JP3794301B2 - Content protection method and system, content protection program, and computer-readable recording medium storing content protection program - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention stores a content protection method and system, a content protection program, and a content protection programComputer readable recording mediaIn particular, a content protection method and system, a content protection program, and a content protection program for protecting copyright in digital content distribution over a network are stored.Computer readable recording mediaAbout.
[0002]
[Prior art]
With the spread of information networks such as the Internet and the digitization of content, content distribution on the network has become active. An electronic mail is widely used as a communication means using a network. In electronic mail, an electronic mail user generally registers himself / herself in an electronic mail server device operated by an ISP (Internet Service Provider) to send and receive mail.
[0003]
[Problems to be solved by the invention]
However, there is a problem that copyright infringement becomes easy due to the characteristics of digital contents. In other words, once digital data is obtained, anyone can easily make copies without deterioration any number of times, and since it can be a sender of data, the receiver of content data is the original. It becomes possible to distribute a copy in an unintended form by the sender (copyright holder) of the content data.
[0004]
E-mail, which is a general communication means, is basically one-to-one or one-to-many communication, and generally the exchange of e-mail is not noticed by anyone other than the sender / receiver. If unauthorized content is distributed using e-mail, the ISP, who is the administrator of the e-mail server device, may be liable for the responsibility. However, as described above, It's difficult to identify who has done the wrong. As a similar case, there is a problem that it is difficult to identify the criminal even if the employee leaks outside confidential information using e-mail in a company or the like.
[0005]
In addition, considering that the content data owner (copyright owner) distributes content data using e-mail, it is difficult for the user to whom the content data is distributed to prevent the above-mentioned unauthorized distribution after obtaining the data. There's a problem.
[0006]
  The present invention has been made in view of the above points, and in content distribution using e-mail, while preventing unauthorized distribution by an e-mail user registered in a certain e-mail server device, content data is e-mailed. A content protection method and system capable of preventing unauthorized distribution of received users, a content protection program, and a content protection program are stored.Computer readable recording mediaThe purpose is to provide.
[0007]
[Means for Solving the Problems]
FIG. 1 is a diagram for explaining the principle of the present invention.
[0008]
The present invention (Claim 1) is a content protection method for preventing unauthorized distribution of content during content distribution using network communication including electronic mail.
In an email server device,
Disassemble the e-mail sent from the e-mail user device into an e-mail body and attached data (step 1),
Extract the header information described in the header part of the email (step 2),
Embed digital watermark in the attached data using header information and digital watermark technology (step 3),
Attached data embedded with a digital watermark is combined with the text of the email to create a watermarked email (step 4),
The watermarked e-mail is transferred to another e-mail server device by a normal delivery method (step 5),
In the digital watermark detection device,
The content data is received from the e-mail user device on the receiving side that has received the watermarked e-mail via the e-mail server device (step 6),
When the digital watermark is detected from the content data and the digital watermark is detected, the embedded information is output as information related to unauthorized transmission (step 7).
The present invention (Claim 2) is an electronic mail server device,
Get a message ID that uniquely identifies the email,
Embed the message ID in the attached data using digital watermark technology,
Register the message ID and header information as a set in the header information database,
In the digital watermark detection device,
The information output by the digital watermark detection process is regarded as the message ID, and the corresponding electronic mail in the header information database is acquired.
[0009]
  The present invention (Claim 3)In a content protection method for preventing unauthorized distribution of content at the time of computer distribution using network communication including electronic mail,
  In an email server device,
  Decomposing the first e-mail sent from the e-mail user device into a first e-mail body and first attached data;
  Extracting first header information described in a header portion of the first e-mail;
  Embedding a digital watermark in the first attached data using the first header information and the digital watermark technology,
  Combining the first attached data embedded with the electronic watermark with the first e-mail body to create a first watermarked e-mail;
  Transferring the first watermarked email to another email server device by a normal delivery method;
  Digital watermark embeddedReceive a second email,
  The second e-mail is changed to the second e-mail body and the second attached data.Disassembled into
  In the header of the second emailContains the destination email address describedGet the second header information,
  Second attached dataIf the watermark is detected successfully and the watermark is detected successfully, the embedded destination email address andSecond header informationCheck the consistency of the destination e-mail address described in, or use the specified conditions.Second emailCheck the legitimacy of
  If the validity cannot be confirmed, processing for preventing fraud is performed.
[0010]
FIG. 2 is a principle configuration diagram of the present invention.
[0011]
The present invention (Claim 4) is a content protection system for preventing unauthorized distribution of content during content distribution using network communication including electronic mail,
An attached data decomposing means 21 for decomposing the e-mail sent from the e-mail user device 10 into an e-mail body and attached data;
Header information acquisition means 22 for extracting header information described in the header part of the e-mail;
Digital watermark embedding means 23 for embedding header information as digital watermark in attached data using digital watermark technology;
Attached data combining means 24 for combining the attached data embedded with the electronic watermark with the e-mail body to create a watermarked e-mail;
An e-mail server device 20 having transmission means 25 for transferring a watermarked e-mail to another e-mail server device by a normal delivery method;
Receiving means 64 for receiving content data from the receiving-side email user device 50 that has received the watermarked email via the email server device 40;
A digital watermark detection apparatus 60 having a digital watermark detection means 61 that outputs the embedded information as information related to unauthorized transmission when the digital watermark is detected from the content data and the digital watermark is detected.
