JP2005276085A - Recording medium for preventing unauthorized copy, content reproducing device, method for preventing unauthorized copy, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording medium for preventing unauthorized copy capable of allowing authorized users to use contents without limit, and providing detailed contents in accordance with user's need such as permission of duplicating of contents and the limit of the number of times. <P>SOLUTION: A decode key 121 for decoding the encrypted content is held in a storage part 110 in an IC card 100 by every content ID 120 of the encrypted content. In a case when the encrypted content is decoded by a PC (content reproducing device) 200, the information on the content ID and the request for transmission of decode key are transmitted from the content reproducing device 200 to the IC card 100, and the encrypted content is reproduced by acquiring the decode key 121 from the IC card 100. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an illegal copy prevention recording medium, a content reproduction apparatus, an unauthorized copy prevention method, which prevents unauthorized copying of software contents (video contents and the like) and enables fine service support for users. And programs.

  Conventionally, copyright protection of software content (simply referred to as “content”) was protected with a copy guard function, etc., but due to the development of network system distribution and rental industry, these are adequately protected. I couldn't say. In many cases, a uniform copy guard function is applied to all contents, which does not satisfy diversifying user requirements.

  Further, as a prior art related to such copyright protection, an invention for preventing unauthorized use in order to protect the copyright of a book content in a rental business by electronic commerce is disclosed. In this invention, when a user sets a flash memory in a store terminal such as a convenience store and selects a desired electronic book content, the encrypted electronic book content and software (reader) for reading the electronic content are downloaded. The The user can browse the electronic book content by setting the flash memory in which the electronic book content or the like has been downloaded to the reading terminal. The electronic content rented by the user is preliminarily applied to the electronic content so that it disappears in a certain period (see, for example, Patent Document 1).

However, the above invention is mainly intended to protect the copyright in the rental system, and allows the user to browse the book by inputting the password printed out from the storefront terminal into the reading terminal. It has not been possible to protect copyrights, protect the copyrights of content distributed over the network, and provide detailed services to users according to the content.
JP 2002-189958 A

  The present invention has been made to solve such a problem, and an object of the present invention is to use an unauthorized copy prevention recording medium such as an IC card so that a legitimate user can use content without restriction. Unauthorized copy prevention recording medium and content that can provide fine-grained content according to user needs, such as permission to copy content and limit the number of times by setting permission conditions stored in unauthorized copy prevention recording media such as cards It is an object of the present invention to provide a playback device, an unauthorized copy prevention method, and a program.

  The present invention has been made to solve the above-mentioned problems, and the unauthorized copy prevention recording medium of the present invention is used to prevent unauthorized copy used in a content playback apparatus that decrypts encrypted content using a decode key. For each content ID of the encrypted content, and a mutual authentication between the content reproduction device and a decoding key holding means for holding a decoding key for decoding the encrypted content Mutual authentication between the content reproduction apparatus, content ID information from the content reproduction apparatus, decode key request reception means for receiving a decode key transmission request corresponding to the content ID, and the content reproduction apparatus by the mutual authentication means. The decode key of the content ID requested to the content reproduction device when it is normally performed Characterized in that it comprises a decoding key transmission means for transmitting.

  Further, the unauthorized copy prevention recording medium of the present invention includes a copy permission number holding means for holding information on the number of times of copy permission for each content ID of the encrypted content, A copy decode key holding means for holding a copy decode key for copy for each content ID of the content, a content ID information from the content reproduction device, and a request for transmitting a copy decode key corresponding to the content ID When a copy decoding key request receiving unit and a copy decoding key request receiving unit receive a copy decoding key transmission request from the content reproduction apparatus, the copy permission request is referred to by referring to the copy permission count information corresponding to the content ID. A copy permission number determination means for determining whether there is a remaining number of times, and the mutual authentication means When the mutual authentication with the content playback apparatus is normally performed and the copy permission count confirmation means determines that there is a remaining number of times of copy permission, a copy decode key of the content ID requested by the content playback apparatus is obtained. And a duplicate decode key transmitting means for transmitting.

  The unauthorized copy prevention recording medium of the present invention is characterized in that the encrypted content is content encrypted with a public key, and the decoding key and the duplicate decoding key are secret keys.

