JP2002288376A - Contents providing method and data reproducing device and data recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a contents providing method for distributing enciphered contents data divided into a plurality of blocks and a plurality of licenses for decoding and reproducing the enciphered data included in those blocks. SOLUTION: Enciphered contents data 90 or 93 obtained by enciphering music data are composed of trial enciphered music data 91 or 94 and main enciphered music data 92 or 95. The enciphered music data 91 and 94 are decoded by a license key Kc1, and the enciphered music data 92 and 95 are decoded by a license key Kc2. A distributing server holds the enciphered contents data 90 and 93 and the license keys Kc1 and Kc2, and distributes the trial enciphered music data 91 or 94 and the license key Kc1, and the main enciphered music data 92 or 95 and the license key Kc2 in this order in response to a distribution request.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a content providing method, a data reproducing apparatus, and a data recording apparatus in a data distribution system capable of protecting copyright of copied information.

[0002]

2. Description of the Related Art In recent years, with the advancement of digital information communication networks such as the Internet, it has become possible for each user to easily access network information using personal terminals using cellular phones and the like.

In such a digital information communication network, information is transmitted by digital signals. Therefore, for example, even when music or video data transmitted in the information communication network described above is copied by each individual user, the data is copied with almost no deterioration in sound quality or image quality due to such copying. It is possible.

[0004] Therefore, when content data such as music data and image data, etc., for which a writer's right exists, is transmitted over such a digital information communication network, no appropriate copyright protection measures have been taken. In this case, the rights of the copyright holder may be significantly infringed.

On the other hand, giving priority to the purpose of copyright protection,
If it is not possible to distribute content data through the rapidly expanding digital information communication network, basically, even for copyright owners who can collect a certain copyright fee when copying content data, On the contrary, it is disadvantageous.

Here, considering not a distribution via the digital information communication network as described above but a recording medium on which digital data is recorded as an example, a CD (compact disc) on which music data which is usually sold is recorded is considered. Regarding (2), music data can be freely copied from a CD to a magneto-optical disk (MD or the like) in principle as long as the copied music is stopped for personal use. However, an individual user who performs digital recording or the like indirectly pays a certain amount of the price of the digital recording device itself or a medium such as an MD as a deposit to the copyright holder.

Furthermore, when music data as a digital signal is copied from a CD to an MD, the music information is transferred from a recordable MD to another MD in consideration of the fact that the information is digital data with little copy deterioration. Copying as digital data is not possible due to copyright protection due to equipment configuration.

[0008] Even in such circumstances, distributing music data and image data to the public through a digital information communication network is itself an act limited by the public transmission right of the copyright holder. Sufficient measures need to be taken.

In this case, for content data such as music data and image data which are copyrighted works transmitted to the public through a digital information communication network, once received content data is prevented from being copied without permission. Is required.

[0010] Therefore, a distribution server that holds encrypted content data obtained by encrypting the content data is a data server that distributes the encrypted content data to a memory card mounted on a terminal device such as a mobile phone via the terminal device. A distribution system has been proposed. In this data distribution system, a public encryption key of a memory card and a certificate thereof, which have been authenticated by a certificate authority in advance, are transmitted to a distribution server at the time of a distribution request of encrypted content data. After confirming the reception, the encrypted content data and the license key for decrypting the encrypted content data are transmitted to the memory card. When distributing the encrypted content data and the license key, the distribution server and the memory card generate a different session key for each distribution, and encrypt the public encryption key with the generated session key. The keys are exchanged between the memory cards.

[0011] Finally, the distribution server transmits the license encrypted by the public encryption key of each memory card and further encrypted by the session key, and the encrypted content data to the memory card. Then, the memory card records the received license and the encrypted content data.

When playing back the encrypted content data recorded on the memory card, the user inserts the memory card into the portable telephone. The mobile phone has a dedicated circuit for decrypting the encrypted content data from the memory card and reproducing and outputting the decrypted content data to the outside in addition to the normal telephone function.

As described above, the user of the mobile phone can use the mobile phone to receive the encrypted content data from the distribution server and reproduce the encrypted content data.

In the distribution of encrypted content data, for example, music data is separated into encrypted music data for trial listening and encrypted music data for distribution, and music data for trial listening is first distributed. As a result of decrypting and reproducing the music data for trial listening and listening, the encrypted music data for distribution and the license are distributed when it is desired to distribute the encrypted music data for distribution and the license. In such a case, the sound quality of the trial music data is inferior to that of the main body music data, and even if the trial music data is downloaded, the right of the copyright holder is not impaired.

[0015]

However, the user can specify the music data to be purchased using the music data for trial listening, but cannot confirm the sound quality of the music data for distribution provided. Further, there is no guarantee that the music data for trial listening and the music data for distribution are the same.

Such a problem is not limited to music data.
The same occurs in the distribution of content data such as reading data, teaching material data, video data, and games.

Furthermore, in content data such as reading data, teaching material data, and games, all data is not purchased at once. For example, reading data is read for each chapter, and teaching data or games are read for each stage. When distribution is performed in response to a user's distribution request, there is a problem that it is difficult to collectively manage content data due to distribution performed in a plurality of times.

Accordingly, the present invention has been made to solve such a problem, and has as its object to decrypt encrypted content data separated into a plurality of areas and encrypted data contained in the plurality of areas. And a content providing method for distributing a plurality of licenses for reproduction.

It is another object of the present invention to provide a data reproducing apparatus capable of reproducing encrypted content data divided into a plurality of areas by a plurality of licenses.

Still another object of the present invention is to provide a data recording device that records encrypted content data divided into a plurality of areas and a plurality of licenses.

[0021]

According to the present invention, a content providing method includes a first step of receiving a request to obtain encrypted content data obtained by encrypting content data, and a step of receiving the request received in the first step. A second step of providing the encrypted content data in response to the request, and a third step of receiving a request to provide a first license corresponding to a part of the encrypted content data and decrypting the part. And providing a first license in response to the provision request received in the third step.
And a request for providing a second license for decrypting the other part corresponding to another part different from the first license and not corresponding to the first license of the encrypted content data. A fifth step of receiving, a sixth step of providing a second license in response to the provision request received in the fifth step, and a seventh step of performing a charging process for provision of the second license. Steps.

Preferably, the encrypted content data, the first license, and the second license are distributed from the same server.

Preferably, the encrypted content data and the first license are distributed from a first server, and the second license is distributed from a second server different from the first server.

[0024] Preferably, the encrypted content data and the first license are supplied to the first server via a recording medium.

[0025] Preferably, the encrypted content data is provided from a first server, and the first and second licenses are distributed from a second server different from the first server.

Preferably, the encrypted content data is
The information is supplied to the first server via the recording medium.

Preferably, in the third step, the authentication data is received together with the provision request, and when the authentication data is authenticated, the first license is provided. In the fifth step, the authentication data is received together with the provision request. And providing a second license when the authentication data is authenticated.

According to the invention, the data reproducing apparatus is a data reproducing apparatus for decrypting and reproducing encrypted content data composed of a plurality of blocks with a plurality of licenses corresponding to the plurality of blocks. An interface for exchanging content data and a data recording device on which a plurality of licenses are recorded, an operation unit for inputting an instruction, and a content reproduction unit for decrypting and reproducing the encrypted content data with the plurality of licenses; And a control unit. The control unit, in the content reproduction unit, generates an n-th license in which the encrypted data included in the n-th (n is a natural number) block forming the encrypted content data corresponds to the n-th block License is being decoded and played back by Providing the content playback unit to acquire from the data recording apparatus via the over scan.

Preferably, the content reproducing section holds a first license key holding section for holding an n-th license key included in the n-th license, and holds an (n + 1) -th license key included in the (n + 1) -th license. Second
And the n-th license key and the (n + 1) -th license key are selectively obtained from the first and second license key holding units, and the corresponding encrypted data is decrypted by the obtained license keys. A decoding unit that performs
And a reproducing unit for reproducing the content data decoded by the decoding unit.

Preferably, the control unit acquires the key change information from the data recording device via the interface, selects the nth license key and the (n + 1) th license key based on the key change information, and sends the selected key to the decryption unit. give.

Preferably, in a session for acquiring each of a plurality of licenses from the data recording device, a session key generating unit for generating a different session key, a session key generated by the session key generating unit, and receiving the session key by the session key A license key decryption unit for decrypting the encrypted license key and providing the decrypted license key to the first or second license key holding unit, wherein the control unit stores the session key generated by the session key generation unit. The data is input to the data recording device via the interface, the encrypted license key encrypted by the session key is obtained from the data recording device via the interface, and given to the license key decryption unit.

Preferably, the data reproducing apparatus further includes a data transmitting / receiving section for performing communication for downloading a license key from a license distribution server providing the license key, and the control section reproduces all of the encrypted content data. When the license required for the data recording device is not recorded, only blocks that can be reproduced by a plurality of licenses corresponding to the encrypted content data stored in the data recording device, according to the reproduction order of the encrypted content data, The license key corresponding to the block constituting the encrypted content data is obtained from the license distribution server via the data transmission / reception unit in accordance with a new license key acquisition instruction input from the operation unit. Received and the received license To record the scan key to the data recording device.

Further, according to the present invention, the data recording apparatus records the encrypted content data including a plurality of blocks and the plurality of licenses for decrypting the plurality of encrypted data included in the plurality of blocks. The recording apparatus stores a license area for storing a plurality of licenses, encrypted content data, and license correspondence information indicating correspondence between each of the plurality of licenses and a plurality of blocks constituting the encrypted content data. A data area.

[0034]

Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding portions have the same reference characters allotted, and description thereof will not be repeated.

FIG. 1 is a schematic diagram for conceptually explaining the overall configuration of a data distribution system in which a data recording device according to the present invention acquires encrypted content data.