[0012]
The present invention (Claim 5) is provided in the electronic mail server device 10,
Means for obtaining from the e-mail a message ID uniquely indicating the e-mail;
It further has means for registering the message ID and header information as a set in the header information database,
In the digital watermark embedding means 23,
Means for embedding the message ID as a digital watermark in the attached data using a digital watermark technique;
In the digital watermark detection apparatus 60,
The information output by the digital watermark detection means 61 is regarded as a message ID, and includes a means for acquiring a corresponding electronic mail from the header information database.
[0013]
  The present invention (Claim 6)A content protection system for preventing unauthorized distribution of content at the time of computer distribution using network communication including electronic mail,
  E-mail server device
  First attached data decomposing means for decomposing the first e-mail sent from the e-mail user device into a first e-mail body and first attached data;
  First header information acquisition means for extracting first header information described in a header portion of the first e-mail;
  First watermark embedding means for embedding the digital watermark in the first attached data using the first header information and the digital watermark technique;
  First attached data combining means for combining the first attached data in which the electronic watermark is embedded with the first electronic mail body to create the first watermarked electronic mail;
  First transmission means for transferring the first watermarked electronic mail to another electronic mail server device by a normal delivery method;
  The second electronic mail in which the received electronic watermark is embedded is changed to the second electronic mail text and the second attached data.Break down intoA second attached data decomposition means;
  Second emailContains the destination email address described in the headerSecond header information acquisition means for acquiring second header information;
  Second attached dataDetect watermarks fromDoneIf the digital watermark detection is successful, the embedded email address andIn the second header informationConfirm the consistency of the destination e-mail address that was written or use the specified conditionsSecond emailMeans to confirm the legitimacy of
  A means of performing processing to prevent fraud if legitimacy cannot be confirmed;,Have
[0014]
  The present invention (Claim 7) is a content protection system for preventing unauthorized distribution of content during content distribution using network communication including electronic mail.On a computer used as an email server,
  Attached data decomposition that decomposes an email sent from an email user device into an email body and attached dataStepWhen,
  Header information acquisition that extracts header information including the sender email address, destination email address, title, and transmission date and time described in the header part of the emailStepWhen,
  Digital watermark embedding of watermark information in attached data using digital watermark technologyStepWhen,
  Attached data combination that creates a watermarked email by combining the embedded data with the watermark embedded with the body of the emailStepWhen,
  Sending a watermarked e-mail to another e-mail server using the normal delivery methodStep and executeIt is a program.
[0015]
  The present invention (Claim 8) acquires a message ID uniquely indicating an electronic mail.StepWhen,
  Register message ID and header information in header information databasePerform further steps,
  Digital watermarkIn step
  Instead of header information, message ID is embedded in attached data using digital watermark technologyIt is a program that performs steps.
[0016]
  The present invention (Claim 9) provides an electronic mail server in a content protection system for preventing unauthorized distribution of content during content distribution using network communication including electronic mail.As a computer used as
  A first attached data decomposing step of decomposing the first e-mail sent from the e-mail user device into a first e-mail body and first attached data;
  A first header information acquisition step of extracting first header information described in a header portion of the first e-mail;
  A first watermark embedding step of embedding a digital watermark in the first attached data using first header information and a digital watermark technique;
  A first attached data combining step of combining the first attached data in which the electronic watermark is embedded with the first electronic mail body to create the first watermarked electronic mail;
  A first sending step of transferring the first watermarked e-mail to another e-mail server device by a normal delivery method;
  A second attached data disassembling step for disassembling the received second electronic mail in which the electronic watermark is embedded into a second electronic mail text and second attached data;
  A second header information acquisition step of acquiring second header information including a destination electronic mail address described in a header part of the second electronic mail;
  When the digital watermark is detected from the second attached data and the digital watermark is detected successfully, the embedded destination email address matches the destination email address described in the second header information. Confirming the legitimacy of the second e-mail using a sex check or a predetermined condition;
  If the validity cannot be confirmed, a step for performing processing to prevent fraud is executed.It is a program.
[0017]
  The present invention (Claim 10) provides a digital watermark detection apparatus in a content protection system for preventing unauthorized distribution of content during content distribution using network communication including electronic mail.As a computer used as
  Receiving content data from a receiving e-mail user device that has received a watermarked e-mail via an e-mail server deviceStepWhen,
  Digital watermark detection to detect digital watermark from content dataStepWhen,
  When a digital watermark is detected, the header information embedded as the digital watermark is output as a log together with the location information of the content data as information related to illegal transmission. Output to outputAnd a program for executing steps.
[0018]
  The present invention (claim 11) provides outputStep, The information embedded as the electronic watermark is a message ID, based on the message ID from the header information database on the electronic mail server device registered in combination with the message ID and the header information of the electronic mail. And get the corresponding emailA program that executes steps.
[0019]
  The present invention (Claim 12) provides an electronic mail server device in a content protection system for preventing unauthorized distribution of content during content distribution using network communication including electronic mail.Used as a computer,
  Attached data decomposition that decomposes an email sent from an email user device into an email body and attached dataStepWhen,
  Header information acquisition that extracts header information including the sender email address, destination email address, title, and transmission date and time described in the header part of the emailStepWhen,
  Digital watermark embedding of watermark information in attached data using digital watermark technologyStepWhen,
  Attached data combination that creates a watermarked email by combining the embedded data with the watermark embedded with the body of the emailStepWhen,
  Sending a watermarked e-mail to another e-mail server using the normal delivery methodA computer-readable recording medium storing a content protection program for executing the steps.
[0020]
  The present invention (Claim 13) obtains a message ID uniquely indicating an electronic mail.StepWhen,
  Register message ID and header information in header information databaseLet the step run,
  Digital watermarkIn stepsIs
  Instead of header information, message ID is embedded in attached data using digital watermark technologyA computer-readable recording medium storing a program for performing steps.
