JP2007018300A - Content distribution system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that it is not possible for the receiver of a transfer destination IC card to extend the term of validity of a license after transferring a license between IC cards in a communication distribution system. <P>SOLUTION: When transferring a license between IC cards, the IC card of the transfer origin transmits the license movement notification of an EMM to an EMM server. In this case, a storage region corresponding to the transferred license in the IC card of the transfer origin becomes write-disabled. The EMM server which has received the license transfer notification prepares release information for releasing the write disabled status of the IC card of the transfer origin, and transmits it to the IC card of the transfer origin, and changes the sending destination of the EMM to the IC card of the transfer destination. The IC card of the transfer origin receives the release information from the EMM server, and transfers this to a write disabled status release information interpreting part. Then, the write disabled status release information interpreting part sets the release information in the storage region. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a content distribution system that determines whether or not a copyright-protected content can be used based on a license and provides the content to a user. The present invention relates to a system for extending the expiration date of a license at a destination receiver with respect to movement.

  In recent years, services that distribute copyright-protected content using broadcasting and communication have become widespread. Here, the content refers to digital data such as a moving image, a still image, and sound. As a service for distributing content via broadcasting, there is a pay broadcasting service using BS (Broadcast Satellite) / CS (Communication Satellite). These use the limited reception system (Conditional Access System: hereinafter referred to as CAS) standardized by ARIB (Association of Radio Industries and Businesses), which is a digital broadcasting standardization organization in Japan.

  Also, the start of a service called server-type broadcasting is being considered. In server-type broadcasting, encrypted content is stored in a receiver as it is. The stored content cannot be used as it is, but can be used by determining whether or not a license composed of content usage conditions and a key for decrypting the content can be used.

  In the server-type broadcast CAS, at least three types of encryption keys are used: a content key, a work key, and a master key. The content is encrypted with the content key, and information including the content key is encrypted with the work key. Also, the information including the work key is encrypted with the master key and transmitted to the receiver. The content key is a key created for each content, and the same content is encrypted using the same content key. This content key is transmitted to all the receivers at once using an ECM (Entirement Control Message) or ACI (Access Control Information) for Kc transmission. The ECM and ACI for Kc transmission are encrypted with a work key that is transmitted only to a receiver with a content usage contract. Since the work key is transmitted using an EMM (Entitlement Management Message) encrypted with a master key unique to the receiver, the EMM can be decrypted and the work key can be extracted only by a receiver with a contract. Eventually, the content can be used only by the receiver that has a usage contract.

  A license including a content key may be distinguished as a sub license, and a license including a work key as a main license. The main license has an expiration date of the contract information. Before the expiration date, an EMM is periodically sent to extend the main license time limit, and the old license is overwritten with the new license to extend the time limit.

In such a license distribution system, for example, Patent Document 1 discloses a system that moves (moves) a main license between IC cards of a receiver. The IC card inserted into the receiver performs processing related to the license. Here, the process of moving means two operations: copying to the moving destination and invalidation at the moving source. In the system of Patent Document 1, as a process at the time of transfer, there is a method of copying a main license having a temporary expiration date to a transfer destination IC card and invalidating the copied main license for the expiration date on the transfer source IC card. It has been taken. For this reason, the moved main license is limited to temporary use.
Japanese Patent Laid-Open No. 2002-125211

  However, in the system of Patent Document 1, when it is assumed that the main license expiration date is extended, the expiration date can be extended on the source IC card, but the main license on the destination IC card can be temporarily used. Since it is limited, the expiration date extension process cannot be performed on the destination IC card.

  Thus, in the conventional system, the license expiration date cannot be extended at the destination IC card in the license transfer between the IC cards, and there is a problem in user convenience.

  In order to solve the above-described problems, the present invention is a system for extending the expiration date of a transfer destination IC card when a license is transferred. The transfer source IC card that has received the license transfer completion notification from the transfer destination IC card transmits the license transfer notification to the EMM server. At this time, the moved source IC card puts the moved license in a write-inhibited state. The EMM server that has received the license transfer notification creates the write prohibition state release information with reference to the EMM transmission schedule, and transmits this to the transfer source IC card. The source IC card that has received the write prohibition state release information releases the write prohibition state according to the write prohibition state release information.

