JP2002007912A - Digital content rental system and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rental system for digital content having an effective term to prevent a fraudulent use. SOLUTION: A user terminal 10 transmits the user information inputted by a user to a digital content rental server 20, and the digital content rental server 20 certifies the user. The digital content rental server 20 sets the effective term in the digital content requested by the user, encodes it with the user information, and downloads it to the user terminal 10. An accounting server 30 accounts for the charge to the user. The user terminal 10 decodes the downloaded digital content with the user information inputted by the user and displays the digital content when it is within the effective term.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital contents rental system, and more particularly, to a digital contents rental system and method for preventing unauthorized use of digital contents so that they can be lent for a limited period of use.

[0002]

2. Description of the Related Art Conventionally, most digital contents are provided on the Internet for the purpose of sales, and there is no rental concept method such as a rental CD or a rental video store.

The cause lies in the following characteristics of digital contents on the Internet.

(1) Copying is easy.

(2) Dissemination to an unspecified number of persons can be easily performed.

(3) It is difficult to forcibly erase data that has been once held and can be permanently used.

[0007] For this reason, digital contents are purchased even if rental is sufficient.

[0008]

However, the above-mentioned prior art has the following problems.

That is, there is no effective solution to the illegal use of digital contents, so there is no digital contents rental system, and digital contents must be purchased even if rental is sufficient.

An object of the present invention is to solve the above problems,
An object of the present invention is to provide a digital content rental system and method that can prevent digital content from being used illegally and lend it for a limited period of use.

[0011]

According to a first aspect of the present invention, there is provided a digital contents rental system which downloads digital contents from a digital contents lending server and displays the digital contents, and a request from a user of the user terminal. A digital content lending server that downloads the digital content to the user terminal and requests a charging server to charge the user, a charging server that charges the user by a request from the digital content lending server, the user terminal, It is characterized by comprising a digital content lending server and a communication network connecting the billing server.

[0012] In the digital content rental system according to a second aspect of the present invention, in the first aspect, the digital content lending server includes a digital content requested by the user, a user ID of the user, and a digital content requested by the user. The content ID includes an encrypted time-limited digital content, a user ID of the user, a content ID of the digital content requested by the user, and an expiration date set for the digital content requested by the user. It is characterized by comprising means for downloading the encrypted digital content authentication information to the user terminal.

The digital content rental system according to a third aspect of the present invention is the digital content rental system according to the second aspect, wherein the time-limited digital content and the digital content authentication information are encrypted using a user ID and a password of the user who received the digital content authentication information from the user terminal as a key. It is characterized by comprising means for performing.

According to a fourth aspect of the present invention, in the digital content rental system according to the first aspect, the user terminal downloads and decodes time-limited digital content and digital content authentication information from the digital content rental server to decrypt the digital content authentication information. Means for displaying digital content decrypted from the time-limited digital content when the expiration date is within the expiration date indicated in the information.

[0015] In the digital contents rental system according to a fifth aspect of the present invention, in the fourth aspect, the time-limited digital content and the digital content authentication information are decrypted using a user ID and a password of a user input from the user terminal as a key. It is characterized by comprising means.

The digital content rental system according to a sixth aspect of the present invention is the digital content rental system according to the fourth aspect, wherein the date and time indicated in the digital content authentication information and the date and time acquired from a time synchronization server connected to the communication network. It is characterized by comprising means for comparing and judging whether it is within the expiration date.

[0017] In the digital contents renting method according to a seventh aspect of the present invention, the user inputs user information and transmits it to a digital contents lending server. The digital contents lending server receives the user information and authenticates the user. The user sends a digital content request to the digital content lending server, and the digital content lending server receives the digital content request, downloads the digital content requested by the user to the user, and charges the user to a charging server. And the charging server charges the user, and the user browses the digital content downloaded from the digital content lending server.

[0018] In the digital content renting method according to an eighth aspect of the present invention, in the seventh aspect, the digital content lending server may include a digital content requested by the user, a user ID of the user, and a digital content requested by the user. Encrypted time-limited digital content including a content ID, an encryption including a user ID of the user, a content ID of the digital content requested by the user, and an expiration date set for the digital content requested by the user Downloads the converted digital content authentication information to the user terminal, and the user terminal decrypts the downloaded time-limited digital content and the digital content authentication information and indicates the decrypted digital content authentication information in the digital content authentication information. And displaying the digital decrypted contents from said timed digital content when within expiration date.

The digital content renting method according to a ninth aspect of the present invention is the digital content renting method according to the eighth aspect, wherein the time-limited digital content and the digital content authentication information are encrypted or decrypted using a user ID and a password of the user as a key. It is characterized by that.

