FILE MANAGEMENT SYSTEM, INFORMATION PROCESSING APPARATUS, PROGRAM AND INFORMATION PROCESS

Abstract

To provide a server capable of further safely managing an attachment file of an e-mail.SOLUTION: A server stores an encrypted attachment file in a storage part, generates inquiry information obtained by associating the address of an e-mail with the encrypted attachment file, and transmits the e-mail obtained by deleting the attachment file and inserting the inquiry information to the address. Then, the server performs external authentication of a user on a given authentication server in the case of receiving the inquiry information from the user, and authenticates the user on the basis of an address managed on the authentication server and an address associated with the inquiry information in the case that the external authentication of the user is permitted. When the user's authentication is permitted, the attachment file associated with the inquiry information is decrypted, and the decrypted attachment file is controlled to be able to be downloaded or browsed by the user side.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to a server. [Background technology]

[0002] Electronic mail has been used as a communication tool for a long time, and there exists an MTA (Mail Transfer Agent) that accepts electronic mail from an MUA (Mail User Agent) and delivers (distributes, sends, forwards) the electronic mail.

[0003] Here, MUA is a client program used to send and receive e-mail on a terminal on the Internet, and MTA is a server (mail server) that receives and delivers e-mail on the network via SMTP (Simple Mail Transfer Protocol).

[0004] As a conventional technique, for example, there is a file management system that encrypts an attachment when an email has an attachment, and delivers the email with the encrypted file attached to the destination (Patent Document 1).

[0005] For example, according to Patent Document 1, when server 10 determines that a received e-mail contains an attachment, it encrypts the attachment and sends the e-mail to the destination. Then, by clicking on the URL (URL stands for Uniform Resource Locator; the same applies below) of the password inquiry information, destination user B can view the password for decrypting the encrypted file, and can decrypt the encrypted attachment, provided that the password is set to public (see paragraphs 0061 to 0067 of Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2017-215744 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, the conventional technology shown in Patent Document 1 may allow a person other than the destination user B to easily share the attached file. For example, if the destination user B mistakenly forwards an email with an encrypted file to a third party user X and further forwards the URL of the password reference information, if the password is in a public state, user X may easily obtain the password and decrypt the encrypted file.

[0008] Furthermore, the conventional technology disclosed in Patent Document 1 has a problem in that the user must decrypt the attached file, which is time-consuming.

[0009] The present invention has been made in consideration of the above-mentioned problems, and has as its object to provide a server that manages email attachments more safely and with improved convenience for users. [Means for solving the problem]

[0010] (1) The present invention provides A server that performs processing to manage attachments to e-mails, A receiving unit for receiving an e-mail sent from a sender; a storage processing unit that performs processing for storing the encrypted attached file in a storage unit when the email has an attachment; a query generating unit that generates query information that associates a destination of the electronic mail with the encrypted attached file; a sending unit that sends the email from which the attachment has been removed and from which the inquiry information has been inserted to the destination; an authentication processing unit that, when receiving the inquiry information from a user, performs external authentication of the user on a given authentication server, and, when the external authentication of the user is permitted, authenticates the user based on a destination managed on the authentication server and a destination associated with the inquiry information; and a file control unit that, when authentication of the user is permitted, decrypts an attachment corresponding to the inquiry information, and controls the decrypted attachment so that it can be downloaded to the user side or so that it can be viewed.

[0011] The present invention also relates to a program for causing a computer to function as each part of the server, and to an information storage medium on which the program is stored.

[0012] Here, the "query information" may be, for example, a URL for uniquely specifying a web page on the Internet using a protocol such as HTTP (Hyper Text Transfer Protocol) or HTTPS (Hyper Text Transfer Protocol Secure). Note that the query information may also be information on a server capable of sending and receiving data using other communication protocols such as FTP (File Transfer Protocol). In addition, "when query information is received" refers to, for example, when access to information specified by a URL is received.

[0013] According to the present invention, when external authentication of a user is permitted on the authentication server, the user is authenticated based on "the destination received from the authentication server" and "the destination associated with the query information", and when user authentication is permitted, attachments are made downloadable or viewable, thereby making it possible to manage email attachments even more safely.

[0014] Therefore, even if the reference information is known to a third party (a user other than the destination user), it is possible to deny permission through external authentication. Also, even if a third party is permitted through external authentication, if there is a mismatch between the "destination received from the authentication server" and the "destination associated with the reference information," it is possible to deny authentication of the user, thereby preventing the unauthorized downloading and viewing of attachments.

[0015] Furthermore, according to the present invention, a legitimate user can download or view a decrypted attachment, which eliminates the need for the user to decrypt the attachment on the user's terminal, thereby improving convenience.

[0016] (2) The server, program, and information storage medium of the present invention are The authentication processing unit: When the query information is received from a user in a logged-in state in which external authentication of the user is permitted, external authentication of the user may be omitted, and the user may be authenticated based on the user's destination managed on the authentication server and the destination associated with the query information.

[0017] According to the present invention, if a user of a legitimate destination accesses the query information while in a logged-in state in which external authentication is already permitted, the user can avoid the trouble of external authentication and seamlessly download or view the decrypted attachment.

[0018] (3) The server, program, and information storage medium of the present invention are The authentication processing unit: It may be determined that authentication of the user is permitted when new inquiry information is received from the user within a predetermined period of time from when authentication of the user is permitted.

[0019] According to the present invention, when the destination user newly accesses the query information within a specified period from the time authentication is permitted, it is determined that authentication of the user is permitted, and the decrypted attachment can be seamlessly downloaded or viewed.

[0020] (4) The server, program, and information storage medium of the present invention are The inquiry information generating unit generating a single query in which the destination and the encrypted multiple attachments are associated with each other when a single email has multiple attachments; The file control unit When there are multiple attachments associated with the inquiry information, the multiple attachments associated with the inquiry information may be decrypted, and the decrypted multiple attachments may be controlled so that they can be downloaded to the user or viewed.

[0021] According to the present invention, even if one e-mail contains multiple attachments, the user can obtain or view the multiple decrypted attachments using one password associated with one inquiry information, thereby improving convenience for the user.

[0022] (5) The server, program, and information storage medium of the present invention are The file control unit After the email with the inserted inquiry information is sent to the destination, the decrypted attachment may be controlled to prohibit downloading and viewing by the user based on instructions from a specific user.

[0023] Here, the "prescribed user" refers to, for example, the sender user, the administrator user, etc. According to the present invention, the decrypted attachment is controlled to be prohibited from being downloaded and viewed by the user based on the instruction from the prescriber user, so that the attachment can be managed more safely.

[0024] (6) The server, program, and information storage medium of the present invention are The file control unit Based on an instruction from a predetermined user, the decrypted attached file may be controlled so as to be downloadable or viewable by the predetermined user.

[0025] Here, the "predetermined user" refers to, for example, the sender user, the administrator user, etc. According to the present invention, the decrypted attachment is controlled so that it can be downloaded or viewed by the predetermined user based on the instruction from the predetermined user, so that the convenience for the predetermined user can be improved. [Brief description of the drawings]

[0026] [Figure 1] FIG. 2 is a diagram showing an outline of attachment management according to the present embodiment. [Diagram 2] FIG. 4 is a diagram showing an outline of password notification according to the embodiment. [Diagram 3] FIG. 2 is an example of a network diagram of the file management system according to the present embodiment. [Figure 4] FIG. 2 is a functional block diagram of the server 10 according to the present embodiment. [Diagram 5] 13 shows an example of a password issuance screen according to the present embodiment. [Figure 6] 13 shows an example of a password input screen according to the present embodiment. [Figure 7] 13 is an example of a download screen according to the present embodiment. [Figure 8] 3 shows an example of a management data storage unit of the present embodiment. [Figure 9A] FIG. 4 is a flowchart showing the flow of processing according to the embodiment. [Figure 9B] FIG. 4 is a flowchart showing the flow of processing according to the embodiment. [Figure 10] FIG. 2 is a diagram showing an overview of file control using an authentication server according to the present embodiment. [Figure 11] FIG. 4 is a flowchart showing the flow of processing by a server that uses the authentication server of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] The present embodiment will be described below. Note that the present embodiment described below does not unduly limit the contents of the present invention described in the claims. Furthermore, not all of the configurations described in the present embodiment are necessarily essential components of the present invention.