  A content distribution system according to a first aspect of the present invention is a content distribution system that determines whether or not content can be used based on contract information, and a license including contract information and usage conditions regarding the use of the content is assigned to the one-way communication path. The information transmitting apparatus is configured to include an information transmitting apparatus that transmits information and an information receiving apparatus that receives a license. The information receiving apparatus indicates means for moving a license between information receiving apparatuses, and indicates that a license has been moved between the information receiving apparatuses. Means for transmitting a license transfer notification to the information transmitting apparatus.

  In the content distribution system according to claim 2 of the present invention, the information receiving apparatus further transmits the information from the information transmitting apparatus when the license is transferred between the storage area for storing the license and the information receiving apparatus. There is provided a means for setting the storage area in a write-inhibited state for the license to be executed.

  In the content distribution system according to claim 3 of the present invention, the means for prohibiting writing does not write the license to the area previously associated with the license secured in the storage area.

  In the content distribution system according to claim 4 of the present invention, when the license is moved, the means for setting the write-inhibited state stores information relating to the license as a movement history, and for the license transmitted from the information transmitting apparatus. When information is registered in the movement history, writing is not performed.

  In the content distribution system according to claim 5 of the present invention, the information transmitting apparatus further includes means for transmitting write prohibition state release information for canceling the write prohibition state of the information receiver.

  In the content distribution system according to claim 6 of the present invention, the write prohibition state release information is time information until the write prohibition state is released or time information when the write prohibition state is released.

  In the content distribution system according to claim 7 of the present invention, the information transmitting apparatus transmits a license update number together with a license to the information receiving apparatus, and the write prohibition state release information is a license update for determining whether to cancel the license write prohibition state. Number.

  In the content distribution system according to the eighth aspect of the present invention, the write prohibited state release information is write prohibited state forced release information for forcibly releasing the write prohibited state.

  In the content delivery system according to claim 9 of the present invention, the write-inhibited state release information is generated by the information receiving device by the information receiving device, and the information receiving device further includes means for transmitting to the information transmitting device. .

  In the content distribution system according to claim 10 of the present invention, the write-forbidden state forced release information is a random number generated by the information receiving apparatus.

  In the content distribution system according to claim 11 of the present invention, the information transmitting device further includes means for transmitting the write-inhibited state release information via the one-way communication path.

  In a content distribution system according to a twelfth aspect of the present invention, the information transmitting device further includes means for transmitting the write-inhibited state release information via the bidirectional communication path.

  The content distribution system according to claim 13 of the present invention comprises means for transmitting the write-inhibited state release information in addition to the response message for the movement notification transmitted from the information receiving apparatus.

  In the content distribution system according to the fourteenth aspect of the present invention, the information receiving device further includes means for releasing the write-inhibited state according to the received write-inhibited state releasing information.

  In the content distribution system according to the fifteenth aspect of the present invention, when the write prohibition state cancellation information is time information, the means for canceling the write prohibition state cancels the write prohibition state after a lapse of time.

  In the content distribution system according to the sixteenth aspect of the present invention, when the write prohibition state release information is time information, the means for canceling the write prohibition state releases the write prohibition state after the elapse of time.

  In the content distribution system according to the seventeenth aspect of the present invention, when the write prohibition state release information is an update number, the means for canceling the write prohibition state determines based on the license update number and cancels the write prohibition state.

  In the content delivery system according to claim 18 of the present invention, when the write prohibition state release information is the write prohibition state forcible release information, the means for releasing the write prohibition state immediately after receiving the write prohibition state forcible release information. Release the write-protected state.

  In the content distribution system according to the nineteenth aspect of the present invention, the information receiving device further includes a transfer permission / inhibition determining unit when the information receiving device is in a write-inhibited state with respect to license transfer between cards.

  In the content distribution system according to claim 20 of the present invention, when the license transfer is performed between the information receiving apparatuses, the transfer permission / inhibition determining means indicates that the transfer source information receiving apparatus is in a write prohibited state and the license transfer notification is received. If it has not been transmitted to the information transmitting device, the transfer of the license between the receiving devices is prohibited.

