JP2002352153A - System, method and server for renting digital contents - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily rent digital contents, such as a movie and also to prevent the occurrence of the problem of the digital contents being unable to be rented due to their being rented. SOLUTION: This system has a process S1 for installing reproduction software, capable of reproducing digital contents of a prescribed format in a computer 110 of a member 100 who is a user, a process S2 for downloading digital contents that cannot be reproduced with the reproduction software to the computer 110 and a process S3 for measuring the time, starting from when the digital contents are downloaded to the computer 110 and eliminating the digital contents from the computer 110, when a preset time has elapsed. An elimination program for eliminating the digital contents is included in the reproducing software and is made, so as to overwrite at least a portion of the stored digital contents so that the stored digital contents cannot be reproduced with a reproducing program.

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 for renting digital contents such as movie works, music works, and computer games.
Rental method and rental server.

[0002]

2. Description of the Related Art In recent years, the spread of computers and the improvement in performance have been remarkable, and it has become possible to play back movies, music, and the like that were previously played on a VCR or a CD player. For example, a movie recorded on a DVD can be played by a computer equipped with DVD playback software.

[0003]

However, in order to appreciate a movie recorded on a DVD, for example, a DVD containing the movie has to be purchased or rented at a store. In other words, it was necessary for the user to go to a nearby store. Even if you go to a store, a DVD you want to rent may be on rental.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is capable of easily renting digital contents such as movie works, and has no problems such as being unable to rent during rent. It aims to provide a method for renting content.

[0005]

A digital content rental system according to the present invention stores a plurality of digital contents in a predetermined format, and stores a reproduction software capable of reproducing the digital contents, and a server storing the reproduction software. And a user's computer that downloads the playback software and the digital content from the user.The playback software includes a playback program that plays back the digital content and a time that elapses after the user's computer downloads the digital content from the server. A measurement program for measuring, and a deletion program for deleting digital content from the user's computer when a predetermined time has elapsed after downloading are incorporated, and the deletion program is stored. So that they can not be reproduced by the reproduction program digital content adapted to overwrite at least a portion.

[0006] In a rental method of digital contents according to the present invention, a step of installing reproduction software capable of reproducing digital contents of a predetermined format on a user's computer, and a step of converting the digital contents reproducible by the reproduction software to the computer. Downloading the digital content to the computer, measuring the time since downloading to the computer, and having a step of deleting the digital content from the computer if a preset time has elapsed, A measurement program for measuring time and a deletion program for deleting digital content are incorporated in the playback software, and the deletion program is at least partially overwritten so that the stored digital content cannot be played back by the playback program. It has become way.

Further, the digital content rental server according to the present invention stores a plurality of digital contents of a predetermined format in a database and stores reproduction software capable of reproducing the digital contents, and has accessed the database. The computer causes the computer to download the playback software and the digital content, and the playback software measures the time since the computer downloaded the digital content, and incorporates the playback software when the preset time has elapsed. The deleted digital program deletes the digital content whose time has elapsed.

[0008]

FIG. 1 is a schematic flowchart showing a procedure of a digital content rental method according to an embodiment of the present invention, and FIG. 2 is a schematic flowchart of a digital content rental method according to an embodiment of the present invention. FIG. 3 is a schematic flowchart showing a procedure for registering a member and installing reproduction software in a digital content rental method according to an embodiment of the present invention, and FIG. 4 is a digital content rental according to an embodiment of the present invention. FIG. 5 is a schematic explanatory view of a screen displayed on a member's computer at the time of membership registration of a method and installation of playback software, and FIG. 5 shows a digital content rental procedure of a digital content rental method according to an embodiment of the present invention. FIG. 6 is a schematic flow chart, and FIG. FIG. 7 is a schematic explanatory view of a screen displayed on a member's computer when renting digital content according to the law, and FIG. 7 is a schematic diagram showing a procedure for playing and deleting digital content in a digital content rental method according to an embodiment of the present invention. FIG. 8 is a schematic explanatory diagram of a screen displayed on a member's computer when playing and deleting digital content in the digital content rental method according to the embodiment of the present invention.

