Data transfer system, data transfer apparatus, data recording apparatus, data transfer method Number:7,437,770 from the United States Patent and Trademark Office (PTO) owispatent A data transfer apparatus referred to as a primary-recording-medium apparatus implements proper system operations by acquisition of information on a secondary recording medium mounted on a secondary-recording-medium apparatus to serve as a destination of a transfer (or a check-out) of a content. If a medium adopting its own unique management technique as is the case with a mini disc is used as the secondary recording medium serving as a destination of a check-out, the primary-recording-medium apparatus acquires information on the secondary recording medium from the secondary-recording-medium apparatus, which is typically a data-recording apparatus. The information includes an indicator as to whether or not the secondary recording medium has been mounted on the data-recording apparatus, the name of the secondary recording medium, the name of each content stored in the secondary recording medium, the number of contents stored in the secondary recording medium and attributes of each content stored in the secondary recording medium.<H apparatus, recording, Data, transfer, s, 7437770.html, Patent, pto, 7437770

Title: Data transfer system, data transfer apparatus, data recording apparatus, data transfer method

Abstract: A data transfer apparatus referred to as a primary-recording-medium apparatus implements proper system operations by acquisition of information on a secondary recording medium mounted on a secondary-recording-medium apparatus to serve as a destination of a transfer (or a check-out) of a content. If a medium adopting its own unique management technique as is the case with a mini disc is used as the secondary recording medium serving as a destination of a check-out, the primary-recording-medium apparatus acquires information on the secondary recording medium from the secondary-recording-medium apparatus, which is typically a data-recording apparatus. The information includes an indicator as to whether or not the secondary recording medium has been mounted on the data-recording apparatus, the name of the secondary recording medium, the name of each content stored in the secondary recording medium, the number of contents stored in the secondary recording medium and attributes of each content stored in the secondary recording medium.

Patent Number: 7,437,770 Issued on 10/14/2008 to Abe, et al.

Inventors: Abe; Miki (Kanagawa, JP), Hosoi; Takafumi (Tokyo, JP), Matsuda; Hiromi (Kanagawa, JP), Tanaka; Masao (Kanagawa, JP)
Assignee: Sony Corporation (Tokyo, JP)

Appl. No.: 10/344,867

Filed: June 18, 2002

PCT Filed: June 18, 2002

PCT No.: PCT/JP02/06062

371(c)(1),(2),(4) Date: August 08, 2003

PCT Pub. No.: WO02/103530

PCT Pub. Date: December 27, 2002

Foreign Application Priority Data


Jun 18, 2001 [JP]			2001-183217

Current U.S. Class: 726/29 ; 705/58; 713/193

Current International Class: G06F 21/22 (20060101); H04L 9/00 (20060101)

References Cited [Referenced By]

U.S. Patent Documents


5857021	January 1999	Kataoka et al.
6141702	October 2000	Ludtke et al.
6496802	December 2002	van Zoest et al.
6539468	March 2003	Inoue et al.
6782190	August 2004	Morito
6832319	December 2004	Bell et al.
6834348	December 2004	Tagawa et al.
6847950	January 2005	Kamibayashi et al.
6865552	March 2005	Inoue et al.
6868494	March 2005	Shitara et al.
6959366	October 2005	Abe et al.
7134145	November 2006	Epstein
7159244	January 2007	Matsushima et al.
7191346	March 2007	Abe et al.
7209642	April 2007	Utsumi
7240033	July 2007	Kuriya et al.
7350238	March 2008	Abe et al.
2001/0032088	October 2001	Utsumi et al.
2002/0078178	June 2002	Senoh
2002/0181355	December 2002	Shikunami et al.

Foreign Patent Documents


1 037 460	Sep., 2000	EP
1 037 460	Sep., 2000	EP
1037460	Sep., 2000	EP
1 045 320	Oct., 2000	EP
1045320	Oct., 2000	EP
1 083 474	Mar., 2001	EP
1 083 474	Mar., 2001	EP
2000-149414	May., 2000	JP
2000-315193	Nov., 2000	JP
2000-322826	Nov., 2000	JP
2000304854	Nov., 2000	JP
2000315193	Nov., 2000	JP
2000-357127	Dec., 2000	JP
2000357201	Dec., 2000	JP
2001-60174	Mar., 2001	JP
2001-84339	Mar., 2001	JP
2001160054	Jun., 2001	JP
WO 99/38093	Jul., 1999	WO
WO 01/67668	Sep., 2001	WO

Other References

"WS.sub.--FTP Limited Edition v5.08", [online], Impress Corporation, Mar. 11, 2000. cited by other .
"AV/C Disc Subunit General Specification," 1394 Trade Association, Jan. 26, 1999. cited by other .
European Search Report mailed by the European Patent Office on Jul. 16, 2007 for counterpart Application No. 02733508.2. cited by other .
Yoshio, Taro, "Protecting Music Copyright with Small-size Memory Card," Nikkei Electronics, Mar. 22, 1999, pp. 49-53, No. 739. cited by other.

Primary Examiner: Revak; Christopher A
Attorney, Agent or Firm: Finnegan, Henderson, Farabow, Garrett & Dunner, L.L.P.