  In the content distribution system according to claim 21 of the present invention, the movement permission / inhibition determining means determines whether or not movement is possible according to the movement prohibition information set in the storage area by referring to the license history.

  According to the present invention, after the license is transferred between the IC cards, the expiration date of the license can be extended on the destination IC card, the range of the user's content usage form is expanded, and the convenience for the user is improved. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Embodiment 1>
(System configuration)
The system according to the present invention includes an EMM server 101, receivers 102 and 112, and IC cards 103 and 113, as shown in FIG. The EMM server 101 transmits the created EMM via broadcasting. The receivers 102 and 112 receive the EMM from the EMM server 101 and transmit it to the IC cards 103 and 113. The IC cards 103 and 113 process EMMs received from the receivers 102 and 112 and acquire licenses. Each component will be described below.

(Receiver configuration)
As shown in FIG. 1, the receiver according to the present invention includes receiving units 104 and 114, receiver control units 105 and 115, communication control units 106 and 116, storage units 107 and 117, and content playback units 108 and 118. Is done.

  The receiving units 104 and 114 receive an EMM transmitted from the EMM server 101. The receiver control units 105 and 115 have a function of controlling each module of the receiver. The communication control units 106 and 116 are units that control data transmission and reception when communicating with the other receivers 102 and 112 and the EMM server 101. The storage units 107 and 117 have a function of receiving and storing content transmitted via broadcasting. The content reproduction units 108 and 118 perform decryption processing on the encrypted content sent from the storage units 107 and 117, and output the decrypted content to the display devices 109 and 119. The display devices 109 and 119 display the video signals sent from the content reproduction units 108 and 118 on the display.

  The EMM received by the receiving unit 104 of the receiver A102 is transmitted to the receiver control unit 105, and is transmitted from the receiver control unit 105 to the IC card A103. The encrypted content transmitted via the broadcast is stored in the storage unit 107, and when it is determined by the IC card A103 that the content can be used, the content playback unit 108 decrypts the content and starts playback, and the display device 109 Output data to.

(Configuration of IC card)
Next, the configuration of the IC cards A103 and B113 according to the present invention will be described. Here, the IC cards A103 and B113 will be described as the IC card 200. As shown in FIG. 2, the IC card 200 includes an IC card input / output interface unit 201, an EMM decryption unit 202, an EMM interpretation unit 203, a license write enable / disable determination unit 204, a license write unit 205, and a write prohibition state release information interpretation unit 206. , A write prohibition state release information storage area 207 and a license storage area 208. The IC card input / output interface unit 201 receives data transmitted from the receivers 102 and 112 and transmits the data to the EMM decoding unit 202. The EMM decryption unit 202 decrypts the EMM using a master key that is a key unique to the IC card, and passes it to the EMM interpretation unit 203. The EMM interpretation unit 203 interprets the decrypted EMM passed from the EMM decryption unit 202 and acquires information such as a license. The license write permission / non-permission determination unit 204 refers to the license storage area 208 or the write prohibition state cancellation information storage area 207 regarding the permission of writing the license passed from the EMM interpretation unit 203 to the license storage area 208. Judgment. The license writing unit 205 writes the license passed from the license writing permission / inhibition determination unit 204 in the license storage area 208. The write prohibition state cancellation information interpretation unit 206 receives the write prohibition state cancellation information from the input / output interface unit 201, interprets it, and transmits it to the write prohibition state cancellation information storage area 207. The write prohibition state cancellation information storage area 207 stores the write prohibition state cancellation information transmitted from the write prohibition state cancellation information interpretation unit 206. The license storage area 208 stores license data and information for controlling the license data.