In the digital content renting method according to a tenth aspect of the present invention, in the eighth aspect, the determination as to whether or not the expiration date has passed is based on the date and time indicated in the digital content authentication information and the time connected to the communication network. It is characterized in that it is performed by comparing the date and time obtained from the synchronization server.

[0021]

Embodiments of the present invention will be described in detail with reference to the drawings.

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

Referring to FIG. 1, the embodiment of the present invention comprises a user terminal 10, a digital content lending server 20, a billing server 30, a time synchronization server 40, and a communication network 50. .

The user terminal 10 is an information processing device such as a personal computer that allows a user to access the digital content lending server 20 to download and browse digital content.

A digital content lending client, which is a tool for downloading and browsing digital content operating on the user terminal 10, may be permanently installed in the user terminal 10, or may be connected to the digital content lending server 20 via the communication network 50. May be obtained via Note that digital contents include electronic publications, moving images, music, and game software.

The digital content lending client is:
It mainly does the following: -The user information (user ID and password of the user) input by the user is transferred to the digital content lending server 20.
Send to Transmit the desired digital content designation information (content ID of the digital content that the user wants to browse) to the digital content lending server 20. Digital content information (content ID for identifying digital content, digital content name,
Digital content author name and digital content viewing fee) are received from the digital content lending server 20. Download the time-limited digital content and the digital content authentication information from the digital content lending server 20. Decrypt the downloaded time-limited digital content and digital content authentication information, check the expiration date based on the date and time acquired from the time synchronization server 40, and display the digital content.

The digital content lending server 20 is an information processing device for lending digital content managed and operated by a digital content seller. The digital content lending server 20 includes a database for holding and managing various information.

The digital contents lending server 20 mainly performs the following. -Retain digital content and digital content information. Holds user information (user ID, password, etc.) related to the user. Holds the rented content ID for the user ID and its expiration date. -The maximum number of concurrently held user IDs (the maximum number of digital contents that can be borrowed by the same user at the same time) and the number of lent digital contents are held. Transmitting digital content information to the user terminal 10; Receiving user information (user ID and password of the user) from the user terminal 10; -Authenticate the user. Receives the user's browsing desired digital content designation information from the user terminal 10, generates time-limited digital content and digital content authentication information for the digital content the user wishes to browse, and downloads it to the user terminal 10. -Check the maximum number of users that can be held simultaneously The expiration date of the digital content to be lent is set based on the date and time acquired from the time synchronization server 40. Request the user authentication and accounting for the lending user to the accounting server 30.

The accounting server 30 is an information processing device for accounting managed and operated by a credit company or the like.
Note that a plurality of billing servers 30 can exist on the communication network 50.
One billing server corresponds.

The accounting server 30 mainly performs the following. Holds user information (user ID, password, financial institution account, etc.) regarding the user. The digital content lending server 20 authenticates the user who lends the digital content and charges the user's financial institution account.

The time synchronization server 40 provides the digital content lending server 20 and the user terminal 10 with the date and time.

The communication network 50 is connected to the user terminal 10
And digital contents lending server 20 and billing server 30
And a network such as the Internet for interconnecting the time synchronization server 40 with the time synchronization server 40.

FIG. 1 shows the operation of the embodiment of the present invention.
This will be described in detail with reference to FIGS.

FIG. 2 is a diagram showing the flow of the entire operation.

FIG. 3 is a diagram showing the flow of the operation for generating timed digital content.

FIG. 4 is a diagram showing a flow of an operation for generating digital content authentication information.

FIG. 5 is a diagram showing the flow of the operation for browsing timed digital content.

First, the overall operation will be described with reference to FIG.

(1) At the user terminal 10, a digital content lending client is activated and connected to the digital content lending server 20. Thereafter, all communication information between the digital content lending server 20 and the user terminal 10 is encrypted.

(2) The user inputs a user ID and a password in response to the input request of the digital content lending client, and the digital content lending client transmits the input data to the digital content lending server 20.

(3) Digital Content Lending Server 20
Retrieves the user ID and password information of the user from the database of the digital content lending server 20,
Check with the data received from the digital content lending client.

(4) Digital Content Lending Server 20
Authenticates the user as a valid user if the user ID and the password match, and prompts the digital content lending client to input the content ID of the digital content desired to be browsed.

(5) The digital content lending client transmits to the digital content lending server 20 the content ID of the digital content desired to be browsed input by the user.

(6) Digital Content Lending Server 20
Receives the content ID of the digital content that the user wants to browse.

(7) Digital content lending server 20
Checks if the maximum number of concurrent users is not exceeded. If the maximum number is not exceeded, continue processing.
If it exceeds, the request for browsing by the user is rejected, the digital content lending client is notified, and the process is terminated.

(8) Digital Content Lending Server 20
Is a charging server 3 using an encrypted communication protocol.
0 and requests authentication for the user.