[0009] In a digital content rental method according to an embodiment of the present invention, a member 100 who is a user is required to provide reproduction software capable of reproducing digital content in a predetermined format.
Installing S1 on the computer 110,
A step S2 of downloading digital content that can be played back by the playback software to the computer 110, and measuring a time since the digital content is downloaded to the computer 110; And a step S3 of deleting digital content from the digital content 110. The deletion program for deleting the digital content is incorporated in the playback software.

In the following description, as an example of digital content, a movie work recorded as a digital signal (digital content) will be described.

The computer 110 of the member 100 in the digital content rental method is a normal personal computer, and includes a display, a CPU,
It is provided with a memory, a hard disk, and the like. The computer 110 is connected to the telephone line 40 via a modem device.
0 so that the Internet 300 can be used.

The computer 110 of the member 100
Is a concept including a portable terminal device (so-called PDA) other than a normal personal computer, a mobile phone, and the like.

On the other hand, the rental company 200 has a server 210 in which many movie works are recorded in the form of digital signals (digital contents). This server 210 is also connected to the Internet 300.
Further, the rental company 200 is provided with a memory 220 that records data relating to the member 100, for example, a name, an address, a credit card number, an email address, an ID number, a password, the name of a work rented so far, and the like. . Further, the rental company 200 is provided with a determination unit 230 for determining whether or not rental is possible. The digital content has been subjected to an encryption process so that it can be reproduced only by dedicated reproduction software, not by general-purpose reproduction software. The digital content is compressed in data amount.

Further, the server 210 stores the reproduction software.

The rental company 200 can be accessed via an Internet homepage or the like.

Next, a procedure of a digital content rental method according to an embodiment of the present invention will be described. This procedure can be roughly divided into a procedure (step) S1 for becoming a member and installing reproduction software on the computer 110 of the member 100, a procedure (step) S2 for the member 100 to download digital contents to its own computer 110, and a procedure for the member 100 The digital content is reproduced or the digital content is transferred to the computer 1
The process is divided into a step (step) S3 of deleting from step S10.

First, a procedure for becoming a member who can rent digital contents recorded on the server 210 of the rental company will be described with reference to FIGS. 3 and 4. Those who wish to register with the member 100 access the homepage (see FIG. 4) of the rental company 200 via the Internet 300 (S11), and transmit predetermined self-information to the rental company 200 (S12). As shown in FIG. 4A, a screen 500 for inputting self information is displayed.
A has a name input section 510A and an address input section 520.
A, input section 530A for credit card number used for settlement of rental fee, input section 540 for mail address
A, ID number input section 550A, password input section 5
There is 60A.

If the rental company 200 checks the self information (S13) and approves the member registration (S1).
4) The self-information is recorded in the memory 220, and a notification that the member has been registered is transmitted to the new member 100 on the screen 500B shown in FIG. 4B (S1).
6). As shown in FIG. 4 (B), the member 1
00 and the unique ID number and password are also described. The ID number and the password are keywords for identifying the member 100. The self-information check includes an inquiry to a credit card company.

In parallel with this membership registration, FIG.
A screen 500C shown in (C) is displayed, and dedicated reproduction software is also installed (S17). The installation of the playback software on the computer 110 of the member 100 is performed via the Internet 300 via the telephone line 400. Thus, the digital content can be reproduced on the computer 110 of the member 100. When the installation of the reproduction software is completed, the completion of the installation is notified to the member 100 as shown in a screen 500D shown in FIG.

Next, a procedure when the member 100 rents digital content will be described with reference to FIGS. Those registered as the member 100 access the homepage of the rental company 200 (see FIG. 6A) via the Internet 300 (S2).
1). On this homepage, a list of rentable digital contents and data indicating the contents of the digital contents, such as a trailer, can be browsed (S22). For example, a screen 60 shown in FIG.
At OA, a window 610A for displaying a trailer of the digital content and a window 620A for displaying character information describing the content of the digital content are displayed. Note that 630A in FIG. 6A is a scroll bar.