(Configuration of EMM server)
As shown in FIG. 3, the EMM server 101 according to the present invention includes an EMM server input / output interface unit 301, a license migration notification processing unit 302, a write prohibition state release information generation unit 303, an EMM transmission scheduler 304, an EMM generation unit 305, It consists of an EMM management storage area 306. The EMM server input / output interface unit 301 receives an inter-card license transfer notification transmitted from the IC card 200 and transmits an EMM according to the EMM transmission scheduler 304. The license migration notification processing unit 302 interprets the license migration notification transmitted from the input / output interface unit 301, and transmits an EMM destination change request to the EMM generation unit 305. The write prohibition state release information generation unit 303 creates the write prohibition state release information with reference to the EMM transmission scheduler 304 and the EMM management storage area 306. The EMM scheduler 304 manages an EMM schedule to be transmitted. The EMM generation unit 305 refers to the EMM management storage area 306 and creates an EMM. The EMM management storage area 306 manages information related to EMM.

  Next, the data structure of the license storage area 208 in the IC card 200 will be described below.

  FIG. 4 shows the data structure of the license storage area 208 in the IC card 200. The license storage area 208 includes a license data area 401, a write prohibition flag 402, a license use prohibition flag 403, and a move back prohibition flag 404. The license data area 401 is an area for storing license data. The write prohibition flag 402 is used for determining whether or not writing to the license data area 401 is possible. When the write prohibition flag 402 is ON, data writing to the license data area 401 is prohibited. The license use prohibition flag 403 is used for determining a state in which license use is prohibited. The move back prohibition flag 404 prohibits the move back when this flag is ON. In FIG. 5, when the license is transferred from the IC card D501 to the IC card E502, the license is returned from the IC card E502 to the IC card D501 again when the IC card D501 is in a write-protected state. Means that The license use prohibition flag 403 and the move back prohibition flag 404 are used only in the third embodiment and will be described later.

  Next, processing of the source IC card A103 when the license is transferred between the cards will be described with reference to FIGS. 7, 9, and 10. FIG.

  The IC card A103 receives the license transfer request from the IC card B113. Then, the IC card A103 transmits a license to the IC card B113, locks the license storage area, and waits for a license transfer completion notification transmitted from the card B113. When the IC card A 103 receives the license transfer completion notification from the card B 113, the IC card A 103 determines that the license transfer has been completed, deletes the license held by the IC card A 103, and releases the lock.

  Next, the IC card A103 sets the write prohibition flag 402 in the area in which the transferred license is stored to ON, thereby setting the write prohibition state (step S701). Next, the IC card A103 creates a license transfer notification message including the identifier of the transferred license and the identifier of the transfer destination IC card B113 (step S702). Next, the IC card A103 transmits a license transfer notification message to the EMM server 101 (step S703).

  Next, the IC card A103 receives a license transfer notification response message from the EMM server 101 (step S901). Next, the IC card A103 acquires the EMM update number that is the write prohibition state release information from the license transfer notification response message, and stores it in the write prohibition state release information storage area 207 (step S902).

  Next, processing when a license is about to be written in the license data area 401 when a write prohibition flag 402 of a license in the license storage area 208 of the IC card A 103 is ON is shown.

  The IC card input / output interface unit 201 of the IC card A103 receives the EMM from the receiver A102. The IC card input / output interface unit 201 transmits the EMM to the EMM decryption unit 202, and decrypts the EMM using the master key of the card (step S1001). Next, the EMM interpretation unit 203 acquires an EMM update number and a license from the EMM, and passes them to the license write permission determination unit 204. Next, the license writability determination unit 204 refers to the write prohibition flag 402 in the license storage area 208 to determine whether the received license is in a write prohibition state (step S1002). When it is determined that the writing is not prohibited (No in step S1002), the license is transferred to the license writing unit 205, and the license is written in the license storage area 208 (step S1006). On the other hand, when it is determined that it is in the write-inhibited state (Yes in step S1002), the IC card A103 acquires the write-inhibited state release EMM update number from the write-inhibited state release information storage area 207 (step S1003). If the EMM update number of the received EMM is newer than the prohibition state cancellation EMM update number, the write prohibition state is canceled by turning off the write prohibition flag 402 (step S1004), and the license is passed to the license writing unit 205, The license is written in the license storage area 208 (step S1005). In step S1004, if the received EMM update number of the EMM is older than the acquired write prohibition state release EMM update number, the write prohibition state is not released by leaving the write prohibition flag 402 ON, and the license is written. Is not performed (step S1007).