Claims

The invention claimed is:

1. A data transfer system including a data transfer apparatus and a data-recording apparatus wherein: the data transfer apparatus comprises: means for storing content data in an encrypted state, a first content ID unique to the content data, and table data onto the primary recording medium of the data transfer apparatus; means for transferring content data to the data-recording apparatus as a result of a check-out operation of the content data; means for receiving a second content ID generated by the data-recording apparatus based on the transferred content data of the check-out operation, wherein the second content ID is stored as an element of the table data: means for transmitting a command requesting, from the data-recording apparatus, information including a third content ID which corresponds to the content data stored on a secondary recording medium of the data-recording apparatus, as a result of a check-in operation of the content data; means for receiving a third content ID generated by the data-recording apparatus; means for comparing the third content ID to the second content ID previously received from the data-recording apparatus, for ensuring that the content data checked-in corresponds to the content data checked-out; and means for checking-in the content data corresponding to the first content ID if the second content ID and the third content ID match; and the data-recording apparatus comprises: means for exchanging content data with the data transfer apparatus; means for recording and reproducing data onto and from the secondary recording medium; means for decrypting encrypted content data received from the data transfer apparatus; means for recording the decrypted content data onto the secondary recording medium; means for generating the second content ID and the third content ID based on data extracted from two sampling locations in the content data, wherein the locations are determined in accordance with the data length of the content data; and means for transmitting the second content ID or the third content ID to the data transfer apparatus.

2. A data transfer system according to claim 1, wherein the information on the secondary recording medium further includes information indicating whether or not the secondary recording medium has been mounted on the data-recording apparatus.

3. A data transfer system according to claim 1, wherein the information on the secondary recording medium further includes a name of the secondary recording medium mounted on the data-recording apparatus or a name of each content data recorded on the secondary recording medium.

4. A data transfer system according to claim 1, wherein the information on the secondary recording medium further includes a capacity of the secondary recording medium mounted on the data-recording apparatus.

5. A data transfer system according to claim 1, wherein the information on the secondary recording medium further includes the number of contents stored on the secondary recording medium mounted on the data-recording apparatus.

6. A data transfer system according to claim 1, wherein the information on the secondary recording medium further includes attributes of each content data recorded on the secondary recording medium mounted on the data-recording apparatus.

7. A data transfer system according to claim 1, wherein the data transfer apparatus forms a judgment as to whether or not data content stored in the primary recording medium should be transmitted to the data-recording apparatus on the basis of the information on the secondary recording medium.

8. A data transfer apparatus comprising: means for storing content data in an encrypted state, a first content ID unique to the content data, and table data onto a primary recording medium; means for transferring content data as a result of a check-out operation of the content data to an external data-recording apparatus which stores the content data onto a secondary recording medium; means for receiving a second content ID generated by the data-recording apparatus based on the transferred content data of the check-out operation, wherein the second content ID is stored as an element of the table data; means for transmitting a command requesting, from the data-recording apparatus, information including a third content ID which corresponds to the content data stored on the secondary recording medium of the data-recording apparatus as a result of a check-in operation of the content data; means for receiving a third content ID generated by the data-recording apparatus; means for comparing, the third content ID to the second content ID previously received from the data-recording apparatus, for ensuring that the content data checked-in corresponds to the content data checked-out; and means for checking-in the content data corresponding to the first content ID if the second content ID and the third content ID match; wherein the second content ID and the third content ID are generated based on data extracted from two sampling locations in the content data stored in said secondary recording medium, wherein the locations are determined in accordance with the data length of the content data.

9. A data transfer apparatus according to claim 8, wherein the information on the secondary recording medium further includes information indicating whether or not the secondary recording medium has been mounted on the data-recording apparatus.

10. A data transfer apparatus according to claim 8, wherein the information on the secondary recording medium further includes a name of the secondary recording medium mounted on the data-recording apparatus or a name of each content data recorded on the secondary recording medium.

11. A data transfer apparatus according to claim 8, wherein the information on the secondary recording medium further includes a capacity of the secondary recording medium mounted on the data-recording apparatus.

12. A data transfer apparatus according to claim 8, wherein the information on the secondary recording medium further includes the number of contents stored on the secondary recording medium mounted on the data-recording apparatus.

13. A data transfer apparatus according to claim 8, wherein the information on the secondary recording medium further includes attributes of each content data recorded on the secondary recording medium mounted on the data-recording apparatus.

14. A data transfer apparatus according to claim 8, wherein the data transfer apparatus forms a judgment as to whether or not data content stored in the primary recording medium should be transmitted to the data-recording apparatus on the basis of said information on said secondary recording medium.

15. A data-recording apparatus comprising: means for exchanging content data with an external data transfer apparatus; means for decrypting encrypted content data received from the data transfer apparatus; means for recording the decrypted content data onto a secondary recording medium; means for generating a first content ID based on data extracted from two sampling locations in the content data, wherein the locations are determined in accordance with the data length of the content data; and means for transmitting information including the first content ID to the data transfer apparatus for comparing the first content ID to a second content ID stored on said data transfer apparatus, wherein the content data can be checked-in to the data transfer apparatus when the first content ID and the second content ID match.

16. A data-recording apparatus according to claim 15, wherein the information further indicates whether or not the secondary recording medium has been mounted on the data-recording apparatus.

17. A data-recording apparatus according to claim 15, wherein the information further indicates a name of the secondary recording medium mounted on the data-recording apparatus or a name of each content data recorded on the secondary recording medium.

18. A data-recording apparatus according to claim 15, wherein the information further indicates a capacity of the secondary recording medium mounted on the data-recording apparatus to the data transfer apparatus.

19. A data-recording apparatus according to claim 15, wherein the information further indicates the number of contents stored on the secondary recording medium mounted on the data-recording apparatus to the data transfer apparatus.

20. A data-recording apparatus according to claim 15, wherein the information further indicates attributes of each content data recorded on the secondary recording medium mounted on the data-recording apparatus to the data transfer apparatus.

