JP2005025438A - Time-limited rental system, rental processing method, and perusal processing device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rental system capable of protecting a copyright of contents of an electronic book and the like during its rental and not requiring great communication capacity for prolonging a rental period. <P>SOLUTION: The copyright can be protected when the number of contents is managed by a library server and the contents are transmitted in encrypted form. The contents are encrypted by a time-limit key and the time-limit key is canceled/deleted when the rental date expires. In this way, only transmission of the time-limit key with a changed limit is required for prolonging the rental date or allowing rental of the contents again, and a communication time can be shortened greatly since transmission of a book again is not necessary. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to the rental of content by protecting the copyright of content such as an electronic book.
[0002]
[Prior art]
In recent years, with the widespread use of communication infrastructure such as personal computers and the Internet, contents such as books have been digitized and easily distributed. Accordingly, an electronic library (rental bookstore) that rents electronic contents via the Internet has been proposed (see, for example, Patent Document 1).
[0003]
FIG. 6 is a block diagram of the loan system disclosed in Patent Document 1.
[0004]
In FIG. 6, a library server 401 stores electronic books. The recording medium 402 acquires the digitized book from the library server 401 and stores it. The user can browse the book by connecting the recording medium 402 that has acquired the digitized book to the browsing device 403.
[0005]
A processing flow will be described. Books lent from the library server 401 are stored in the recording medium 402 (N01).
[0006]
The browsing device 403 searches for a book to be browsed on the recording medium 402 (N03), and displays the book to be browsed (N04). When the loan term expires, the book is returned to the library server (N02). Alternatively, the book on the recording medium 402 is deleted.
[0007]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-189867
[Problems to be solved by the invention]
In the above lending system, the book itself is encrypted by a password method using a unique symbol, and if the password itself is made public, it is possible to obtain and view the book even if it is not a lender. Cannot be protected.
[0009]
In addition, when re-renting or extending a book that has already been lent, it is necessary to send the book content and the encryption key (unique symbol) again. If the book content is large, the communication time There is a problem that becomes very long.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the lending system with time limit according to the present invention generates a time key including lending time limit information when there is a server for accumulating content and a request for lending the content. The encryption key generation device that outputs an encrypted signal obtained by encrypting the content encrypted with the time key and the content encrypted with the time key with a secret key, and the output from the encryption key generation device A recording medium on which an encrypted signal is recorded; and a browsing device for decrypting the encrypted signal stored in the recording medium and browsing the content, wherein the loan deadline indicated by the loan deadline information has passed The browsing of the content is not permitted by invalidating or deleting the time key.
[0011]
Further, the browsing device of the present invention is a browsing device that browses content encrypted with a time key that has been lent from a server for a limited time, and can decrypt the encrypted time key and the content And the result of the determination of the loan expiration date by the loan expiration date determination unit, whether or not the loan expiration date has been exceeded for the decrypted time key. A time key invalidation / deletion device that invalidates or deletes the time key, and as a result of determining the lending date by the lending date determination, the content is only received if the lending date has not passed. It is characterized by decoding.
[0012]
In the first lending processing method of the present invention, when there is a content lending request from a user, it is determined whether or not the content is in a lendable state, and the content is in a lendable state. In some cases, performing mutual authentication with a recording medium held by a user, generating a time key including lending date information when the recording medium is valid as a result of the mutual authentication, and Encrypting content with the time key, encrypting the time key and the content encrypted with the time key with a secret key unique to the recording medium, and generating an encrypted signal; Transmitting the digitized signal to the user.
[0013]
In addition to the first lending processing method, the second lending processing method of the present invention includes a step of notifying a user of a schedule that can be lent when the content is not in a lentable state, and the schedule If the user wishes to make a lending reservation as a result of the notification, the content reservation process is further included.
[0014]
Further, the browsing method of the present invention includes a step of making a content lending request to a server storing content, a step of performing mutual authentication with the server, and an encrypted signal encrypted with the secret key from the server Receiving a time key and content encrypted with the time key, and decrypting the content encrypted with the time key with the time key. Decrypting with a key to obtain plain text content, and when the loan term has expired, invalidating or deleting the time key and disallowing browsing of the content, To do.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the lending apparatus and method of the lending system with time limit according to the present invention will be described with reference to FIGS.