In the following, digital music data is distributed to a memory card 110 mounted on a user's mobile phone via a mobile telephone network, or digital music data is distributed to a memory card 110 mounted on a card writer via the Internet. An example of the configuration of a data distribution system will be described, but as will be apparent from the following description, the present invention is not limited to such a case, and content data as another copyrighted work, for example, image data, The present invention can also be applied to the case of distributing moving image data and the like.

Referring to FIG. 1, distribution carrier 20 relays a distribution request (distribution request) from a user obtained through his / her own mobile telephone network to distribution server 10. The distribution server 10 that manages copyrighted music data includes:
Whether the memory card 110 attached to the mobile phone 100 of the mobile phone user who has accessed for data distribution has valid authentication data, that is, whether the memory card 110 is a regular memory card having a content protection function Authentication processing is performed, and the encrypted content data and the license are given to a mobile phone company that is a distribution carrier 20 that distributes a license for decrypting the encrypted content data to an authorized memory card.

The distribution carrier 20 transmits the encrypted content data and the license to the memory card 110 attached to the cellular phone 100 which has transmitted the distribution request via its cellular phone network, via the cellular phone network and the cellular phone 100. To deliver.

In FIG. 1, for example, a detachable memory card 11 is attached to a portable telephone 100 of a portable telephone user.
0 is attached. Memory card 110
Receives the encrypted content data received by the mobile phone 100, decrypts the encryption performed for the distribution, and provides the data to a music playback unit (not shown) in the mobile phone 100.

Further, for example, a portable telephone user can “play” such content data via the headphone 130 or the like connected to the portable telephone 100 and listen to it.

With such a configuration, first, unless the memory card 110 is used, it is difficult to receive the distribution of the content data from the distribution server 10 and reproduce the music.

In addition, the distribution carrier 20 counts the frequency each time content data of, for example, one song is distributed, so that a mobile phone user receives (downloads) content data and receives a copyright fee. Is collected by the distribution carrier 20 together with the communication charge of the mobile phone, the copyright holder can easily secure the copyright charge.

In the data distribution system shown in FIG. 1, the encrypted content data {Dc} Kc includes a trial listening area {Dc1} Kc1 which is an area encrypted by the license key Kc1 and a license key. It is composed of a main area {Dc2} Kc2 encrypted with Kc2, and is configured as one piece of encrypted content data. Therefore, a trial license requires a trial license including the license key Kc1, and reproduction of the entire content requires a trial license and a main body license including the license key Kc2.

The distribution server 10 first transmits the trial content license including the encrypted content data {Dc} Kc and the license key Kc1 to the mobile phone 10 via the mobile phone network.
Deliver to 0. Then, in the content reproduction circuit (not shown) provided in the mobile phone 100, the user
The trial listening area {Dc1} Kc1, which is a part of the encrypted content data {Dc} Kc, is decrypted by the license key Kc1 of the trial license and listens to the reproduced music. If the user wants to download this content, it is distributed again. The server 10 transmits a license distribution request to the server 10. Then, distribution server 10 distributes the main body license including license key Kc2 to mobile phone 100 via the mobile phone network in response to the received distribution request.

Then, the content reproduction circuit of the portable telephone 100 uses the license key Kc1 included in the trial license and the license key K included in the main body license.
All of the encrypted content data {Dc} Kc can be reproduced using c2.

In FIG. 1, the distribution server 10
Distributes a trial listening license including the encrypted content data {Dc} Kc and the license key Kc1 to the personal computer 50 via the Internet network 30. And the personal computer 50 is a USB
(Universal Serial Bus) A distribution request for a trial license including the encrypted music data {Dc} Kc and the license key Kc1 is received via the cable 70 and the card writer 80, and the validity of the memory card 110 attached to the card writer 80 is verified. Is determined by the same method as described above, and a trial listening license including the encrypted music data {Dc} Kc and the license key Kc1 is recorded on a proper memory card. Then, the memory card 11
0 is removed from the card writer 80 and the mobile phone 100
Attached to. The user of the mobile phone 100 reads the encrypted music data {Dc} K from the attached memory card 110.
c and the license key Kc1 are read out, and the area {Dc1} Kc1 that can be decrypted by the license key Kc1 which is a part of the encrypted music data {Dc} Kc is decrypted and reproduced for trial listening. Then, the user enters the encrypted music data $ D
When you want to download the license for the main unit including the license key Kc2 to reproduce all of c @ Kc,
A distribution request for the main body license including the license key Kc2 is transmitted to the distribution server 10 via the mobile phone network 30.
Then, the distribution server 10 returns to the memory card 1 again.
After confirming that 10 is a legitimate memory card, the main body license including the license key Kc2 is distributed to the mobile phone 100 via the mobile phone network. Then, the mobile phone 100 records the received main body license including the license key Kc2 on the memory card 110. The user decrypts and reproduces the entirety of the encrypted music data {Dc} Kc recorded on the memory card 110 using the mobile phone 100 using the license key Kc1 and the license key Kc2.

The CD-ROM 60 stores encrypted content data {Dc} Kc and encrypted content data {Dc}.
A trial license including a license key Kc1 for decrypting the trial listening area {Dc1} Kc1 of Kc is recorded. The personal computer 50 has a CD-ROM 6
From 0, the encrypted content data {Dc} Kc and the trial listening license are read. Then, the personal computer 50 checks the validity of the memory card 110 attached to the card writer 80 via the card writer 80 and the USB cable 70, and records the trial listening license including the license key Kc1 on the authorized memory card. . Then, the memory card 110 is removed from the card writer 80 and is mounted on the mobile phone 100. Mobile phone 100
Of the encrypted music data {Dc} Kc in the listening area {Dc
1 @ Kc1 and the license key Kc1 are read, and a part of the encrypted music data {Dc} Kc is decrypted and reproduced for trial listening. When the user desires to download the main body license including the license key Kc2, the license key Kc is transmitted to the distribution server 10 via the mobile phone network 30.
2 is transmitted.

Then, after confirming that memory card 110 is a proper memory card, distribution server 10 distributes the main body license including license key Kc2 to portable telephone 100 via the portable telephone network. And
The mobile phone 100 records the received license key Kc2 on the memory card 110. The user can use the mobile phone 10
0, the encrypted music data {Dc} Kc, license key Kc1 and license key Kc2 recorded on the memory card 110 are read out and the encrypted content data {D
Play all c｝ Kc.

At this time, the trial listening license recorded on the CD-ROM 60 is recorded after being encrypted, and must be accessible only by a dedicated program for recording the license on the memory card 110. is there. Even if the license on the CD-ROM 60 is copied as it is, it cannot be used to reproduce the encrypted content data {Dc} Kc.

Further, the CD-ROM 60 records only the encrypted music data {Dc} Kc. The personal computer 50 reads the encrypted music data {Dc} Kc from the CD-ROM 60. Then, the personal computer 50 records the encrypted music data {Dc} Kc on the memory card 110 via the card writer 80 and the USB cable 70. Then, the memory card 110
Is removed from the card writer 80 and attached to the mobile phone 100. The user of the mobile phone 100 reads the encrypted music data {D} recorded on the attached memory card 110.
The distribution server 10 requests the distribution server 10 to distribute a trial listening license for c @ Kc via the mobile phone network and the distribution carrier 20.

In the data distribution system shown in FIG. 1, the encrypted content data {Dc} Kc is composed of a trial area {Dc1} Kc1 which is an area encrypted by the license key Kc1 and a license key. It is composed of a main area {Dc2} Kc2 encrypted with Kc2, and is configured as one piece of encrypted content data. Therefore, the trial listening requires a trial listening license including the license key Kc1, and the reproduction of the entire content requires a trial listening license and a main body license including the license key Kc2.

The distribution server 10 first transmits the trial content license including the encrypted content data {Dc} Kc and the license key Kc1 to the mobile phone 10 via the mobile phone network.
Deliver to 0. Then, in the content reproduction circuit (not shown) provided in the mobile phone 100, the user
If you want to listen to the music that has been decrypted and reproduced by the trial key license key Kc1 which is a part of the encrypted content data {Dc} Kc, and download this content,
The distribution request for the main body license is transmitted to the distribution server 10 again. Then, distribution server 10 distributes the main body license including license key Kc2 to mobile phone 100 via the mobile phone network in response to the received distribution request.

Then, the content reproduction circuit of portable telephone 100 can reproduce all of the encrypted content data {Dc} Kc using license key Kc1 included in the trial license and Kc2 included in the main body license. .

Although not described, the main body license can be acquired by the personal computer 50 via the Internet 30 and recorded on the memory card 110 in the same manner as the trial listening license. When delivering a trial listening license or a main body license to the personal computer 50 via the Internet network 30, encrypted communication is used.

As described above, the memory card 110 obtains the encrypted music data {Dc} Kc, the trial listening license including the license key Kc1, and the main body license including the license key Kc2 by various methods.

In the configuration as shown in FIG. 1, in order for the content data distributed in an encrypted form to be reproducible on the user side of the portable telephone, the system firstly requires communication. The second is the method itself for encrypting the content data to be distributed, and the third is the unauthorized copying of the content data thus distributed. This is a configuration for implementing content data protection for prevention.

In the embodiment of the present invention, especially when each session of distribution and reproduction occurs, the authentication and checking functions for the destination of these content data are enhanced, and the non-authentication or decryption key is broken. A configuration for enhancing the copyright protection of content data by preventing output of content data to a recording device and a data playback terminal (a data playback terminal capable of playing content is also referred to as a mobile phone; the same applies hereinafter) will be described.

In the following description, content data (encrypted content data and license) is transmitted from distribution server 10 to a memory card via each mobile phone or from a personal computer to a memory card via a card writer. The processing will be referred to as “delivery”.