[0021]
  The present invention (Claim 14) is an electronic mail server in a content protection system for preventing unauthorized distribution of content during content distribution using network communication including electronic mail.As a computer used as
  A first attached data decomposing step of decomposing the first e-mail sent from the e-mail user device into a first e-mail body and first attached data;
  A first header information acquisition step of extracting first header information described in a header portion of the first e-mail;
  A first watermark embedding step of embedding a digital watermark in the first attached data using first header information and a digital watermark technique;
  A first attached data combining step of combining the first attached data in which the electronic watermark is embedded with the first electronic mail body to create the first watermarked electronic mail;
  A first sending step of transferring the first watermarked e-mail to another e-mail server device by a normal delivery method;
  A second attached data disassembling step for disassembling the received second electronic mail in which the electronic watermark is embedded into a second electronic mail text and second attached data;
  Second emailAcquire second header information including the destination e-mail address described in the header partA second header information acquisition step;
  Detect the digital watermark from the second attached data,If the digital watermark detection is successful, the embedded email address andSecond header informationCheck the consistency of the destination e-mail address described in the2 emailCheck the validity ofSteps,
  If the correctness cannot be confirmed, processing is performed to prevent fraudSteps,
Is a computer-readable recording medium storing a content protection program for executing.
[0022]
  The present invention (Claim 15) provides a digital watermark detection apparatus in a content protection system for preventing unauthorized distribution of content during content distribution using network communication including electronic mail.As a computer used as
  Receiving content data from a receiving e-mail user device that has received a watermarked e-mail via an e-mail server deviceStepWhen,
  Digital watermark detection to detect digital watermark from content dataStepWhen,
  When a digital watermark is detected, the header information embedded as the digital watermark is output as a log together with the location information of the content data as information related to illegal transmission. Output to outputAnd a computer-readable recording medium storing a content protection program for executing.
[0023]
  The present invention (Claim 16) provides output.Step, The information embedded as the electronic watermark is a message ID, based on the message ID from the header information database on the electronic mail server device registered in combination with the message ID and the header information of the electronic mail. And get the corresponding emailA computer-readable recording medium storing a program for executing steps.
[0024]
As described above, according to the present invention, when content is distributed as attachment data of an e-mail, information specifying the sender and the recipient is embedded by the digital watermark technology. It is possible to track who is the person who has done this, and this enables psychological deterrence of unauthorized distribution.
[0025]
Further, according to the present invention, the content data is delivered by e-mail only to the user designated by the copyright owner, so that it is possible to actually make unauthorized distribution impossible.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0027]
[First Embodiment]
FIG. 3 shows the configuration of the content protection system according to the first embodiment of the present invention.
[0028]
The system shown in FIG. 1 is connected to a network 30 such as the Internet, and performs an ordinary e-mail delivery server 40 and an electronic mail server device 20 with an electronic watermark embedding function having an electronic watermark embedding function. In addition, a plurality of e-mail user devices 10 connected to the e-mail server device 20 and content data distributed and distributed on the network 30 including the WWW (World Wide Web) are searched, and a digital watermark is detected therefrom. And an electronic mail user device 50 connected to the electronic mail server device 40.
[0029]
Note that, in the above configuration, the e-mail user device 10 is described as a transmitting side, and the e-mail user device 50 is described as a receiving side.
[0030]
Next, the operation in the above configuration will be described.
[0031]
FIG. 4 is a sequence chart of processing of the content protection system according to the first embodiment of the present invention.
[0032]
Step 101) The sending-side e-mail user device 10 creates an e-mail and sends it to the e-mail server device 20 with an e-mail embedding function.
[0033]
Step 102) The e-mail server device 20 with the e-mail embedding function embeds the header information of the received e-mail in the content data attached to the e-mail using a digital watermark technique.
[0034]
Step 103) The electronic mail server device 20 with the electronic mail embedding function delivers the watermarked electronic mail by a normal mail delivery procedure, and transmits it to the electronic mail server device 40 that manages the destination user.
[0035]
Step 104) The watermarked e-mail arrives at the e-mail user device 50 of the destination user. Up to this point, the exchange process by electronic mail has been completed. Thereafter, the receiver can acquire the content data transferred to the watermarked mail.
[0036]
Hereinafter, the operation when unauthorized distribution is performed by the receiver will be described.
[0037]
Step 105) The watermarked content data is distributed and distributed from the recipient's electronic mail user device 50 using WWW or the like.
[0038]
Step 106) The digital watermark detection apparatus 60 acquires content data to be detected by WWW page search or the like.
[0039]
Step 107) The digital watermark detection device 60 attempts to detect a digital watermark from the detection target content data. If the digital watermark detection device 60 can detect the digital watermark, the digital watermark detection device 60 identifies the user who performed illegal distribution from the embedded header information.
[0040]
Next, the configuration and processing of the electronic mail server device 20 with an electronic watermark embedding function will be described.
[0041]
FIG. 5 shows the configuration of an electronic mail server device with a digital watermark embedding function according to the first embodiment of the present invention.
[0042]
The electronic mail server device 20 with an electronic watermark embedding function is an SMTP that is a function of an attached data decomposition unit 21, a header information acquisition unit 22, an electronic watermark embedding unit 23, an attached data combining unit 24, and an ordinary electronic mail server device. (Simple Mail Transfer Protocol) The SMTP processing unit 25 has a function as a server device.
[0043]
FIG. 6 is a flowchart of processing of the electronic mail server device with an electronic watermark embedding function according to the first embodiment of the present invention.