[0016]
FIG. 1 is a block diagram of a lending system with a time limit according to the present invention. In FIG. 1, a library server 101 stores digitized books. The encryption key generator 102 issues a time-limited encryption key. The recording medium 103 acquires an electronic book and stores it. The user browses the book using the browsing device 104.
[0017]
The flow of loan information will be described with reference to FIG. The book / lending information extracted from the library server 101 is sent to the encryption key generating apparatus 102 (C01). The encryption key generation apparatus 102 generates a time key based on the loan information acquired from the library server, and encrypts the book with the time key generated. Here, the time key is valid during the lending period and becomes invalid when the lending period ends. The encryption key generation device 102 and the recording medium 103 perform mutual authentication. If the mutual authentication is successful, an encrypted signal obtained by encrypting the encrypted book and the time key with a secret key (unique password) unique to the recording medium 103 is transmitted and stored (C02). Since the mutual authentication is performed and the encrypted book and the time key are transmitted in an encrypted state, the communication path between the encryption key generation apparatus 102 and the recording medium 103 can be kept safe. The encrypted signal is decrypted using a private key (unique password) unique to the recording medium in response to a request from the user, and becomes a book and plaintext time key encrypted with the time key.
[0018]
When a user browses a book using the browsing device 104, the browsing device 104 transmits to the recording medium 103 a time key encrypted with a secret key and a book double-encrypted with the secret key and the time key. A request signal for requesting is output (C03). The recording medium 103 to which the request signal is input transmits to the browsing device 104 the time key encrypted with the secret key and the book double-encrypted with the secret key and the time key (C04). The browsing device 104 decrypts the time key using the secret key, does not display the book if the time key is invalid, and uses the time-key to use the encrypted book if the time key is within the loan period. To decrypt and display the book. If the time limit key has passed the lending period, the browsing device 104 invalidates the read time key and outputs the encrypted signal to the recording medium 103 (C05).
[0019]
By forcibly invalidating the time key, it is possible to lend to the next user without waiting for the user to return the book to the library server 101. Further, when lending again or extending the lending, it is only necessary to transmit a time key with a changed deadline, so that the communication time can be greatly reduced as compared with the case where the book itself is transmitted.
[0020]
FIG. 2 is a processing flowchart of the library server 101 and the encryption key generating apparatus 102 according to the present invention. First, when there is a book rental request from a user, the library server 101 performs a book search process (201). After the search is completed, it is determined whether or not the book desired to be lent can be lent in the book rentability confirmation processing 202. If it is determined that the book can be lent, the process proceeds to the recording medium identification code reading process 203. The process proceeds to the notification process 211. The determination of whether or not a book can be lent is made by comparing the number of books held by the library server 101 with the number of books already lent. If they match, it means that the book has already been rented, and it is determined that it cannot be lent.
[0021]
When the lending is possible, the identification code of the recording medium 103 is read in the recording medium identification code reading process 203. This identification code is used in the borrower confirmation process 204 to determine who is the borrower. If the identification code is found, it is possible to recognize a secret key unique to the recording medium. The library server 101 has registered a valid borrower. When the borrower is registered, it is determined that lending is possible, but when the borrower is not registered, it is determined that lending is impossible. Thus, by performing mutual authentication between the recording medium 103 and the library server 101, the copyright of the book can be protected.
[0022]
If it is determined in the lender confirmation process 204 that the loan is possible, the process proceeds to the loan number generation process 205. If it is determined that the loan is not possible, the process proceeds to the loan non-permission notice 210. In the loan number generation process 205, a loan number is generated, and the process proceeds to the time key generation process 206. The loan number is used for managing loan information. In the time key generation process 206, the loan number and the loan expiration date are connected to generate a time key, and the process proceeds to the encrypted book generation process 207. In the encrypted book generation process 207, the book is encrypted with the time key, and the time key and the book encrypted with the time key are used with the secret key (unique password) recognized in the recording medium identification code reading step (203). The encrypted data is transferred to the encrypted signal transmission process 208.
[0023]
In the encrypted signal transmission processing 208, the time key and the encrypted signal obtained by encrypting the book encrypted with the time key with the secret key are transmitted to the recording medium 103. In the recording medium storing process 209, the recording medium 103 stores the encrypted signal in the encryption key storage area as a time key encrypted with a secret key, and a book double-encrypted with the secret key and the time key. These are transmitted to the browsing device 104 in response to a request from the user.