  The content playback apparatus of the present invention is a content playback apparatus that holds encrypted content and decrypts it using a decode key, and holds the encrypted content and decrypts it using the decode key A reproduction apparatus, comprising: a mutual authentication unit that performs mutual authentication with the unauthorized copy prevention recording medium; a content ID reading unit that reads a content ID of an encrypted content to be reproduced; and the content ID reading unit. Decoding key transmission request means for transmitting the read content ID information and a decoding key transmission request corresponding to the content ID to an unauthorized copy prevention recording medium holding a decoding key for each content ID; and the mutual authentication means If the mutual authentication with the unauthorized copy prevention recording medium is successfully performed by In, wherein the unauthorized copy protection recording medium, and a decoding key receiving means for receiving a decoding key of the requested content ID.

  In addition, the unauthorized copy prevention method of the present invention uses an unauthorized copy prevention recording medium used in a content reproduction device that decrypts encrypted content using a decode key for each content ID of the encrypted content. A decoding key holding procedure for holding a decoding key for decrypting the encrypted content, a mutual authentication procedure for performing mutual authentication with the content reproduction device, content ID information from the content reproduction device, and the content The content ID requested by the content reproduction device when the mutual authentication with the content reproduction device is normally performed by the decode key request reception procedure for receiving the transmission request of the decode key corresponding to the ID and the mutual authentication procedure. And a decoding key transmission procedure for transmitting a decoding key of That.

  Also, the computer program program of the present invention provides each content ID of encrypted content to a computer in an unauthorized copy prevention recording medium used in a content reproduction apparatus that decrypts encrypted content using a decode key. A decoding key holding procedure for holding a decoding key for decrypting the encrypted content, a mutual authentication procedure for performing mutual authentication with the content playback device, content ID information from the content playback device, Requested by the content playback device when the decode key request receiving procedure for receiving the decode key transmission request corresponding to the content ID and the mutual authentication with the content playback device are normally performed by the mutual authentication procedure. Decode key sender that sends the content ID decode key Is a program for executing and.

In the unauthorized copy prevention recording medium of the present invention, the encrypted content is decrypted in the unauthorized copy prevention recording medium such as an IC card for each content ID (content identification information) of the encrypted content. Hold the decoding key. When decrypting the content encrypted by the content reproduction device, the content reproduction device transmits “content ID information” and “decode key transmission request” to the unauthorized copy prevention recording medium, and from the IC card. Obtain the decode key and play the encrypted content.
As a result, a decoding key can be stored for each content ID in an unauthorized copy prevention recording medium such as an IC card, and unauthorized copying can be prevented for each content. Can be used.

Also, in the unauthorized copy prevention recording medium of the present invention, information on the number of times permitted for copying for each content ID is held in the unauthorized copy prevention recording medium such as an IC card, and the content ID of the encrypted content is stored. A copy decoding key for each copy is held. When “content ID information” and “copy decoding key transmission request” are received from the content reproduction device, when there is a remaining number of times of copy permission with reference to the information of the number of times of copy permission corresponding to the content ID The duplicate decode key is transmitted to the content reproduction apparatus. In the content reproduction apparatus, a copy decoding key is obtained from an unauthorized copy prevention recording medium such as an IC card, and the encrypted content is copied.
Thereby, the copy permission count and the copy decode key for each content can be stored in a recording medium such as an IC card, and detailed contents according to the user's needs such as copy permission and number limit can be provided.

In the unauthorized copy prevention recording medium of the present invention, the encrypted content is content encrypted with a public key, and the decode key and the duplicate decode key are secret keys.
Thereby, an advanced illegal copy prevention function can be realized.

Further, the content playback apparatus of the present invention holds a decode key for decrypting the encrypted content for each content ID of the encrypted content in an unauthorized copy prevention recording medium such as an IC card. Keep it. Then, when decrypting the encrypted content, the content playback apparatus transmits “content ID information” and “decode key transmission request” to an unauthorized copy prevention recording medium such as an IC card, and the IC card. The decoding key is obtained from the encrypted content and the encrypted content is reproduced.
As a result, a decoding key can be stored for each content ID in an unauthorized copy prevention recording medium such as an IC card, and unauthorized copying can be prevented for each content. Can be used.