  Next, processing of the destination IC card B113 will be described.

  A user who operates the receiver B112 in which the IC card B113 is inserted transmits a license transfer request to the receiver A102 in which the IC card A103 having a license necessary for using the content is inserted. The IC card B113 that has normally received the license transmitted from the IC card A103 transmits a license transfer completion notification to the IC card A103. As a result, the transfer of the license from the IC card A103 to the IC card B113 is completed, and the user can use the contents available with the transferred license in the receiver B112 in which the IC card B113 is inserted.

  Next, the IC card B 113 receives the EMM for extending the license expiration date from the EMM server 101 by the input / output interface unit 201. The input / output interface unit 201 passes the data to the EMM decoding unit 202. The EMM decryption unit 202 decrypts the EMM using the master key of the IC card B 113 and transmits the decrypted EMM to the EMM interpretation unit 203. The EMM interpretation unit 203 acquires a license from the EMM and transmits the license to the license write permission / inhibition determination unit 204. The license writability determination unit 204 refers to the write prohibition flag 402 in the license storage area 208, but the write prohibition flag 402 is OFF, so that license writing is permitted and transmitted to the license writing unit 205. The license writing unit 205 writes the license in the license data area 401 in the license storage area 208. Thereby, the expiration date of the license is extended in the destination IC card B113.

  Next, processing of the EMM server 101 will be described with reference to FIG.

  When receiving the license transfer notification message from the IC card A 103, the EMM server 101 acquires the identifier of the license and the identifier of the IC card B 113 that is the license transfer destination (step S801). Next, the EMM server 101 searches the EMM transmission scheduler 304 for an EMM corresponding to the license identifier (step S802). Next, referring to the EMM transmission schedule, the EMM update number for completing the transmission of the corresponding EMM is acquired, and the EMM server 101 creates the write-inhibited state release information including the write-inhibited state release EMM update number (step) S803). Further, the information in the EMM management storage area 306 that manages the destination of the EMM that transmits the license to be transmitted is changed from the IC card A103 to the IC card B113 (step S804), and the write prohibition state release information is transmitted to the IC card A103. (S805).

  Note that the write prohibition state release information to be created starts transmission of an EMM obtained by referring to the EMM transmission scheduler 304 and whose EMM destination is changed from the IC card A103 to the IC card B113 by the inter-card license transfer notification. It may be time information or time information until transmission of the EMM in which the destination of the EMM is changed from the IC card A103 to the IC card B113 by the inter-card license transfer notification. In this case, in S1003 and S1004, the license writing permission / inhibition determination unit 204 of the IC card A103 refers to time information or time information stored in the writing prohibition information storage area 207 and performs a determination to cancel the writing prohibition state. A similar effect can be obtained.

  Note that the write prohibition state release information to be created may be write prohibition state forcible release information for forcibly releasing the write prohibition state of a license of the IC card A103. In this case, the write prohibition state cancellation information interpretation unit 206 of the IC card A 103 deletes the write prohibition state cancellation information stored in the write prohibition information storage area 207 according to the received write prohibition state forcible cancellation information. Further, the write prohibition flag 402 in the license storage area 208 is turned off. Thereby, the same effect is acquired.

  Next, the EMM server 101 creates a license transfer notification response message based on the write prohibition state release information. This is transmitted to the IC card A103 via communication. The EMM server 101 may store the write prohibition state release information in the EMM and transmit it to the IC card A103 via broadcast.

<Embodiment 2>
In the second embodiment, in FIG. 5, after the license is transferred from the IC card D501 to the IC card E502, the write prohibition flag 402 in the license storage area 208 of the source IC card D501 is ON and the write prohibition state is set. The processing when the license is returned from the transfer destination IC card E502 back to the transfer source IC card D501 is shown. This corresponds to the part of the license transfer process between cards in the first embodiment.