[0028] [1] Overview The file management system of this embodiment relates to control of an email relay server managing attachments to emails. For example, a case will be described in which a user A, who is a sender (A@example.com), sends an email with an attachment to a user B, who is a destination (B@example.net).

[0029] 1, the server 10 receives an email M (with an email ID of 001) sent from a sender (A@example.com) and designated as a destination (B@example.net). The server 10 then determines whether or not an attachment is present in the email M. If an attachment is present, the server 10 stores the attachment in the storage unit 30.

[0030] In this embodiment, in order to improve security, the attachment is automatically encrypted when stored in the storage unit 30, and the encrypted attachment (note that the encrypted attachment is also called the encrypted file; the same applies below) is stored in the storage unit 30.

[0031] Then, the server 10 generates query information L (URL) that associates the destination (B@example.net) with the identification information of the attachment. The identification information of the attachment is information that can uniquely identify the attachment. For example, the server 10 generates query information L (URL) based on the destination (B@example.net) and the identification information of the attachment. In other words, the query information L is information that can identify the destination and one or more attachments. Note that the attachment that can be identified by the query information L is an encrypted attachment.

[0032] Then, the server 10 deletes the data portion of the attachment file of the email M and inserts instead the query information L. Then, the server 10 transmits the email M to the destination (B@example.net).

[0033] 2, when the server 10 accepts access to the query L, it identifies the destination (B@example.net) from the query L and notifies the identified destination (B@example.net) of the password. Therefore, when a user B of a legitimate destination (B@example.net) clicks on the query L, the password is notified. It can be done like this.

[0034] Then, when the server 10 accepts access based on the query information L, it performs password authentication, and if the authentication is permitted, it decrypts the encrypted attachment and controls the decrypted attachment so that it can be downloaded or viewed.

[0035] Therefore, even if user B mistakenly sends (mis-forwards) email M to another user X, or if the inquiry information L is illegally known to user X, the destination of the password notification is limited to the destination user B, so that control can be performed so that the password is not notified to user X. In other words, according to this embodiment, even if the inquiry information is known to another person, user X, it is possible to prevent user X from obtaining the password, and passwords can be managed safely. This makes it possible to control so that user X cannot illegally download or view attachments.

[0036] In the following explanation, an example will be given in which a sender, user A (A@example.com), creates an e-mail with an attachment, and the destination of the e-mail M is user B (B@example.net).

[0037] [2] Network 3 shows an example of a network diagram of the file management system. In the file management system of this embodiment, a server 10 and a user terminal 20 are connected via a network (such as the Internet or an intranet).

[0038] The server 10 is an information processing device capable of providing a mail service using a terminal 20 communicatively connected via the Internet.

[0039] The server 10 of this embodiment has a mail server function (MTA function) that receives an e-mail consisting of an envelope destination, an envelope sender, and a message, and delivers the e-mail. The server 10 is also called a "relay device" or an "information processing device" that controls the relay of e-mail.

[0040] The terminal 20 is a client device, and is an information processing device such as a smartphone, a mobile phone, a PHS, a computer, a game device, a PDA, or an image generating device, and is a device that can be connected to the server 10 via a network such as the Internet (WAN) or a LAN.

[0041] The server 10 includes a storage unit 30 that stores files. The storage unit 30 functions as a file server that manages files. The storage unit 30 may be provided in a device separate from the server 10.

[0042] [3] Configuration Fig. 4 is an example of a functional block diagram of the server 10 of this embodiment. Note that the server 10 of this embodiment does not need to include all the units in Fig. 4, and may have a configuration in which some of them are omitted.

[0043] The storage unit 170 stores programs and various data for causing a computer to function as each unit of the processing unit 100, and also functions as a storage area for the processing unit 100.

[0044] The storage unit 170 includes a temporary storage area and storage. The storage is a device that permanently stores data, such as a hard disk, an optical disk, a flash memory, or a magnetic tape. The storage unit 170 may also store programs and data stored in the information storage medium 180.

[0045] The storage unit 170 of this embodiment includes a main storage unit 171 used as a work area, a user information storage unit 172, and a management data storage unit 173. Note that some of these may be omitted.

[0046] The main storage unit 171 can be realized by a RAM or the like. The main storage unit 171 is a storage area used in the processing of this embodiment. The user information storage unit 172 stores user information (user account, password, email address, etc.). The user information storage unit 172 may be configured by a DB (DB is an abbreviation for database, the same applies below).

[0047] The management data storage unit 173 stores at least identifiable and unique reference information (URL) for each attached file, a destination, and information on the attached file (e.g., a file name) in association with each other. The management data storage unit 173 may be configured with a DB. The management data storage unit 173 may also store a generated password, a flag indicating validity or invalidity (1 is valid and 0 is invalid), an expiration date, the number of accesses K, and the like.

[0048] Furthermore, the management data storage unit 173 may store an email ID (message ID) for identifying an email with an attached file.

[0049] Information storage medium 180 (computer-readable medium) stores programs, data, etc., and its functions can be realized by storage such as an optical disk (CD, DVD), magneto-optical disk (MO), magnetic disk, hard disk, magnetic tape, or memory (ROM).

[0050] The communication unit 196 performs various controls for communicating with the outside (e.g., terminals, other servers, or other network systems), and its functions can be realized by hardware such as various processors or communication ASICs, programs, etc.

[0051] The processing unit 100 performs various processes of this embodiment based on programs (data) stored in the storage unit 170 or the information storage medium 180 .

[0052] The processing unit 100 (processor) performs various processes using a main memory unit 171 in a storage unit 170 as a work area. The functions of the processing unit 100 can be realized by hardware such as various processors (CPU, DSP, etc.) or programs.

[0053] The processing unit 100 includes a receiving unit 111, an analyzing unit 112, an authentication processing unit 113, a transmitting unit 114, a notifying unit 115, a storage processing unit 116, a query information generating unit 117, a password generating unit 118, a file control unit 119, and a Web processing unit 120.

[0054] The receiving unit 111 receives e-mails on the network via SMTP. That is, the receiving unit 111 performs a process of receiving e-mails that are sent by the MUA of the sender terminal 20 and have an envelope destination specified.

[0055] The analysis unit 112 performs a process of analyzing received e-mail. For example, the analysis unit 112 performs a process of analyzing the envelope destination, the envelope sender, the message header, and the main text of the message body. For example, the analysis unit 112 performs a process of extracting the domain from the envelope destination, a process of extracting To, Cc, Bcc, Subject, and Message-ID from the message header, a process of extracting the main text from the message body, and a process of extracting attached files from the message body.

[0056] When the authentication processing unit 113 receives inquiry information from a user, it performs external authentication of the user on a given authentication server, and if the external authentication of the user is permitted, it authenticates the user based on the destination managed on the authentication server and the destination associated with the inquiry information.

[0057] When the authentication processing unit 113 receives query information from a user in a logged-in state in which external authentication of the user is permitted, the authentication processing unit 113 may omit external authentication of the user and authenticate the user based on the user's destination managed on the authentication server and the destination associated with the query information.

[0058] The authentication processing unit 113 may determine that the authentication of a user is permitted when new inquiry information is received from the user within a predetermined period of time from when the authentication of the user is permitted.