[0044]
When the e-mail server device 20 receives an e-mail created by the e-mail user device 10 (step 201), the e-mail is first decomposed into an e-mail text and attached data in the attached data decomposing unit 21. (Step 202).
[0045]
Next, the header information acquisition unit 22 acquires header information from the e-mail body (step 203). The header information is an arbitrary combination of sender information, destination information, title, transmission date and time, and the like.
[0046]
Next, the digital watermark embedding processing unit 23 embeds header information in the attached data using a digital watermark technique to create watermarked attached data. Here, when all the attached data is embedded with digital watermarks and the attached data with watermarks is created (Yes in step 204), the electronic mail body and the attached data with watermarks are combined again by the attached data combining unit 24. (Step 206) In the SMTP processing unit 25, normal mail processing is performed (Step 207). If the digital watermark embedding has not been completed for all the attached data (step 204, No), the header information is embedded in the attached data as a digital watermark, and the process proceeds to step 204 (step 205).
[0047]
Next, the configuration and processing of the digital watermark detection apparatus 60 will be described.
[0048]
FIG. 7 shows the configuration of the digital watermark detection apparatus in the first embodiment of the present invention. The digital watermark detection apparatus 60 shown in the figure includes a digital watermark detection unit 61, a detection result logging unit 62, and a log database 63.
[0049]
FIG. 8 is a flowchart of processing of the digital watermark detection apparatus in the first embodiment of the present invention.
[0050]
The digital watermark detection apparatus 60 receives content data and location information of the content data (step 301). Examples of location information include URL (Uniform Resource Locator). For example, the digital watermark detection apparatus 60 acquires content one after another from the WWW or the like, and detects the digital watermark (step 302). If detection of the digital watermark fails (step 303, No), a detection result is created for information indicating the detection failure (step 304). If the detection of the digital watermark is successful (step 303, Yes), the detection result is shaped based on the embedded header information to create a detection result (step 305).
[0051]
The detection result created as described above is output to the log database 63 as a log in the detection result logging unit 62 (step 306).
[0052]
From the output log data, you can know when and from whom the content data was delivered to by e-mail (determining header information to be embedded depending on what information you want to know). Source information of illegally distributed content data can be acquired.
[0053]
According to the first embodiment, when content data is distributed using e-mail, the e-mail recipient is obtained by embedding e-mail header information as a digital watermark in the content data. When content data is illegally distributed, an unauthorized distributor can be identified by detecting a digital watermark from the distributed content data. As a result, illegal distribution by the e-mail recipient can be psychologically suppressed.
[0054]
Further, by referring to the sender address in the header information, the user who sent the e-mail can be specified, and the effect of suppressing the content distribution using the e-mail can be realized.
[0055]
Also, in a normal content protection system using digital watermark technology, it is necessary to incorporate a digital watermark embedding function into the content sender's device, which takes time to install, but in this embodiment, a mail server By incorporating the electronic watermark function into the device, the user device that transmits contents using the mail server device can be easily operated without any changes.
[0056]
[Second Embodiment]
In this embodiment, an example in which a message ID is used instead of header information as a target of digital watermark will be described.
[0057]
This embodiment is the same as the first embodiment described above except for the points described below.
[0058]
FIG. 9 is a sequence chart of processing of the content protection system in the second exemplary embodiment of the present invention.
[0059]
In the processing shown in the figure, the differences from the operation of FIG. 4 are as follows.
[0060]
In step 402, the electronic mail server device 20 with the electronic watermark embedding function embeds the message ID given to the electronic mail in the content data attached to the electronic mail. At the same time, the message ID and the header information of the email are registered in the header information database in the email server device 20 with the electronic watermark embedding function.
[0061]
In step 407, the digital watermark detection device 60 attempts to detect a digital watermark from the detection target content data. If the digital watermark detection device 60 can detect the digital watermark, the digital watermark detection device 60 obtains header information corresponding to the embedded message ID from the header information database. Identify the user who made the distribution.
[0062]
Next, a configuration of the electronic mail server device 20 with the electronic watermark embedding function will be described.
[0063]
FIG. 10 shows the configuration of an electronic mail server device with a digital watermark embedding function according to the second embodiment of the present invention.
[0064]
The electronic mail server device 20 with an electronic watermark embedding function shown in the figure includes an attached data decomposition unit 21, a header information acquisition unit 22, an electronic watermark embedding unit 23, an attached data combining unit 24, and an SMTP processing unit 25 shown in FIG. In addition, the message ID acquisition unit 26 and the header information database 27 are included.
[0065]
FIG. 11 is a flowchart of processing of the electronic mail server device with a digital watermark embedding function according to the second embodiment of the present invention.
[0066]
When the e-mail server device 20 receives an e-mail created by the e-mail user device 10 (step 401), the e-mail is first decomposed into an e-mail text and attached data in the attached data decomposing unit 21. (Step 402).
[0067]
Next, the message ID acquisition unit 26 acquires a message ID from the electronic mail text (step 403). The message ID is an identifier for uniquely identifying the e-mail, which is usually given by the e-mail user device 10 or the e-mail server device 20 that receives the e-mail from the e-mail user device 10. In the present embodiment, when the message ID is assigned on the electronic mail user device 10 side, the message ID is read from the electronic mail as described above, and the message ID is assigned on the electronic mail server device 20 side. The electronic mail server device 20 generates a message ID representing the received electronic mail and embeds the message ID in the electronic watermark embedding unit 23. If the digital watermark is not embedded for all attached data that can be embedded with a digital watermark (step 404, No), the message ID is embedded as a digital watermark in the attached data, and the process proceeds to step 404 (step 404). Step 405). When digital watermark embedding has been performed on all attached data (step 404, Yes), the header information acquisition unit 22 reads out the header information from the body of the email (step 406), and sets the header information database 27 in combination with the message ID. (Step 407). The electronic mail text and the watermarked attached data are combined again by the attached data combining unit 24 (step 408), and normal mail processing is performed by the SMTP processing unit 25 (step 409).