21. A data transfer method comprising: storing encrypted content data, a first content ID unique to said content data, and table data onto a primary recording medium in a data transfer apparatus; recording and reproducing the content data onto and from a secondary recording medium in a data recording apparatus in an unencrypted state, the data transfer apparatus being connected to the data-recording apparatus so that the data transfer apparatus and the data-recording apparatus are capable of communicating with each other; confirming that the secondary recording medium has been mounted onto the data-recording apparatus; acquiring information on the secondary recording medium from the data-recording apparatus, wherein the information includes at least a second content ID generated by the data-recording apparatus, based on data extracted from two sampling locations in the content data, wherein the locations are determined in accordance with the data length of the content data; confirming that the data-recording apparatus is a valid destination of a transfer of the content data stored in the primary recording medium, based on the information; judging whether or not the content data should be transferred to the data-recording apparatus, based on the information; and upon judging that the content data should be transferred, transferring the content data to the data-recording apparatus, wherein the second content ID generated by the data-recording apparatus is associated with the first content ID, thereby completing a check-out operation for the content data.

22. A data transfer method according to claim 21, wherein acquiring information includes acquiring a name of the secondary recording medium or a name of each content data recorded on the secondary recording medium.

23. A data transfer method according to claim 21, wherein acquiring information includes acquiring a capacity of the secondary recording medium from the data-recording apparatus.

24. A data transfer method according to claim 21, wherein acquiring information includes acquiring the number of contents recorded on the secondary recording medium from the data-recording apparatus.

25. A data transfer method according to claim 21, wherein acquiring information includes acquiring attributes of the content data recorded on the secondary recording medium from the data-recording apparatus.

Description

TECHNICAL FIELD

The present invention relates to a data transfer system, a data transfer apparatus, a data-recording apparatus and a data transfer method that are well suitable for transferring and/or recording content data such as music.

BACKGROUND ART

In typical usage of content data such as music, the data stored in a primary recording medium such as an HDD (hard disk drive) of a personal computer is transferred to another recording medium used as a secondary recording medium so as to allow the data reproduced from the secondary recording medium to be enjoyed. It is to be noted that the content data includes musical data, video data, game data and computer software, which are provided mainly for distribution, transfer and utilization purposes.

In this case, the HDD employed in the personal computer is used for storing content data such as music reproduced from a package recording medium such as a CD-DA (Compact Disc Digital Audio) and a DVD (Digital Versatile Disc) or used for storing content data downloaded from an external musical server or the like by way of a communication network to the personal computer, which is connected to the network. Then, the user connects the personal computer to a recording apparatus for recording data onto the secondary recording medium, and copies or moves content data from the HDD to the secondary recording medium. In order to enjoy the content data, a reproduction apparatus is used to reproduce the data from the secondary recording medium.

Conceivable examples of the secondary recording medium are a memory card employing a semiconductor memory such as a flash memory, a mini disc used as a magneto-optical disc, a CD-R (CD-Recordable), a CD-RW (CD-Rewritable), a DVD-RAM, a DVD-R and a DVD-RW.

As a recording apparatus and a reproduction apparatus for the secondary recording medium, respectively, a recorder and a player for these recording mediums including the semiconductor memory, the mini disc, the CD-R, the CD-RW, the DVD-RAM, the DVD-R and the DVD-RW have been becoming very popular. The recorder and the player are designed into a variety of implementations such as a stationary recording/reproduction apparatus and a portable recording/reproduction apparatus. The user can thus record and reproduce content data by using an implementation of the recorder and the player that is a favorite with the user or matches an apparatus already owned by the user.

It is to be noted that, when considering such usage of content data, for example, protection of copyrights of the content data must be taken into account. Assume for example that the user obtains content data by using a service to distribute the content data or by purchasing a package medium containing the content data and, after storing the content data into an HDD, the user is allowed to copy the content data to secondary recording mediums without any limitation. In this case, such usage of the content data results in a condition in which the owner of the copyright is not properly protected. In order to solve this problem, there have been proposed a variety of agreements and technologies for assuring protection of copyrights in handling content data as digital data. One of the agreements is a standard called an SDMI (Secure Digital Music Initiative).

A data path prescribed in the SDMI standard will be described later. At any rate, a content stored in an HDD employed in a personal computer as a primary recording medium can be properly transferred to or recorded onto a secondary recording medium after protection of a copyright and benefits of general users are taken into consideration. The benefits include a right to privately copy the content. Examples of the content stored in the HDD include a network content and a disc content. The network content is content data distributed by an external server to the personal computer by way of typically a network to be stored in the HDD. On the other hand, a disc content is read out from a package recording medium to be stored in the HDD. As described above, examples of the package recording medium are a CD-DA and a DVD. The package recording medium is mounted on a disc drive for reproducing the disc content. Typically, the disc drive is embedded in the personal computer or connected to the personal computer. Examples of the disc drive include a CD-ROM drive.

By the way, when content data is transferred in a copy operation from a primary recording medium such as an HDD to a secondary recording medium such as a mini disc or a memory card, measures are taken to satisfy protection of both a copyright and a private copying right.

In order to satisfy such protection, data is transferred from a secondary recording medium conforming to the SDMI standard as follows.

A secondary recording medium conforming to the SDMI standard is assumed to be a recording medium including a memory card employing a semiconductor memory such as a flash memory in conformity with the SDMI standard. Such a secondary recording medium is used for storing a content in an encrypted state. In a primary recording medium like an HDD, for example, a content conforming to the SDMI standard is stored in an encrypted state so that such a content will be copied to a secondary recording medium also in the encrypted state as it is.