[0059] The transmitting unit 114 transmits (distributes, distributes, relays, and transfers) e-mails over the network via SMTP. That is, the transmitting unit 114 performs processing to transmit e-mails received by the receiving unit 111 to their destinations.

[0060] Here, sending an e-mail includes the process of sending a received e-mail to another MTA via SMTP, the process of sending to a local delivery agent MDA (Mail Delivery Agent) for sending to a user who has an account in the same system in which server 10 is running, and the process of sending to a user who has an account in the same system in which server 10 is running without going through an MDA.

[0061] In particular, the transmission unit 114 of the present embodiment transmits the query information to the destination. The query information is associated with at least the destination and the attached file (encrypted attached file), and is information that can identify the destination and the attached file.

[0062] The sending unit 114 deletes the attached file and sends the email with the inquiry information inserted to the destination.

[0063] That is, in the case where an attachment is included in an e-mail received by the receiving unit 111, the sending unit 114 in this embodiment deletes the attachment and transmits to the destination an e-mail in which the query information is inserted (added) instead of the attachment. Note that, in the case where the first query information and the second query information are generated, the first query information is inserted instead of the attachment.

[0064] Furthermore, in the case where an email received by the receiving unit 111 includes an attachment, the sending unit 114 of this embodiment may encrypt the attachment before sending it to the destination.

[0065] When the notification unit 115 receives the inquiry information, it notifies the destination associated with the inquiry information of the password associated with the inquiry information. Here, the "notification" means at least one of the following: the server 10 sends to the terminal 20 an e-mail (which may be a mail magazine or the like) sent and received by SMTP, sending by a given protocol not limited to SMTP, sending a push notification, presenting (controlling to display and make viewable) a given screen (banner display screen, notice screen, pop-up screen, etc.) of a given application, and the server 10 notifying by a web page, and indicates that the server 10 actively sends to the user's terminal 20. Note that the server 10 may also send information to the requested terminal 20 in response to a request from the user's terminal 20, which is one aspect of the "notification". Note that a push notification is a message displayed in a partial area (such as the top edge) of the screen of the terminal (smartphone). The first thing to do is to display the message window.

[0066] Furthermore, when the notification unit 115 receives the query, it notifies the destination associated with the query of the password associated with the query. That is, the query and the password have a one-to-one relationship.

[0067] In addition, when the first query information and the second query information are generated, the notification unit 115 notifies the destination associated with the first query information of the second query information upon receiving the first query information.

[0068] When the e-mail received by the receiving unit 111 has an attachment, the storage processing unit 116 performs a process of storing the encrypted attachment in the storage unit 30 .

[0069] The query generator 117 generates query information that associates the destination with the encrypted attachment.

[0070] Furthermore, when one e-mail has multiple attachments, the query generating unit 117 generates one query in which the destination is associated with the multiple encrypted attachments.

[0071] Furthermore, the query generating unit 117 may generate the first query and the second query in which the destination and the encrypted attached file are associated with each other.

[0072] In addition, when an email has multiple attachments, the query information generating unit 117 may generate a first query information and a second query information that associate a destination with the encrypted multiple attachments.

[0073] In addition, when an email has multiple attachments, the query information generating unit 117 may generate a first query information and a second query information that associate a destination with the encrypted multiple attachments.

[0074] The password generating unit 118 generates a password required to download the attached file.

[0075] The file control unit 119 decrypts the encrypted attached file, and controls the decrypted attached file so that it can be downloaded or viewed by the user.

[0076] For example, when the file control unit 119 receives query information, it performs authentication based on the password received from the user and a password associated with the query information (a password registered and managed on the server side), and if the authentication is permitted, it decrypts the encrypted attachment associated with the query information, and controls the decrypted attachment so that it can be downloaded to the user side or viewed.

[0077] Furthermore, when one e-mail contains multiple attachments, file control unit 119 performs the following control: When file control unit 119 receives inquiry information, it performs authentication based on the password received from the user and the password associated with the inquiry information, and if the authentication is permitted, it decrypts the multiple attachments associated with the inquiry information, and controls the decrypted multiple attachments so that they can be downloaded to the user side or viewed.

[0078] In addition, when the file control unit 119 receives the second inquiry information, it may decrypt the attachment corresponding to the second inquiry information, and control the decrypted attachment so that it can be downloaded to the user side or viewed.

[0079] In addition, when the file control unit 119 receives the second inquiry information, it may decrypt the multiple attachments associated with the second inquiry information, and control the decrypted multiple attachments to be downloadable or viewable to the user.

[0080] Furthermore, the file control unit 119 may perform anti-virus processing on the decrypted attached file before it is downloaded to the user's terminal or before it is viewed.

[0081] In addition, the file control unit 119 may determine whether or not certain conditions are met before downloading to the user's terminal or before viewing, and if the certain conditions are met, control the decrypted attachment to be available for download to the user side or available for viewing, or may control the attachment to be prohibited from being downloaded to the user's terminal or viewed.

[0082] In addition, after the email with the inserted inquiry information is sent to the destination, the file control unit 119 may control the decrypted attachment file to prohibit the user from downloading and viewing it based on instructions from the specific user.

[0083] Furthermore, the file control unit 119 may control the decrypted attached file so that it can be downloaded or viewed by the predetermined user based on an instruction from the predetermined user.

[0084] The Web processing unit 120 performs processing to transmit (provide) data such as HTML (HyperText Markup Language) documents and images in response to requests from client software such as a Web browser installed in the terminal 20 via HTTP (Hypertext Transfer Protocol), and processing to receive data accepted by the Web browser of the terminal. The server then processes emails, updates the DB, and so on, based on information received from each terminal of the administrator or user.

[0085] The Web processing unit 120 may perform processing to send (provide) data for management settings, etc. to the administrator's terminal 20 in response to an access request from the Web browser of the administrator's terminal 20, and may also perform processing to receive information from the administrator's terminal 20.

[0086] That is, the Web processing unit 120 may add, delete, update, and so on each piece of data to the DB based on an input from the administrator. Note that only the administrator is given the authority to access the Web page (URL) for the administrator.

[0087] Furthermore, the Web processing unit 120 performs a login process and, in response to a request from the Web browser of the terminal 20, a process of controlling a Web page of information related to the logged-in user so that the user can view the Web page.

[0088] For example, the Web processing unit 120 may control a screen for inputting a password or a screen for downloading an attached file in response to a request from a Web browser of the terminal 20 so that the screen can be viewed.

[0089] The storage processing unit 116 performs processing for registering, updating, and deleting data stored in the management data storage unit 173 and the storage unit 30. For example, the storage processing unit 116 receives A process of updating the database may be performed based on the collected data.

[0090] Note that some or all of the processing of the processing unit 100 and the memory unit 170 may be executed by a single device, or each process may be distributed to different devices depending on the purpose of the process.

[0091] [4] Encryption and storage of attachments First, when the server 10 of this embodiment receives an e-mail sent from the MUA of the terminal 20, it analyzes the received e-mail to determine whether or not there is an attachment.

[0092] When the server 10 determines that the e-mail has an attachment, it performs a process of encrypting the attachment and generates an encrypted attachment.

[0093] Then, the server 10 stores the encrypted attachment in a memory area of ​​the storage unit 30. That is, the attachment is automatically encrypted when it is stored in the storage unit 30. Note that the (encrypted) attachment stored in the storage unit 30 is controlled to be decrypted when downloaded.

[0094] Moreover, the storage unit 30 sequentially accumulates and stores the encrypted attachments received from the server 10.

[0095] The storage unit 30 may be a storage area of ​​the server 10 or a storage area on the cloud. In other words, it may be a storage area (storage device) on the Internet that can be connected to the server 10 via the Internet.

[0096] According to this embodiment, the sender, user A, can save the trouble of performing encryption work, and the attachment is encrypted and stored in the storage unit 30, thereby preventing tampering with the attachment and information leakage of the attachment.