[0024]
If the library server 101 rents all the books that have been requested to be rented out, a rental reservation can be made. The library server 101 searches for a scheduled lending date in consideration of the lending number of the book that has been lent and its lending date. The retrieved rentable scheduled date is notified to the user who made the rent request in the rentable scheduled date notification process 211. The user determines whether or not to make a lending reservation with reference to the scheduled lending date. The library server 101 determines whether or not the user has made a lending reservation in a lending schedule confirmation process 212. When the lender makes a reservation, the process proceeds to the recording medium identification code reading 213, and when not making a reservation, the process ends. In the recording medium identification code reading process 213, the recording medium identification code is read, and the process proceeds to the lending reservation process 214. In the lending reservation processing 214, lending reservation processing is performed and the process ends.
[0025]
In the present invention, when the loan deadline comes, the lending period is terminated by forcibly invalidating the time key, so it becomes possible to perform reservation processing without worrying about delinquency and legally protect the copyright of the book. Reservation processing can be performed.
[0026]
Next, with reference to FIGS. 3, 4, and 5, a book browsing apparatus, method, and recording medium for storing books in the time-limited lending system of the present invention will be described.
[0027]
FIG. 3 is a block diagram of the browsing apparatus according to the present invention. In FIG. 3, the browsing apparatus according to the present invention includes an operation device R01 for selecting a book to be browsed, a display device R02 for displaying the book to be browsed, a decryptor R03 for decrypting the encrypted book, and a criterion for determining a loan expiration date. A reference clock R04, a lending time limit determining unit R05 for determining the lending time limit of the time key, a time key disabling device R06 for disabling the time key, and R07 which is a recording medium connecting unit for joining the recording medium. Note that R03 to R07 form one semiconductor integrated circuit.
[0028]
The browsing apparatus used for the lending system with a time limit of this invention is demonstrated referring FIG. The user searches for books stored in the recording medium connected to the recording medium connection unit R07 using the operation device R01. A list of retrieved books is displayed on the display R02. When a book to be browsed is selected from the list of books displayed on the display device R02 using the operation device R01, a time key encrypted with a private key corresponding to the book is transmitted from the recording medium via the recording medium connection unit R07. It is sent to the decoder R03. The time key sent to the decryptor R03 is decrypted using the private key unique to the recording medium 103, and sent to the lending term determiner R05.
[0029]
The time limit key sent to the lending date limiter R05 is compared with the reference clock R04 by the lending date limiter R05. As a result of the comparison, if it is within the lending period, a book double-encrypted with the secret key and the time key stored in the recording medium is read from the recording medium connection unit R07, and the decryptor is used with the secret key and the time key Decoded by R03, the book is displayed on the display. On the other hand, if the loan expiration date is exceeded, the time key is invalidated by the time key invalidator R06 and stored in the recording medium connected to the recording medium connection unit R07.
[0030]
FIG. 4 is a block diagram of a recording medium according to the present invention. In FIG. 4, a recording medium 103 according to the present invention includes a recording medium identification code S01 for identifying a recording medium, an encryption key storage area S02 for storing a time key, and an encrypted book storage area S03 for storing an encrypted book. .
[0031]
With reference to FIG. 4, a recording medium used in the lending system with time limit of the present invention will be described. The recording medium identification code S01 is recorded with a unique number for specifying the recording medium. The library server 101 and the recording medium 103 perform mutual authentication using a recording medium identification code. The encryption key storage area S02 stores a time key encrypted with a secret key generated by the library server 101. In the encrypted book storage area S03, a book double-encrypted with a secret key and a time key generated by the library server 101 is stored and can be taken out by a browsing device.