It is needless to say that a reproduction apparatus provided for such a secondary recording medium has a decryption function allowing content data copied to the secondary recording medium in an encrypted state to be reproduced.

In a secondary recording medium conforming to the SDMI standard, a recording format includes an area for recording a content ID used as an identifier for identifying each piece of content data.

A content ID is generated for each piece of content data stored in the primary recording medium such as an HDD employed in an apparatus for the primary recording medium and is stored along with the piece of content data. When content data is copied to a secondary recording medium, a content ID identifying the content data is also stored in the secondary recording medium.

Content IDs are used for managing content rights in primary and secondary recording mediums. A content right of a content in a primary recording medium is a right to transfer the content from the primary recording medium to a secondary recording medium in an operation to copy the content to the secondary recording medium. On the other hand, a content right of a content in a secondary recording medium is a right to reproduce the content from the secondary recording medium.

It is to be noted that, in the following description, a transfer of content data (a transfer of a right) from a primary recording medium to a secondary recording medium is referred to as a check-out. On the other hand, a transfer of content data (in actuality, a transfer of a right only) from a secondary recording medium to a primary recording medium is referred to as a check-in.

In accordance with the SDMI standard, transfer usage rules are established for check-outs and check-ins.

For example, for a piece of content data, only up to three check-outs from a primary recording medium to a secondary recording medium are allowed. Thus, a transfer right allows the piece of content data to be transferred up to three times.

In a check-out, a right is also transferred from a primary recording medium to a secondary recording medium. Thus, the transfer right in the primary recording medium now allows the piece of data to be transferred only up to two times. On the other hand, a reproduction right is given to the secondary recording medium.

In a check-in, on the other hand, a right is returned from a secondary recording medium to a primary recording medium. Thus, the secondary recording medium loses a reproduction right while one transferred right is restored to the primary recording medium.

Such check-outs and such check-ins are managed for each piece of content data by using a content ID for identifying the piece of content data.

In addition, in a check-out, a piece of content data and a content ID for identifying the piece of content data are recorded onto a secondary recording medium. The secondary recording medium is given a reproduction right to reproduce the piece of content data. On the other hand, the primary recording medium is considered to have transferred one content ID and lost one transfer right in accordance with the usage rules.

In a check-in, on the other hand, no content data is actually returned. Instead, the content data is merely erased from the secondary recording medium, and the content ID is returned to the primary recording medium to increment the number of transfer rights prescribed by the usage rules by one. The secondary recording medium loses the reproduction right to reproduce the content data.

As described above, content data is copied to a secondary recording medium conforming to the SDMI standard in an encrypted state to be stored into the recording medium also in an encrypted state, and content rights are managed in the event of a check-out or a check-in in order to prevent content data to be copied an unlimited number of times and to protect copyrights as well as to assure the private-copy right of the user at the same time.

It is to be noted that content data downloaded from typically an external server to an HDD serving as a primary recording medium is stored in the HDD in a state of being encrypted by using a content key CK.

In this specification, content data stored in the HDD is assumed to have been obtained as a result of compressing original content data by adoption of an ATRAC3 technique or another compression technique and encrypting the compressed data A3D by using the content key CK. In this specification, notation E (x, y) denotes encrypted data obtained as a result of encrypting data y by using a key x.

On the other hand, notation D {x, E (x, y)} denoted decrypted data obtained as a result of decrypting encrypted data E (x, y) by using the key x.

Thus, the content data obtained as a result of compressing original content data and encrypting the compressed data A3D by using the content key CK can be expressed by notation: E (CK, A3D) On the other hand, decrypted data obtained as a result of the decrypting encrypted data E (CK, A3D) by using the key CK is expressed by notation: D {CK, E (CK, A3D)}

In addition to the encrypted content data E (CK, A3D), the HDD serving as the primary recording medium is also used for storing E (KR, CK), which is the content key CK in a state of being encrypted by using a root key KR. Thus, in the case of encrypted content data E (CK, A3D) downloaded from an external server, for example, the encrypted content key E (KR, CK) is also downloaded from the server.

In this case, in a check-out of the encrypted content data E (CK, A3D) to a secondary recording medium, the encrypted content data E (CK, A3D) and the encrypted content key E (KR, CK) need to be transferred from the HDD serving as the primary recording medium to the secondary recording medium.

The apparatus for the secondary recording medium holds the root key KR for decrypting the encrypted content key E (KR, CK) to produce the original content key CK. The content CK is then used for decrypting the encrypted content data E (CK, A3D) to produce the original content data A3D.

In accordance to the will of the copyright owner or for a variety of reasons, however, the root key KR can be changed. That is to say, a root key KR can be set for each piece of content data. In addition, there is provided a function for imposing restrictions on targets of content distribution by processing of the root key KR. This function will be described later concretely.

Thus, in some cases, data called an EKB (Enabling Key Block) is distributed. In addition, in some cases, a regular terminal for receiving transferred content data adopts a technique for confirming a root key by using an EKB. That is to say, an EKB is distributed from a server to be stored in an HDD along with encrypted content data and an encrypted content key.

Consider a case in which a mini disc (or a magneto-optical disc), which has been becoming very popular, is used as a secondary recording medium in a mini-disc recording apparatus conforming to the SDMI standard. In this case, encrypted content data E (CK, A3D) transferred to the mini disc in a check-out is stored in the mini disc in an encrypted state as it is.