[0097] In addition, when an email contains multiple attachments, the server 10 may generate a single encrypted file for the multiple attachments, or may generate individual encrypted files for each of the multiple attachments.

[0098] In this way, the server 10 performs a process of encrypting the attached file when storing it in the storage unit 30. Note that, as will be described later, when the server 10 receives an instruction to download the attached file to the user's terminal 20, the server 10 controls the attachment to be decrypted and made downloadable. In addition, when the server 10 receives an instruction to display (allow the user to view) the attached file on the user's terminal 20, the server 10 performs a process of decrypting the attached file and displaying (allowing the user to view) it.

[0099] [5] Email sending process Furthermore, when the server 10 determines that the email M has an attachment, it removes the attachment and inserts the inquiry information. Then, the server 10 sends the email M including the inquiry information to the destination. In other words, the server 10 separates the attachment from the email M and stores the attachment in the storage unit 30, which makes it possible to prevent information leakage of the attachment in the event of erroneous sending.

[0100] For example, as shown in Fig. 1, the server 10 inserts the inquiry information into the body of the email M. The server 10 may insert the inquiry information into the header of the email M or as a new attachment to the email M. The server 10 may also insert not only the inquiry information but also other information into the email M. You may also include instructions (e.g., click this URL to download the attachment).

[0101] It should be noted that, for an email that does not have an attachment, the server 10 performs a process of sending the email as is.

[0102] [6] Method of generating reference information The server 10 generates a reference (eg, a URL) that serves as a reference for downloading the attachment. For example, the reference is a URL that is required for downloading the attachment.

[0103] The query information is a character string that can specify at least the destination and the attachment file name (e.g., the storage destination in the storage unit 30) according to a predetermined format (URL format). For example, this query information is an identifier for unique identification (also called UUID). Note that the destination and the attachment file name may be encoded and written in the parameter portion according to the URL format.

[0104] When a single e-mail has multiple attachments, the server 10 generates a single piece of reference information that associates a destination with the multiple encrypted attachments.

[0105] [7] Password Generation The server 10 generates a password based on a given encryption algorithm when an instruction to generate a password is received. The generated password is stored in the management data storage unit 173 in association with the reference information. Even when a single e-mail has multiple attachments, the server 10 generates one password associated with the reference information. The server 10 may generate a password when the reference information is received, rather than when an instruction to generate a password is received.

[0106] In order to prevent the password character string from being easily analyzed, the password may be a character string of 20 or more characters including symbols, numbers, uppercase letters, and lowercase letters.

[0107] Also, the password may be a one-time password that is valid only once. For example, a one-time password generation program that generates a one-time password with the same algorithm as that of the server 10 is installed in advance on the terminal 20, and authentication is performed using the one-time password. For example, the algorithm and seed number of the one-time password generation program installed on the terminal 20 and the one-time password generation program installed on the server 10 match, and as a result, the one-time password generated on the terminal side and the password generated on the server 10 match. For example, the one-time password generation program performs a process of generating a one-time password based on the time and seed number at a predetermined cycle (for example, every 30 seconds).

[0108] [8] Password notification When the server 10 receives inquiry information from a given user, it notifies the destination associated with the inquiry information of the password. Note that notifying the destination associated with the inquiry information means designating the destination associated with the inquiry information as the destination of an email for notifying the password and sending an email including the password. Note that notifying the destination associated with the inquiry information may be controlled so that the user of the destination associated with the inquiry information can perform login authentication and view the password on a screen dedicated to the user.

[0109] In other words, when server 10 receives inquiry information regarding email M (email ID=001) from user B of destination (B@example.net), server 10 notifies the destination (B@example.net) associated with the inquiry information of the password required to download the attachment attached to email M (email ID=001).

[0110] For example, the server 10 may notify the terminal 20 of user B of a password issuance screen Sc1 as shown in Fig. 5. For example, when the server 10 receives inquiry information from user B of destination (B@example.net), the server 10 displays the password issuance screen Sc1. Then, when the server 10 receives an instruction to issue a password (generate a password) from user B (for example, an instruction by user B clicking on link L52), the server 10 may notify the destination (B@example.net) associated with the inquiry information of the password.

[0111] Furthermore, the server 10 may display the destination and the attachment file name of the email M (email ID=001) on the password issue screen Sc1 as shown in Fig. 5. Although not shown, the header and the body of the email M may also be displayed.

[0112] Furthermore, even if an inquiry is received from user X who is not related to the destination user B, the password will be notified to the destination (B@example.net) associated with the inquiry, thereby preventing the password from being leaked to anyone other than the destination user B.

[0113] In addition, when the server 10 receives inquiry information from a user in a case where one email contains multiple attachments, the server 10 notifies the destination associated with the inquiry information of one password associated with the inquiry information.

[0114] [9] Attachment Control When the server 10 receives the inquiry from the user B, the server 10 controls the attachment (encrypted attachment) associated with the inquiry so that it can be downloaded or viewed.

[0115] Fig. 6 shows a password entry screen Sc2 displayed on the terminal 20 of user B. For example, when the server 10 receives inquiry information from user B as shown in Fig. 6, the server 10 notifies the user B of a password and then displays the password entry screen Sc2 to the user B.

[0116] Then, user B inputs the notified password into text box field T61. That is, when the server 10 receives a password input instruction from user B (for example, an instruction by user B clicking link L62), the server 10 performs a password authentication process.

[0117] For example, the server 10 authenticates the user based on the password received from the user and the password associated with the query information registered in the server 10 (the password corresponding to the query information stored in the management data storage unit 173). For example, if the password received from the user matches the password registered in the server 10, the authentication is permitted.

[0118] If the server 10 permits the authentication, it displays a download screen Sc3 on the terminal 20 of the user B, as shown in FIG.

[0119] 7, when the server 10 receives an instruction to download the attachment from the authenticated user B (for example, an instruction by user B clicking on link L72), the server 10 transmits the decrypted attachment associated with the reference information to the terminal 20 of user B. In other words, user B can download the attachment to the terminal 20 of user B by clicking on link L72.

[0120] Although not shown, when the server 10 receives an instruction to view the attached file from the authenticated user B (for example, an instruction by user B clicking a link), the server 10 may control the terminal 20 of user B so that the decrypted attached file associated with the inquiry information can be viewed. In other words, user B clicks on a link for viewing to display the contents of the attached file on the terminal 20 of user B. In this way, user B can check the contents of the attached file even if he uses a browser that prohibits downloading (saving to the terminal side), for example.

[0121] In addition, even if there are multiple attachments, the server 10 performs authentication processing using a single password received from user B who has been authorized to be authenticated, and if authentication is authorized, controls the multiple attachments corresponding to the inquiry information to be downloadable to user B's terminal or viewable.

[0122]

[10] Effectiveness control In order to improve information security regarding attachments, the server 10 sets a validity (for example, the value of flag F) for identifying whether a process for generating a password for an attachment, a process for transmitting the password, and a control for enabling downloading are valid or invalid. In other words, the server 10 performs a process for determining the validity of an attachment, and when it is determined to be valid (for example, when flag F=1), performs a process for generating a password, a process for transmitting the password, and a control for enabling downloading.

[0123] For example, the server 10 sets a flag indicating validity for each attached file (or for each piece of reference information, or for each email). For example, flag F=1 means valid, and flag F=0 means invalid.

[0124] If the flag F=1, the server 10 performs a process of generating a password, a process of transmitting the password, and a control that enables downloading of the attached file.

[0125] On the other hand, when the flag F=0, the server 10 performs a process not to generate a password, a process not to transmit the password, and a control to prohibit downloading of the attached file.

[0126] In this embodiment, the server 10 receives a valid or invalid instruction from a predetermined user for each attached file (or for each piece of inquiry information, or for each email).