[0068]
Next, the digital watermark detection apparatus in this embodiment will be described.
[0069]
FIG. 12 shows the configuration of a digital watermark detection apparatus according to the second embodiment of the present invention. The digital watermark detection apparatus shown in the figure is the same as the configuration shown in FIG. 7 in the first embodiment described above. This embodiment differs from the first embodiment described above only in that the information obtained by the digital watermark detection process is not header information but a message ID. The digital watermark detection apparatus 60 outputs the message ID and the location information as a set to the log database 63.
[0070]
  FIG. 13 shows the first aspect of the present invention.2It is a figure for demonstrating the unauthorized user specific procedure in embodiment of this.
[0071]
Message ID and header information are stored in the header information database 27 of the electronic mail server device 20 with the electronic watermark embedding function, and the message ID and location information are stored in pairs in the log database 63. By matching the records in the two databases with the message ID, the header information and the location information are associated with each other. At this time, for example, the ISP managing the header information database sends a message ID to the administrator of the digital watermark detection apparatus 60, and “I want to know the location information log of the content in which this message ID is embedded.” The message ID may be sent from the administrator of the digital watermark detection apparatus 60 to the ISP, and “I want to know the header information of the mail represented by this message ID”. The association may be performed in the form of
[0072]
FIG. 14 is a flowchart of processing of the digital watermark detection apparatus in the second embodiment of the present invention.
[0073]
The digital watermark detection unit 61 inputs content data and content location information (step 501), and detects a digital watermark from the content data (step 502). If the detection of the digital watermark is not successful (step 503, No), the fact that it was not detected is created as a detection result (step 504). If successful, the message ID embedded as a watermark is used as the detection result (step 505). The detection result logging unit 62 outputs a log to the log database 63 by combining the detection result and the location information (step 506).
[0074]
According to the above-described embodiment, the amount of information to be embedded as a digital watermark can be reduced because the message ID is generally smaller than the entire header information compared to the first embodiment described above. Furthermore, in the digital watermark technique, since the amount of embedded information and resistance (hardness to disappear) are in a trade-off relationship, the resistance of the digital watermark can be improved.
[0075]
In addition, as an operation mode of the present invention, it is considered that there are many modes in which an entity that operates a mail server device and an entity that operates an electronic watermark detection device that reads an electronic watermark from content on the network are different. In this case, the operating entity of the mail server device sends the location information (URL, etc.) of the content in which the message ID of XX is embedded to the electronic watermark detecting device operating entity that creates the electronic watermark detection log as needed. In response to this request, the digital watermark detection device operator provides location information.
[0076]
In the present embodiment, the information embedded in the digital watermark is the message ID, and the header information corresponding to the message ID is on the mail server device side, so the header information cannot be obtained on the digital watermark detection device side.
[0077]
In general, the header information includes information related to the privacy of the user such as an e-mail sender and a destination user. Although it is not preferable that these pieces of information are transmitted to the digital watermark detection apparatus operating entity unrelated to the user, according to the present embodiment, as described above, this problem can be solved and it is also useful for privacy protection.
[0078]
[Third Embodiment]
In the present embodiment, a case where an electronic mail server apparatus has a digital watermark detection function will be described.
[0079]
This embodiment performs the same configuration and operation as those of the first embodiment described above except for the points described below.
[0080]
FIG. 15 shows the configuration of a content protection system according to the third embodiment of the present invention. The system shown in the figure includes an electronic mail server device 20 with an electronic watermark embedding function having an electronic watermark embedding function and an electronic mail with an electronic watermark detection function having an electronic watermark detection function connected to a network 30 such as the Internet. It comprises a server device 70 and a plurality of electronic mail user devices 10 and 50 connected to the electronic mail server device 20 with an electronic watermark embedding function.
[0081]
FIG. 16 is a sequence chart of processing of the content protection system in the third exemplary embodiment of the present invention.
[0082]
Step 601) An e-mail is created by the sender-side e-mail user device 10 and transmitted to the e-mail server device 20 with an e-mail embedding function.
[0083]
  Step 602) The e-mail server device with e-mail embedding function 20 uses the content data attached to the e-mail as header information including the destination address of the received e-mail.TEmbed the image using digital watermark technology.
[0084]
Step 603) The electronic mail server device 20 with the electronic mail embedding function delivers the watermarked electronic mail by a normal mail delivery procedure, and transmits it to the electronic mail server device 70 with the electronic watermark detection function managing the destination user. To do.
[0085]
Step 604) The electronic mail server device 70 with the electronic watermark detection function tries to detect the electronic watermark from the attached data attached to the received electronic mail with watermark, and if the detection is successful, the embedded destination address and electronic Check if the destination address matches the email body header. If they match, the process proceeds to step 605. If they do not match, a mismatch process is performed. As the mismatch processing, for example, processing such as sending a warning mail such as “Attempted to deliver mail with content data attached to an unauthorized destination” to the sender of the watermarked electronic mail is conceivable.
[0086]
Step 605) If they match, the watermarked electronic mail is delivered to the electronic mail user device 50 indicated by the destination address as usual.
[0087]
The electronic mail server device 20 with an electronic watermark embedding function in the present embodiment embeds the destination address information of the electronic mail as essential information as the header information embedded in the attached data.
[0088]
FIG. 17 shows a configuration of an electronic mail server device with a digital watermark detection function according to the third embodiment of the present invention.
