and a plurality of transfer servers, A transfer server for managing resource statuses of adjacent transfer servers; resource transfer means for selecting a transfer destination server based on the resource status; and file transfer control means for controlling file transfer. A transfer server management unit that manages a resource state of the transfer server, and a file transmission processing unit that performs file transmission processing, and a file reception processing unit that performs file reception processing. And the file transmission processing means is adjacent to the transfer server management means of the management server. Confirming the resource state of the transfer server to be selected, selecting a transfer server having a sufficient resource state as the transfer destination, and transmitting the file to the selected transfer server. In the transfer server, the transfer destination selecting means includes the resource Check the resource status of the adjacent transfer server with respect to the management means, select a transfer server with sufficient resource status as the transfer destination, or select the receiving terminal when it is adjacent to the receiving terminal. The file transfer control means transfers the file to the selected transfer server or the receiving terminal, and the file receiving processing means receives the file at the receiving terminal.

  According to the present invention, it is possible to shorten the time required for decoding on the file receiving side.

FIG. 1 is a diagram illustrating a configuration example of a file transfer system. FIG. 2 is a diagram illustrating a configuration example of the management server. FIG. 3 is a diagram illustrating a configuration example of the transfer server. FIG. 4 is a diagram illustrating a configuration example of a sender terminal and a receiver terminal. FIG. 5 is a flowchart showing the file transfer process. FIG. 6 is a flowchart showing the transmission processing of the sender terminal. FIG. 7 is a flowchart showing transfer processing of the transfer server. FIG. 8 is a flowchart showing the reception process of the receiver terminal. FIG. 9 is a flowchart showing file transfer stop and delete processing.

  Embodiments of a file transfer system according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment.
FIG. 1 is a diagram illustrating a configuration example of a file transfer system according to the present embodiment. The file transfer system includes a sender terminal 1, a management server 2, a transfer server 3, and a receiver terminal 4. The management server 2 and the transfer server 3 constitute a network 5. The sender terminal 1 is a terminal that transmits a file. When sending a file, the file is divided, encrypted and sent. The management server 2 manages the file division state, the resource state of the transfer server 3, and the like. The transfer server 3 is a server that transfers files between the sender terminal 1 and the receiver terminal 4. Also, the file is divided as necessary. The recipient terminal 4 is a terminal that receives a file. Concatenate and decrypt the divided files.

  Next, the configuration of the management server 2 will be described. FIG. 2 is a diagram illustrating a configuration example of the management server. The management server 2 includes a transfer control processing unit 21, a transfer server management unit 22, and a user public key management unit 23. The transfer control processing unit 21 controls the transfer server 3 to delete a file or stop transferring a file. The transfer server management unit 22 manages resource information of the transfer server 3 in the network 5. The user public key management unit 23 manages the public keys of the system user and the receiver terminal 4.

  Next, the configuration of the transfer server 3 will be described. FIG. 3 is a diagram illustrating a configuration example of the transfer server. The transfer server 3 includes a file transfer control unit 31, a file division processing unit 32, a transfer destination selection unit 33, a file deletion processing unit 34, and a resource management unit 35. The file transfer control unit 31 controls transfer processing of the received file. The file division processing unit 32 performs file division and encryption as necessary. The transfer destination selection unit 33 selects the transfer server 3 to be the next transfer destination based on the resource state. Note that, when connected to the receiver terminal 4, the receiver terminal 4 is selected. The file deletion processing unit 34 performs file deletion processing when instructed by the management server 2. The resource management unit 35 manages the resource state of the own server and other adjacent transfer servers 3.