In the unauthorized copy prevention method of the present invention, a decoding key for decrypting the encrypted content is held for each content ID of the encrypted content in an unauthorized copy prevention recording medium such as an IC card. Keep it. When decrypting the content encrypted by the content reproduction device, the content reproduction device transmits “content ID information” and “decode key transmission request” to the unauthorized copy prevention recording medium, and from the IC card. Obtain the decode key and play the encrypted content.
As a result, a decoding key can be stored for each content ID in an unauthorized copy prevention recording medium such as an IC card, and unauthorized copying can be prevented for each content. Can be used.

Next, the best mode for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing an outline of an unauthorized copy prevention system according to the present invention. The unauthorized copy prevention system of the present invention is a content providing server 310 of a provider 300 of encrypted software content (also simply referred to as “content”). And a PC (content reproduction device) 200 such as a personal computer for reproducing the content, an IC card reader / writer 201 attached to the PC 200, and an IC card (unauthorized copy prevention recording medium) 100. The IC card 100 is a non-contact IC card, and performs communication using radio waves as a medium by the antenna 202 of the reader / writer 201 and the antenna of the IC card 100.

  Note that the software content in the present invention is intended for video content, music content, package software for applications for personal computers, online distribution software thereof, and the like. The PC 200 is not limited to a personal computer, and may be a dedicated content playback device.

  In the unauthorized copy prevention system shown in FIG. 1, the encrypted content provided by the content provider is provided to the user's PC 200 in advance by a portable recording medium such as a DVD-ROM 301, in addition to the content providing server. From 310, it is provided online to the PC 200 via the communication network 1.

  The provided encrypted content is encrypted (encoded) with a public key for each content and provided to the PC 200. In the storage unit (decode key holding means) 110 in the IC card 100, a decode key 121 using a secret key is recorded for each content ID (content identification information) 120.

  When the PC 200 reproduces the encrypted content, the PC 200 acquires the decode key 121 from the IC card 100 and decrypts the encrypted content. In this case, mutual authentication is performed between the PC 200 and the IC card 100, and after confirming the validity, the content ID 120 is notified from the PC 200 to the IC card 100, and the decode key 121 recorded in the IC card from the IC card 100 is received. Acquire and play software content.

  The storage unit 110 in the IC card 100 also stores information on the copy permission count 122 and the copy decode key 123 for each content ID 120. The copy decoding key 123 is a secret key necessary for copying the content encrypted in the PC 200. The copy permission count 122 is information for limiting the number of times the content encrypted by the PC 200 is copied.

  Note that the decode key 121, the duplicate decode key 123, and the like can be purchased online from the content providing server 310 via the communication network 1. Further, in the IC card 100, billing correspondence information (for example, electronic money information) or the like can be recorded if necessary, and billing can be performed according to the use of a decode key or the like.

  Moreover, although the example shown in FIG. 1 shows an example in which a decode key or the like is recorded on a non-contact IC card, the IC card may be a contact IC card. Further, the unauthorized copy prevention recording medium for recording the decode key is not limited to the IC card, but may be a flash memory or the like. For example, it is provided in the form of an IC chip in a portable terminal such as a cellular phone. Also good.

  FIG. 2 is a diagram showing an example of an IC card used in the unauthorized copy prevention system of the present invention, and is a diagram showing an example of a non-contact IC card. The IC card 100 includes an IC chip 101 and an antenna 150, and communicates with radio waves (for example, radio waves in the 13.56 MHz band) through the antenna 202 of the reader / writer 201. In addition, the IC chip 101 includes a CPU (arithmetic control unit) 102, a power source unit 103, a transmission / reception unit 104, a storage unit 110, and the like. Each of them shares functions and exchanges data with the reader / writer 201 by radio waves. I do.

  The power supply unit 103 in the IC chip 101 generates power by rectifying electromotive force (electromagnetic induction or the like) generated in the antenna 150 by radio waves radiated from the reader / writer 201, and operates the CPU 102 and the like. In addition, the transmission / reception unit 104 performs processing for transmitting information stored in the storage unit 110 from the antenna 150 to the reader / writer 201, and performs processing for receiving information transmitted from the reader / writer 201 via the antenna 150. .