FIG. 2 is a diagram for explaining characteristics of data, information, and the like for communication used in the data distribution system shown in FIG.

First, data distributed from the distribution server 10 will be described. Dc is content data such as music data. The content data Dc is encrypted so as to be decryptable with the license key Kc. The content data Dc includes a trial listening area Dc1 and a main body area Dc2, each of which is encrypted with a different encryption key. The trial area Dc1 is a trial area {Dc1} Kc1 encrypted by the license key Kc1 and the main area Dc2 is an encrypted main area {Dc2 decryptable by the license key Kc2. ｝
One encrypted content data {Dc} K as Kc2
Construct c. Content data Dc is always distributed to mobile phone 100 or personal computer 50 as encrypted content data {Dc} Kc. As a result, as a whole, the content data D
c is the license key Kc (consisting of Kc1 and Kc2)
The content is distributed from the distribution server 10 to the user of the mobile phone 100 or the personal computer 50 as encrypted content data {Dc} Kc that has been subjected to encryption.

In the following, it is assumed that the notation {Y} X indicates that the data Y has been encrypted with the decryption key X.

Referring to FIG. 3, information database 304
The format of the encrypted content data {Dc} Kc held by is described. When the encrypted content data {Dc} Kc is encrypted music data, the encrypted content data {Dc} Kc has a format shown in FIG. The encrypted music data 90 includes a trial listening area 91 ({Dc1} Kc1) and a main body area 92 ({Dc2}).
Kc2). Audition area 91 ({Dc1} Kc
1) can be decrypted using the license key Kc1.
The main body area 92 ({Dc2} Kc2) contains the license key K
It can be decoded by c2. Audition area 91 (｛Dc
1 @ Kc1) is the encrypted content data {Dc} Kc
, The body region 92 ({Dc2} Kc2) is divided into two. In this case, the encrypted music data 91 for trial listening is composed of rust of the music. Audition area 91 (｛Dc
1｝ Kc1) is shown as one continuous area,
Similarly to the main body area 92 (｛Dc2｝ Kc2), the area may be divided by the main body area 92 (｛Dc2｝ Kc2).

Further, the encrypted content data {Dc} K
c may have the format shown in FIG. The encrypted music data 93 includes encrypted music data 94 for trial listening and encrypted music data 95 for the main body. The encrypted music data 94 for trial listening has a license key K
It can be decoded by c1. The encrypted music data 95 for the main body can be decrypted by the license key Kc2. The encrypted music data 94 for trial listening is included at the beginning of the encrypted content data {Dc} Kc. In this case, the encrypted listening music data 94 is composed of a song intro.

Referring to FIG. 4, generation of encrypted content data {Dc} Kc84 will be described. Blocks BLK1, B having a fixed length of M bytes, which is a minimum encryption unit, are used as source data Dc81, which is plaintext content data.
LK2,..., BLKk divided into block data 8
2 is generated (k is a natural number). When the last block BLKk is less than M bytes, meaningless dummy data is added to the end of the data to form an M-byte block (hatched portion). Then, the blocks BLK1, BLK2,
.., BLKk are individually encrypted to generate encrypted data 83. At this time, it is determined which of the license keys Kc1 and Kc2 corresponds to each block. The correspondence between the license key and the block is determined by the additional information Dc-
It is recorded as license key correspondence information in inf. Then, blocks BLK1, BLK2,..., BLKk
Of the encrypted content data {D
Generate cεKc84. That is, the block BLK1
Consists of a header 841 and encrypted data 842,
The block BLK2 includes a header 843 and encrypted data 84.
4, and the block BLKk includes a header 845 and encrypted data 846. Headers 841, 843
Reference numeral 845 denotes N-byte data, in which a scramble flag indicating whether the block is an encrypted block or an unencrypted block is recorded. That is, the headers 841, 843, and 845 include “1” indicating an encrypted block or “0” indicating an unencrypted block. Therefore, the encrypted content data shown in FIG. 3 has the data format shown in FIG.
The trial listening area and the main body area are constituted by a plurality of non-overlapping blocks.

Referring again to FIG. 2, the distribution server 10 sends the encrypted content data together with license key correspondence information for the encrypted content data, information on the copyright of the content data, or plaintext information such as server access related information. Is distributed as additional information Dc-inf. Also, the license key K
c, a license ID, which is a management code for specifying a license key or the like from the distribution server 10,
And the mobile phone 100 or the personal computer 5
0 and is recorded on the memory card 110 together with the license key Kci. Further, the license is based on a content ID, which is a code for identifying the content data Dc, and a license purchase condition AC including information such as a license type and a function limitation determined by designation from the user side. There are generated access control information ACm which is information relating to restrictions on license access in the recording device (memory card) and reproduction control information ACp which is control information relating to reproduction in the data reproducing terminal. Specifically, the access control information ACm is control information for outputting a license or a license key from the memory card to the outside, and includes the number of reproducible times (the number of outputting the license key for reproduction) and the license. Restriction information on transfer / replication of data. The reproduction control information ACp is
This is information for restricting the reproduction after the content reproduction circuit receives the license key for reproduction, and includes a reproduction time limit, a restriction on a change in reproduction speed, and a reproduction range specification (partial license).

Thereafter, the content ID and the license key Kc
i (i = 1, 2), license ID, access control information ACm, and reproduction control information ACp are collectively referred to as a license. The license including the license key Kc1 is a trial license, and the license including the license key Kc2 is a main body license.

Hereinafter, for the sake of simplicity, the access control information ACm includes the number of times of reproduction (0: reproduction impossible, 1-254: number of times reproduction possible,
255: no restriction), a move / copy flag for restricting the transfer and duplication of the license (1: move / copy not possible, 2: move only, 3: move / copy prohibited), and the reproduction control information ACp can be reproduced. It is assumed that only the playback time limit (UTCtime code), which is control information for defining the time limit, is limited.

FIG. 5 is a diagram for explaining characteristics of data, information, and the like for authentication used in the data distribution system shown in FIG.

The content reproduction circuit and the memory card are provided with unique public encryption keys KPpy and KPmw, respectively. The public encryption keys KPpy and KPmw are provided with a secret decryption key Kpy unique to the content reproduction circuit and a secret decryption unique to the memory card. Each can be decrypted with the key Kmw. These public encryption key and secret decryption key have different values for each type of content reproduction circuit and memory card. The public encryption key and the secret decryption key are collectively referred to as a class key, the public encryption key is referred to as a class public encryption key, the secret decryption key is referred to as a class secret decryption key, and a unit sharing the class key is referred to as a class. The class differs depending on the manufacturing company, the type of product, the lot at the time of manufacturing, and the like.

Further, a content reproducing circuit (a portable telephone,
Cpy is provided as the class certificate of the playback terminal, and Cmw is provided as the class certificate of the memory card.
These class certificates have different information for each class of the content reproduction circuit and the memory card. Classes in which the tamper-resistant module has been broken or the encryption with the class key has been broken, that is, the class in which the secret decryption key has been leaked, are listed in the prohibited class list and are subject to license prohibition.

The class public encryption key and the class certificate of these content reproduction circuits are provided by the authentication data {KPpy /
In the format of / Cpy @ KPa, the class public encryption key and class certificate of the memory card are authentication data $ KPmw //
The data is recorded in the data reproducing circuit and the memory card at the time of shipment in the format of Cmw @ KPa. As will be described in detail later, KPa is a public authentication key common to the entire distribution system.

Further, as keys for managing data processing in the memory card 110, a public encryption key KPmcx and a public encryption key K
There is a unique secret decryption key Kmcx capable of decrypting data encrypted with Pmcx. The public encryption key and the private decryption key for each memory card are collectively referred to as an individual key, the public encryption key KPmcx is referred to as an individual public encryption key, and the secret decryption key Kmcx is referred to as an individual secret decryption key.

Each time content data is distributed and reproduced, the distribution server 10, the cellular phone 100, and the memory are used as encryption keys for maintaining confidentiality in data exchange between the memory card and the outside of the memory card. Common key Ks1 generated in card 110
Ks3 is used.

Here, the common keys Ks1 to Ks3 are “sessions” which are units of communication or access between the distribution server, the content reproduction circuit or the memory card.
Each of the common keys Ks1 to Ks3 is also referred to as a “session key”.

The session keys Ks1 to Ks3
Has a unique value for each session,
It is managed by a distribution server, a content reproduction circuit, and a memory card. Specifically, the session key Ks
1 is generated by the distribution server for each distribution session. The session key Ks2 is generated for each distribution session and reproduction session by the memory card, and the session key Ks3 is generated for each reproduction session in the content reproduction circuit. In each session, these session keys are transmitted and received, a session key generated by another device is received, encryption is performed using the session key, and a license key or the like is transmitted. Can be improved.

In communication between the personal computer 50 and the memory card 110 via the card writer 80 and the USB cable 70, the functions of the distribution server 10 and the mobile phone 100 are replaced with the personal computer 50, and the memory card interface 1200 is used. May be replaced with the card writer 80 and the USB cable 70.

FIG. 6 is a schematic block diagram showing the configuration of distribution server 10 shown in FIG. The distribution server 10 includes an information database 304 for storing distribution information such as data obtained by encrypting content data according to a predetermined method and a content ID, and charging for each user of the mobile phone according to the start of access to the content data. A charging database 302 for storing information, a menu database 307 for storing a menu of content data stored in the information database 304, and a transaction ID and the like for specifying distribution of content data and license keys for each license distribution A distribution record database 308 holding a log relating to distribution, and data from the information database 304, the billing database 302, the menu database 307, and the distribution record database 308 are received via the bus BS1, and a predetermined process is performed. A data processing unit 310 for performing, via a communication network,
A communication device 350 for exchanging data between the distribution carrier 20 and the data processing unit 310 is provided.