  In FIG. 11, when the user operating the receiver in which the write-protected IC card D501 is inserted tries to move the license from the IC card E502 to use the content, the license storage area 208 of the IC card D501 is stored. If the write prohibition flag 402 is ON and in the write prohibition state, the IC card D501 determines whether or not a license transfer notification has been transmitted to the EMM server 101 (step S1101). If it is determined in step S1101 that the license transfer notification has been transmitted, the IC card D501 permits transfer between the cards, and the license transfer is started (step S1102). Thereafter, the process continues to step S701 of the first embodiment. If it is determined in step S1101 that the license transfer notification has not been transmitted, the IC card D501 prohibits the transfer of the license between the IC cards, and the user is told that “the license cannot be transferred between the cards. Is displayed (step S1103). The IC card D501 stops the license transfer process between the cards.

  From the EMM server 101, the license transfer notification message of the IC card E502, which may occur when the license is moved back by the above processing, is transmitted before the license transfer notification message of the IC card D501. This prevents the EMM destination for extending the expiration date of the transmitted license from being set in the IC card E502.

<Embodiment 3>
In the third embodiment, in FIG. 6, after the IC card F601 transfers the license to the IC card G602, the license transfer notification sent from the IC card H603 to the EMM server 101 is not transmitted. This is a case where a license is to be written into the license storage area 208 which is in a write-inhibited state due to the movement of. In this case, since the license transfer to the IC card F601 is prohibited by the method of only the second embodiment, the IC card H603 cannot transfer the license to the IC card F601. In order to solve this problem, a license use prohibition flag 403 and a moveback prohibition flag 404 are added to the license storage area 208 of the IC card 200 to enable determination of moveback, and the IC card F601 transfers the license to the EMM server 101. Even when the notification is not transmitted, the license can be transferred between the IC cards.

  The IC card G602 transmits a license transfer request to the IC card F601. Next, the transfer source IC card F601 transfers the license to the transfer destination IC card G602, and the write prohibition flag 402 in the license storage area 208 of the transfer source IC card F601 is turned on to enter the write prohibition state. At this time, the IC card F601 keeps the license moved in the license data area 401 as a history without deleting it, and turns on the license use prohibition flag 403 to prohibit the use of the license.

  Next, in FIG. 12, the IC card F601 issues a license transfer request to the IC card H603. At this time, the IC card F601 determines whether or not the license transfer notification message has been transmitted to the EMM server 101 (step S1201). When it is determined in step S1201 that the transfer notification has been transmitted, the write prohibition flag 402 is ignored during transfer between IC cards, and the transfer of licenses between cards is permitted (step S1202). Next, the license writing unit 205 writes the license in the license storage area 208 of the IC card F601 (step S1203), and the license of the IC card H603 is moved to the IC card F601. Thereafter, the process continues to step S701 of the first embodiment.

  When it is determined in step S1201 that the IC card F601 has not yet transmitted the license transfer notification to the EMM server 101, the license and IC card left as a history are determined to determine whether the next license to be transferred is a move back. The license transmitted from H603 is compared to determine whether the licenses are the same (step S1204). If it is determined in S1204 that the move-back is made, the license transfer notification to the EMM server 101 of the IC card H603 and IC card F601 is canceled and not transmitted (step S1205). Next, the license writing unit 205 writes the license in the license data area 401 in the license storage area 208 of the IC card F601 (step S1206). Next, the write prohibition state is canceled by turning off the write prohibition flag 402 (step S1207). This prevents the license transfer prohibition period between IC cards from existing in the second embodiment.

  When it is determined in S1204 that it is not a move back, the license transfer notification to the EMM server 101 of the IC card H603 and the IC card F601 is transmitted as it is (step S1208). Next, the license writing unit 205 writes the license in the license data area 401 in the license storage area 208 of the IC card F601 (step S1209). Next, the move back prohibition flag 404 is set to ON to prohibit the subsequent move back (step S1210).

  Here, the license use prohibition flag 403 and the move back prohibition flag 404 are simultaneously turned OFF when the write prohibition flag 402 is turned OFF. As a result, the license can be transferred between the IC cards even before the IC card 200 transmits the license transfer notification to the EMM server 101, which is impossible in the second embodiment. Further, in step S1210, by prohibiting the subsequent move back, the license issued by the IC card F601 to the other IC card 200 is moved back again, and the extension of the license expiration date is prohibited.