  Further, as information recorded in the storage unit 110, attribute information 111 of the IC card itself such as a card ID, a plurality of content IDs 120, and a decode key 121 for each content ID are recorded. Further, information on the number of permitted copies (number of times of copying) 122 and a copy decoding key (decoding key for copying content) 123 are recorded for each content ID. The storage unit 110 can also record information on the electronic money balance 130 necessary when the IC card 100 is used as a card for accounting.

FIG. 3 is a diagram showing a processing flow of the unauthorized copy prevention system of the present invention, and shows a procedure in which the PC 200 acquires a decode key from the IC card 100.
Referring to FIG. 3, first, PC 200 is activated (step S101). When the PC 200 is activated, the PC 200 requests the IC card 100 to transmit a card ID (step S102).

  When receiving the card ID transmission request from the PC 200 (step S103), the IC card 100 transmits the card ID recorded on the IC card 100 to the PC 200 (step S104). The PC 200 receives the card ID (step S105). Thereafter, mutual authentication is performed between the IC card 100 and the PC 200 (steps S106 and S107).

  When the mutual authentication between the IC card 100 and the PC 200 is completed, the PC 200 reads the content ID from the content (step S108), and transmits a decode key transmission request together with the read content ID to the IC card (step S109).

  When receiving the decode key transmission request (step S110), the IC card 100 determines whether or not the decode key for the received content ID is held (step S111). If there is no decode key corresponding to the content ID, the fact is notified to the PC 200 and the process is terminated (step S112). If the decode key for the received content ID is held, the decode key is transmitted to the PC 200 (step S113).

  The PC 200 receives the decode key (step S114), and decrypts and reproduces the encrypted content using the decode key (step S115).

FIG. 4 is a diagram showing a processing procedure in the case of granting content duplication permission.
In FIG. 4, the process from the activation of the PC 200 (process step S101) to the completion of mutual authentication (S107) is the same process as in FIG. 3, and the description thereof will be omitted, and the process from step S201 will be described.

  When the mutual authentication is completed in step S107, the PC 200 reads the content ID from the content (step S201), and transmits the “duplication decoding key transmission request” to the IC card 100 together with the read “content ID information” (step S201). S202).

  When the IC card 100 receives the “duplication decoding key transmission request” and the “content ID” (step S203), the IC card 100 first determines whether or not the content is to be permitted to be duplicated. That is, it is determined whether or not a duplicate decode key is held for the corresponding content ID (step S204).

  If the IC card 100 does not hold a copy decode key for the content ID to be copied, the IC card 100 notifies the PC 200 to that effect and stops the processing (step S205). If the copy decode key is held, it is next determined whether or not there is a remaining copy count (remaining copy count) (step S206). If there is no remaining copy count, the PC 200 is notified to that effect and the process is stopped (step S207).

  If there is a remaining copy count, the copy remaining count is set to “−1” (step S208), and a copy decode key is transmitted to the PC 200 (step S209). The PC 200 receives the duplicate decode key (step S210) and duplicates the content (step S211).

  Although the copy permission processing procedure has been described above, a method of copying the copy decoding key itself as a distribution right is also conceivable. Further, as a method for charging, a method of storing the remaining amount of electronic money or the like in the IC card 100 and reducing the amount of electronic money each time it is copied can be used.

FIG. 5 is a diagram showing a procedure for downloading an encrypted content decoding key from a content providing server online.
Referring to FIG. 5, a user (user) who wants to purchase a content decode key and store it in IC card 100 sets IC card 100 in the reader / writer of PC 200 (step S301). The PC 200 reads the card ID of the IC card 100 (step S302). The user operates the PC 200, accesses the content providing server 310 via the communication network, and transmits a “decode key purchase request” and a “card ID” (step S303).

  The content providing server 310 receives “decode key purchase request” and “card ID” from the PC 200 (step S304), and authenticates the validity of the IC card 100 (step S305).

  If the IC card 100 is normally authenticated, the content providing server 310 transmits “purchase permission” to the PC 200 (step S306). When receiving “purchase permission” from the content providing server 310 (step S307), the PC 200 transmits a “download request” of decoding key information to the content providing server 310 (step S308).