When the encrypted content data {Dc} Kc is read-aloud data, teaching material data, or game software data, the encrypted content data {Dc} Kc has the format shown in FIG. The encrypted content data 96 includes a plurality of areas 961 to 967. Each of the areas 961 to 967 includes a license key Kc1, Kc2, Kc3, Kc4, Kc5, Kc6, K
Decoding is possible by c7.

When the encrypted content data {Dc} Kc is video data having an area to be tried in the same manner as the music data described above, the encrypted content data {Dc} Kc
c｝ Kc has the format shown in FIG. The encrypted data 97 includes an area 971 for attachment and an area 972 for main body. The attached area 971 can be decrypted using the license key Kc1. The main body area 972 can be decrypted by the license key Kc2. The attachment area 971 includes a video or game subtitle. Encrypted content data 96, 97
The decoding of the content reproduction circuit 15 shown in FIG.
50 are acceptable. In this case, the music playback unit 1520
Is replaced with a reproduction circuit suitable for each content.

The data processing unit 310 is controlled by the distribution control unit 315 for controlling the operation of the data processing unit 310 according to the data on the bus BS1 and the session key Ks1 during the distribution session. And the authentication data {KPmw /
/ Cmw @ KPa, an authentication key holding unit 313 for holding two types of public authentication keys KPa, and authentication data {KPmw /
/ Cmw @ KPa via communication device 350 and bus BS1, and receives public authentication key K from authentication key holding unit 313.
Pa, a decryption processing unit 312 that performs decryption processing, a session key generation unit 316 that generates a session key Ks1 for each distribution session, and a session key generation unit 31
Decrypts the session key Ks1 generated from
And an encryption processing unit 318 for encrypting using the class public encryption key KPmw obtained by step 12 and outputting the encrypted data to the bus BS1, and receiving data transmitted after being encrypted by the session key Ks1 from the bus BS1. And a decoding processing unit 320 that performs a decoding process.

Data processing section 310 further encrypts license key Kc and access control information ACm provided from distribution control section 315 with individual public encryption key KPmcx for each memory card obtained by decryption processing section 320. The encryption processing unit 326 and the output of the encryption processing unit 326 are further encrypted by the session key Ks2 given from the decryption processing unit 320, and the bus BS
1 and an encryption processing unit 328 for outputting the data to the output unit 1.

The operation of the distribution server 10 in a distribution session will be described later in detail using a flowchart.

FIG. 7 is a schematic block diagram for explaining the configuration of mobile phone 100 shown in FIG.

The mobile phone 100 includes a bus BS2 for transmitting and receiving data to and from each section of the mobile phone 100, an antenna 1101 for receiving a signal wirelessly transmitted by the mobile phone network, and a base for receiving a signal from the antenna. A transmitting / receiving unit 110 for converting to a band signal or modulating data from a mobile phone and giving the data to an antenna 1101
2 is included.

The mobile phone 100 further includes a microphone 11 for capturing voice data of the user of the mobile phone 100.
03 and an AD converter 1104 for converting audio data from the microphone 1103 from an analog signal to a digital signal.
And an audio encoding unit 1105 that modulates audio data from the AD converter 1104 into a predetermined method.

The portable telephone 100 further includes an antenna 1
Audio reproduction unit 1 for reproducing the audio data of another user of the mobile phone received via communication unit 101 and transmission / reception unit 1102
And a DA converter 1107 for converting data from the audio reproducing unit 1106 from a digital signal to an analog signal
And a speaker 1108 for outputting audio data from the DA converter 1107 to the outside.

The portable telephone 100 further includes a bus BS2
A controller 1109 for controlling the operation of the mobile phone 100 via the
An operation panel 1111 for giving 0 to the display unit and a display panel 1110 for giving information output from the controller 1109 and the like to the user as visual information.

[0103] The mobile phone 100 further stores content data (music data) from the distribution server 10,
In addition, it includes a removable memory card 110 for performing a decoding process, and a memory card interface 1200 for controlling the transfer of data between the memory card 110 and the bus BS2.

The mobile phone 100 further decrypts the class public encryption key KPp1 and the class certificate Cp1 with the public authentication key KPa to encrypt the data so that its validity can be authenticated {KPp1 // Cp1} KPa And an authentication data holding unit 1500 that holds the authentication data. Here, it is assumed that the class y of the reproduction terminal 102 is y = 1.

The portable telephone 100 further includes a Kp1 holding unit 1502 for holding a class-specific decryption key Kp1.
And a decryption processing unit 1504 that decrypts data received from the bus BS2 with Kp1 and obtains a session key Ks2 generated by the memory card 110.

[0091] Portable telephone 100 further has a session key Ks3 for encrypting data exchanged with memory card 110 over bus BS2 in a reproduction session for reproducing content data stored in memory card 110. And a session key generation unit 1508 for generating a license key Kc (consisting of Kc1 and Kc2; the same applies hereinafter) and playback control information ACp from the memory card 110 in a playback session of encrypted content data. An encryption processing unit 1506 that encrypts the session key Ks3 generated by the key generation unit 1508 with the session key Ks2 obtained by the decryption processing unit 1504, and outputs the encrypted data to the bus BS2.

The portable telephone 100 further includes a bus BS2
The above data is decrypted by the session key Ks3,
A decryption processing unit 1510 that outputs the license key Kc and the reproduction control information ACp, and a license key Kc1 or Kc2 output from the decryption processing unit 1510 in accordance with an instruction from the controller 1109, and a Kc holding unit 1514 via a terminal 1512. And a switch 1511 for outputting one of the license keys Kc1 and Kc2 to the Kc holding unit 1515 via the terminal 1513.

The mobile phone 100 further includes a terminal 151
And a license key different from the license key held by the Kc holding unit 1514 input from the terminal 1513, that is, the Kc holding unit 151.
4 holds the license key Kc1 and the license key K
and a Kc holding unit 1515 for holding c2.

The portable telephone 100 further includes a switch 1518 for selecting either the Kc holding unit 1514 or one of the two license keys Kc 1 and Kc 2 held in the Kc holding unit 1515 and outputting to the decryption processing unit 1519. . The switch 1518 includes a terminal 1516 for receiving a license key from the Kc holding unit 1514 and a Kc holding unit 151.
And a terminal 1517 for receiving a license key from the terminal 5.
The switch 1518 selects the terminal 1516 or the terminal 1517 according to an instruction from the controller 1109, and outputs the license key Kc1 or the license key Kc2 to the decryption processing unit 1519.

The portable telephone 100 further includes a bus BS2
Upon receiving the encrypted content data {Dc} Kc, the encrypted content data {Dc} Kc is received by the license key Kc1 or Kc2 input from the switch 1518.
And a decoding processing unit 1519 for decoding. When only the trial license is recorded on the memory card 110, only the trial listening area {Dc1} Kc1 that can be decrypted and reproduced with the license key Kc1 can be reproduced.

Further, mobile phone 100 further includes a music reproducing unit 1520 for reproducing the content data in response to the output from decoding processing unit 1519, and a DA for converting the output of music reproducing unit 1520 from a digital signal to an analog signal.
It includes a converter 1521 and a terminal 1522 for outputting the output of the DA converter 1521 to an external output device (not shown) such as a headphone.

In FIG. 7, the area surrounded by the dotted line constitutes a content reproducing circuit 1550 for decrypting the encrypted content data and reproducing the music data.

The operation of each component of the mobile phone 100 in each session will be described later in detail with reference to flowcharts.

FIG. 8 is a schematic block diagram for describing a configuration of memory card 110 shown in FIG.

As described above, KPmw is used as the class public encryption key and the class secret decryption key of the memory card.
And Kmw are provided, and the class certificate Cmw of the memory card is provided. In the memory card 110, it is assumed that a natural number w = 3. Also, a natural number x for identifying a memory card is represented by x = 4.

Therefore, memory card 110 holds authentication data holding section 1400 holding authentication data {KPm3 // Cm3} KPa and individual secret decryption key Kmc4 which is a unique decryption key set for each memory card. Kmc holding unit 1402, Km holding unit 1421 holding class secret decryption key Km3, and individual secret decryption key Kmc4
K holding public encryption key KPmc4 that can be decrypted by
Pmc holding unit 1416.

By providing an encryption key for a recording device called a memory card, management of distributed content data and an encrypted license key is executed for each memory card, as will be apparent from the following description. It becomes possible to do.

The memory card 110 further transmits a signal to the terminal 142 between the
14 and a bus BS for exchanging signals between the interface 1424
And a decryption processing unit 1422 that receives the class secret decryption key Km3 from the Km holding unit 1421 from the data supplied from the interface 1424 to the bus BS4, and outputs the session key Ks1 generated in the distribution session by the distribution server 10 to the contact point Pa. Receives the public authentication key KPa from the KPa holding unit 1414, executes a decryption process using the public authentication key KPa from the data supplied to the bus BS4, and outputs the decryption result and the obtained class certificate to the controller 142.
0, a decryption processing unit 1408 that outputs the obtained class public key to the encryption processing unit 1410, and a changeover switch 1442.
And an encryption processing unit 1406 for encrypting data selectively provided by the changeover switch 1446 with a key selectively provided by the switch and outputting the encrypted data to the bus BS4.

The memory card 110 further stores a session key Ks2 in each of the distribution and reproduction sessions.
And a session key Ks2 output from the session key generator 1418
Is encrypted by the class public encryption key KPpy or KPmw obtained by the decryption processing unit 1408 and the bus B
An encryption processing unit 1410 for sending to S4, a decryption processing unit 1412 for receiving data encrypted with the session key Ks2 from the bus BS4 and decrypting with the session key Ks2 obtained from the session key generation unit 1418;
The license key Kc and the playback control information ACp read from the memory 1415 in the playback session of the encrypted content data are converted into the individual public encryption key KPmcx (x
# 4) and an encryption processing unit 1417 for performing encryption.