Then, in a reproduction operation, the mini-disc recording apparatus conforming to the SDMI standard decrypts the encrypted content data E (CK, A3D) to produce the content data-D {CK, E (CK, A3D)}=A3D, which is the content data compressed by adoption of the ATRAC3 compression technique. Then, the mini-disc recording apparatus carries out a predetermined decoding process on the compressed content data A3D to output reproduced data such as music.

In a mini disc used in an ordinary mini-disc system, which has been becoming popular too, on the other hand, data is stored not in an encrypted state. Thus, as a mini-disc reproduction apparatus, the mini-disc system naturally does not have a decryption function.

As a result, content data recorded in a mini disc by the mini-disc recording apparatus conforming to the SDMI standard cannot be reproduced by most of mini-disc players, which do not conform to the SDMI standard. That is to say, the content data recorded in a mini disc by the mini-disc recording apparatus conforming to the SDMI standard is not reproduction-compatible with the mini-disc players.

This means that correct use of an SDMI content purchased by the general user is limited and the value of the service to provide an SDMI content to the ordinary user as well as the level of user satisfaction with the service are hence reduced considerably.

In order to solve the problem described above, in a recording operation to copy an SDMI content to a secondary recording medium such as a mini disc mounted on a mini-disc recording apparatus not conforming to the SDMI standard, the SDMI content is decrypted so that the content can be stored in the mini disc in an unencrypted state as it is.

If such a copy operation can be carried out, however, it is possible to copy content data with ease. Such a copy operation also leaves room for possible illegal copies, resulting in a fear of impossibility to implement copyright protection, which is the original objective of the SDMI standard.

In order to solve the problem described above, as a method of transferring content data, the applicant of a patent for the present invention has proposed a content transfer technique described as follows.

In an operation to transfer content data, a data transfer apparatus serving as a primary-recording-medium apparatus authenticates a data-recording apparatus used as a secondary-recording-medium apparatus to serve as a transfer destination. If the result of the authentication is OK, the transfer of the content data is allowed on the condition that the content provider (such as the copyright owner) approves the transfer. Then, the content data is transmitted in an encrypted state through a transmission line and the encrypted content data is decrypted before being stored in a secondary recording medium. In addition, rights are managed for check-outs and check-ins.

In this way, since an operation to copy and record content data in an unencrypted state is permitted, more convenience is offered to the user without losing the function to protect a copyright.

By adoption of such a technique in a system including a personal computer used as the data transfer apparatus and a mini-disc recorder used as a data-recording apparatus, a transfer of a content from a primary recording medium implemented by an HDD employed in the personal computer to a secondary recording medium implemented by a mini disc mounted on the mini-disc recorder is actually well suitable for both the content provider and the user.

By using a medium such as a mini disc, which has been becoming popular in general, as the destination of a check-out described above, the usefulness of the mini disc in practical use is increased. However, there are cases in which the data transfer apparatus such as a personal computer may not be capable of recognizing the condition or other attributes of a medium adopting its own unique data management method. An example of the medium adopting its own unique data management method is a mini disc.

For instance, content data recorded in a memory card given as an example of a medium conforming to the SDMI standard is managed by using a FAT so that the memory card is well compatible with a personal computer. That is to say, the personal computer serving as a data transfer apparatus is capable of obtaining information on the state of the memory card connected as a removable medium used as a destination in a check-out by merely reading out a FAT from the card. The state of the memory card typically includes the storage capacity of the card and the number of contents recorded on the card.

Thus, when it is desired to transfer out certain content data to the memory card in a check-out, it is possible to form a judgment as to whether or not the content data can be transferred out to the memory card on the basis of the storage capacity of the card and other information.

In the case of a medium developed as a medium adopting its own unique data management method for typically audio-data applications as is the case with a mini disc, however, the personal computer is not capable of directly obtaining information on the state of the medium so that the judgment cannot be formed in a check-out or other operations.

Thus, when the use of a mini disc or another medium as a secondary recording medium at the destination of a check-out is assumed, the personal computer serving as a data transfer apparatus is required to have a method allowing the state of the mini disc or the other medium to be recognized.

DISCLOSURE OF INVENTION

It is thus an object of the present invention addressing the problems described above to provide a data transfer apparatus with a capability of properly recognizing a state of a secondary recording medium for recording content data in an unencrypted state prior to a transfer of content data in an unencrypted state between a primary recording medium employed in the data transfer apparatus and the secondary recording medium.

In order to achieve the object described above, present invention provides a data transfer system including the data transfer apparatus and a data-recording apparatus, on which the secondary recording medium is mounted.

The data transfer apparatus provided by the present invention includes primary-recording-medium drive means for recording and reproducing data onto and from a primary recording medium, storage control means for controlling the primary-recording-medium drive means to store content data onto the primary recording medium in an encrypted state, communication means for carrying out a variety of data communications including a transfer of content data between the data transfer apparatus and an external data-recording apparatus for recording and reproducing data onto and from a secondary recording medium command-transmission control means for controlling the communication means to transmit a command making a request for information on the secondary recording medium to the data-recording apparatus, and information acquisition means for obtaining the information on the secondary recording medium transmitted by the data-recording apparatus.

The data transfer apparatus forms a judgment as to whether or not content data stored in the primary recording medium is to be transferred to the data-recording apparatus on the basis of the information on the secondary recording medium obtained by the information acquisition means.