  Next, configurations of the sender terminal 1 and the receiver terminal 4 will be described. FIG. 4 is a diagram illustrating a configuration example of a sender terminal and a receiver terminal. In the present embodiment, for convenience, the sender terminal 1 and the receiver terminal 4 are used, but both have the same configuration and functions, and files can be transferred from the receiver terminal 4 to the sender terminal 1. It is. Here, the receiver terminal 1 will be described. The recipient terminal 1 includes a file transmission processing unit 11, a file reception processing unit 12, a display unit 13, a transfer server control processing unit 14, and a public key management unit 15. The file transmission processing unit 11 divides the file, further encrypts it, and transmits it. At this time, the divided files can be made redundant and transferred to a plurality of transfer servers 3. The file reception processing unit 12 concatenates and decodes the received files. The display unit 13 provides a GUI (Graphical User Interface) that displays the processing status. The transfer server control processing unit 14 instructs file deletion or transfer stop for a file being transferred by the transfer server 3 in the network 5. The public key management unit 15 manages the private key / public key of its own terminal and the public keys of other terminals. The public key management unit 15 can acquire the public keys of other terminals from the user public key management unit 23 of the management server 2.

  Next, file transfer processing in the file transfer system will be described. FIG. 5 is a flowchart showing the file transfer process. First, the sender terminal 1 performs a process of transmitting a file (step S1). Here, the transmission process in the sender terminal 1 will be described in detail with reference to FIG. FIG. 6 is a flowchart showing the transmission processing of the sender terminal.

  In the sender terminal 1, first, the file transmission processing unit 11 accesses the transfer server management unit 22 of the management server 2, and acquires the resource state of the transfer server 3 to which the own terminal is connected. Then, the file transmission processing unit 11 selects the transfer server 3 that is the optimal transfer destination based on the resource state (step S11). Examples of the resource state include, but are not limited to, the performance of the CPU of the transfer server 3, the size of the memory, the free capacity of the disk, and the like. The file transmission processing unit 11 selects a transfer server 3 having a sufficient resource state as a transfer destination. Note that the file transmission processing unit 11 may select a plurality of transfer servers 3.

  Next, the file transmission processing unit 11 encrypts the file to be transmitted using the public key of the sender terminal 4 managed by the public key management unit 15 (step S12). The public key management unit 15 acquires the public key of the sender terminal 4 registered in the user public key management unit 23 of the management server 2 in advance.

  Next, the file transmission processing unit 11 checks whether or not the size of the file to be transferred is larger than the minimum division size (step S13). When larger than the minimum division size (step S13: Yes), the file transmission processing unit 11 divides the transmission target file (step S14), and then transmits the divided file to the transfer server 3 selected in step S11. (Step S15). At this time, if a plurality of transfer servers 3 are selected, the divided files may be duplicated, and the same divided file may be transmitted to the plurality of transfer servers 3 for redundancy. When the file is divided, the file transmission processing unit 11 notifies the management server 2 of file division information. This is because the recipient terminal 4 uses the division information when connecting the files.

  On the other hand, when it is smaller than the minimum division size (step S13: No), the file transmission processing unit 11 transmits the file to the transfer server 3 selected in step S11 without dividing the transmission target file (step S15). . At this time, the file may be duplicated, made redundant, and the same file may be transmitted to a plurality of transfer servers 3 as in the case of the division.

  Returning to FIG. 5, next, the transfer server 3 performs a process of transferring a file (step S2). Here, the transfer process in the transfer server 3 will be described in detail with reference to FIG. FIG. 7 is a flowchart showing transfer processing of the transfer server.

  In the transfer server 3, first, the resource management unit 35 acquires and manages the resource state from the resource management unit 35 of another adjacent transfer server 3. Then, the transfer destination selection unit 33 compares the resource states of the transfer servers 3 managed by the resource management unit 35 of the own server (step S21). The transfer destination selection unit 33 selects the transfer server 3 that is the optimal transfer destination based on the resource state (step S22). Similar to the selection at the sender terminal 1 (step S11), the transfer destination selection unit 33 selects a transfer server 3 having a sufficient resource state as a transfer destination. The transfer destination selection unit 33 may select a plurality of transfer servers 3.

  Next, the file division processing unit 32 checks whether or not the size of the received file is an optimum size for transfer (step S23). When it is larger than the optimum size (step S23: Yes), the file division processing unit 32 divides the file (step S24). Thereafter, the file transfer control unit 31 transmits the divided file to the transfer server 3 selected in step S22 (step S25). At this time, if a plurality of transfer servers 3 have been selected, the divided files may be duplicated, and redundancy for transferring the same divided files to the plurality of transfer servers 3 may be performed.