The memory card 110 further includes a bus BS
4, a decryption processing unit 1404 for decrypting the data on the memory card 110 paired with the individual public encryption key KPmc4, the encrypted content data {Dc} Kc, and the encrypted content data {D
License for reproducing c @ Kc (Kc, ACp,
ACm, license ID, content ID) and a memory 1415 for receiving and storing the additional information Dc-inf from the bus BS4. The memory 1415 is configured by, for example, a semiconductor memory. Also, the memory 141
5 is a license area 1415A and a data area 141
5B. The license area 1415A is an area for recording a license. Data area 1415
B is an area for recording the encrypted content data {Dc} Kc and the additional information Dc-inf of the encrypted content data. The data area 1415B is
Externally accessible.

The memory card 110 further includes a bus BS.
4. Data is exchanged with the outside via bus 4 and bus BS
4 includes a controller 1420 for receiving playback information and the like and controlling the operation of the memory card 110.

The license area 1415A is configured as a tamper-resistant module area. The license area 1415A and the data area 1415B do not need to be configured in one memory 1415.
They may be configured separately. Further, the memory 1415
May be a license-only area without the data area 1415B.

The operation of each session in the data distribution system shown in FIG. 1 will be described below.

[Distribution for Preview] Distribution server 10 shown in FIG.
Stores encrypted music data {Dc} Kc, in the memory card 110 attached to the mobile phone 100 via the mobile phone network.
The operation of distributing the trial listening license including the license key Kc1 and the main body license including the license key Kc2 will be described. FIG. 9 is a flowchart showing the entire operation of distribution of the encrypted music data {Dc} Kc, the trial listening license including the license key Kc1, and the licenses Kc1 and Kc2 from the distribution server 10 to the memory card 110. The mobile phone 100 is a mobile phone 100
Transmits a request for distribution of a trial listening license including the encrypted music data {Dc} Kc and the license key Kc1 to the distribution server 10 via the mobile phone network in response to the user's instruction. ｛Dc｝ Kc
And receive a trial license. Then, the mobile phone 100 records the received trial music license including the encrypted music data {Dc} Kc and the license key Kc1 on the memory card 110 (step S10). After that, the mobile phone 100 reads the encrypted music data {Dc} from the memory card 110 in response to the preview instruction from the user.
The trial listening area {Dc1} Kc1 and the license key Kc1 which are part of Kc are read out, and the content reproducing circuit 1550 is read.
License key K included in the trial license
Encrypted music data {Dc1} K that can be decrypted by c1
Decode and play back c1. Then, the user listens to the reproduced music data via the headphone 130 (step S20).

When the user desires to purchase the music data that he has listened to, he or she inputs a request for downloading a main body license including the license key Kc2 to the mobile phone 100.
Then, the mobile phone 100 transmits a distribution request of the main body license including the license key Kc2 to the distribution server 10 via the mobile telephone network, receives the main body license including the license key Kc2 from the distribution server 10, and receives the request. The main body license including the obtained license key Kc2 is recorded on the memory card 110 (step S30). Thereafter, the mobile phone 100 responds to the user's playback request by
The encrypted music data {Dc} Kc and the two license keys Kc1 and Kc2 are read from the memory card 110, and the encrypted music data {Dc} Kc is converted into the encrypted content data {Dc} Kc in the content reproduction circuit 1550.
Decryption and reproduction using the license key Kc1 and the license key Kc2 suitable for each of the regions.

The details of steps S10, S20 and S30 will be described below. FIGS. 10 and 11 are flowcharts for explaining the detailed operation of the license distribution process in steps S10 and S30 in FIG. First, the details of step S10 of downloading a trial listening license and encrypted content data {Dc} Kc from distribution server 10 will be described.

Prior to the processing in FIG.
It is assumed that the user No. 00 connects to the distribution server 10 via the telephone network, acquires the content ID of the content desired to be purchased, and determines the type of license required. The license key Kci (i = 1, 2) in the flowchart is either the license key Kc1 or the license key Kc2. In this case, the license key Kci is intended to acquire the trial listening license including the license key Kc1, so that i = 1 It is. The distribution of the trial listening license will be described by replacing i of the license key Kci in FIGS. 10 and 11 with i = 1.

Referring to FIG. 10, a distribution request is made from the user of portable telephone 100 via operation panel 1111 by designating a content ID (step S10).
0). Then, the purchase condition AC for purchasing the license Kc1 of the encrypted music data for trial listening {Dc1} Kc1 is input via the operation panel 1111 (step S).
102). That is, the selected encrypted music data {Dc}
As a condition for downloading the license key Kci for decrypting Kc, the license key Kc1 or the license key Kc2, that is, whether it is a trial listening license or a main body license is instructed. Further, in the case of the main body license, a condition for setting the access control information ACm of the encrypted content data and the reproduction control information ACp is input as the license purchase condition AC.

When the purchase condition AC for the encrypted content data is input, controller 1109 gives an instruction to output authentication data to memory card 110 via bus BS2 and memory card interface 1200 (step S104). Controller 1 of memory card 110
420 receives the authentication data transmission request via the terminal 1426, the interface 1424, and the bus BS4 (step S106). And the controller 1420
Reads authentication data {KPm3 // Cm3} KPa from authentication data holding unit 1400 via bus BS4,
{KPm3 // Cm3} KPa is output via bus BS4, interface 1424 and terminal 1426 (step S108).

Controller 1109 of mobile phone 100
Is the authentication data {KPm3 /
In addition to / Cm3 @ KPa, a content ID, license purchase condition data AC, and a distribution request are transmitted to distribution server 10 (step S110).

In the distribution server 10, the distribution request, the content ID, and the authentication data {KP
m3 // Cm3 @ KPa and the license purchase condition data AC are received (step S112), and the decryption processing unit 312 decrypts the authentication data output from the memory card 110 with the public authentication key KPa (step S114). ).

The distribution control unit 315 performs an authentication process for judging from the decryption processing result of the decryption processing unit 312 whether or not an authorized organization has received encrypted authentication data for certifying its validity. (Step S116).
If it is determined that the authentication data is valid, the distribution control unit 315 approves and accepts the class public encryption key KPm3 and the class certificate Cm3. Then, control goes to the next process (step S118). If it is not valid authentication data, it is rejected and the distribution session is terminated without accepting the class public encryption key KPm3 and the class certificate Cm3 (step S164).

As a result of the authentication, when it is confirmed that the access is from a mobile phone equipped with a memory card having valid authentication data, session key generating section 316 in distribution server 10 transmits a session key for distribution. K
s1 is generated (step S118). The session key Ks1 is encrypted by the encryption processing unit 318 using the class public encryption key KPm3 corresponding to the memory card 110 obtained by the decryption processing unit 312 (step S120).

The distribution control unit 315 generates a license ID (step S122), and stores the license ID and the encrypted session key Ks1 in the license ID //
As {Ks1} Km3, the bus BS1 and the communication device 3
The data is output to the outside through the device 50 (step S124).

The portable telephone 100 has a license ID //
Upon receiving {Ks1} Km3, the controller 1109
Inputs the license ID // {Ks1} Km3 into the memory card 110 (step S126). Then, in the memory card 110, the controller 14 is connected via the terminal 1426 and the interface 1424.
20 receives the license ID // {Ks1} Km3 (step S128). And the controller 142
0 gives {Ks1} Km3 to the decoding processing unit 1422 via the bus BS4, and the decoding processing unit 1422
By decrypting with the class secret decryption key Km3 unique to the memory card 110 held in 21, the session key Ks1 is decrypted and the session key Ks1 is received (step S132).

The controller 1420 controls the distribution server 10
When the reception of the session key Ks1 generated in step (1) is confirmed, the session key generation unit 1418 is instructed to generate the session key Ks2 generated during the distribution operation in the memory card 110. Then, the session key generation unit 1418 generates a session key Ks2 (Step S134).

The encryption processing unit 1406 is provided with the changeover switch 1
A changeover switch 1 is provided by a session key Ks1 provided from the decryption processing unit 1422 via the contact point Pa of the switch 442.
The session key Ks2 and the individual public encryption key KPmc4 given by sequentially switching the contacts of 446
Is encrypted as one data string, and {Ks2 // KP
mc4 @ Ks1 is output to bus BS4. Encrypted data {Ks2 // KPmc4} Ks output to bus BS4
1 is output from the bus BS4 to the mobile phone 100 via the interface 1424 and the terminal 1426 (step S138).
(Step S140).

Referring to FIG. 11, distribution server 10
Upon receiving {Ks2 // KPmc4} Ks1, the decryption processing unit 320 performs decryption processing using the session key Ks1, and obtains the session key Ks2 generated by the memory card 110 and the public encryption key KPmc4 unique to the memory card 110. It is accepted (step S142).

The distribution control unit 315 obtains the license key Kc1 from the information database 304 according to the content ID and the purchase condition AC obtained at step S112 (step S144), and accesses the license key Kc1 according to the license purchase condition data AC obtained at step S112. The control information ACm and the reproduction control information ACp are determined (step S146).

The distribution control unit 315 gives the generated license, that is, the license ID, the content ID, the license key Kc, the reproduction control information ACp, and the access control information ACm to the encryption processing unit 326. The encryption processing unit 326 encrypts the license with the public encryption key KPmc4 unique to the memory card 110 obtained by the decryption processing unit 320, and encrypts the license.
/// Content ID // Kc1 // ACm // ACp｝
Kmc4 is generated (step S148). Then, the encryption processing unit 328 outputs the encrypted data from the encryption processing unit 326 {license ID // content ID // Kc1
// ACm // ACp @ Kmc4 is converted to a decoding processing unit 320
Encrypted with the session key Ks2 from the server and the encrypted data {license ID // content ID // Kc
1 // ACm // ACp {Kmc4} Ks2 is output. The distribution control unit 315 includes the bus BS1 and the communication device 3
50 encrypted data {license ID // content ID // Kc1 // ACm // ACp} Kmc
4 @ Ks2 is transmitted to the mobile phone 100 (step S
150).