The data-recording apparatus provided by the present invention includes communication means for carrying out a variety of data communications with an external data transfer apparatus, which include reception of content data from the data transfer apparatus, secondary-recording-medium drive means for recording and reproducing data onto and from a secondary recording medium, decryption means for decrypting encrypted content data received from the data transfer apparatus into content data in an unencrypted state, recording control means for controlling the secondary-recording-medium drive means to store the encrypted content data decrypted by the decryption means onto the secondary recording medium in an unencrypted state, and command-transmission control means for controlling the communication means to transmit information on the secondary recording medium, which is information requested by the data transfer apparatus, to the data transfer apparatus in accordance with a command received from the data-recording apparatus making a request for the information.

In addition, the present invention provides a data transfer apparatus having a primary recording medium for storing encrypted content data with a data transfer method to be implemented when the data transfer apparatus is connected to a data-recording apparatus capable of recording and reproducing the content data onto and from a secondary recording medium in an unencrypted state to make the data transfer apparatus and the data-recording apparatus capable of communicating with each other in order to execute a confirmation procedure for confirming that the secondary recording medium has been mounted on the data-recording apparatus, an information acquisition procedure for acquiring information on the secondary recording medium mounted on the data-recording apparatus, an authentication procedure for authenticating validity of the data-recording apparatus as an apparatus to serve as a destination of a transfer of content data stored in the primary recording medium, a judgment procedure for forming a judgment as to whether or not processing is to be carried out to transfer the content data stored in the primary recording medium to the data-recording apparatus on the basis of the information acquired by the information acquisition procedure, and a transfer procedure for transferring the content data in accordance with a result of the judgment formed by the judgment procedure.

In the data transfer system, the data transfer apparatus, the data-recording apparatus and the data transfer method, the information on a secondary recording medium includes information indicating whether or not the secondary recording medium has been mounted on the data-recording apparatus, information on the name of the secondary recording medium mounted on the data-recording apparatus, information on the names of pieces of content data stored in the secondary recording medium mounted on the data-recording apparatus, information on the storage capacity of the secondary recording medium mounted on the data-recording apparatus, information on the number of pieces of content data stored in the secondary recording medium mounted on the data-recording apparatus and information on attributes of pieces of content data stored in the secondary recording medium mounted on the data-recording apparatus.

In accordance with the present invention described above, prior to a check-out of content data from the data transfer apparatus to the data-recording apparatus, the data transfer apparatus is capable of acquiring information on a secondary recording medium used as the destination of the check-out. To be more specific, the data transfer apparatus is capable of obtaining information on the secondary recording medium such as a mini disc, which is information on the secondary recording medium's name, storage capacity, track count (content count), track names and attributes. Thus, the data transfer apparatus is capable of forming a proper judgment as to whether or not the check-out is to be accomplished on the basis of the condition of the secondary recording medium.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an explanatory diagram showing a tree structure of an encryption technique adopted by an embodiment of the present invention;

FIGS. 2A and 2B are each an explanatory diagram showing an EKB of the encryption technique adopted by the embodiment;

FIG. 3 is an explanatory diagram showing the structure of the EKB of the encryption technique adopted by the embodiment;

FIG. 4 is a block diagram showing the structure of a data transfer system implemented by the embodiment;

FIG. 5 is an explanatory diagram showing typical data paths of an SDMI content according to the embodiment;

FIG. 6 is a block diagram showing a primary-recording-medium apparatus provided by the embodiment;

FIG. 7 is a block diagram showing a secondary-recording-medium apparatus provided by the embodiment;

FIG. 8 is an explanatory diagram showing a cluster format of a mini-disc system;

FIG. 9 is an explanatory diagram showing an area structure of a mini disc;

FIG. 10 is an explanatory diagram showing U-TOC (user table of contents) sector 0 of a mini-disc system;

FIG. 11 is an explanatory diagram showing linking in U-TOC sector 0 of a mini-disc system;

FIG. 12 is an explanatory diagram showing U-TOC sector 1 of a mini-disc system;

FIG. 13 shows a flowchart representing an authentication process according to the embodiment;

FIG. 14 is an explanatory diagram showing distributed content data to be transferred and a process to encrypt the data;

FIGS. 15A and 15B are explanatory diagrams showing a typical encryption technique adopted by the embodiment and DNKs (device node keys) used in the technique;

FIG. 16 is an explanatory diagram showing a procedure adopted by the embodiment to decrypt content data;

FIG. 17 shows a flowchart representing check-out operations carried out by the embodiment;

FIG. 18 shows a continuation flowchart representing check-out operations carried out by the embodiment;

FIG. 19 is an explanatory diagram showing a record-object control command used in the embodiment;

FIG. 20 is an explanatory diagram showing a record-object response command used in the embodiment;

FIG. 21 is an explanatory diagram showing a check-out control command used in the embodiment;

FIG. 22 is an explanatory diagram showing a check-out response command used in the embodiment;

FIG. 23 shows a flowchart representing check-in operations carried out by the embodiment;

FIG. 24 is an explanatory diagram showing a check-in control command used in the embodiment;

FIG. 25 is an explanatory diagram showing sub-functions of the check-in control command used in the embodiment;

FIG. 26 is an explanatory diagram showing a check-in response command used in the embodiment;

FIG. 27 is an explanatory diagram showing generation of a content ID in the embodiment;

FIG. 28 shows a table associating content IDs in the embodiment;

FIG. 29 shows a flowchart representing operations carried out by the embodiment to acquire medium information;

FIG. 30 shows a continuation flowchart representing operations carried out by the embodiment to acquire medium information;

FIG. 31 is an explanatory diagram showing an inclusive log-in control command used in the embodiment;

FIG. 32 is an explanatory diagram showing an inclusive log-out control command used in the embodiment;

FIG. 33 is an explanatory diagram showing a get-disc-status control command used in the embodiment;