  Here, the optimum file size for transfer is determined by the performance of each transfer server 3, and the file may be divided smaller than the file divided by the sender terminal 1.

  When the file is divided, the file division processing unit 32 notifies the management server 2 of file division information. This is because the recipient terminal 4 uses the division information when connecting the files. Further, when the file division processing unit 32 divides the file, the file division processing unit 32 may encrypt the divided file. In this case, as with the sender terminal 1, encryption can be performed by obtaining the public key of the sender terminal 4 registered in the user public key management unit 23 of the management server 2.

  On the other hand, when the file size is smaller than the optimum size (step S23: No), the file division processing unit 32 does not divide the transmission target file, and the file transfer control unit 31 selects the file in step S22. (Step S25). Similarly, files may be made redundant and the same file may be transferred to a plurality of transfer servers 3.

  Returning to FIG. 5, next, the receiver terminal 4 performs processing for receiving the file (step S3). Here, the reception process in the recipient terminal 4 will be described in detail with reference to FIG. FIG. 8 is a flowchart showing the reception process of the receiver terminal.

  In the recipient terminal 4, first, the file reception processing unit 12 repeatedly receives and combines the files until all the divided file data are collected (steps S31 to S34). The file reception processing unit 12 acquires file division information from the management server 2 when combining files (step S33). Thereby, the division number of the received file can be grasped. When all the files are prepared, the file reception processing unit 12 uses the private key of its own terminal managed by the public key management unit 15 to decrypt the concatenated file (step S35).

  In this way, when the sender terminal 1 and the transfer server 3 select a file transfer destination, the sender terminal 1 and the transfer server 3 acquire the resource state of the adjacent connection server 3 and select the transfer server 3 having a sufficient resource state. When each transfer server 3 performs the same processing each time it is transferred, the file transfer system can transfer the file through an optimum path. As a result, in the receiver terminal 4, it is possible to shorten the time until decoding compared to the conventional case.

  Next, a process for stopping the file transfer and deleting the file with respect to the file being transferred will be described. For example, there is a case where the user transmits a file from the sender terminal 1 to the receiver terminal 4 but wants to stop transferring the file because the wrong file is transmitted. In such a case, if the file transfer can be stopped, it will benefit the user. In addition, if unnecessary files can be deleted from the network 5, the resource state of the transfer server 3 can be improved, which also benefits other users.

  FIG. 9 is a flowchart showing file transfer stop and delete processing of the file transfer system. As an example, a case where a file is deleted will be described. First, the user instructs the management server 2 to delete a file from the transfer server control processing unit 14 of the sender terminal 1 (step S41). At this time, a file to be deleted is designated using information (for example, a file name) that can identify the file. Next, the transfer control processing unit 21 of the management server 2 instructs the transfer server 3 in the network 5 to delete the file based on the instruction (step S42). In the transfer server 3 that has received the deletion instruction, the file deletion processing unit 34 performs a process of deleting the file when the file to be deleted exists in the own server (step S43). Thus, when the sender terminal 1 instructs the deletion of the file, the transfer server 3 in the network 5 can delete the designated file.

  By deleting unnecessary files in the network 5, in the file transfer system, the resources of the transfer server 3 can be afforded. If there is room in the transfer server 3, the receiver terminal 4 can further reduce the time until decoding.

  Note that, as an example, the case of deleting a file has been described, but the case of stopping the transfer of a file can also be performed by the same processing as described above. In this case, in the transfer server 3, the file transfer control unit 31 controls the stop of the file transfer.

  Moreover, although the case where the instruction | indication of the deletion of a file, etc. was performed from the sender terminal 1 was demonstrated, it is not limited to this, It is also possible to instruct the deletion of a file also from the receiver terminal 4. FIG. For example, when the recipient terminal 4 receives all the divided files and decrypts them, it is not necessary to receive the decrypted files thereafter. However, it is conceivable that the transfer server 3 continues to perform transfer processing in the network 5. In such a case, since the receiver terminal 4 actively transmits a file deletion instruction, an unnecessary file can be deleted in the network 5, so that the resources of the transfer server 3 can be improved. The specific processing procedure is the same as the procedure described in steps S41 to S43 except that the transmission source of the deletion instruction is changed from the sender terminal 1 to the receiver terminal 4.

  If there is a file that could not be received, the receiver terminal 4 does not request a retransmission process to the sender terminal 1 but transmits a retransmission request to the adjacent transfer server 3 and receives the retransmission request. The server 3 may retransmit a desired file. The case where the file could not be received can be determined by, for example, the reception of the remaining divided files within a predetermined time after the first reception of the divided files. It is not limited.

  Here, when the redundant file is transferred from a plurality of paths, the recipient terminal 4 does not originally know which transfer server 3 the file is transferred from. Therefore, the receiver terminal 4 may be limited to transmit a retransmission request to the transfer server 3 that has transmitted a file other than the desired file. This is because the transfer server 3 that has transferred a file in the past is considered to be more likely to transfer a desired file than the transfer server 3 that has never transmitted the file. In this way, by making a retransmission request, the load on the transfer server 3 can be reduced in the network 5 even when a retransmission request is made to the sender terminal 1.

  As described above, in this embodiment, the sender terminal that is the source of the file and the transfer server that performs the file transfer check the resource state of the adjacent transfer server, and the resource state has a surplus transfer. The server is selected as the transfer destination. As a result, the sender terminal and the transfer server do not select a transfer server having no resource state. Therefore, the receiver terminal does not have all the divided files or it takes time until all the divided files are received. Such a situation can be avoided and the time until decoding can be shortened.

  As described above, the file transfer system according to the present invention is useful for transferring files via a network, and is particularly suitable for transferring large-capacity files.

DESCRIPTION OF SYMBOLS 1 Sender terminal 11 File transmission process part 12 File reception process part 13 Display part 14 Transfer server control process part 15 Public key management part 2 Management server 21 Transfer control process part 22 Transfer server management part 23 User public key management part 3 Transfer Server 31 File transfer control unit 32 File division processing unit 33 Transfer destination selection unit 34 File deletion processing unit 35 Resource management unit 4 Receiver terminal 5 Network

Claims (18)

A file transfer system in which terminals transfer files via a network composed of a management server and a plurality of transfer servers,
The transfer server manages resource status of adjacent transfer servers, transfer destination selection means for selecting a transfer destination server based on the resource status, file transfer control means for controlling file transfer,
With
A transfer server managing means for managing the resource state of the transfer server by the management server;
With
A file transmission processing means for performing file transmission processing; a file reception processing means for performing file reception processing;
With
In the terminal on the transmission side, the file transmission processing unit confirms the resource state of the transfer server adjacent to the transfer server management unit of the management server, selects a transfer server having a margin in the resource state as a transfer destination, Send the file to the selected transfer server,
In the transfer server, the transfer destination selection unit confirms a resource state of a transfer server adjacent to the resource management unit, selects a transfer server having a sufficient resource state as a transfer destination, or a receiving terminal. And the file transfer control means transfers the file to the selected transfer server or receiver terminal,
In the receiving terminal, the file reception processing means receives the file.
A file transfer system characterized by that. The file transmission processing unit of the terminal on the transmission side divides the file when the size of the file to be transferred is larger than the minimum division size, and transmits the divided file to the transfer server.
The file transfer system according to claim 1. Furthermore, the transfer server
File division processing means for dividing the file to be transferred,
With
The file division processing means divides the file when the size of the file to be transferred is larger than the optimum file size for transfer,
The file transfer control means transmits the divided file to a transfer server or a receiving terminal.
The file transfer system according to claim 1 or 2, characterized in that In the receiving terminal, if the file reception processing means receives the divided file for the first time and does not finish receiving the remaining divided files within a predetermined period of time, it has received the file to the adjacent transfer server. No request to resend file after splitting,
The file transfer system according to claim 2 or 3, wherein In the transmitting terminal,
The file transmission processing means, when selecting a plurality of transfer servers, transmits the same duplicated file to each selected transfer server,
The file transfer system according to any one of claims 1 to 4, wherein: In the transfer server,
When the transfer destination selection means selects a plurality of transfer servers,
The file transfer control means transfers the copied identical file to each selected transfer server,
The file transfer system according to any one of claims 1 to 5. The resource state is the transfer server's CPU performance, memory size, and free disk space.
The file transfer system according to claim 1, wherein the file transfer system is a file transfer system. further,
A user public key management means for managing a public key for each terminal by the management server;
With
A public key managing means for managing the private key and public key of the terminal and acquiring information on the public key of another terminal;
With
In the transmission side terminal, the public key management unit encrypts a file using the public key of the reception side terminal acquired from the user public key management unit of the management server, and the file transmission processing unit Send the converted file to the transfer server,
The receiving terminal decrypts the private key of the terminal managed by the public key managing means;
The file transfer system according to any one of claims 1 to 7, wherein further,
The transfer server deletes a file;
With
Transfer control processing means for the management server to instruct the transfer server to delete a file or stop transferring a file;
With
Transfer server control processing means for the terminal to instruct the management server to delete a file or stop transferring a file;
With
The transfer server control processing means of the terminal instructs the management server to delete a file or stop transferring a file,
The transfer control processing means of the management server transfers a file deletion or file transfer stop instruction to the transfer server,
In the transfer server, when the file deletion instruction is received, the file deletion unit deletes the target file, and when the file transfer stop instruction is received, the file transfer control unit Stop transferring files,
The file transfer system according to claim 1, wherein: A file transfer method executed by a file transfer system in which terminals transfer files via a network composed of a management server and a plurality of transfer servers,
A first selection step in which the terminal on the transmission side confirms the resource state of the transfer server adjacent to the management server, and selects a transfer server having a sufficient resource state as a transfer destination;
A file sending step in which the sending terminal sends the file to the selected transfer server; and
The forwarding server checks the resource status of the neighboring forwarding server, selects a forwarding server with a sufficient resource status as the forwarding destination, or selects the receiving terminal when it is adjacent to the receiving terminal. A second selection step;
A file transfer step in which the transfer server transfers a file to a selected transfer server or a receiving terminal; and
A file receiving step in which the receiving terminal receives the file;
A file transfer method comprising: In the file transmission step, if the size of the file to be transferred is larger than the minimum division size, the file is divided, and the divided file is transmitted to the transfer server.
The file transfer method according to claim 10. In the file transfer step, if the size of the file to be transferred is larger than the optimum file size for transfer, the file is divided, and the divided file is transmitted to the transfer server or the receiving terminal.
12. The file transfer method according to claim 10, wherein the file transfer method is performed. In the file receiving step, if reception of the remaining divided files is not completed within a predetermined period after the first divided file is received, a request is made to resend the divided files that have not been received to the adjacent transfer server. To
The file transfer method according to claim 11 or 12, wherein: When selecting a plurality of transfer servers in the first selection step,
In the file transmission step, the copied identical file is transmitted to each selected transfer server.
The file transfer method according to any one of claims 10 to 13. When selecting a plurality of transfer servers in the second selection step,
In the file transfer step, the copied identical file is transferred to each selected transfer server.
The file transfer method according to any one of claims 10 to 14, wherein: The resource state is the transfer server's CPU performance, memory size, and free disk space.
16. The file transfer method according to any one of claims 10 to 15, wherein: When the management server manages the public key for each terminal, and the terminal manages the private key and public key of its own terminal and can acquire the public key information of other terminals,
In the file transmission step, the file is encrypted using the public key of the receiving terminal acquired from the management server, and the encrypted file is transmitted to the transfer server,
In the file receiving step, decryption is performed using the private key of the terminal.
The file transfer method according to any one of claims 10 to 16, wherein: further,
An instruction transmission step in which the terminal instructs the management server to delete a file or stop transferring a file;
An instruction transfer step in which the management server transfers an instruction to delete the file or stop transferring the file to the transfer server;
An instruction execution step of deleting the target file when the transfer server receives an instruction to delete the file, and stopping the transfer of the target file when receiving an instruction to stop transferring the file;
The file transfer method according to claim 10, further comprising:

Images