The portable telephone 100 transmits the encrypted data {license ID // content ID // Kc1
// ACm // ACp {Kmc4} Ks2 is received and input to the memory card 110 via the bus BS2 (step S152). In the memory card 110, the received data provided to the bus BS4 is decoded by the decoding processing unit 1412 via the terminal 1426 and the interface 1424. The decryption processing unit 1412 outputs the session key Ks2 given from the session key generation unit 1418.
Is used to decode the received data on the bus BS4.
(Step S154).

At this stage, in the bus BS4, an encrypted license {license ID // contents I which can be decrypted with the secret decryption key Kmc4 held in the Kmc holding unit 1402
D // Kc1 // ACm // ACp {Kmc4} is output (step S154).

In accordance with an instruction from controller 1420, encrypted license $ license ID // content ID /
/ Kc1 // ACm // ACp @ Kmc4 is decrypted by the individual secret decryption key Kmc4 in the decryption processing unit 1404, and the license (license key Kc1, license ID, content ID, access control information ACm, and reproduction control information ACp) is obtained. Accepted (step S15
6).

Then, controller 1420 of memory card 110 transmits the received license (license I
D, content ID, license key Kc1, access control information ACm, and playback control information ACp) are stored in license area 1415A (step S160).
Then, billing process is performed in distribution server 10. That is, the distribution control unit 315 records the billing information in the billing database 302 (Step S162). In this case, the charging fee for distribution of the trial listening license is lower than the charging fee for distribution of the main body license described later. Then, the license distribution operation ends (step S164).

The encrypted content data {Dc} Kc is a mere download process, and will not be described in detail. However, after the distribution of the trial license is completed, the controller 1109 of the mobile phone 100 sets the encrypted content data Is transmitted to the distribution server 10, and the distribution server 10 receives the distribution request of the encrypted content data. Then, the distribution control unit 315 of the distribution server 10 acquires the encrypted content data {Dc} Kc and the additional information Dc-inf from the information database 304, and outputs these data via the bus BS1 and the communication device 350. I do.

[0131] The portable telephone 100 has a function of {Dc} Kc // D
Upon receiving the c-inf, the encrypted content data {D
c｝ Kc and additional information Dc-inf are received. Then, controller 1106 transmits encrypted content data {Dc} Kc and additional information Dc-inf to bus B.
The data is input to the memory card 110 via S2 and the memory card interface 1200. Memory card 110
The controller 1420 records the received encrypted content data {Dc} Kc and the additional information Dc-inf in the data area 1415B of the memory 1415. In addition,
The additional information Dc-inf includes a license for changing a license key indicating which block of the encrypted content data {Dc} Kc should be decrypted with which license key, and corresponding information of the block.

As described above, when distributing the license, the memory card 11 attached to the cellular phone 100 is
0 is a device that holds regular authentication data, and at the same time, it is possible to distribute the content data after confirming that the public encryption key KPm3 that has been encrypted and transmitted together with the class certificate Cm3 is valid, It is possible to prohibit distribution of content data to an unauthorized memory card.

Further, by transmitting and receiving the encryption keys respectively generated by the distribution server and the memory card, executing the encryption using the encryption keys received by each other, and transmitting the encrypted data to the other party, In the transmission and reception of encrypted data, mutual authentication can be performed in effect, and the security of the data distribution system can be improved.

In the above description, it has been described that the distribution of the trial license is charged (step S1).
62) The trial listening is a service for the purpose of having the main body license downloaded, and it is necessary to have more users listen. Therefore, there is no need to charge for distribution of the trial license. It is possible.

[Trial Listening] Next, the trial listening in step S20 will be described in detail. In playback for audition,
The controller 1109 of the mobile phone 100 adds the additional data Dc-in of the music to be reproduced from the memo card 110
f, read out the block constituting the trial listening area {Dc1} Kc1 reproducible with the trial license, and virtually generate one new encrypted content data composed only of the identified block. Then, the virtually generated encrypted content data is decrypted and reproduced.
Referring to FIG. 3A, encrypted content data {D
If c @ Kc is the encrypted content data 90, the block constituting the trial listening area 91 ({Dc1} Kc1) is confirmed, and a data string composed only of the pertinent block is reproduced as one music piece. Referring to FIG. 3B, similarly, when the encrypted content data {Dc} Kc is the encrypted content data 93, the preview area 94 ({Dc1} Kc1) is reproduced as one music piece.

For reproduction, first, the license key K included in the trial license stored in the memory card 110 is used.
c1 is held in one of the two Kc holding units 1514 and 1515 in the content playback circuit 1550, and “Kc holding units 1514 and 1515 are set after“ play permission ”.
The license key Kc1 stored in any one of the license keys 15 is selected by the switch 1518 and supplied to the decryption processing unit 1519. The encrypted content data virtually configured for trial listening corresponds to the trial listening area {Dc1} Kc1. Therefore, the encrypted content data virtually configured for trial listening is also referred to as encrypted content data {Dc1} Kc1.

Then, controller 1109 transmits encrypted content data {Dc1} from memory card 110.
The blocks constituting Kc1 are read out in accordance with the reproduction order and supplied to the decoding processing unit 1519. Decryption processing unit 1519
Decrypts the blocks constituting the input encrypted content data using the license key Kc1,
A plain text block (a block forming the source data) constituting the content data obtained by decrypting the encrypted content data {Dc1} Kc1 is extracted. Then, the decryption processing unit 1519 outputs the extracted block to the music reproduction unit 1520. The music playback unit 1520 digitally plays music based on the data included in the block supplied from the decoding processing unit 1519, and
21. Then, the AD converter 1521
The content data is converted from a digital signal to an analog signal and output to the terminal 1522. Then, all the blocks constituting the encrypted content data {Dc1} Kc1 are read from the memory card 110 in the order of reproduction, and when a series of processing ends, the reproduction for trial listening ends. The user
The trial listening area {Dc1} Kc1 of the encrypted content data {Dc} Kc can be previewed by the headphone 130 or the like connected to the terminal 1522.

[0138] At this time, it has been described that the reproduction for trial listening ends when a series of processing for all blocks to be reproduced ends, but reading of all blocks to be reproduced is performed on the premise of repeated trial listening. Is completed, it is possible to return to the top block of the encrypted content data {Dc1} Kc1 and to continuously play back. In this case, the end of the trial listening is configured such that the user operates the operation panel 1111 to instruct the controller 1109 to end the trial listening, and the controller 1109 terminates the reproduction in accordance with the instruction.

Next, "reproduction permission" for holding the license key Kc1 included in the trial license in one of the two Kc holding units 1514 and 1515 in the content reproduction circuit 1550 will be described. FIG. 12 shows “Reproduction permission”.
5 is a flowchart for explaining the operation of FIG. "Reproduction permission" is the license key Kc1
In addition to holding the license key Kc2 of the main body license in Kc,
This is also processing to be held in one of the holding units 1514 and 1515, and the license key is described as Kci in FIG. In the trial listening, description will be made by replacing the identifier i for distinguishing the license key with i = 1. Also, the description will be made assuming that the license key Kc1 is held in the Kc holding unit 1514.

Referring to FIG. 12, when the reproduction operation for the trial listening is started, a reproduction permission request is input to mobile telephone 100 from the user of mobile telephone 100 via operation panel 1111 (step S200). Then, the controller 1109 makes a request to output the authentication data to the content reproduction circuit 1550 via the bus BS2 (step S202), and outputs the authentication data.
50 receives an authentication data output request (step S2).
04). Then, authentication data holding section 1500 outputs authentication data {KPp1 // Cp1} KPa (step S206), and controller 1109 sends authentication data {KPp1 // Cp1} KPa to memory card 110 via memory card interface 1200. Is input (step S208).

Then, memory card 110 receives authentication data {KPp1 // Cp1} KPa, and decryption processing section 1408 receives received authentication data {KPp1 // Cp
p1 @ KPa is decrypted with the public authentication key KPa held in the KPa holding unit 1414 (step S210),
The controller 1420 performs an authentication process based on the decryption processing result in the decryption processing unit 1408. That is, an authentication process is performed to determine whether the authentication data {KPp1 // Cp1} KPa is legitimate authentication data (step S).
212). If decryption has failed, the process moves to step S260, and the reproduction operation ends. When the authentication data can be decrypted, the controller 1420 controls the session key generation unit 1418, and the session key generation unit 1418
A session key Ks2 for a reproduction session is generated (step S214). Then, the encryption processing unit 1410
Outputs to the bus BS4 {Ks2} Kp1 obtained by encrypting the session key Ks2 from the session key generation unit 1418 with the public encryption key KPp1 decrypted by the decryption processing unit 1408. Then, the controller 1420
Is transmitted to the memory card interface 1200 via the interface 1424 and the terminal 1426 {Ks2} K
p1 is output (step S216). Mobile phone 10
0 controller 1109 obtains {Ks2} Kp1 via the memory card interface 1200. Then, controller 1109 gives {Ks2} Kp1 to decryption processing section 1504 of content reproduction circuit 1550 via bus BS2 (step S218), and decryption processing section 1504 outputs public encryption key output from Kp1 holding section 1502. {Ks2} Kp1 is decrypted by the secret decryption key Kp1 paired with KPp1, and the session key Ks
2 is output to the encryption processing unit 1506 (step S22).
0). Then, the session key generation unit 1508
Generate a session key Ks3 for a playback session,
The session key Ks3 is output to the encryption processing unit 1506 (step S222). The encryption processing unit 1506 encrypts the session key Ks3 from the session key generation unit 1508 with the session key Ks2 from the decryption processing unit 1504, and outputs {Ks3} Ks2 (step S2).
24), the controller 1109 sends {Ks3} via the bus BS2 and the memory card interface 1200.
Ks2 is output to the memory card 110 (step S2
26).