When the user browses these contents and finds the digital contents desired to be rented, the user applies for rental to a rental company (S22). This application is performed by clicking a window 610A displaying a trailer. When you make this application,
A screen 600B shown in (B) is displayed. Screen 600B
Are input to the ID number input section 610B and the password input section 620B, respectively.
Then, click the send button 630B and click your own ID.
The number and the password are transmitted (S23).

The rental agent 200 sends the transmitted ID
It is checked whether the number and the password match the recorded ones (S24), and only when they match, the process proceeds to the next step. If the ID numbers do not match,
The rental agent 200 requests repeated transmission of an ID number and a password. And I
If the mismatch between the D number and the password is repeated a predetermined number of times, it is determined that the access is unauthorized, and the rental is rejected.

The reset button 640B in FIG. 6B is clicked when the user mistypes the ID number or the like or interrupts the operation.

If the ID number and the password transmitted by the member 100 match those recorded in the memory 220 of the rental agent 200, a screen 60 shown in FIG.
At 0C, the rental period desired by the member 100 is input to the rental period input section 610C and transmitted (S25).
This transmission is performed by a transmission button 620 shown in FIG.
This is done by clicking C. Note that the reset button 630C in FIG. 6C is clicked when the rental period is mistyped or the work is performed in the middle.

Rental company 200 who received rental period
Displays a screen 600D as shown in FIG.
The name of the digital content to be rented, the rental period, and the contents of the rental fee are stored in the computer 1 of the member 100.
Send to 10 for confirmation. After confirming the name of the digital content to be rented, the rental period, and the rental fee, the member 100 clicks the confirmation button 610D.

The confirmed rental period is taken into the playback software installed on the computer 110 of the member 100, and the playback software recognizes the time limit for deleting the digital content to be rented, and indicates that the time limit has been recognized. Is transmitted to the rental company 200 (S28).

When the rental company receives the transmission that the time limit has been recognized, the rental company 200 downloads the digital contents to be rented to the computer 110 of the member 100 via the telephone line 400 via the Internet 300. In the computer 110 of the member 100, the downloaded digital content is recorded on the hard disk.

When reselecting the digital content at the stage of confirming the name of the digital content to be rented, if the user rejects the confirmation by clicking the reset button 620D, data indicating the content of the digital content, for example, a trailer Etc. (S
27).

Next, a procedure when the member 100 reproduces digital contents will be described with reference to FIGS. When reproducing the rented digital content, the power of the computer 110 is first turned on (S31), and the reproduction software is started (S32). When the reproduction software is started, a real timer clock (system clock) built in the computer 110 of the member 100 is monitored, and whether or not the time limit is exceeded is confirmed by a measurement program included in the reproduction software (S3).
3). Note that the real timer clock is
The computer 10 operates on a built-in power supply such as a built-in lithium battery, and can continue to calculate the current time even when the main power supply of the computer 110 is off.

If the time limit has not been exceeded, it is determined that the rental period has been reached, and the digital content is reproduced (S34). The reproduction is performed on the screen 7 shown in FIG.
The process is started by clicking a 00A play button 710A. When the digital content is not to be reproduced, the reset button 720A is clicked. Further, during the reproduction of the digital content, buttons for instructing stop, stop, rewind, fast forward, etc. are displayed at the bottom of the screen.

If the time limit has expired, it is determined that the rental period has expired, and the playback software deletes the digital content recorded on the hard disk by the deletion program (S35), and the member 100
7B is displayed on the display of the computer 110 of FIG. On this screen 700B, for example, “The rental period has elapsed, so the digital content is deleted from the hard disk. Is output. This completes a series of rental and playback procedures. The deletion program deletes the stored digital content by overwriting at least a part of the digital content so that the content cannot be reproduced by the reproduction program.