[0089]
The electronic mail server device 70 with a digital watermark detection function shown in the figure includes an STMP processing unit 71, an attached data decomposition unit 72, a header information acquisition unit 73, a digital watermark detection unit 74, a matching confirmation unit 75, a mismatch processing unit 76, and an electronic The mail delivery part 77 is comprised.
[0090]
FIG. 18 is a flowchart of the process of the electronic mail server device with a digital watermark detection function in the third embodiment of the invention.
[0091]
The electronic watermark detection function-equipped electronic mail server device 70 first receives a normal electronic mail in accordance with the SMTP protocol by the SMTP processing unit 71 and inputs a watermarked electronic mail (step 701).
[0092]
Next, the attached data decomposition unit 72 decomposes the watermarked e-mail into an e-mail body and attached data (step 702). Next, the header information acquisition unit 73 acquires destination mail address information from the header of the e-mail body (step 703).
[0093]
Next, the digital watermark detection unit 74 attempts to detect a digital watermark from the attached data. At this time, if the electronic watermark cannot be detected from the attached data (step 704, No), the electronic mail is delivered to the electronic mail user device 50 indicated by the destination address as usual (step 707). When the detection of the digital watermark is successful (step 704, Yes), the match confirmation unit 75 checks whether the embedded destination address information matches the destination address information read from the header. (Step 705, Yes), the electronic mail is delivered to the electronic mail user device 50 indicated by the destination address (step 707). If they do not match (step 705, No), the mismatch processing unit 76 performs processing that is performed when there is a mismatch, for example, sending the above-described warning mail (step 706).
[0094]
  According to the above-described embodiment, an authorized content distributor uses a digital watermark embedding function-equipped electronic mail server device 20 to embed a digital watermark into a destination of the content data and deliver it. Type email server deviceButIn the case of the electronic mail server device 70 with the electronic watermark detection function, the content can be distributed without any problem.
[0095]
Furthermore, when the destination user of the content data tries to illegally distribute the content data to another user, the email server device on the other user side is an email server device with a digital watermark detection function Content distribution becomes impossible and illegal distribution is impossible. Such unauthorized distribution prevention can be realized by changing only the ISP side apparatus that operates the e-mail server apparatus without any change to the e-mail user apparatus on the user side. High affinity. In addition, many ISPs wish to avoid fraud of users managed by themselves, and when an electronic mail server device with a digital watermark detection function is used in each ISP, the illegal distribution prevention according to the present invention can further improve the function. Can do. In this embodiment, the content is protected by performing a matching check on the destination e-mail address. However, using other information, for example, date and time information, “year, month, day, hour and minute” Different content protection such as “can be delivered until” can be easily realized.
[0096]
Further, the components of the electronic mail server device and digital watermark detection device in the above embodiment are constructed as a program and installed in a computer used as the electronic mail server device and digital watermark detection device, or distributed via a network. It is possible to make it.
[0097]
Further, the constructed program is stored in a hard disk device connected to a computer used as an electronic mail server device and a digital watermark detection device, a portable storage medium such as a floppy disk, a CD-ROM, etc. The present invention can be easily realized by installing at the time of implementation.
[0098]
【The invention's effect】
As described above, according to the present invention, when content is distributed as attachment data of an electronic mail, information specifying a sender and a recipient is embedded by a digital watermark technology, so that a user can illegally distribute the content. But you can keep track of who has done the fraud.
[0099]
This also makes it possible to achieve psychological deterrence of unauthorized distribution by the user.
[0100]
Further, the content data is delivered by e-mail only to the user designated by the copyright holder, so that illegal distribution can actually be made impossible.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining the principle of the present invention.
FIG. 2 is a principle configuration diagram of the present invention.
FIG. 3 is a configuration diagram of the content protection system according to the first embodiment of the present invention.
FIG. 4 is a sequence chart of the content protection system according to the first embodiment of the present invention.
FIG. 5 is a configuration diagram of an electronic mail server device with a digital watermark embedding function according to the first embodiment of the present invention;
FIG. 6 is a flowchart of processing of the electronic mail server device with a digital watermark embedding function according to the first embodiment of the present invention.
FIG. 7 is a configuration diagram of a digital watermark detection apparatus according to the first embodiment of the present invention.
FIG. 8 is a flowchart of processing of the digital watermark detection apparatus according to the first embodiment of the present invention.
FIG. 9 is a sequence chart of processing of the content protection system according to the second embodiment of the present invention.
FIG. 10 is a configuration diagram of an electronic mail server device with a digital watermark embedding function according to a second embodiment of the present invention.
FIG. 11 is a flowchart of processing of an electronic mail server device with a digital watermark embedding function according to a second embodiment of the present invention.
FIG. 12 is a configuration diagram of a digital watermark detection apparatus according to a second embodiment of the present invention.
FIG. 13 is a diagram for explaining an unauthorized user specifying procedure in the second embodiment of the present invention;
FIG. 14 is a flowchart of processing of the digital watermark detection apparatus according to the second embodiment of the present invention.
FIG. 15 is a configuration diagram of a content protection system according to a third embodiment of the present invention.
FIG. 16 is a sequence chart of processing of the content protection system according to the third embodiment of the present invention.
FIG. 17 is a configuration diagram of an electronic mail server device with a digital watermark detection function according to a third embodiment of the present invention.
FIG. 18 is a flowchart of processing of an electronic mail server device with a digital watermark detection function according to a third embodiment of the present invention.