[0127] For example, when server 10 receives a valid instruction from a specified user regarding an attachment to email M (mail ID=001), server 10 sets flag F corresponding to the attachment to 1, and when server 10 receives an invalid instruction from the specified user, server 10 sets flag F corresponding to the attachment to 0.

[0128] Here, the "predetermined user" refers to the user who is the sender (RCPT FROM, envelope FROM) of the email containing the attached file.

[0129] The "predetermined user" may be a user other than the sender. For example, When setting a group consisting of multiple users, a user other than the sender who belongs to the same group as the sender may be set as the specified user. Also, for example, a user who is the sender's superior may be set as the specified user. Also, when multiple destinations are specified in an e-mail, a user other than the sender who is one of the multiple destinations whose domain is the same as that of the sender may be set as the specified user. Also, a system administrator may be set as the specified user.

[0130]

[11] Download and viewing restrictions Furthermore, the server 10 may count the number K of times that the inquiry information is received, and when the number K reaches a predetermined number or more (e.g., 3 times or more), at least one of download prohibition and viewing prohibition may be controlled. For example, regardless of the information of the flag F, when the number K reaches a predetermined number or more (e.g., 3 times or more), at least one of download prohibition and viewing prohibition may be controlled.

[0131] Furthermore, the server 10 may set an expiration date corresponding to the inquiry information, and when the expiration date has passed, regardless of the information of the flag F, control may be performed to prohibit at least one of downloading and viewing.

[0132]

[12] Management data 8 is an example of information stored in management data storage unit 173 of server 10. For example, management data storage unit 173 stores a URL (query information), a file name of an attached file, a destination, a generated password, a flag F indicating validity, an expiration date, and a count K indicating the number of times the URL is accessed.

[0133] For example, the destination indicates the envelope To, and the password is the password used to download or view the attached file.

[0134] In the example of Figure 8, the destination (B@example.net) has flag F = 1, so the password can be obtained and the attachment can be retrieved, but the destination (G@example.org) has flag F = 0, so the password cannot be obtained and the attachment cannot be retrieved or viewed.

[0135] The expiration date indicates the date and time until which the attached file can be obtained. The number of times K indicates the number of times the reference information has been received. In other words, it indicates the number of times the reference information has been accessed.

[0136] The password data stored in management data storage unit 173 may not be the password itself, but may be a character string (such as a hash value) for determining the password.

[0137]

[13] Flowchart The process flow of this embodiment will be described with reference to FIGS. 9A and 9B.

[0138] 9A, a terminal 20-A of a sending user A (A@example.com) sends an e-mail with an attachment (step S1). The destination of this e-mail is assumed to be a user B (B@example.net).

[0139] When the server 10 receives an e-mail with an attachment (step S11), it encrypts the attachment (step S12) and stores the encrypted attachment in the storage unit 30 (step S13).

[0140] Then, the reference information (URL) is generated (step S14), and the received email is Then, the attached file is deleted, and the inquiry information is inserted (step S15), and the email is sent to the destination (step S16).

[0141] Then, the destination user B's terminal 20-B receives the e-mail (step S100).

[0142] Next, referring to FIG. 9B, the destination user B's terminal 20-B accesses the reference information (URL) (step S111). When the server 10 receives the inquiry information from the terminal 20-B (step S17), it notifies the terminal 20-B of a password (step S18). Note that when the server 10 receives a password generation instruction from the terminal 20-B, the server 10 may generate a password and notify the terminal 20-B of the password.

[0143] Then, the terminal 20-B receives the password (step S112), and inputs the password (step S113). For example, the password is input into a password input screen. The input password is transmitted to the server 10.

[0144] The server 10 performs an authentication process based on the password (step S19). For example, the server 10 performs the authentication process of receiving the password and determining whether or not the password registered in the server 10 matches the received password.

[0145] If the authentication process determines that the file is permitted (Y in step S20), the server 10 controls the attachment so that it can be decrypted and downloaded to the terminal 20-B or viewed (step S21). Note that even if the authentication is permitted, the server 10 may control the attachment so that it can be prohibited from being downloaded to the terminal 20-B or viewed if a given condition is not satisfied (for example, if the flag F indicating validity is 0).

[0146] Then, the terminal 20-B downloads or browses and displays the attached file transmitted from the server 10 (step S114).

[0147] On the other hand, if the server 10 determines that the authentication process is not permitted (N in step S20), the process ends. Then, the process ends.

[0148]

[14] Application Examples [14.1] Notification of inquiry information When the server 10 determines that the email M has an attachment, the server 10 may send the email M with the attachment removed to the destination and notify the destination user of the inquiry information individually. For example, the server 10 may send an email including the inquiry information to the destination.

[0149] [14.2] Multiple attachments When multiple attachments exist in one email, the server 10 may generate a password for each attachment. Then, the server 10 may control the attachments so that they can be downloaded or viewed when authentication based on the password is permitted.

[0150] Furthermore, the server 10 may generate query information corresponding to each of the multiple attached files, or may generate query information that collectively includes the multiple attached files.

[0151] The server 10 may control a plurality of attachments so that they can be downloaded or viewed on a file-by-file basis, or so that a plurality of attachments can be downloaded all at once. Alternatively, the user may be able to control whether the information can be displayed or viewed.

[0152] [14.3] First and second reference information The server 10 of the present embodiment may be configured to allow downloading of an attached file using reference information (URL) instead of a password.

[0153] For example, if an attachment is present in an email M (email ID=001) sent from a sender (A@example.com), the server 10 encrypts the attachment and stores the encrypted attachment in the storage unit 30.

[0154] Then, the server 10 generates the first reference information L1 (first URL) and the second reference information L2 (second URL) based on the destination (B@example.net) and the identification information of the attached file.

[0155] The first query L1 is associated with a destination (B@example.net) and identification information of the attached file. The second query L2 is also associated with the destination (B@example.net) and identification information of the attached file.

[0156] In other words, the first query L1 and the second query L2 are information that can identify the destination and the attached file. The attached file that can be identified by the first query L1 and the second query L2 is an encrypted attached file.

[0157] The second query information L2 is information (URL) different from that of the first query information L1. The server 10 stores the first query information L1 and the second query information L2 in association with each other.

[0158] Then, the server 10 deletes the data portion of the attachment file of the email M, inserts the query information L1 instead, and transmits the email M to the destination (B@example.net).

[0159] If the server 10 determines that the email M has an attachment, the server 10 may send the email M with the attachment removed to the destination and notify the destination user of the query information L1 individually. For example, the server 10 may send an email including the query information L1 to the destination.

[0160] Thereafter, when the server 10 accepts the access of the query L1, the server 10 identifies the destination (B@example.net) from the query L1 and notifies the identified destination (B@example.net) of the query L2. That is, the server 10 notifies the destination (B@example.net) of the query L2 corresponding to the query L1.

[0161] When the server 10 receives the access of the query L2, the server 10 identifies the attachment based on the query L2, decrypts the attachment, and controls so that the decrypted attachment can be downloaded. In other words, the destination user B can display the download screen Sc3 as shown in Fig. 7 on his / her terminal by simply clicking the query L2, and can save the trouble of inputting a password.

[0162] According to this embodiment, the notification destination of the inquiry information L2 is limited to the destination user B, so even if user B mistakenly sends (mis-forwards) the email M to another user X or if the inquiry information L1 is illegally known to user X, it is possible to control so that the inquiry information L2 is not notified to user X. In other words, it is possible to control so that user X cannot illegally download or view attached files.

[0163] When the server 10 receives the access based on the query L2, the server 10 may internally issue a password, perform authentication based on the issued password, and display a download screen to the destination user B.