In the above-described embodiment, the concept of the rental period is used for determining whether or not to delete the digital content. However, the concept of the number of reproductions may be used. For example, when the digital content is rented, the member 100 sets the number of reproducible times, counts the number of times the reproduction has been started by the reproduction software (the number of replays), compares the reproducible number with the number of replays, If the number of times already played exceeds the number of times that can be played, it is determined that the rental has ended, and the digital content recorded on the hard disk is deleted by the deletion program. Delete. Is output.

The deletion program may overwrite at least a part of the stored digital content so that the stored digital content cannot be reproduced by the reproduction software.

Further, the concept of the rental period and the concept of the number of reproducible times may be used in combination, and the digital content recorded on the hard disk may be deleted at the end of the process.

Further, in the above description, it is determined whether the rental period or the like has elapsed at the time of starting the reproduction software. However, when the main power of the computer 110 of the member 100 is turned on, A determination may be made.

By the way, the above description is for the case where there is one rented digital content.
It is also possible to rent a plurality of digital contents at the same time. In this case, a rental period (the number of reproducible times) is designated for each digital content, and when the digital content to be reproduced is designated, the elapse of the rental period of the digital content designated to be reproduced may be determined. Good.

The reproduction software is provided by a rental company 200
Is installed on the computer 110 of the member 100 via the telephone line 400 from the CD-ROM,
It may be installed via a recording medium such as a flexible disk. In this way, the reproduction software can be distributed free of charge, such as a magazine appendix, which is very useful for the spread of the digital content rental method according to the present invention. In this case, the member registration can be performed online using a telephone line or off-line such as by mailing a data entry form to a rental agent without using the telephone line.

Also, although a normal personal computer is used as the computer 110 of the member 100, a reproduction device dedicated to this digital content rental method may be used instead of a normal personal computer.

The memory 220 of the rental company 200
Has recorded the information of the digital contents rented so far as the member information. By analyzing the record, the taste of the member 100 is analyzed, and new digital contents determined to be suitable for the taste are provided. Server 21
If it is recorded as 0, the member can be notified to that effect by e-mail. This preference can be registered by the member 100 in advance.

In the above description, a movie work has been described as an example of digital content. However, the digital content includes concepts such as music works, video game software, and computer application software.

The procedure described in the detailed description is an example of the digital content rental method according to the present invention, and the present invention is not limited to this. Can be changed.

Further, in the above-described embodiment, the digital content information is stored as a unit on the hard disk of the computer 110 of the member 100 as the user, but may be stored separately. In this case, in addition to the reproducing program, the measuring program (counting program), and the deleting program, the reproducing software includes a dividing program for dividing the downloaded digital content into a plurality of pieces, and a program for encrypting the divided digital program. It is necessary to have an encryption program to be encrypted, and a decryption / reproduction device program for decrypting the content encrypted by the encryption program and unifying and reproducing the divided content.

In addition, a part of the divided and encrypted digital contents may be incorporated in the reproduction software, and the others may be stored in a file other than the reproduction software in a different file format.

The server 210 of the rental company
Is a list of digital contents downloaded to the computer 110 of the specific member 100 (memory 220).
The digital content downloaded to the computer 110 of the member 100 who has requested the digital content to be downloaded again is compared with the digital content described in the list. The download of the new digital content is permitted only when the IDs match, and when the IDs do not match, at least the user's computer may be warned.

With this configuration, when a certain member 100 has copied the digital content downloaded by a different member 100, the digital content described in the list and the digital content downloaded to the computer 110 of the certain member 100 are copied. Therefore, illegal copying of digital content can be effectively prevented.

Further, it is preferable that the reproduction software can be installed in the computers 110 of a plurality of members 100, and that the number of installable computers 110 of the members 100 is set in advance.

With this configuration, when a member 100 owns a plurality of computers 110, for example, a desktop computer and a portable computer (including a PDA and a mobile phone) are owned. In this case, the digital content can be used by one download, which is more desirable from the viewpoint of user friendliness.