(Other variations)
Although the present invention has been described based on the above embodiment, it is needless to say that the present invention is not limited to the above embodiment. The following cases are also included in the present invention.

  (1) Each of the above devices is specifically a computer system including a microprocessor, a ROM, a RAM, a hard disk unit, a display unit, a keyboard, a mouse, and the like. A computer program is stored in the RAM or hard disk unit. Each device achieves its functions by the microprocessor operating according to the computer program. Here, the computer program is configured by combining a plurality of instruction codes indicating instructions for the computer in order to achieve a predetermined function.

  (2) A part or all of the components constituting each of the above devices may be configured by one system LSI (Large Scale Integration). The system LSI is a super multifunctional LSI manufactured by integrating a plurality of components on one chip, and specifically, a computer system including a microprocessor, a ROM, a RAM, and the like. . A computer program is stored in the RAM. The system LSI achieves its functions by the microprocessor operating according to the computer program.

  (3) A part or all of the components constituting each of the above devices may be configured as an IC card that can be attached to and detached from each device or a single module. The IC card or the module is a computer system including a microprocessor, a ROM, a RAM, and the like. The IC card or the module may include the super multifunctional LSI described above. The IC card or the module achieves its function by the microprocessor operating according to the computer program. This IC card or this module may have tamper resistance.

  (4) The present invention may be the method described above. Further, the present invention may be a computer program that realizes these methods by a computer, or may be a digital signal composed of the computer program.

  The present invention also provides a computer-readable recording medium such as a flexible disk, hard disk, CD-ROM, MO, DVD, DVD-ROM, DVD-RAM, BD (Blu-ray Disc). ), Recorded in a semiconductor memory or the like. The digital signal may be recorded on these recording media.

  In the present invention, the computer program or the digital signal may be transmitted via an electric communication line, a wireless or wired communication line, a network represented by the Internet, a data broadcast, or the like.

  The present invention may be a computer system including a microprocessor and a memory, wherein the memory stores the computer program, and the microprocessor operates according to the computer program.

  In addition, the program or the digital signal is recorded on the recording medium and transferred, or the program or the digital signal is transferred via the network or the like, and executed by another independent computer system. It is good.

  (5) The above embodiment and the above modifications may be combined.

  The system according to the present invention extends the expiration date of the license at the destination IC card when the license is transferred between the IC cards that process the license in the content distribution system that controls the use of the content according to the license. It becomes possible. For this reason, after that, it becomes possible to continue using the content with the IC card of the destination, and it is possible to provide a content distribution system with high user convenience.

The figure which shows the structure of the system which concerns on this invention The figure which shows the structure of IC card based on this invention The figure which shows the structure of the EMM server which concerns on this invention. The figure which shows the data structure of the license memory area which concerns on this invention The figure which shows the flow of the license transfer between several IC cards based on Embodiment 2 of this invention. The figure which shows the flow of the license transfer between several IC cards based on Embodiment 3 of this invention. The flowchart which shows the processing operation of the IC card after the completion of the license transfer according to Embodiment 1 The flowchart which shows the processing operation of the EMM server after receiving the license transfer notification according to the first embodiment of the present invention. The flowchart which shows the processing operation of the IC card after receiving write prohibition state release information according to Embodiment 1 of the present invention The flowchart which shows the processing operation which cancels | releases the write-in prohibition state in IC card based on Embodiment 1 of this invention. The flowchart which shows the processing operation of the license transfer prohibition between IC cards based on Embodiment 2 of this invention. The flowchart which shows the processing operation at the time of performing move back determination based on Embodiment 3 of this invention

Explanation of symbols

101 EMM server 102 Receiver A
103 IC card A
104, 114 Receiver 105, 115 Receiver controller 106, 116 Communication controller 107, 117 Storage unit 108, 118 Content playback unit 109, 119 Display device 112 Receiver B
113 IC card B
DESCRIPTION OF SYMBOLS 200 IC card 201 IC card input / output interface part 202 EMM decoding part 203 EMM interpretation part 204 License writing availability determination part 205 License writing part 206 Write prohibition state cancellation information interpretation part 207 Write prohibition state cancellation information storage area 208 License storage area 301 EMM Server input / output interface unit 302 License transfer notification processing unit 303 Write prohibition state release information generation unit 304 EMM transmission scheduler 305 EMM generation unit 306 EMM management storage area 401 License data area 402 Write prohibition flag 403 License use prohibition flag 404 Move back prohibition flag 501 IC card D
502 IC card E
601 IC card F
602 IC card G
603 IC card H