[0164] Furthermore, when an e-mail contains multiple attachments, the server 10 generates a first query and a second query that associate a destination with the encrypted multiple attachments. When the server 10 receives the second query, the server 10 decrypts the multiple attachments associated with the second query, and controls the decrypted multiple attachments so that they can be downloaded to the user or viewed.

[0165] [14.4] Anti-virus processing The server 10 may perform anti-virus processing on the decrypted attachment before downloading it to the user's terminal or before viewing it. Anti-virus processing refers to processing to remove computer viruses from the attachment. For example, the server 10 records a specific code pattern contained in a predefined known virus, checks whether there is a match in the target attachment, and performs processing to remove the code if there is a match. Note that, if a code matching the specific code is detected in the target attachment, the code may not be removed, but the user may be notified that a computer virus has been detected and downloading of the attachment may be prohibited.

[0166] The server 10 may perform anti-virus processing on the attachment before storing the attachment in the storage unit 30 .

[0167] [14.5] Filtering The server 10 may determine whether a predetermined condition is satisfied before downloading to the user's terminal or before viewing, and when the predetermined condition is satisfied, control the decrypted attachment to be downloadable to the user side or to be viewable. Alternatively, the server 10 may control the decrypted attachment to be prohibited from being downloaded to the user's terminal or to be prohibited from being viewed, when the predetermined condition is satisfied.

[0168] The predetermined condition is a predetermined rule condition. The server 10 may define the predetermined condition in advance, or may set the predetermined condition based on input information from an administrator or a user. The server 10 may set a plurality of predetermined conditions.

[0169] For example, when a predetermined condition A is satisfied in which the destination domain of the header information (or envelope) is a specific domain (e.g., "example.net"), the server 10 controls the decrypted attachment so that it can be downloaded or viewed by the user.

[0170] In addition, for example, if a predetermined condition B is met in which the subject of the header information contains the word “Confidential”, the server 10 controls the decrypted attachment so that it is not downloaded to the user's terminal or so that it is not viewed.

[0171] Furthermore, the server 10 may determine whether or not a predetermined condition is satisfied before storing the attachment in the storage unit 30, and if the predetermined condition is satisfied, store the attachment in the storage unit 30. Alternatively, the server 10 may control the attachment so as to prohibit storage in the storage unit 30 if the predetermined condition is satisfied.

[0172] [14.6] Authentication Tokens The server 10 may notify an authentication token instead of a password. That is, when the server 10 accepts the access based on the query L, the server 10 identifies the destination (B@example.net) from the query L, and notifies the identified destination (B@example.net) of the authentication token.

[0173] The authentication token is a program or URL for generating a password (e.g., a one-time password) for accessing a file stored in the storage unit 30, and may be referred to as a security token. For example, when authentication is permitted based on a password generated using the authentication token in response to an instruction from a user, the server 10 controls to decrypt an encrypted attachment and make the decrypted attachment downloadable or viewable. Furthermore, once authentication based on an authentication token from a user is permitted, the server 10 may maintain the authentication permission of the user for a predetermined period of time (e.g., 10 minutes after authentication is permitted).

[0174] [14.7] Control of receiving email The server 10 may manage attachments in the above manner even when it functions as a receiving server for importing received e-mails to the user side. Note that the server function for importing received e-mails to the user side includes, for example, POP (Post Office Protocol), IMAP (Internet Message Access Protocol), etc.

[0175] The following describes the case where the server functions as a receiving server. First, the server 10 receives an email Mr (assuming the email ID is 002) sent from a sender (A@example.com) and designated as a destination (B@example.net). The server 10 then determines whether or not an attachment exists for the received email Mr (hereinafter referred to as the "received email"). If an attachment exists, the server 10 encrypts the attachment and stores the encrypted attachment in the attachment storage unit 40.

[0176] Then, the server 10 generates the query information L (URL) that associates the destination (B@example.net) with the identification information of the attached file. The identification information of the attached file is information that can uniquely identify the attached file. For example, the server 10 generates the query information L (URL) based on the destination (B@example.net) and the identification information of the attached file.

[0177] The server 10 then deletes the data portion of the attached file of the email Mr, inserts the reference information L instead, and stores the email Mr in the received mail storage unit 50.

[0178] Then, for example, based on a reception instruction from user B of destination (B@example.net), the email Mr stored in the received mail storage unit 50 is taken in as a received mail for user B.

[0179] When user B accesses the query information L included in the email Mr, the server 10 accepts the access of the query information L, identifies the destination (B@example.net) from the query information L, and notifies the identified destination (B@example.net) of the password.

[0180] Then, when the server 10 accepts access to the query information L, it performs password authentication, and if the authentication is permitted, it decrypts the attachment stored in the attachment storage unit 40 and controls so that the decrypted attachment can be downloaded or viewed.

[0181] Incidentally, even when the server 10 functions as a receiving server, it may perform the processes given in the above-mentioned application examples.

[0182] The received mail storage unit 50 and the attachment storage unit 40 may be a storage area of ​​the server 10, or may be a storage area on the cloud (for example, a storage area on the Internet that can be connected to the server 10 and the terminal 20 via the Internet).

[0183] [14.8] Download location In this embodiment, the download destination of the attached file etc. may be not only the user's terminal 20 but also a storage area on the cloud.

[0184] In other words, controlling the attachment so that it can be downloaded to the user side includes not only making the attachment downloadable to the user's terminal 20, but also controlling the attachment so that it can be stored in a memory area on the Internet that can be connected to the terminal 20 via the Internet, in association with the user ID of the user (so that the user can access it).

[0185]

[15] Explanation of user authentication by the authentication server [15.1] Overview As shown in Fig. 10, the server 10 of this embodiment may determine whether or not to authenticate a user through an external authentication server (authentication authority), and determine whether or not to permit authentication of the user based on user information (e.g., destination) received from the authentication server, and allow the user to download or view attachments to e-mails if authentication of the user is permitted. For example, the authentication server may be an authentication server of Google (registered trademark) or the like.

[0186] In this embodiment, the user is required to register in advance user information (eg, account and password) corresponding to the destination user in an external authentication server.

[0187] [15.2] Example of file control using an authentication server Assume that the server 10 accepts an email M1 (email ID=101) sent from a sender (A@example.com) to B@example.net, which is the email address of user B. If an attachment exists in the email M1, the server 10 performs a process of storing the attachment in the storage unit 30. Note that in this embodiment, the attachment is encrypted when storing it in the storage unit 30, but it is not necessarily required to encrypt the attachment.

[0188] The server 10 then generates the query information L-M1 (URL) based on the destination (B@example.net) and the identification information of the attachment (for example, the name of the attachment or information that can uniquely identify the attachment).The server 10 then deletes the attachment from the email M1, inserts the query information L-M1 instead, and sends the email M1 to the destination.

[0189] Then, as shown in FIG. 10, it is assumed that user B refers to this email M1 and clicks on reference information L-M1.

[0190] Then, the server 10 accepts the access of the reference information L-M1 from the user B, and delegates to an external authentication server the authentication of the user B. That is, the server 10 first determines the legitimacy of the user B on the authentication server.

[0191] The authentication process of the authentication server is left to the authentication server itself, and authentication is performed using various methods, such as authentication using User B's account and password, authentication using a one-time password, biometric authentication (face recognition), device authentication, telephone number authentication, and authentication methods that request input of questions to verify the user's identity and determine whether the input is correct.

[0192] The authentication server is an authentication device that is connected to the server 10 via the Internet and performs authentication, and may also be called an authentication system or an authentication organization.

[0193] There may be multiple types of authentication servers, such as Google (registered trademark), Amazon (registered trademark), and Facebook (registered trademark), and an instruction to select one authentication server may be received from the user. Then, the server 10 delegates authentication to the selected authentication server.

[0194] When the terminal 20B of the user B accesses the query information L-M1, the screen transitions to an authentication screen of the authentication server. If necessary, the user B inputs information required for authentication (for example, inputting a password, etc.) on the authentication screen.