FIG. 34 is an explanatory diagram showing a get-disc-status response command used in the embodiment;

FIG. 35 is an explanatory diagram showing a get-disc-name control command used in the embodiment;

FIG. 36 is an explanatory diagram showing a get-disc-name response command used in the embodiment;

FIG. 37 is an explanatory diagram showing a get-disc-capacity information control command used in the embodiment;

FIG. 38 is an explanatory diagram showing a get-disc-capacity information response command used in the embodiment;

FIG. 39 is an explanatory diagram showing a get-disc-capacity information response command used in the embodiment;

FIG. 40 is an explanatory diagram showing a get-audio-track-count control command used in the embodiment;

FIG. 41 is an explanatory diagram showing a get-audio-track-count response command used in the embodiment;

FIG. 42 is an explanatory diagram showing a get-audio-track-names control command used in the embodiment;

FIG. 43 is an explanatory diagram showing a get-audio-track-names response command used in the embodiment;

FIG. 44 is an explanatory diagram showing a read-info-block-for-track-attributes control command;

FIG. 45 is an explanatory diagram showing a read-info-block-for-track-attributes response command;

FIG. 46 is an explanatory diagram showing a read-info-block-for-track-mode control command;

FIG. 47 is an explanatory diagram showing a read-info-block-for-track-mode response command;

FIG. 48 is an explanatory diagram showing a read-info-block-for-track-size control command; and

FIG. 49 is an explanatory diagram showing a read-info-block-for-track-size response command.

BEST MODE FOR CARRYING OUT THE INVENTION

A preferred embodiment of the present invention is explained in paragraphs arranged in the following order. 1. Tree Structure of Encryption Keys and EKB 2. System Configuration 3. Data Paths of SDMI Contents 4. Typical Configuration of Data Transfer Apparatus (Primary-Recording-Medium Apparatus or PC) 5. Typical Configuration of Data-Recording Apparatus (Secondary-Recording-Medium Apparatus or Recording/Reproduction Apparatus) 6. Management Technique of Mini Disc 7. Authentication Process 8. Content Encryption Technique 9. Content Check-Outs/Check-Ins 10. Generation and Management Technique of Content IDs 11. Acquisition of Medium Information 1. Tree Structure of Encryption Keys and EKB

First of all, before the transfer system implemented by an embodiment of the present invention is explained concretely, an organization of encryption keys used in distribution of contents is described.

To begin with, the following description explains an encryption-key ownership scheme for devices and a data distribution scheme, which are adopted when encrypted data is distributed from a content distributor to the devices each serving as a content recipient, by referring to FIGS. 1, 2A, 2B and 3.

FIG. 1 is an explanatory diagram showing a tree structure of encryption keys. Reference notations DV0 to DV15 at the bottom layer of the hierarchical tree structure shown in FIG. 1 each denote a device on the content-recipient side. Thus, each leaf of the hierarchical tree structure corresponds to such a device.

Each of the devices DV0 to DV15 is given a set of keys at a manufacturing time, at a shipping time or thereafter. Stored in a memory employed in each of the devices, the set of keys given to a device includes a leaf key assigned to a leaf representing the device in the hierarchical tree structure shown in FIG. 1 and node keys each assigned to a node between the leaf and the root in the hierarchical tree structure. Keys included in this key set are referred to as DNKs (Device Node Keys), examples of which are explained as follows.

K0000 to K1111 at the bottom layer of the hierarchical tree structure shown in FIG. 1 are leaf keys given to the devices DV0 to DV15 respectively. KR is the root key assigned to the root on the top of the hierarchical tree structure. K000 to K111 are node keys assigned to nodes on a second hierarchical layer from the bottom layer. In the following description, the node keys may mean node keys including root key KR assigned to the root.

In the hierarchical tree structure shown in FIG. 1, DNKs given to device DV0 include a leaf key K0000, node keys K000, K00 and K0 as well as a root key KR. The node keys K000, K00 and K0 and the root key KR, which are included in the DNKs, are each held by device DV0 in a state of being encrypted by using the leaf key K0000.

By the same token, DNKs given to device DV5 include a leaf key K0101, node keys K010, K01 and K0 as well as the root key KR. In the same way, DNKs given to device DV15 include a leaf key K1111, node keys K111, K11 and K1 and the root key KR.

It is to be noted that, while only 16 devices DV0 to DV15 are shown in the tree structure shown in FIG. 1 and the tree structure is designed as a balanced right-left symmetrical structure having 4 hierarchical layers, the tree structure may include more devices and has a configuration with a layer count varying from portion to portion.

In addition, a variety of information-processing apparatus included in the tree structure shown in FIG. 1 have a variety of recording mediums. The information-processing apparatus are devices of a variety of types. The devices have recording mediums such as a DVD, a CD, an MD and a flash memory, which are either embedded in the devices or can be mounted on and dismounted from the devices with a high degree of freedom. In addition, a variety of application services may be rendered for the information-processing apparatus. The tree structure shown in FIG. 1 is used for distributing contents and keys to the devices carrying out a variety of applications.

In a system wherein these various information-processing apparatus (or devices) and application exist, let a group be set to include devices DV0, DV1, DV2 and DV3 using the same recording medium. In the tree structure shown in FIG. 1, the device group is enclosed by a dashed line. Assume for example that, for all the devices, a content provider encrypts a content to be transmitted to the devices pertaining to the group enclosed by the dashed line to be used as a content common to the devices. In this case, the content provider also transmits contents keys to the devices to be used by the devices as keys common to the devices. Other processing in the system includes transmission of encrypted payment data of content fees from the devices to the content provider, a financial settlement institution or another enterprise. The enterprise such as the content provider or the financial settlement institution carries out processing to transmit collectively data to the devices enclosed by the dashed line, namely, DV0, DV1, DV2 and DV3. The enterprise exchanges data with the devices, which form the aforementioned group. A plurality of such groups exists in the tree structure shown in FIG. 1. The enterprise such as the content provider or the financial settlement institution, which exchanges data with the devices, functions as message-data distribution means.