  Upon receiving the “download request” from the PC 200 (step S309), the content providing server 310 transmits a decode key for the content requested by the user to the PC 200 (step S310). The PC 200 receives the decode key from the content providing server 310 (step S311), and writes the received decode key to the IC card 100 (step S312).

  Note that the decoding key download procedure described above also applies to the case of downloading a duplicate decoding key.

  FIG. 6 is a diagram showing functions (processing units) of each system constituting the unauthorized copy prevention system of the present invention, and shows the functions directly related to the present invention.

The IC card 100 has a processing unit shown below.
The decode key request reception processing unit (decode key request receiving means) 141 is a processing unit for receiving a “decode key transmission request” from the PC 200 together with information on the content ID. The authentication processing unit (mutual authentication unit) 142 performs mutual authentication processing with the PC 200.

  The copy permission number determination processing unit (duplication permission number determination unit) 143 refers to the information of the copy permission number 122 recorded in the storage unit 110, determines whether or not to permit the content to be copied by the PC 200, and is permitted. In this case, the duplicate decode key 123 is transmitted to the PC 200, and the PC 200 duplicates the encrypted content using the duplicate decode key.

  The encryption processing unit 144 performs processing for encrypting information transmitted from the IC card 100 to the outside. For example, an encryption process is performed so that the contents of communication with the PC 200 by radio waves are not read by a third party.

  The decode key transmission processing unit (decode key transmission means) 145 performs processing for transmitting a decode key corresponding to the content ID to the PC 200. A duplicate decode key request reception processing unit (duplicate decode key request receiving means) 146 performs a process of accepting a duplicate decode key request from the PC 200.

  The duplicate decode key transmission processing unit (duplicate decode key transmission means) 147 performs a process of transmitting a duplicate decode key corresponding to the content ID to the PC 200.

  The decoding key reception processing unit 148 and the content providing server 310 perform processing for storing the decoding key, the duplicate decoding key, and the like received via the PC 200 in the storage unit 110.

  The electronic money balance confirmation processing unit 149 is a function used when charging processing is performed by the IC card 100. The electronic money balance confirmation processing unit 149 confirms information on the electronic money balance 130 recorded in the storage unit 110, and when there is an electronic money balance As long as the transmission of the decoding key or the like to the PC 200 is permitted, and the transmission of the decoding key or the like is permitted, the electronic money balance is updated (counted down).

The PC (or content playback apparatus) 200 has a processing unit shown below.
The encrypted content reading processing unit 211 reads the encrypted content recorded on a portable recording medium such as a DVD-ROM in the PC 200 and stores it in the storage unit 230.

  The content ID reading processing unit (content ID reading unit) 212 performs processing for acquiring a content ID from the encrypted content stored in the storage unit 230.

  The decode key transmission request processing unit (decode key transmission request means) 213 performs processing for transmitting a “decode key transmission request” to the IC card 100 together with information on the content ID of the encrypted content to be decoded.

  The decode key reception processing unit (decode key receiving means) 214 performs a process of receiving a decode key corresponding to the content ID from the IC card 100. The encryption processing unit 215 performs processing for encrypting information that the PC 200 communicates with the IC card 100.

  The authentication processing unit (mutual authentication unit) 216 performs processing for performing mutual authentication with the IC card 100. The copy decoding key transmission request processing unit 217 transmits a “duplication decoding key transmission request” to the IC card 100 together with information on the content ID to be copied, when copying the encrypted content. I do.

  The duplicate decode key reception processing unit 218 performs a process of receiving a duplicate decode key from the IC card 100. The content duplication processing unit 219 performs a process for duplicating the encrypted content using the duplication decoding key acquired from the IC card 100.

  The decode processing unit 220 performs a process of decoding the encrypted content using the decode key acquired from the IC card 100. The encrypted content download processing unit 221 performs processing for downloading the encrypted content from the content providing server 310 via the communication network 1.

  The purchase request processing unit 222 such as a decode key performs a process of transmitting a “decode key purchase request” to the content providing server 310 when purchasing a decode key, a duplicate decode key, or the like. The decoding key reception processing unit 223 receives a decoding key, a duplicate decoding key, and the like from the content providing server 310 and performs a process of writing to the IC card 100.