[Explanation of symbols]
10,50 E-mail user device
20, 40 E-mail server device, e-mail server device
21 Attached data decomposition means, attached data decomposition section
22 Header information acquisition means, header information acquisition unit
23 Digital watermark embedding means, digital watermark embedding unit
24 Attached data combining means, attached data combining unit
25 Transmission means, SMTP processing section
26 Message ID acquisition unit
27 Header information database
30 network
60 Electronic watermark detection device
61 Digital watermark detection means, digital watermark detection unit
62 Detection result logging section
63 Log database
64 receiving means
70 Electronic Mail Server Device with Electronic Watermark Detection Function
71 SMTP processor
72 Attached data decomposition part
73 Header information acquisition unit
74 Digital Watermark Detection Unit
75 Match confirmation part
76 Mismatch processing section
77 E-mail delivery department

Claims (16)

In a content protection method for preventing unauthorized distribution of content during content distribution using network communication including e-mail,
In an email server device,
Disassemble the email sent from the email user device into email text and attached data,
Extracting header information described in the header part of the e-mail;
Embed a digital watermark in the attached data using the header information and digital watermark technology,
Combining the attached data embedded with the digital watermark with the text of the email to create a watermarked email,
Transfer watermarked e-mail to another e-mail server using the normal delivery method,
In the digital watermark detection device,
Receiving the content data from the receiving-side email user device that has received the watermarked email via the email server device;
A content protection method, wherein a digital watermark is detected from the content data, and when the digital watermark is detected, the embedded information is output as information related to unauthorized transmission. In the electronic mail server device,
Get a message ID that uniquely identifies the email,
The message ID is embedded in the attached data using the digital watermark technology,
The message ID and the header information are paired and registered in the header information database,
In the digital watermark detection apparatus,
The content protection method according to claim 1, wherein the information output by the digital watermark detection process is regarded as a message ID, and the corresponding electronic mail in the header information database is acquired. In a content protection method for preventing unauthorized distribution of content at the time of computer distribution using network communication including electronic mail,
In an email server device,
Decomposing the first e-mail sent from the e-mail user device into a first e-mail body and first attached data;
Extracting first header information described in a header portion of the first e-mail;
Embedding a digital watermark in the first attached data using the first header information and the digital watermark technique,
Combining the first attached data in which the electronic watermark is embedded with the first electronic mail text to create a first watermarked electronic mail;
Transferring the first watermarked email to another email server device by a normal delivery method;
Receive a second email with an embedded watermark,
Decomposing the second e-mail into a second e-mail body and second attached data ;
Obtaining second header information including a destination email address described in a header portion of the second email ;
When the electronic watermark is detected from the second attached data and the electronic watermark is successfully detected, the embedded destination electronic mail address and the destination electronic mail address described in the second header information Confirm the validity of the second e-mail using a certain condition or a predetermined condition,
A content protection method, wherein a process for preventing fraud is performed when validity cannot be confirmed. A content protection system for preventing unauthorized distribution of content during content distribution using network communication including e-mail,
An attachment data disassembling means for disassembling an email sent from an email user device into an email body and attached data;
Header information acquisition means for extracting header information described in the header portion of the email;
A digital watermark embedding means for embedding the header information as a digital watermark in attached data using a digital watermark technique;
Attached data combining means for combining the attached data embedded with the electronic watermark with the e-mail body to create a watermarked e-mail;
An e-mail server device having transmission means for transferring the watermarked e-mail to another e-mail server device by a normal delivery method;
Receiving means for receiving content data from an e-mail user device on the receiving side that has received the watermarked e-mail via an e-mail server device;
A digital watermark detection apparatus comprising: a digital watermark detection unit configured to detect the digital watermark from the content data and output the embedded information as information related to unauthorized transmission when the digital watermark is detected. Content protection system. The e-mail server device
Means for obtaining from the e-mail a message ID uniquely indicating the e-mail;
Means for registering the message ID and the header information as a set in a header information database;
The digital watermark embedding means includes:
Means for embedding the message ID as a digital watermark in the attached data using the digital watermark technique;
The digital watermark detection apparatus comprises:
5. The content protection system according to claim 4, further comprising means for obtaining the corresponding electronic mail from the header information database by regarding the information output by the electronic watermark detection means as a message ID. A content protection system for preventing unauthorized distribution of content at the time of computer distribution using network communication including electronic mail,
E-mail server device
First attached data decomposing means for decomposing the first e-mail sent from the e-mail user device into a first e-mail body and first attached data;
First header information acquisition means for extracting first header information described in a header portion of the first e-mail;
First digital watermark embedding means for embedding a digital watermark in first attached data using the first header information and digital watermark technology;
First attached data combining means for combining the first attached data in which the electronic watermark is embedded with the first electronic mail text to create a first watermarked electronic mail;
First transmission means for transferring the first watermarked electronic mail to another electronic mail server device by a normal delivery method;
Second attached data decomposing means for decomposing the received second e-mail with the embedded electronic watermark into a second e-mail body and second attached data;
Second header information acquisition means for acquiring second header information including a destination electronic mail address described in a header part of the second electronic mail ;
When the electronic watermark is detected from the second attached data and the electronic watermark is successfully detected, the embedded destination electronic mail address and the destination electronic mail address described in the second header information Means for confirming the consistency of the second e-mail using a predetermined condition,
A means to prevent fraud if legitimacy cannot be confirmed ,
A content protection system comprising: In a computer used as an e-mail server in a content protection system for preventing unauthorized distribution of content at the time of content distribution using network communication including e-mail ,
An attachment data decomposition step for disassembling the email sent from the email user device into an email body and attached data;
A header information acquisition step of extracting header information including a source e-mail address, a destination e-mail address, a title, and a transmission date and time described in the header part of the e-mail;
An electronic watermark embedding step of embedding an electronic watermark in said attached data to the header information by using the electronic watermark technique,