Then, the decryption processing unit 1412 of the memory card 110 includes the terminal 1426 and the interface 142
4, and {Ks3} Ks2 are input via the bus BS4. The decryption processing unit 1412 includes the session key generation unit 1
｛Ks3｝ Ks2 is decrypted by the session key Ks2 generated by 418, and the session key Ks3 generated by the reproduction terminal 100 is received (step S2).
28).

The controller 1109 of the mobile phone 100
Acquires the entry number in which the license is stored from the license management file of the reproduction request music acquired in advance from the memory card 110 (step S23).
0), and outputs the obtained entry number and license output request to the memory card 110 via the memory card interface 1200 (step S232).

The controller 142 of the memory card 110
0 receives the entry number and the license output request, and acquires the license stored in the area specified by the entry number (step S234).

Then, controller 1420 checks access restriction information ACm (step S236).

In step S236, by checking the access restriction information ACm, which is information relating to restrictions on memory access, more specifically, by checking the number of times of reproduction, if the reproduction is already disabled, When the reproduction operation is completed and the number of times of reproduction of the access restriction information is limited, the number of reproduction of the access restriction information ACm is changed (step S238), and then the process proceeds to the next step (step S240). On the other hand, access restriction information AC
If the reproduction is not restricted by the number of reproductions of m, step S238 is skipped, and the process proceeds to the next step (step S240) without changing the number of reproductions of the access restriction information ACm.

If it is determined in step S236 that the reproduction operation can be performed, the license key Kc1 and the reproduction control information ACp of the reproduction request music recorded in the license area 1415A of the memory 1415 are stored on the bus BS4. (Step S24)
0).

The obtained license key Kc and reproduction control information ACp are sent to the encryption processing unit 1406 via the contact Pf of the changeover switch 1446. Encryption processing unit 1406
Is the license key Kc1 received through the changeover switch 1446 by the session key Ks3 received from the decryption processing unit 1412 through the contact Pb of the changeover switch 1442.
And the reproduction control information ACp, and ｛Kc1 // AC
p @ Ks3 is output to the bus BS4 (step S24)
0).

The encrypted data output to the bus BS4 is
Playback terminal 102 via interface 1424, terminal 1426, and memory card interface 1200.
Sent to

In mobile phone 100, encrypted data {Kc // ACp} Ks3 transmitted to bus BS2 via memory card interface 1200 is decrypted by decryption processing section 1510, and license key K
c and the playback control information ACp (step S2)
42, S244). The decryption processing unit 1510 switches the license key Kc (the license key Kc1 in this case)
511.

[0151] The decoding processing unit 1510 outputs the reproduction control information ACp to the bus BS2. Controller 110
9 receives the reproduction control information ACp via the bus BS2 and confirms whether or not reproduction is possible (step S246).

If it is determined in step S246 that the reproduction is impossible according to the reproduction control information ACp, the switch 1511 is instructed to output the license key Kci to the terminal 1512, and the Kc holding unit 1514 holds the license key Kci. I do.

As described above, when the license key Kc1 is held in the Kc holding unit 1415 and the "reproduction permission" process is completed, the encrypted content data {Dc1} Kc1 can be reproduced. On the other hand, the process branches at steps S212, S236, and S246, and if "reproduction permission" ends without the license key Kc1 being held in the Kc holding unit 1415, the encrypted content data {Dc1} Kc1 cannot be played.

Therefore, even if the trial listening area {Dc1} Kc1 is a part of the encrypted content data {Dc} Kc
Even if only reproduction is performed, a user who does not have a regular license cannot reproduce. Of course, the encrypted content data {Dc} Kc may be obtained by some means, and the obtained encrypted content data {Dc} Kc may be copied. If the trial listening license is obtained from the distribution server 10, the encrypted content data {Dc} Kc can be reproduced.

Since only the trial license is held in the trial listening, the block outside the trial listening area encrypted to be decrypted with the license key Kc2, ie, the main body area {Dc2} Kc2, does not acquire the main body license. As long as it cannot be reproduced.

[Distribution of Main Body License] Next, downloading of the main body license in step S30 will be described in detail. The download of the main body license is performed in accordance with the flowcharts of FIGS. 10 and 11, similarly to the process of downloading the trial license. In this case, since the license including the license key Kc2 is downloaded, the license purchase condition AC includes information indicating that the main body license is purchased. Further, the identifier i for distinguishing the license key in the flowchart may be replaced with i = 2, that is, the license key Kci may be replaced with Kc2, and the description will be repeated, and the description will be omitted.

Here, even after the main body license is obtained, the license key K is used for reproducing the encrypted content data.
It has been described that reproduction is performed using a trial license including c1. However, the trial license includes access control information AC.
m, for example, with a limit of about three times, and distributed free of charge. Two licenses are used as the main body license: a license including the license key Kc1 and a license key Kc2. A similar service can be provided even if licenses including the above are distributed at the same time. In this case, the mobile phone 100 receives the distribution of the two licenses in step S30 of FIG. That is, it can be obtained by processing the flowcharts shown in FIGS. 10 and 11 twice.

[Reproduction] After downloading the main body license in step S30 and storing the two licenses in the memory card 110, the two license keys Kc
1, encrypted content data {Dc} K using Kc2
The process of reproducing c will be described. Here, the license key Kc1 is stored in the Kc holding unit 15 to simplify the description.
14, the license key Kc2 is stored in the license holding unit 151.
5 will be described, but the present invention is not limited to this, and may be reversed.

With reference to FIG. 3, a case where the encrypted content data 90 is reproduced will be described. Controller 1
Reference numeral 109 denotes the encrypted content data 9 with reference to the additional information Dc-inf for the encrypted content data 90.
At 0, a block belonging to the trial listening area 91 and a block belonging to the main body area 92 are specified.

Next, "reproduction permission" for holding the license key Kc2 necessary for reproducing the first block in the reproduction order in the Kc holding unit 1515 is performed according to the flowchart of FIG. In this case, the identifier i for distinguishing the license key in the flowchart of FIG.
= 2, that is, the license key Kci may be replaced with Kc2, which is the same as “reproduction permission” in the trial playback, and thus the description is omitted.

Subsequently, the terminal 1 is connected to the switch 1518.
517 is selected, the license key Kc2 held in the Kc holding unit 1515 is instructed to be output, and the blocks constituting the encrypted content data 90 are read out from the memory card 110 in the order of reproduction, and the decryption processing unit 151 is read out.
9. Further, the controller 1109 supplies the blocks constituting the encrypted content data 90 to the decryption processing unit 1519 so that the reproduction of the content data is performed continuously, and uses the idle time of the processing to perform another processing. Key Kc1 which is one license key
Is held in the Kc holding unit 1514 before the supply of blocks belonging to the trial listening area 91 is started. "Reproduction permission" for the license key Kc1 is the same as "reproduction permission" in the case of performing reproduction in a trial listening, so that the description is omitted.

Then, the controller 1109 reads the blocks making up the encrypted content data 90 from the memory card 110 and supplies them in the order of reproduction.
516 is selected, and the license key Kc1 held in the Kc holding unit 1514 is instructed to be output to the decryption processing unit 1519. Subsequently, the blocks constituting the encrypted content data 90 are stored in the memory card 110 in the reproduction order.
And supplies it to the decoding processing unit 1519.

When the main area 92 is reached again, the switch 1518 is again instructed to select the terminal 1517 and to output the license key Kc2 held in the Kc holding section 1515 to the decryption processing section 1519. Subsequently, the blocks constituting the encrypted content data 90 are read from the memory card 110 in the reproduction order and supplied to the decryption processing unit 1519. When all the blocks have been supplied, the reproduction of the encrypted content data 90 ends.

Further, a case where the encrypted content data 93 is reproduced will be described with reference to FIG. In the encrypted content data 93, there is a trial listening area 94 to be reproduced by the license key Kc1 at first according to the reproduction order. Accordingly, first, "permission of reproduction" for causing the Kc holding unit 1514 to hold the license key Kc1 is performed. Next, the controller 1109 reads the blocks making up the encrypted content data 93 from the memory card 110 and supplies them to the decryption processing unit 1519 in the order of reproduction. Further, the controller 1109 supplies the blocks constituting the encrypted content data 93 to the decryption processing unit 1519 so that the reproduction of the content data is performed continuously, and uses the idle time of the processing to perform another processing. The license key kc2, which is one license key, is stored in the Kc holding unit 151.
5 is performed before the supply of the blocks belonging to the main body area 95 is started.

When the main body area 95 is reached, the switch 15
18, the terminal 1517 is selected and the Kc holding unit 15 is selected.
14 is output to the decryption processing unit 1519, and subsequently, the blocks constituting the encrypted content data 93 are read out from the memory card 110 according to the reproduction order, and the decryption processing unit 151 is read out.
9. When all the blocks have been supplied, the reproduction of the encrypted content data 93 ends.

The personal computer 50 shown in FIG. 1 acquires only the encrypted music data {Dc} Kc from the distribution server 10 or the CD-ROM 60 and
Can also be stored in the memory card 110 via the.
In this case, the download processing of the encrypted content data in step S10 of FIG. 9 is omitted.