Further, the content providing server 310 has a processing unit shown below.
The content download request acceptance processing unit 311 performs processing for accepting an “encrypted content download request” from the PC 200. The content transmission processing unit 312 performs processing for transmitting the encrypted content to the PC 200.

  The decoding key etc. purchase request acceptance processing unit 313 performs processing for accepting a “decoding key etc. purchase request” from the PC 200. Here, the decode key or the like that accepts a purchase request is, for example, a decode key for each content ID, a duplicate decode key, the number of permitted copies, and the like.

  The authentication processing unit 314 receives the information of the IC card 100 via the PC 200 when the “decode key purchase request reception processing unit 313” receives the “decode key purchase request”, and checks the validity of the IC card 100. Perform authentication process.

  The decoding key transmission processing unit 315 transmits information such as a decoding key requested for purchase to the IC card 100 via the PC 200 when the authentication processing unit 314 authenticates the validity of the IC card 100. I do.

  Further, the database 320 of the content providing server 310 stores encrypted content information 321 and information 322 such as a decode key for each content ID and each user's IC card 100. For example, information on a decode key, a copy decode key, a copy permission count, and the like are stored.

  The functions of the decode key purchase request reception processing unit 313, the authentication processing unit 314, and the decode key transmission processing unit 315 that receive purchase requests for the decode key and the like in the content providing server 310 are different from those of the content providing server 310. You may make it provide independently in this server.

  Although the embodiment of the present invention has been described above, in the present invention, by storing the decode key in a recording medium such as an IC card, a legitimate consumer can use the content without restriction. Further, by setting permission conditions stored in the IC card, it is possible to provide detailed contents according to the user's needs, such as accounting support in the network system, copying permission, number of times restrictions, usage range restrictions, and the like.

  In addition, by recording customer information (history, usage information such as trends) on the IC card and using the information stored in the IC card, it is possible to transmit information in a double direction between the content provider and the user. Become. In that case, by using the information of the encryption key of the IC card as it is, the information can be protected and impersonation and tampering can be prevented.

  Although the embodiment of the present invention has been described above, the unauthorized copy prevention recording medium and the PC (content reproduction apparatus) are not limited to the above-described illustrated examples, and do not depart from the spirit of the present invention. Of course, various changes can be made.

  In the present invention, an unauthorized copy prevention recording medium such as an IC card is used, and a legitimate user can use unrestricted content, and setting of permission conditions stored in an unauthorized copy prevention recording medium such as an IC card. Therefore, it is possible to provide fine-grained content according to the user's needs, such as content duplication permission and number-of-times restrictions, etc., and can be applied to unauthorized copy prevention recording media, content playback devices, unauthorized copy prevention methods, programs, etc. Useful.

It is a figure which shows the outline | summary of the unauthorized copy prevention system by this invention. It is a figure which shows the example of the IC card (recording medium for illegal copy prevention) used for the unauthorized copy prevention system of this invention. It is a figure which shows the flow of a process of the unauthorized copy prevention system of this invention. It is a figure which shows the process sequence in the case of giving the replication permission of content. It is a figure which shows the procedure which downloads the decoding key of the encrypted content from a content provision server. It is a figure which shows the function which each system which comprises the unauthorized copy prevention system of this invention has.

Explanation of symbols

1 Communication Network 100 IC Card 110 Storage Unit 120 Content ID
121 Decode Key 122 Copy Permission Count 123 Duplicated Decode Key 130 Electronic Money Balance 141 Decode Key Request Reception Processing Unit 142 Authentication Processing Unit 143 Duplication Permission Count Determination Processing Unit 144 Encryption Processing Unit 145 Decode Key Transmission Processing Unit 146 Duplicate Decode Key Request Reception Processing Unit 147 Duplicated Decode Key Transmission Processing Unit 148 Decode Key Receiving Processing Unit 149 Electronic Money Balance Confirmation Processing Unit 200 PC (Content Playback Device)
201 Reader / Writer 211 Encrypted Content Reading Processing Unit 212 Content ID Reading Processing Unit 213 Decoding Key Transmission Request Processing Unit 214 Decoding Key Reception Processing Unit 215 Encryption Processing Unit 216 Authentication Processing Unit 217 Duplicated Decoding Key Transmission Request Processing Unit 218 Duplicated Decoding Key Reception processing unit 219 Content duplication processing unit 220 Decoding processing unit 221 Encrypted content download processing unit 222 Decoding key etc. purchase request processing unit 223 Decoding key etc. reception processing unit 230 Storage unit of content playback device 310 Content providing server 311 Content download request acceptance Processing unit 312 Content transmission processing unit 313 Decoding key etc. purchase request reception processing unit 314 Authentication processing unit 315 Decoding key etc. transmission processing unit 320 Database 321 Content information 322 decoding key information such as

Claims (6)

An unauthorized copy prevention recording medium used in a content reproduction device for decrypting encrypted content using a decode key,
Decode key holding means for holding a decode key for decrypting the encrypted content for each content ID of the encrypted content;
Mutual authentication means for performing mutual authentication with the content reproduction device;
Decode key request receiving means for receiving a content ID information from the content reproduction apparatus and a decode key transmission request corresponding to the content ID;
And a decoding key transmission unit that transmits a decoding key of the requested content ID to the content reproduction device when the mutual authentication with the content reproduction device is normally performed by the mutual authentication unit. Copy prevention recording medium. In the unauthorized copy prevention recording medium,
Copy permission count holding means for holding information on the number of copies allowed for each content ID of encrypted content;
A copy decode key holding means for holding a copy decode key for copy for each content ID of the encrypted content;
A copy decode key request receiving means for receiving a content ID information from the content reproduction apparatus and a copy decode key transmission request corresponding to the content ID;
When the copy decoding key request receiving means receives a copy decoding key transmission request from the content reproduction apparatus, it is determined whether or not there is a remaining copy permission count by referring to the copy permission count information corresponding to the content ID. Means for determining the permitted number of times to copy,
When the mutual authentication with the content reproduction apparatus is normally performed by the mutual authentication means, and the copy permission number confirmation means determines that there is a remaining number of times of copy permission, the content ID requested by the content reproduction apparatus is The unauthorized copy prevention recording medium according to claim 1, further comprising: a duplicate decode key transmitting unit that transmits a duplicate decode key. The unauthorized copy prevention record according to claim 1 or 2, wherein the encrypted content is content encrypted with a public key, and the decoding key and the duplicate decoding key are secret keys. Medium. A content playback device that holds encrypted content and decrypts it using a decode key,
Mutual authentication means for performing mutual authentication with the unauthorized copy prevention recording medium;
Content ID reading means for reading the content ID of the encrypted content to be reproduced;
Decoding key transmission requesting means for transmitting the content ID information read by the content ID reading means and a decoding key transmission request corresponding to the content ID to an unauthorized copy prevention recording medium holding a decoding key for each content ID. When,
A decoding key receiving means for receiving a decoding key of the requested content ID from the unauthorized copy prevention recording medium when the mutual authentication with the unauthorized copy prevention recording medium is normally performed by the mutual authentication means; A content playback apparatus comprising: By using a recording medium for preventing unauthorized copying, which is used in a content reproduction device that decrypts encrypted content using a decode key,
A decoding key holding procedure for holding a decoding key for decoding the encrypted content for each content ID of the encrypted content;
A mutual authentication procedure for performing mutual authentication with the content reproduction device;
A decode key request reception procedure for receiving a content ID information from the content reproduction device and a decode key transmission request corresponding to the content ID;
When the mutual authentication with the content reproduction apparatus is normally performed by the mutual authentication procedure, a decode key transmission procedure for transmitting a decode key of the requested content ID to the content reproduction apparatus is performed. Illegal copy prevention method. In a computer in an unauthorized copy prevention recording medium used in a content reproduction device for decrypting encrypted content using a decode key,
A decoding key holding procedure for holding a decoding key for decoding the encrypted content for each content ID of the encrypted content;
A mutual authentication procedure for performing mutual authentication with the content reproduction device;
A decode key request reception procedure for receiving a content ID information from the content reproduction device and a decode key transmission request corresponding to the content ID;
A program for executing a decode key transmission procedure for transmitting a decode key of a requested content ID to the content reproduction device when mutual authentication with the content reproduction device is normally performed by the mutual authentication procedure.

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