By the way, when the system clock of the computer 110 of the member 100 as the user is changed,
Although the rental period has actually expired, the deletion program does not operate, so that there is a problem that unauthorized rental is possible.

Therefore, the computer 1 is stored in the server 210.
Each time the computer 10 accesses, the time indicated by the system clock of the computer 110 is compared with the time indicated by the system clock of the server 210. If the two do not match, the time indicated by the system clock of the computer 110 May be corrected to the time indicated by the system clock of the server 210.

In this way, it is possible to prevent the member 100 from unjustly renting the computer 110 by rewriting the system clock.

In this case, the computer 11 of the member 100
If there is a difference between the time indicated by the system clock of 0 and the time indicated by the system clock of the server 210 that exceeds a preset allowable range, the computer 100 of the member 100 is warned at least to that effect. It is good to do so.

It is desirable that the allowable range is in units of days. Because the rental is performed in the number of days, the system clock of the computer 110 of the member 100 is set to 2
This is because even if the data is rewritten with a difference of less than 4 hours, it is considered that not much actual harm will occur. But,
The allowable range is not limited to a day unit.

Further, the warning of the member 100 to the computer 110 simply indicates "The system clock is not normal. May be issued, as well as a warning to stop downloading digital contents in the future.

[0054]

According to the method for renting digital content according to the present invention, a step of installing reproduction software capable of reproducing digital content in a predetermined format on a user's computer, and a step of installing the digital content reproducible by the reproduction software on the computer. Downloading the digital content to the computer, measuring the time since downloading to the computer, and having a step of deleting the digital content from the computer if a preset time has elapsed, comprising: A program for measuring time and a program for deleting digital content are incorporated in the playback software, and the deletion program overwrites at least a part of the stored digital content so that the stored digital content cannot be played back by the playback program. To You have me.

Therefore, if this digital content rental method is used, digital content can be rented without going to a store. In addition, there is no problem such as being unable to rent during rental. further,
Measuring the time since the digital content was downloaded to the computer, and deleting the digital content from the computer if a preset time has elapsed; and deleting the time measuring program and the digital content. Since the program to be executed is incorporated in the reproduction software, there is also an advantage that the amount of data sent to the computer of the member who is the user is small, so that the time required for transmission is short.

In another method for renting digital content according to the present invention, a step of installing reproduction software capable of reproducing digital content in a predetermined format on a user's computer, and a step of installing the digital content reproducible by the reproduction software. Downloading the digital content to the computer, counting the number of times the digital content has been reproduced using the reproduction software, and deleting the digital content from the computer when a preset number has elapsed. The program for counting the number of times and the program for deleting digital content are incorporated in the playback software, and the deletion program overwrites at least a part of the stored digital content so that the stored digital content cannot be played back by the playback program. Do It has become the jar.

Even with this digital content rental method, the same effects as described above can be obtained. Moreover, since the concept of the number of times of reproduction is introduced, there is an advantage that the viewing time becomes more free.

Further, if the preset time or number is set when the digital content is downloaded, it is convenient for the user because the viewing time can be adjusted to his / her own rhythm.

[Brief description of the drawings]

FIG. 1 is a schematic flowchart showing a procedure of a digital content rental method according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a digital content rental method according to an embodiment of the present invention.

FIG. 3 is a schematic flowchart showing a procedure for registering a member and installing reproduction software in a digital content rental method according to an embodiment of the present invention.

FIG. 4 is a schematic explanatory diagram of a screen displayed on a member's computer when a member is registered and a reproduction software is installed in the digital content rental method according to the embodiment of the present invention.

FIG. 5 is a schematic flowchart showing a digital content rental procedure in the digital content rental method according to the embodiment of the present invention.

FIG. 6 is a schematic explanatory diagram of a screen displayed on a member computer when renting digital content in the digital content rental method according to the embodiment of the present invention.