It is to be noted that that node keys and leaf keys can also be managed by a single key management center in an integrated manner. As an alternative, the keys can also be managed by the message-data distribution means, which exchanges various kinds of data with groups cited above, in group units. As mentioned above, the message-data distribution means is an enterprise such as a content provider or a financial settlement institution. A node key and/or a leaf key are renewed when one of them has been leaked. Processing to renew keys is carried out by a key management center, a provider, a financial settlement institution or another enterprise.

As is obvious from FIG. 1, in this tee structure, the 4 devices, namely, DV0, DV1, DV2 and DV3, which are included in the group, have common keys: node keys K00 and K0 and the root key KR. By assigning these node and root keys to the devices DV0, DV1, DV2 and DV3 in the group as keys common to the devices, a common content can be provided to only the devices.

By setting the shared node key K00 itself as a content key, for example, a content key common to the devices DV0, DV1, DV2 and DV3 can be set for only the devices without transmitting a new key. As an alternative, a new content key CK is encrypted by using the node key K00 to produce an encrypted key E (K00, CK), which is then distributed to the devices DV0, DV1, DV2 and DV3 by way of a network, or by using a recording medium for recording the encrypted key and supplying the medium to the devices. In this way, only the devices DV0, DV1, DV2 and DV3 are capable of decrypting the encrypted key E (K00, CK) by using the node key K00 shared thereby as a common key to produce the content key CK.

Assume that it is discovered at a time t that keys K0011, K001, K00, K0 and KR, which are owned by the device DV3, have been analyzed by a hacker and hence exposed to the hacker. In this case, it is necessary to detach the device DV3 from the system or, specifically, the group including the devices DV0, DV1, DV2 and DV3, in order to protect data exchanged with the system thereafter.

In addition, it is also necessary to renew the keys K001, K00, K0 and KR to keys K(t)001, K(t)00, K(t)0 and K(t)R respectively and to transmit the renewed keys K(t)001, K(t)00, K(t)0 and K(t)R to the devices DV0, DV1 and DV2. It is to be noted that notation K(t)aaa denotes a key Kaaa's renewed key of a t generation.

It is needless to say that, in a distribution of a content, node keys and the root key KR may also be renewed in some cases for a variety of reasons including a desire of the copyright owner and a state of transmission to the system.

Thus, when a key is renewed, it is necessary to transmit the renewed key to regular devices owning the pre-renew key.

Next, processing to distribute renewed keys is explained. Updated keys are organized and transmitted by using a table like one shown in FIG. 2A. The table is transmitted to a device by way of a network, or by storing the table in a recording medium and providing the medium to the device. The table contains a block data called an EKB (Enabling Key Block). If the device DV3 is detached from the system as described above, for example, the EKB is supplied to the devices DV0, DV1 and DV2.

It is to be noted that the EKB contains encrypted keys obtained as results of encrypting new keys to be distributed to some devices at leaves of a tree structure like the one shown in FIG. 1. The EKB is also referred to as a KRB (Key Renewal Block).

The block data of the EKB shown in FIG. 2A includes encrypted renewed node keys that can be decrypted by devices needing the renewed node keys. The typical EKBs shown in FIGS. 2A and 2B are each block data created for the purpose of distributing renewed node keys of the t generation to the devices DV0, DV1 and DV2 in the tree structure shown in FIG. 1.

Assume that the keys K001, K001, K00, K0 and KR have been illegally exposed to unauthorized person. In this case, the devices DV0 and DV1 require renewed keys K(t)00, K(t)0 and K(t)R whereas the device DV2 requires renewed keys K(t)001, KT00, K(t)0 and K(t)R.

As shown in FIG. 2A, the EKB includes a plurality of encrypted renewed keys. An encrypted renewed key at the bottom of the EKB is E (K0010, K(t)001), which is a result of encrypting a renewed key K(t)001 by using the leaf key K0010 owned by the device DV2. Thus, the device DV2 is capable of decrypting the encrypted renewed key E (K0010, K(t)01) by using the leaf key owned by the device itself to get the renewed node key K(t)001.

In addition, an encrypted renewed key E (K(t)001, K(t)00) on the second line from the bottom of the EKB shown in FIG. 2A can be decrypted by using the renewed node key K(t)001 to get a renewed node key K(t)00. Then, an encrypted renewed key E (K(t)00, K(t)0) on the second line from the top of the EKB can be decrypted by using the renewed node key K(t)00 to get a renewed node key K(t)0. Finally, an encrypted renewed key E (K(t)0, K(t)R) on the top line of the EKB can be decrypted by using the renewed node key K(t)0 to get a renewed root key K(t)R.

As for the devices DV0 and DV1, the leaf keys K0000 and K0001 as well as the node key K000 are not renewed. Thus, only the renewed keys K(t)00, K(t)0 and K(t)R are needed.

Therefore, in the case of the devices DV0 and DV1, an encrypted renewed key E (K(t)000, K(t)00) on the third line from the top of the EKB shown in FIG. 2A can be decrypted by using the renewed node key K(t)000 to get a renewed node key K(t)00. Then, an encrypted renewed key