[0195] Then, the server 10 performs a process to determine whether or not to permit authentication of the user based on the authentication result on the authentication server. Here, the "authentication result" may be given information that means permission of authentication (for example, user information managed by the authentication server), a result of permission or refusal of authentication, or a result of no response from the authentication server.

[0196] In particular, in this embodiment, the server 10 and the authentication server are defined in advance so that when authentication of a user is permitted on the authentication server, user information (e.g., the user's destination (email address)) managed on the authentication server is sent to the server 10.

[0197] Therefore, when the authentication server permits authentication of user B, it transmits user information including the destination of user B managed on the authentication server to the server 10. On the other hand, when the authentication server does not permit authentication of user B (determines that authentication is not permitted), it performs control not to transmit the user information of user B to the server 10 (or transmits an error result).

[0198] Specifically, as shown in FIG. 10, the server 10 compares the address of user B received from the authentication server (i.e., the address managed on the authentication server) with the address corresponding to the reference information accessed by user B, and if they match, determines to permit authentication of user B. For example, if the address of user B received from the authentication server is "B@example.net" and the address corresponding to the reference information accessed by user B is "B@example.net", it is determined that they match and that authentication of user B is permitted. On the other hand, if the address of user B received from the authentication server does not match the address corresponding to the reference information accessed by user B, the server 10 determines to reject authentication of user B and prohibits user B from downloading and viewing the attached file corresponding to the reference information. In this way, it is possible to avoid the risk that user B may be spoofed, and security can be further improved.

[0199] In addition, the server 10 may send a confirmation email including a confirmation URL (confirmation query information) to the address included in the information received from the authentication server, and if it detects access to the confirmation URL from user B, it may determine that authentication of user B is permitted.

[0200] If the authentication of user B is permitted, the server 10 decrypts the attached file associated with the reference information L-M1 and controls the decrypted attached file so that it can be downloaded to the user B side or can be viewed. For example, the terminal 20B of user B If User B's authentication is permitted, the screen transitions to a download screen as shown in FIG.

[0201] If the server 10 does not receive a response from the authentication server for a predetermined period (one minute) or receives error information from the authentication server, the server 10 prohibits user B from downloading and viewing the attached file corresponding to the inquiry information.

[0202] According to this embodiment, the authentication server can guarantee the authenticity of the destination user, and can prevent unauthorized access from a third party (a user other than the destination user). Also, the server 10 can prevent a third party from masquerading as the original user and making unauthorized access by checking the destination from the authentication server against the destination corresponding to the inquiry information.

[0203] In addition, when server 10 accepts access to inquiry information from a user and performs authentication of the user with the authentication server, it may present information to user B to confirm whether there is any problem in associating the destination (email address) managed on the authentication server with the destination of user B managed by server 10.

[0204] Then, when server 10 obtains consent to the association from user B (for example, when receiving an instruction of consent of "yes" regarding the association), server 10 may associate the destination (email address) managed on the authentication server with the destination of user B managed by server 10, and store the association in memory unit 170 (for example, user information memory unit 172).

[0205] [15.3] Omission of external authentication, etc. Furthermore, when the server 10 receives the query information L-M1 from the user B in a login state in which the external authentication of the user B is permitted, the server 10 may omit the external authentication of the user B. That is, when the server 10 is in a login state in which the external authentication of the user B is permitted, the server 10 receives the "destination of the user B managed on the authentication server" from the authentication server, or refers to the "destination of the user B managed on the authentication server" stored in the storage unit 170. Then, the server 10 may authenticate the user B based on the "destination of the user B managed on the authentication server" and the destination associated with the query information.

[0206] In other words, if this is done, user B, if he is a legitimate user, can seamlessly download or view the decrypted attachment.

[0207] Furthermore, the server 10 may determine to permit authentication of user B when new inquiry information (different inquiry information) is received from user B within a predetermined period (e.g., within 10 minutes) from the time when authentication of user B is permitted. In other words, once the legitimacy is guaranteed, user B can seamlessly download or view the decrypted attachment by simply accessing the inquiry information for a predetermined period.

[0208] Furthermore, when the server 10 receives inquiry information from a user, if the destination of the inquiry information is stored in the storage unit 170 (e.g., the user information storage unit 172) as a destination (email address) managed on the authentication server, the server 10 may omit external authentication on the authentication server. In other words, the server 10 may authenticate the user based on the "destination of the user managed on the authentication server" stored in the storage unit 170 and the "destination associated with the inquiry information."

[0209] [15.4] Flowchart FIG. 11 is a flowchart showing an example of a process flow of a server using an authentication server. vinegar.

[0210] First, the server 10 judges whether or not it has received inquiry information from a user (step S31). If it has received inquiry information (Y in step S31), it delegates authentication of the user to an authentication server (step S32). Note that, when the server 10 receives inquiry information from the user (Y in step S31), it may accept one authentication server from among a plurality of authentication servers such as Google (registered trademark), Amazon (registered trademark), and Facebook (registered trademark) based on a selection instruction from the user, and delegate authentication of the user to the accepted authentication server.

[0211] Then, it is determined whether or not a destination managed on the authentication server has been received from the authentication server (step S33). Note that in this embodiment, "receiving a destination managed on the authentication server" from the authentication server means that authentication of the user is permitted on the authentication server.

[0212] Then, when a destination managed on the authentication server is received (Y in step S33), it is determined whether the destination managed on the authentication server matches the destination corresponding to the reference information (step S34).If the destination managed on the authentication server matches the destination corresponding to the reference information (Y in step S34), the attachment (the attachment corresponding to the reference information) is decrypted and controlled so that it can be downloaded or viewed by the user (step S55).

[0213] If the destination managed on the authentication server is not received (N in step S33), or if the destination managed on the authentication server does not match the destination corresponding to the reference information (N in step S34), the process ends.

[0214] [15.5] Multiple attachments When an e-mail contains multiple attachments, the server 10 may generate a single query that associates a destination with the encrypted multiple attachments. In this case, when a single e-mail contains multiple attachments, the server 10 may decrypt the multiple attachments and control the decrypted multiple attachments to be downloadable or viewable by the user.

[0215] [15.6] Disabled Even when authentication is performed using an authentication server, after email M1 with the inserted query information is sent to the destination (B@example.net), server 10 may control the decrypted attachment to prohibit the user from downloading or viewing it based on instructions from a specific user (e.g., user A who sent it or a user who is superior to user A).

[0216]

[16] Downloads and viewing by designated users The server 10 may control the decrypted attachment so that it can be downloaded or viewed by the specified user based on instructions from a specified user (e.g., the sender user A or an administrator user). For example, the server 10 may control the decrypted attachment so that it can be downloaded or viewed by the sender user based on instructions from the sender user. Also, the server 10 may control the decrypted attachment so that it can be downloaded or viewed by the administrator user based on instructions from the administrator user. When downloading or the like for a specified user, user authentication may be performed to determine the legitimacy of the specified user using the various methods described above.

[0217]

[17] Other The email of this embodiment is not limited to SMTP, and may be sent and received according to a given protocol.

[0218] Furthermore, the data of this embodiment, for example, e-mail data, may be stored in the storage unit 30 or in a storage area on the Internet.

[0219] Furthermore, the server 10 of this embodiment may encrypt attachments of all received e-mails, or may control to encrypt attachments of e-mails that satisfy given rule conditions. For example, the server 10 may set rule conditions in advance based on input information from an administrator or a user. Furthermore, in this embodiment, e-mails that satisfy a given rule condition may be temporarily suspended (suspended from transmission for a certain period of time). Furthermore, e-mails that satisfy a given rule condition may be sent when approval instructions are received from a given user (for example, the superior of the sender user).