FIG. 7 is a schematic flowchart showing a procedure of playing and deleting digital content in the digital content rental method according to the embodiment of the present invention.

FIG. 8 is a schematic explanatory diagram of a screen displayed on a member's computer when playing or deleting digital content in the digital content rental method according to the embodiment of the present invention.

[Explanation of symbols]

 100 member 110 computer 200 rental company 300 internet 400 telephone line

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Claims (23)

[Claims] 1. A server that stores a plurality of digital contents in a predetermined format and stores reproduction software capable of reproducing the digital contents, and a user computer that downloads the reproduction software and the digital contents from the server. The reproducing software comprises: a reproducing program for reproducing digital content; a measuring program for measuring time since the user's computer downloaded the digital content from a server; and a preset time after downloading. And a deletion program that deletes digital content from the user's computer after elapse of the time, the deletion program is configured to at least prevent the stored digital content from being reproduced by the reproduction program. Digital content rental system characterized by partially overwriting. 2. A server which stores a plurality of digital contents in a plurality of predetermined formats and stores reproduction software capable of reproducing the digital contents, and a computer of a user who downloads the reproduction software and the digital contents from the server. The reproduction software includes a reproduction program for reproducing digital contents, a count program for counting the number of times the user's computer has reproduced the digital contents downloaded from the server, and the number of times of reproduction set in advance. And a deletion program for deleting digital content from the user's computer if the number of times exceeds the number of times, the deletion program prevents the stored digital content from being reproduced by the reproduction program. A digital content rental system characterized by at least partially overwriting. 3. The digital content rental system according to claim 1, wherein the preset time or number of times is set by a user's computer when downloading the digital content. 4. The reproduction software according to claim 1, wherein the reproduction software can be installed on a plurality of users 'computers, and the number of installable users' computers is set in advance. Digital content rental system. 5. The reproduction software includes a division program for dividing a downloaded digital content into a plurality of pieces, an encryption program for encrypting the division by the division program, and an encryption program encrypted by the encryption program. It has a decryption and playback device program that decrypts the content and unifies and plays the divided ones. Some of the divided and encrypted digital contents are incorporated in the playback software, and others are in different file formats. The digital content rental system according to claim 1, 2, 3, or 4, wherein the content is stored. 6. The server has a list of digital contents downloaded to a specific user's computer, and stores the digital contents downloaded to the user's computer requesting the digital content to be downloaded again. Compare with the digital contents described in the list, permit download of new digital contents only when both match, and when both do not match, at least inform the user's computer of the fact. 6. The digital content rental system according to claim 1, wherein a warning is issued. 7. The server compares the time indicated by the system clock of the computer with the time indicated by the system clock of the server every time the user's computer accesses, and when the two do not match, 7. The digital content rental system according to claim 1, wherein the time indicated by the system clock of the computer is corrected to the time indicated by the system clock of the server. 8. The digital content rental system according to claim 7, wherein there is a difference between the time indicated by the system clock of the user's computer and the time indicated by the system clock of the server exceeding a preset allowable range. In such a case, at least a warning to the user's computer is given to that effect, a digital content rental system. 9. A step of installing reproduction software capable of reproducing digital content of a predetermined format on a user's computer; a step of downloading digital content reproducible by the reproduction software to the computer; Measuring the time since downloading to the computer, and deleting the digital content from the computer if a preset time has elapsed, and deleting the measurement program and the digital content for measuring the time. Delete program, which is built into the playback software,