An attachment data combining step of combining the attachment data embedded with the electronic watermark with the electronic mail body to create a watermarked electronic mail;
A transmission step of transferring the watermarked e-mail to another e-mail server device by a normal delivery method ;
A content protection program characterized by causing Obtaining a message ID uniquely indicating the e-mail,
In the set of the header information and the message ID to execute the steps of registering the header information database,
In the digital watermark step ,
8. The content protection program according to claim 7 , wherein a step of embedding the message ID in the attached data using the digital watermark technique instead of the header information is performed . In a computer used as an e-mail server in a content protection system for preventing unauthorized distribution of content at the time of content distribution using network communication including e-mail ,
A first attached data decomposing step of decomposing the first e-mail sent from the e-mail user device into a first e-mail body and first attached data;
A first header information acquisition step of extracting first header information described in a header portion of the first email;
A first digital watermark embedding step of embedding a digital watermark in first attached data using the first header information and digital watermark technology;
A first attached data combining step of combining the first attached data in which the electronic watermark is embedded with the first electronic mail body to create a first watermarked electronic mail;
A first sending step of transferring the first watermarked e-mail to another e-mail server device by a normal delivery method;
A second attached data disassembling step for disassembling the received second electronic mail in which the electronic watermark is embedded into a second electronic mail text and second attached data;
A second header information acquisition step of acquiring second header information including a destination electronic mail address described in a header part of the second electronic mail;
When the electronic watermark is detected from the second attached data and the electronic watermark is successfully detected, the embedded destination electronic mail address and the destination electronic mail address described in the second header information Confirming the consistency of the second e-mail using a predetermined condition,
A step to prevent fraud if the legitimacy cannot be confirmed,
A content protection program characterized by causing In a computer used as a digital watermark detection device in a content protection system for preventing unauthorized distribution of content at the time of content distribution using network communication including electronic mail ,
A receiving step of receiving content data from an e-mail user device on the receiving side that has received the watermarked e-mail via an e-mail server device;
A digital watermark detection step for detecting a digital watermark from the content data;
When a digital watermark is detected, the header information embedded as the digital watermark is output as a log together with the location information of the content data as information related to illegal transmission. An output step of outputting the content protection program. In the output step , when the information embedded as the electronic watermark is a message ID, the message is obtained from the header information database on the electronic mail server device in which the message ID and the electronic mail header information are registered as a set. The content protection program according to claim 10 , wherein the step of acquiring a corresponding electronic mail is executed based on the ID. In a computer used as an e-mail server device in a content protection system for preventing unauthorized distribution of content at the time of content distribution using network communication including e-mail,
An attachment data decomposition step for disassembling the email sent from the email user device into an email body and attached data;
A header information acquisition step of extracting header information including a source e-mail address, a destination e-mail address, a title, and a transmission date and time described in the header part of the e-mail;
An electronic watermark embedding step of embedding an electronic watermark in said attached data to the header information by using the electronic watermark technique,
An attachment data combining step of combining the attachment data embedded with the electronic watermark with the electronic mail body to create a watermarked electronic mail;
A computer-readable recording medium storing a content protection program for executing a transmission step of transferring a watermarked electronic mail to another electronic mail server device by a normal delivery method . Obtaining a message ID uniquely indicating the e-mail,
In the set of the header information and the message ID to execute the steps of registering the header information database,
In the digital watermark step ,
13. The computer-readable recording medium according to claim 12 , wherein a program for storing the message ID instead of the header information in the attached data using the digital watermark technique is stored . In a computer used as an e-mail server in a content protection system for preventing unauthorized distribution of content at the time of content distribution using network communication including e-mail ,
A first attached data decomposing step of decomposing the first e-mail sent from the e-mail user device into a first e-mail body and first attached data;
A first header information acquisition step of extracting first header information described in a header portion of the first email;
A first digital watermark embedding step of embedding a digital watermark in first attached data using the first header information and digital watermark technology;
A first attached data combining step of combining the first attached data in which the electronic watermark is embedded with the first electronic mail body to create a first watermarked electronic mail;
A first sending step of transferring the first watermarked e-mail to another e-mail server device by a normal delivery method;
A second attached data disassembling step for disassembling the received second electronic mail in which the electronic watermark is embedded into a second electronic mail text and second attached data;
A second header information acquisition step of acquiring second header information including a destination electronic mail address described in a header part of the second electronic mail ;
When the electronic watermark is detected from the second attached data and the electronic watermark is successfully detected, the embedded destination electronic mail address and the destination electronic mail address described in the second header information Confirming the consistency of the second e-mail using a predetermined condition ,
A step to prevent fraud if the legitimacy cannot be confirmed ,
A computer-readable recording medium storing a content protection program for executing In a computer used as a digital watermark detection device in a content protection system for preventing unauthorized distribution of content at the time of content distribution using network communication including electronic mail ,
A receiving step of receiving content data from an e-mail user device on the receiving side that has received the watermarked e-mail via an e-mail server device;
A digital watermark detection step for detecting a digital watermark from the content data;
When a digital watermark is detected, the header information embedded as the digital watermark is output as a log together with the location information of the content data as information related to illegal transmission. A computer-readable recording medium storing a content protection program for executing an output step . In the output step , when the information embedded as the electronic watermark is a message ID, the message is obtained from the header information database on the electronic mail server device in which the message ID and the electronic mail header information are registered as a set. The computer-readable recording medium according to claim 15, wherein a program for executing a step of acquiring a corresponding electronic mail based on the ID is stored .

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