Claims (21)

A content distribution system for determining whether or not content can be used based on contract information,
An information transmitting device for transmitting a license including the contract information and usage conditions regarding the use of the content using a one-way communication path;
An information receiving device for receiving the license;
Consists of
The information receiving device includes:
Means for moving the license between information receiving devices;
Means for transmitting to the information transmitting apparatus a license movement notification indicating that the license has been moved between the information receiving apparatuses;
A content distribution system comprising: The information receiving device further includes:
A storage area for storing the license;
Means for placing the storage area in a write-inhibited state for the license transmitted from the information transmitting device when the license is transferred between the information receiving devices;
The content distribution system according to claim 1, further comprising: The means for prohibiting writing does not write the license to an area previously associated with the license reserved in the storage area.
The content distribution system according to claim 2. The means for making the write-protected state stores information on the license as a movement history when the license is moved,
For the license transmitted from the information transmitting device, writing is not performed when information is registered in the movement history.
The content distribution system according to claim 2. The information transmitting device further includes:
Means for transmitting write prohibition state release information for canceling the write prohibition state of the information receiving device;
The content distribution system according to claim 2. The write prohibition state release information is time information for performing the write prohibition state release, or time information for performing the write prohibition state release.
The content distribution system according to claim 5. The information transmitting device transmits a license update number together with a license to the information receiving device;
The write prohibition state release information is a license update number for performing a release determination of the write prohibition state of the license.
The content distribution system according to claim 5. The write prohibition state release information is write prohibition state forcible release information for forcibly releasing the write prohibition state.
The content distribution system according to claim 5. The write prohibition state release information is generated by the information receiving device generating the write prohibition state forcible release information,
The information receiving device further includes:
Means for transmitting to the information transmitting device;
The content distribution system according to claim 8, wherein: The write prohibition state forcible release information is a random number generated by the information receiving device.
The content distribution system according to claim 9. The information transmitting device further includes:
Means for transmitting the write prohibition state release information via a one-way communication path;
The content distribution system according to claim 5. The information transmitting device further includes:
Means for transmitting the write prohibition state release information via a bidirectional communication path;
The content distribution system according to claim 5. The write-inhibited state release information includes means for transmitting in addition to the movement notification response message transmitted from the information receiving device,
The content distribution system according to claim 12, wherein: The information receiving device further includes:
Comprising means for releasing the write-inhibited state according to the received write-inhibited state release information,
The content distribution system according to claim 5. When the write prohibition state cancellation information is the time information, the means for canceling the write prohibition state cancels the write prohibition state after the time has elapsed.
The content distribution system according to claim 14. When the write prohibition state cancellation information is the time information, the means for canceling the write prohibition state cancels the write prohibition state after the time has elapsed.
The content distribution system according to claim 14. When the write prohibition state release information is the update number, the means for canceling the write prohibition state makes a determination based on the license update number and releases the write prohibition state.
The content distribution system according to claim 14. When the write prohibition state release information is the write prohibition state forcible release information, the means for releasing the write prohibition state releases the write prohibition state immediately after receiving the write prohibition state forcible release information.
The content distribution system according to claim 14. The information receiving device further includes:
A transfer permission / inhibition determination unit when the information receiving device is in the write-inhibited state with respect to license transfer between cards;
The content distribution system according to claim 2. When the license is transferred between the information receiving apparatuses, the movement permission / inhibition determining means indicates that the information receiving apparatus as the movement source is in the write-inhibited state and the license movement notification is not sent to the information transmitting apparatus. If it is a transmission, the transfer of the license between the receiving devices is prohibited.
The content delivery system according to claim 19. The movement permission / inhibition determining means determines whether to move according to movement prohibition information set in the storage area by referring to the movement history of the license.
The content delivery system according to claim 19.

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