[0220] In the present embodiment, the concept of control to enable downloading may include control to enable printing, and the concept of control to prohibit downloading may include control to prohibit printing.

[0221] In addition, in this embodiment, the inquiry information is inserted into the text, but an attachment containing the inquiry information may be inserted.

[0222] In this embodiment, the user who downloaded or viewed the content may be stored in the storage unit (left in the history).

[0223] The user authentication process performed in this embodiment may be various other authentication processes. For example, the authenticity of a user may be determined by telephone number authentication or authentication process using a terminal device (smartphone) of the user. [Explanation of symbols]

[0224] 10 server, 20 terminal, 30 storage unit, 100 Processing section, 111 Receiving section, 112 Analysis section, 113 Authentication processing section, 114 Transmission section, 115 Notification section, 116 Storage processing section, 117 Inquiry information generating section, 118 Password generating section, 119 File control section, 120 Web processing section, 170 Storage section, 171 Main storage section, 172 User information storage section, 173 Management data storage section, 180 Information storage medium

Claims

1. A file management system that manages attachments to e-mails, A receiving unit for receiving an e-mail sent from a sender; If the email has an attachment, the encrypted attachment is stored in a storage unit. A storage processing unit that performs processing to store The electronic mail address and the encrypted attached file are associated with each other. a query information generating unit for generating a query information; Delete the attachment to the email, insert the inquiry information into the email, a sending unit for sending the email to the destination; When the inquiry information is received from the user, the external authentication information of the user is generated on a given authentication server. If external authentication of the user is permitted, the destination address is managed on the authentication server. and an authentication process for authenticating the user based on the destination of the inquiry and the destination associated with the inquiry. With the Department of Science, If the authentication of the user is permitted, the attachment corresponding to the query information is and a file control unit for decrypting the file.

2. A file management system that performs processing to manage attachments to e-mails, comprising: A receiving unit for receiving an e-mail sent from a sender; If the email has an attachment, the encrypted attachment is stored in a storage unit. A storage processing unit that performs processing to store The electronic mail address and the encrypted attached file are associated with each other. a query information generating unit for generating a query information; Delete the attachment to the email, insert the inquiry information into the email, a sending unit for sending the email to the destination; When the inquiry information is received from the user, the external authentication information of the user is generated on a given authentication server. If external authentication of the user is permitted, the destination address is managed on the authentication server. and an authentication process for authenticating the user based on the destination of the inquiry and the destination associated with the inquiry. With the Department of Science, If the authentication of the user is permitted, the attachment corresponding to the query information is and a file control unit for managing the decrypted attached file. A file management system.

3. In claim 1 or 2, The authentication processing unit: When the user is in a logged-in state in which external authentication is permitted, the user When the user information is received, external authentication of the user is omitted and the information is managed on the authentication server. Based on the destination of the user and the destination associated with the inquiry information, A file management system that performs authentication.

4. In any one of claims 1 to 3, The authentication processing unit: Within a predetermined period from the time when the authentication of the user is permitted, new inquiry information is received from the user. and determining that authentication of the user is permitted when the file is received. Management system.

5. In any one of claims 1 to 4, The inquiry information generating unit When multiple attachments are present in a single email, the destination and the encrypted A file management method characterized by generating a single piece of reference information associated with a plurality of attached files. Management system.

6. In any one of claims 1 to 5, The file control unit The system is characterized by managing the decrypted attachments based on instructions from a specific user. A file management system.

7. An information processing device that performs processing to manage attachments to e-mails, A receiving unit for receiving an e-mail sent from a sender; If the email has an attachment, the encrypted attachment is stored in a storage unit. A storage processing unit that performs processing to store The electronic mail address and the encrypted attached file are associated with each other. a query information generating unit for generating a query information; Delete the attachment to the email, insert the inquiry information into the email, a sending unit for sending the email to the destination; When the inquiry information is received from the user, the external authentication information of the user is generated on a given authentication server. If external authentication of the user is permitted, the destination address is managed on the authentication server. and an authentication process for authenticating the user based on the destination of the inquiry and the destination associated with the inquiry. With the Department of Science, If the authentication of the user is permitted, the attachment corresponding to the query information is and a file control unit for decoding the file.

8. An information processing device for performing processing to manage attachments to e-mails, A receiving unit for receiving an e-mail sent from a sender; If the email has an attachment, the encrypted attachment is stored in a storage unit. A storage processing unit that performs processing to store The electronic mail address and the encrypted attached file are associated with each other. a query information generating unit for generating a query information; Delete the attachment to the email, insert the inquiry information into the email, a sending unit for sending the email to the destination; When the inquiry information is received from the user, the external authentication information of the user is generated on a given authentication server. If external authentication of the user is permitted, the destination address is managed on the authentication server. and an authentication process for authenticating the user based on the destination of the inquiry and the destination associated with the inquiry. With the Department of Science, If the authentication of the user is permitted, the attachment corresponding to the query information is and a file control unit for managing the decrypted attached file. An information processing device.

9. A program that causes a computer to perform a process for managing email attachments. hand, A receiving unit for receiving an e-mail sent from a sender; If the email has an attachment, the encrypted attachment is stored in a storage unit. A storage processing unit that performs processing to store The electronic mail address and the encrypted attached file are associated with each other. a query information generating unit for generating a query information; Delete the attachment to the email, insert the inquiry information into the email, a sending unit for sending the email to the destination; When the inquiry information is received from the user, the external authentication information of the user is generated on a given authentication server. If external authentication of the user is permitted, the destination address is managed on the authentication server. and an authentication process for authenticating the user based on the destination of the inquiry and the destination associated with the inquiry. With the Department of Science, If the authentication of the user is permitted, the attachment corresponding to the query information is A program for causing a computer to function as a file control unit for decoding a file. Hmm.

10. A program that causes a computer to perform a process for managing email attachments. hand, A receiving unit for receiving an e-mail sent from a sender; If the email has an attachment, the encrypted attachment is stored in a storage unit. A storage processing unit that performs processing to store The electronic mail address and the encrypted attached file are associated with each other. a query information generating unit for generating a query information; Delete the attachment to the email, insert the inquiry information into the email, a sending unit for sending the email to the destination; When the inquiry information is received from the user, the external authentication information of the user is generated on a given authentication server. If external authentication of the user is permitted, the destination address is managed on the authentication server. and an authentication process for authenticating the user based on the destination of the inquiry and the destination associated with the inquiry. With the Department of Science, If the authentication of the user is permitted, the attachment corresponding to the query information is The computer is used as a file control unit to decrypt the attachment and manage the decrypted attachment. A program characterized by causing a function to be performed.

11. An information processing method for managing email attachments, comprising: receiving an email sent from a sender; If the email has an attachment, the encrypted attachment is stored in a storage unit. and The electronic mail address and the encrypted attached file are associated with each other. and Delete the attachment to the email, insert the inquiry information into the email, sending the email to the destination; When the inquiry information is received from the user, the external authentication information of the user is generated on a given authentication server. If external authentication of the user is permitted, the destination address is managed on the authentication server. and authenticating the user based on the destination and the destination associated with the inquiry. P and If the authentication of the user is permitted, the attachment corresponding to the query information is and a decrypting step.

12. An information processing method for managing email attachments, comprising: receiving an email sent from a sender; If the email has an attachment, the encrypted attachment is stored in a storage unit. and The electronic mail address and the encrypted attached file are associated with each other. and Delete the attachment to the email, insert the inquiry information into the email, sending the email to the destination; When the inquiry information is received from the user, the external authentication information of the user is generated on a given authentication server. If external authentication of the user is permitted, the destination address is managed on the authentication server. and authenticating the user based on the destination and the destination associated with the inquiry. P and If the authentication of the user is permitted, the attachment corresponding to the query information is and managing the decrypted attachment. Information processing methods.

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