A method for renting digital contents, wherein the deletion program overwrites at least a part of the stored digital contents so that the stored digital contents cannot be reproduced by reproduction software. 10. A step of installing, on a user's computer, reproduction software capable of reproducing digital content in a predetermined format; a step of downloading digital content reproducible by the reproduction software to the computer; Counting the number of times of reproduction using reproduction software, and deleting a digital content from the computer if the number exceeds a preset number, and deleting the digital program and a counting program for counting the number of times. The deletion program is incorporated in the reproduction software, and the deletion program overwrites at least a part of the stored digital content so that the stored digital content cannot be reproduced by the reproduction software. Method. 11. The digital content rental method according to claim 10, wherein the preset time or number of times is set when the digital content is downloaded. 12. The reproduction software according to claim 9, wherein the reproduction software can be installed on a plurality of user computers, and the number of installable user computers is set in advance. How to rent digital content. 13. The reproduction software includes: a division program for dividing a downloaded digital content into a plurality of pieces; an encryption program for encrypting the division by the division program; and an encryption program encrypted by the encryption program. A decryption / reproduction program for decrypting the content and unifying and reproducing the divided content, wherein a part of the divided and encrypted digital content is incorporated in the reproduction software. 9, 10, 1
13. A method for renting digital contents according to item 1 or 12. 14. The server that has recorded the digital content has a list of digital content downloaded to a specific computer, and the digital content downloaded to the computer of the user who has requested the digital content to be downloaded again. Comparing the content with the digital content listed in the list, permitting the download of new digital content only when the two match, and if the two do not match, at least telling the computer 10. A warning is issued to the user.
A method for renting digital content according to item 2 or 13. 15. The server compares the time indicated by the system clock of the computer with the time indicated by the system clock of the server every time the user's computer accesses, and when the two do not match,
The digital content rental method according to claim 14, wherein the time indicated by the system clock of the computer is corrected to the time indicated by the system clock of the server. 16. The digital content rental method according to claim 15, wherein there is a difference between the time indicated by the system clock of the computer of the user and the time indicated by the system clock of the server exceeding a preset allowable range. In this case, at least a warning is given to the user's computer to that effect. 17. A plurality of digital contents in a predetermined format are stored in a database, and reproduction software capable of reproducing the digital contents is stored, and the reproduction software and the digital contents are downloaded to an accessing computer. The playback software measures the time since the computer downloaded the digital content, and when a predetermined time has elapsed, the digital content that has passed the time is deleted by a deletion program incorporated in the playback software. A server for renting digital contents, wherein at least a part of the server is overwritten so that the file cannot be reproduced by reproduction software. 18. A storage device for storing a plurality of digital contents in a predetermined format and storing reproduction software capable of reproducing the digital contents, and downloading the reproduction software and the digital contents to a computer of an accessing user. The playback software counts the number of times the digital content is played back by the playback software after the user's computer has downloaded the digital content.If the number exceeds a preset number, the deletion program incorporated in the playback software executes A server for renting digital contents, wherein at least a part of the digital contents is overwritten so that the digital contents whose number has been exceeded are not reproduced. 19. The digital content according to claim 17, wherein the reproduction software can be installed on a plurality of users' computers, and the number of installable computers is set in advance. Rental server. 20. The reproduction software, comprising: a division program for dividing the downloaded digital content into a plurality of pieces; an encryption program for encrypting the division by the division program; and an encryption program encrypted by the encryption program. A decryption / reproduction program for decrypting the contents and unifying and reproducing the divided contents, wherein a part of the divided and encrypted digital contents is incorporated in the reproduction software. A server for renting digital contents according to 17, 18, or 19. 21. A list of digital contents downloaded to a specific user's computer, and the digital contents downloaded to the user's computer requesting the digital content to be downloaded again are described in the list. Compared with the digital content obtained, download of the new digital content is permitted only when both match, and when both do not match, at least a warning is given to the user's computer to that effect. 21. The digital content rental server according to claim 17, 18, 19, or 20. 22. Every time a user's computer accesses, the time indicated by the system clock of the computer is compared with the time indicated by the system clock of the server. 2. The system according to claim 1, wherein the time indicated by the clock is corrected to the time indicated by the system clock of the server.
A server for renting digital contents according to 7, 18, 19, 20 or 21. 23. The digital content rental server according to claim 22, wherein a difference between a time indicated by a system clock of the user's computer and a time indicated by the system clock of the server exceeds a preset allowable range. A server for renting digital contents, which, if present, warns at least to the computer of the user.