(9) The accounting server 30 notifies the digital content lending server 20 of the result of user authentication.

(10) Digital Content Lending Server 2
If the result of the user authentication in the charging server 30 is normal, 0 sets the expiration date for the digital content that the user wants to browse. If the result of the user authentication in the billing server 30 is abnormal, the user's browsing request is rejected, the digital content lending client is notified, and the process is terminated.

(11) Digital Content Lending Server 2
0 generates time-limited digital content corresponding to the digital content that the user wants to browse. Also, digital content authentication information is generated.

(12) Digital Content Lending Server 2
0 transfers the generated time-limited digital content and digital content authentication information to the digital content lending client of the user terminal 10.

(13) Digital Content Lending Server 2
No. 0 connects to the charging server 30 using the encrypted communication protocol and requests charging for the user.

(14) Digital Content Lending Server 2
0 disconnects the session of the user terminal 10 with the digital content lending client.

(15) The user designates the downloaded time-limited digital content at the user terminal 10 and uses the digital content lending client to display and browse the digital content.

Next, the operation of generating the time-limited digital content in the digital content lending server 20 will be described in more detail with reference to FIG.

(1) Digital content lending server 20
Copies the digital content that the user wants to browse from the digital content storage database.
Thereafter, the copied digital content is to be processed.

(2) A first random number is generated, and a character string combining the user ID of the user and the expiration date of the digital content using the generated first random number (hereinafter, “user ID + expiration date”) ) Is subjected to encryption processing. Hereinafter, the first random number at this time is referred to as a first common key, and the encryption process is referred to as a first common key encryption process.

(3) Generate a second random number and use the second random number to generate a random position in the digital content (hereinafter referred to as a random position).
This position is called an embedding position), and the “user ID + expiration date” (hereinafter, referred to as “user ID + expiration date”) subjected to the first common key encryption processing.
Embedded data) is embedded at an embedding position in the digital content.

(4) A character string obtained by combining the user ID and the password of the user with the combination of the digital content, the user ID of the user, and the content ID of the digital content (hereinafter, “user ID + password”)
Is expressed as a common key. Or later,
The “user ID + password” at this time is the second common key,
The encryption process is referred to as a second common key encryption process. A combination of the digital content subjected to the second common key encryption process, the user ID, and the content ID is referred to as timed digital content.

(5) The first common key, the embedding position, the content ID of the digital content that has become timed digital content, and its expiration date are stored in the database.

Next, the operation of generating digital content authentication information in digital content lending server 20 will be described in more detail with reference to FIG.

(1) Digital Content Lending Server 20
Searches the database for all sets of content IDs and expiration dates of digital contents that are currently viewable by the user, and retrieves the user ID and the content ID as a search result.
Create a plain text file that contains all of the pairs consisting of

(2) The plain text file is subjected to an encryption process (second common key encryption process) using “user ID + password” as a common key (second common key). Hereinafter, the plaintext file subjected to the second common key encryption processing is referred to as digital content authentication information.

Next, the operation of browsing the time-limited digital content in the digital content lending client of the user terminal 10 will be described in more detail with reference to FIG.

(1) In response to an input request from the digital content lending client, the user inputs a user ID and a password.

(2) The digital content lending client performs a decryption process on the time-limited digital content using the input “user ID + password” as a common key. The three parts of the digital content, the user ID and the content ID become readable.

(3) Further, the digital content lending client performs a decryption process on the digital content authentication information using the input “user ID + password” as a common key, and obtains a plain text file.

(4) The user ID and the content ID in the plain text file decrypted from the digital content authentication information are compared with the user ID and the content ID decrypted from the timed digital content,
Further, the expiration date decrypted from the digital content authentication information is compared with the date and time of the time synchronization server 40 to check whether or not the user has the right to view the time-limited digital content specified by the user. Displays the contents of the digital content, and if there is no right, outputs a message to that effect and terminates without displaying the contents of the digital content.

Since the embedded data embedded in the digital content is a kind of digital watermark, there is no problem in displaying and browsing as it is.

The user can make any number of times within the expiration date,
You can browse downloaded digital content. At this time, the processes (1) to (4) are performed.

When the user deletes the downloaded time-limited digital content, if the digital content is within the validity period, the digital content lending server 20 is connected to the digital content lending server 20 without being charged again. In this case, the time-limited digital content and the digital content authentication information can be downloaded to the user terminal 10.

Further, in the unlikely event that the user ID and the password are leaked and the time-limited digital content is decrypted and the digital content is leaked, the digital content lending server 20 stores the embedded data embedded in the leaked digital content. Can be decrypted using the embedding position and the first common key, and the leakage source user can be identified from the decrypted user ID.

In the above embodiment, the digital content lending server 20 or the user terminal 10 sets or checks the expiration date of the lent digital content based on the date and time obtained from the time synchronization server 40. The expiration date may be set or checked based on the system date and time of the digital content lending server 20 or the user terminal 10 without providing a synchronization server.