The personal computer 50 shown in FIG. 1 has encrypted music data {Dc1} Kc1,
A trial listening license including the main body encrypted music data {Dc2} Kc2 and the license key Kc1 can be acquired from the distribution server 10 or the CD-ROM 60 and stored in the memory card 110 via the card writer 80. In this case, the personal computer 50 performs step S10 in FIG.
Is stored in the memory card 110 via the card writer 80 in accordance with the flowcharts shown in FIGS. In this case, the personal computer 50 fulfills the functions of the distribution server 10 and the mobile phone 100 in FIGS. And
The user of the mobile phone 100 removes the memory card 110 from the card writer 80, inserts the memory card 110 into the mobile phone 100,
According to the flowchart shown in FIG. 12, a trial listening area {Dc1} Kc1 of the encrypted music data {Dc} Kc is previewed.
Thereafter, when the user wants to listen to the encrypted music data {Dc} Kc, a license key Kc2 for decrypting the main body encrypted music data {Dc2} Kc2 from the distribution server 10 by the mobile phone 100 is shown in FIGS. Download according to the flowchart. Then, in response to the user's reproduction request, the mobile phone 100 uses the two license keys Kc1 and Kc2 to encrypt the music data {D
Play all c｝ Kc. Although not described, the acquisition of the trial license from the distribution server 10 or the recording of the trial license on the CD-ROM 60 and the reading of the trial license are performed using encryption technology, and the security is secured. And However, here, the method is not limited. Further, the main body license is received from the distribution server 10 by the computer 50 and the memory card 110
Can also be stored.

As described above, the cellular phone 100 receives two licenses including the encrypted music data {Dc} Kc and the license keys Kc1 and Kc2 from various routes, and records them on the memory card 110. Therefore, the user of the mobile phone 100 determines that the encrypted music data $ D
When the user desires to download the data in a state in which all of c @ Kc can be reproduced, the encrypted music data {Dc} Kc and the license key Kc are finally stored in the memory card 110.
Two licenses, each including 1 and Kc2, are stored.

In the above description, the case where the encrypted content data is the encrypted content data obtained by encrypting the music data has been described. However, the encrypted content data may be other reading data, teaching material data, video data, or the like. Also, download, preview, preview and playback of the encrypted content data are performed by the above-described method.

According to the embodiment of the present invention, encrypted content data divided into a plurality of blocks and a plurality of licenses for decrypting the encrypted data included in the plurality of blocks are distributed. Blocks can be decrypted and played with different licenses. As a result, a charging fee can be set according to the license to be distributed.

The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description of the embodiments, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0172]

According to the present invention, encrypted content data divided into a plurality of blocks and a plurality of licenses for decrypting the encrypted data included in the plurality of blocks are distributed. Can be decrypted and played with different licenses.

[Brief description of the drawings]

FIG. 1 is a schematic diagram conceptually illustrating a data distribution system.

FIG. 2 is a diagram showing characteristics of data, information, and the like for communication in the data distribution system shown in FIG.

FIG. 3 is a diagram showing a format of encrypted content data.

FIG. 4 is a diagram for explaining a method of generating encrypted content data.

FIG. 5 is a diagram showing characteristics of data, information, and the like for communication in the data distribution system shown in FIG. 1;

FIG. 6 is a schematic block diagram showing a configuration of a distribution server in the data distribution system shown in FIG.

FIG. 7 is a schematic block diagram showing a configuration of a mobile phone in the data distribution system shown in FIG.

FIG. 8 is a schematic block diagram showing a configuration of a memory card in the data distribution system shown in FIG.

FIG. 9 is a flowchart for explaining an overall configuration of a distribution operation in the data distribution system shown in FIG. 1;

FIG. 10 is a first flowchart for describing the license distribution operation shown in FIG. 9 in further detail;

FIG. 11 is a second flowchart for explaining the license distribution operation shown in FIG. 9 in further detail;

FIG. 12 is a flowchart for explaining in detail reading of a license key in a reproduction permission operation.

FIG. 13 is a diagram showing another format of the encrypted content data.

[Explanation of symbols]

10 distribution server, 20 distribution carrier, 30 Internet network, 50 personal computer, 60 C
D, 70 USB cable, 84, 90, 93, 96,
97 encrypted content data, 81 source data, 82
Block data, 83, 91, 92, 94, 95, 8
42, 844, 846 Encrypted music data 100 Cellular phone, 110 memory card, 130 headphones, 302 billing database, 304 information database, 307 menu database, 308 distribution record database, 310 data processing section, 312, 32
0, 1404, 1408, 1412, 1422, 150
4, 1510, 1519 Decryption processing unit, 313 Authentication key holding unit, 315 Distribution control unit, 316, 1418, 15
08 Session key generator, 318, 326, 32
8, 1406, 1410, 1417, 1506 Encryption processing unit, 350 communication device, 841, 843, 845, 9
71,972 encrypted data, 961 to 967 area,
1109, 1420 controller, 1426, 151
2,1513,1516,1517,1522 terminals,
1101 antenna, 1102 transmitting / receiving unit, 1103
Microphone, 1104 AD converter, 1105 audio encoding unit, 1106 music reproducing unit, 1108 speaker, 111
0 display panel, 1111 operation panel, 1200 memory card interface, 1400, 1500 authentication data holding unit, 1402 Kmc holding unit, 1414 K
Pa holding unit, 1415 memory, 1415A license area, 1415B data area, 1416 KPmc
Holder, 1421 Km Holder, 1424 Interface, 1442, 1446 Changeover Switch, 1502
Kp1 holding unit, 1520 Music playback unit, 1107, 15
21 DA converter, 1514, 1515 Kc holding unit,
1550 Content playback circuit.

Claims (13)

[Claims] A first step of receiving an acquisition request for encrypted content data obtained by encrypting content data; and a step of providing the encrypted content data in response to the acquisition request received in the first step. Step 2, receiving a request for providing a first license corresponding to a part of the encrypted content data and decrypting the part, and receiving in the third step A fourth step of providing the first license in response to the provision request provided to the other part which is different from the first license and which does not correspond to the first license of the encrypted content data. Correspondingly, a fifth step of receiving a request for providing a second license for decrypting the other part, and receiving the request in the fifth step. Depending on the test requirements, the sixth step of providing a second license, the seventh step and the content providing method comprising the performing charging process for providing the second license. 2. The method according to claim 1, wherein the encrypted content data, the first
2. The content providing method according to claim 1, wherein the license and the second license are distributed from the same server. 3. The encrypted content data and the first license are distributed from a first server, and the second license is different from the first server in a second license.
The content providing method according to claim 1, wherein the content is distributed from a server. 4. The content providing method according to claim 3, wherein said encrypted content data and said first license are supplied to said first server via a recording medium. 5. The method according to claim 1, wherein the encrypted content data is provided from a first server, and wherein the first and second licenses are distributed from a second server different from the first server. Content provision method. 6. The content providing method according to claim 5, wherein the encrypted content data is supplied to the first server via a recording medium. 7. In the third step, receiving authentication data together with the provision request, and when the authentication data is authenticated, providing the first license; and in the fifth step, together with the provision request. The content providing method according to any one of claims 1 to 6, further comprising: receiving authentication data, and providing the second license when the authentication data is authenticated. 8. A data reproducing apparatus for decrypting and reproducing encrypted content data composed of a plurality of blocks with a plurality of licenses corresponding to the plurality of blocks, wherein the encrypted content data and the plurality of licenses are An interface for exchanging with the recorded data recording device, an operation unit for inputting an instruction, a content reproduction unit for decrypting and reproducing the encrypted content data with the plurality of licenses, and a control unit The control unit may be configured such that, in the content reproduction unit, an n-th (n is a natural number) constituting the encrypted content data
When the encrypted data included in the block is decrypted and reproduced by the n-th license corresponding to the n-th block, the (n + 1) -th license is obtained from the data recording device via the interface, and A data reproducing device provided to a content reproducing unit. 9. The content reproduction unit includes: a first license key holding unit that holds an nth license key included in the nth license; and an (n + 1) th license key included in the (n + 1) th license. A second license key holding unit to be held; and selectively obtaining the n-th license key and the (n + 1) -th license key from the first and second license key holding units. The data reproducing apparatus according to claim 8, further comprising: a decoding unit that decodes the corresponding encrypted data; and a reproducing unit that reproduces the content data decrypted by the decoding unit. 10. The control unit acquires key change information from the data recording device via the interface, and selects the nth license key and the (n + 1) th license key based on the key change information. The data reproducing device according to claim 9, wherein the data is supplied to the decoding unit. 11. A session key generating unit for generating a different session key in a session for acquiring each of the plurality of licenses from the data recording device; and receiving a session key generated by the session key generating unit. A license key decryption unit for decrypting the encrypted license key with the key and providing the decrypted license key to the first or second license key holding unit. The control unit generates the license key by the session key generation unit. The obtained session key is input to the data recording device via the interface, an encrypted license key encrypted by the session key is obtained from the data recording device via the interface, and the license key is decrypted by the license key decryption unit. The data according to claim 10, which is given. Reproducing apparatus. 12. A data transmission / reception unit for performing communication for downloading the license key from a license distribution server providing the license key, wherein the control unit is configured to reproduce the entire encrypted content data. When the required license is not recorded in the data recording device, only the blocks that can be reproduced by the plurality of licenses corresponding to the encrypted content data stored in the data recording device are reproduced from the encrypted content data. In accordance with the order, it corresponds to the blocks constituting the encrypted content data from the license distribution server according to a new license key acquisition instruction input from the operation unit, obtained from the data recording device and provided to the content reproduction unit. A license key for the data transmitting / receiving unit Received via records the license key that the received said data recording apparatus, according to claim 8
A data reproducing apparatus according to claim 1. 13. A data recording apparatus for recording encrypted content data composed of a plurality of blocks and a plurality of licenses for decrypting a plurality of encrypted data included in the plurality of blocks, wherein the plurality of licenses are And a data area for storing the encrypted content data, and license correspondence information indicating a correspondence between each of the plurality of licenses and the plurality of blocks constituting the encrypted content data. Data recording device.