[0032]
FIG. 5 is a flowchart of the processing of the browsing device according to the present invention. In the browsed book search process 301, a loaned book is searched, and after the search is completed, the process proceeds to an encrypted time key read process 302. The time key encrypted with the secret key in the encrypted time key reading process 302 is read from the encryption key storage area of the recording medium, and the process proceeds to the time key decryption process 303. The time key encrypted with the private key in the time key decryption process 303 is decrypted, and the process proceeds to the lending time limit confirmation process 304. In the lending deadline confirmation process 304, the lending period of the time key is determined. If it is within the lending period, the process proceeds to the encrypted book decryption process 305. Transition. In the encrypted book decrypting process 305, the encrypted book is decrypted with the secret key and the time key, and the process proceeds to the decrypted book browsing operation process 306. The browsing operation process of the book decrypted in the decrypted book browsing operation process 306 is performed, and the process ends. In the time key invalidation processing 307, the time key invalidation processing is performed, the time key is invalidated, stored in the encryption key storage area, and the lending period end notification processing 308 is performed. The lending period end notification process 308 notifies the end of the lending period and ends.
[0033]
As described above, in the present embodiment, the number of contents is managed by the library server, and further, the contents can be protected by protecting the contents by encrypting and transmitting the contents. In addition, by encrypting the content with a time key and invalidating / deleting the time key when the loan expires, only the time key with a different time limit is sent when extending or re-renting the loan. The communication time can be greatly shortened because there is no need to send the book again.
[0034]
In this embodiment, the time key is invalidated, but the time key may be deleted instead of invalidated.
[0035]
In this embodiment, the book rental is described as an example. However, the content to be lent in the present invention is not limited to the book, and can be applied to video data, music data, and the like. Needless to say.
[0036]
【The invention's effect】
In a lending system for electronic data or the like, the copyright of a book can be protected and illegal copying can be prevented.
[0037]
In addition, when extending or renting out a loan, it is only necessary to transmit a time key with a different time limit, and it is not necessary to transmit the book again, so that the communication time can be greatly reduced.
[Brief description of the drawings]
FIG. 1 is a block diagram of a lending system with a time limit according to the present invention. FIG. 2 is a flowchart of a lending processing method according to the present invention. FIG. 3 is a block diagram of a browsing apparatus according to the present invention. FIG. 5 is a flowchart of the browsing processing method of the present invention. FIG. 6 is a block diagram of a conventional lending system.
101 Library Server 102 Encryption Key Generating Device 103 Recording Medium 104 Browsing Device R01 Operation Device R02 Display Device R03 Decryption Device R04 Reference Clock R05 Loan Expiration Date Determiner R06 Time Key Invalidator R07 Recording Medium Connection Unit

Claims (5)

A server for storing content;
When there is a request for lending the content, a time key including lending time limit information is generated, the content is encrypted with the time key, and the content encrypted with the time key and the time key is encrypted with a secret key. An encryption key generation device that outputs an encrypted signal,
A recording medium on which the encrypted signal output from the encryption key generation device is recorded;
A browsing device for decrypting the encrypted signal stored in the recording medium and browsing the content;
A lending system with a time limit characterized in that browsing of the content is not permitted by invalidating or deleting the time key after the lending time limit indicated by the lending time limit information is passed. A browsing device for browsing content encrypted with a time key that has been loaned for a limited time from a server,
A decryptor capable of decrypting the encrypted time key and the content;
A loan term determiner for determining whether or not a loan term has passed for the decrypted time key;
As a result of determining the lending date by the lending date determining unit, if the lending date has passed, a time key invalidating / deleting device that invalidates or deletes the time key is provided,
As a result of determining the loan deadline by the loan deadline determination, the content is decrypted only when the loan deadline has not passed. Determining whether or not the content can be lent when the user has requested to rent the content;
Performing mutual authentication with a recording medium held by a user when the content is in a lendable state;
As a result of the mutual authentication, when the recording medium is valid, generating a time key including lending time limit information;
Encrypting the content with the time key;
Encrypting the time key and the content encrypted with the time key with a secret key unique to the recording medium to generate an encrypted signal;
And lending the encrypted signal to a user. Notifying the user of a schedule for lending when the content is not in a lendable state; and
And a step of performing a reservation process of the content when the user desires a loan reservation as a result of notifying the schedule. Making a request for lending content to a server for storing content;
Performing mutual authentication with the server;
Receiving an encrypted signal encrypted with the secret key from the server;
Decrypting the encrypted signal with the secret key to obtain a time key and content encrypted with the time key;
Decrypting the content encrypted with the time key with the time key to obtain plain text content;
And a step of disabling or deleting the time key and disallowing browsing of the content when a lending time limit has passed.

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