In the above embodiment, the password of the user for the digital content lending server 20 is the same as the password of the user for the accounting server 30, but the passwords may be different.

Further, in the above-described embodiment, the expiration date of the digital content is determined and the content can be browsed for a fee during the period. However, the expiration date of the digital content is determined and the content can be browsed free of charge during the period. The browsing may be performed without checking the expiration date only when there is a charge during or after the period. This makes it possible to realize a system in which content is purchased after trial listening or previewing for a certain period.

Further, in the above-described embodiment, the expiration date of the digital content is determined and the period can be browsed for a fee. However, the expiration date of the digital content is determined and the period can be browsed for free during the period. The expiration date may be determined again and viewed only when there is a charge during or after the period. As a result, it is possible to realize a system in which digital contents are formally rented out after trial listening and previewing for a certain period.

[0076]

A first effect of the present invention is that a digital content lending system can be constructed.

The reason is that a means is provided for setting a period during which browsing is possible for each lent digital content and making it impossible to browse digital contents that have passed a certain period during which browsing is possible.

A second effect of the present invention is that unauthorized use of the lent digital contents can be prevented.

The reason is that a means for decrypting and browsing the lent digital contents is provided. Unauthorized duplication of the rented digital content cannot be viewed without the decryption key.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing a flow of an entire operation;

FIG. 3 is a diagram showing a flow of an operation for generating timed digital content.

FIG. 4 is a diagram showing a flow of an operation for generating digital content authentication information.

FIG. 5 is a diagram showing a flow of an operation for browsing timed digital content.

[Explanation of symbols]

 10 User Terminal 20 Digital Content Lending Server 30 Billing Server 40 Time Synchronization Server 50 Communication Network

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Claims (10)

[Claims] 1. A user terminal that downloads digital content from a digital content lending server and displays the digital content, and downloads digital content requested by a user of the user terminal to the user terminal and sends the digital content to a charging server for the user. A digital content lending server for requesting charging, a charging server for charging the user in response to a request from the digital content lending server, a communication network connecting the user terminal, the digital content lending server, and the charging server, A digital content rental system characterized by comprising: 2. The digital content lending server,
The encrypted time-limited digital content including the digital content requested by the user, the user ID of the user, and the content ID of the digital content requested by the user, and the user ID of the user
Means for downloading, to the user terminal, encrypted digital content authentication information including a content ID of the digital content requested by the user and an expiration date set for the digital content requested by the user. The digital content rental system according to claim 1, wherein: 3. The digital device according to claim 2, further comprising means for encrypting the time-limited digital content and the digital content authentication information using a user ID and a password of the user who have received the digital content authentication information from the user terminal as a key. Content rental system. 4. The user terminal downloads the time-limited digital content and the digital content authentication information from the digital content lending server, decrypts the digital content authentication information, and decrypts the time-limited digital content. 2. The digital contents rental system according to claim 1, further comprising means for displaying digital contents decrypted from the digital contents. 5. The digital content according to claim 4, further comprising means for decrypting the time-limited digital content and the digital content authentication information using a user ID and a password of a user input from the user terminal as a key. Rental system. 6. A means for comparing a date and time indicated in the digital content authentication information with a date and time obtained from a time synchronization server connected to the communication network to determine whether the date and time are within an expiration date. The digital content rental system according to claim 4, further comprising: 7. A user inputs user information and transmits it to a digital content lending server. The digital content lending server receives the user information and authenticates the user, and the user sends a digital content request to the digital content lending server. The digital content lending server receives the digital content request, downloads the digital content requested by the user to the user, requests the charging server to charge the user, and the charging server transmits the digital content request to the user. A digital content rental method, wherein the user browses the digital content downloaded from the digital content rental server. 8. The digital content lending server includes an encrypted time-limited digital content including a digital content requested by the user, a user ID of the user, a content ID of the digital content requested by the user, and the user. Downloading to the user terminal encrypted digital content authentication information including a user ID, a content ID of the digital content requested by the user, and an expiration date set for the digital content requested by the user, The user terminal decrypts the downloaded time-limited digital content and the digital content authentication information, and decodes the time-limited digital content from the time-limited digital content when the validity period is within the validity period indicated in the digital content authentication information. The digital content renting method according to claim 7, wherein the digital content is displayed. 9. The digital content rental method according to claim 8, wherein the time-limited digital content and the digital content authentication information are encrypted or decrypted using a user ID and a password of the user as a key. . 10. The determination as to whether or not it is within the expiration date is made by comparing the date and time indicated in the digital content authentication information with the date and time obtained from a time synchronization server connected to the communication network. The digital content renting method according to claim 8, wherein: