DATA TRANSFER SYSTEM, DATA TRANSFER APPARATUS,
DATA RECORDING APPARATUS, DATA TRANSFER METHOD,
AND RECORDING MEDIUM
BACKGROUND OF THE INVENTION
The present invention relates to a data transfer
system, data transfer apparatus, a data recording
apparatus, a data transfer method, and a recording medium
which are suitable for transfer and recording of content
data such as music to be copyright protected.
For example, content data such as music are stored
in a hard disk drive (hereafter referred to as a HDD),
the recording medium, of a personal computer, the stored
content data are transferred to another recording medium
(the secondary recording medium), and the content data
are reproduced from this secondary recording medium.
In this case, the HDD stores content data such as
music reproduced from a package medium such as CD-DA
(Compact Disk Digital Audio) and DVD (Digital Versatile
Disk) or content data downloaded from an external music
server for example via a communication network to which
the personal computer is connected. The user of the
personal computer connects a recording apparatus for the
secondary recording medium to the personal computer,
copies or moves the content data from the HDD to the
secondary recording medium, and reproduces the content
data such as music through a reproducing apparatus
compatible with the secondary recording medium.
The secondary recording medium may be a memory card
based on a semiconductor memory such as a flash memory, a
Mini Disc (trademark), a CD-R (CD Recordable), a CD-RW
(CD Rewritable), a DVD-RAM, a DVD-R, or a DVD-RW, which
is a magneto-optical disk.
Recorders/players capable of recording and/or
playing these recording media are in wide use as
recording/reproducing apparatuses compatible with the
secondary recording medium. These recorders/players are
various in type; stationary type, portable type, and so
on. Users can record/playback content data in accordance
with their preference and the types of their apparatuses.
Given the above-mentioned content data usage forms,
the copyright protection of these content data must be
taken into consideration. For example, if users can store
content data into the HDD of their personal computers by
downloading the content data through content data
distribution services or from purchased package media and
then copy the stored content data without restriction to
secondary recording media, a problem of copyright
violation occurs. To overcome this problem to maintain
the copyright protection in the handling of content data
as digital data, various technological and data handling
standards have been proposed. One of them is SDMI (Secure
Digital Music Initiative).
FIG. 1 illustrates a data path formulated by SDMI.
It should be noted that, in a personal computer having a
HDD as the primary recording medium, this data path
i
stores and transfers music content to external devices
(on the secondary recording medium side). In other words,
this data path is implemented by an installed software
program which stores and/or transfers music content. The
procedures and processing on the data path shown in FIG.
1 are denoted by references DP21 through DP 28. In what
follows, these references are used for corresponding
descriptions.
The software installed in the personal computer
having the HDD determines whether the content data
distributed by an external server via a network
(hereafter referred to as network content) are based on
SDMI for copyright protection (DP21) .
The network content to be distributed includes the
content data which are transmitted by the server side as
SDMI-compliant content (hereafter referred to as SDMIcompliant
content) and content data which are not
associated with SDMI (hereafter referred to as non-SDMI
content).
With the SDMI-compliant content, the content data
are encrypted by content key CK based on DBS (Data
Encryption Standard) for example. The content data
themselves are originally encoded by a compression
algorithm such as ATRAC3 or MP3 (Moving Picture Experts
Group 1/2 layer 3), which are then encrypted for
distribution.
It should be noted that, for the convenience of
description, data y encrypted by key x are represented as
E(x, y).
For the encrypted data E(x, y), the data decrypted
by key x are represented as D{x, E(x, y)}.
Therefore, if the compressed data based on ATRAC3
is represented as A3D, then the SDMI-compliant content to
be encrypted by key CK for distribution is represented as
E(CK, A3D).
If the distributed network content is SDMI -
compliant, it is stored in the primary recording medium
such as the HDD as SDMI content (DP21 and DP22).
In this case, the content data are written to the
HDD in the state of encrypted E(CK, A3D). Alternatively,
the content data are decrypted and then encrypted by
another key CK' , namely encryption keys are changed, and
then the newly encrypted content data are written to the
HDD in the state of E(CK', A3D) .
On the other hand, if the network content is non-
SDMI content, then watermark check, namely screening by
electronic watermark is executed (DP21 to DP23).
Further, direct watermark check is executed (DP23)
on the content data read from package media such as CD-DA
and DVD for example (hereafter referred to as disk
content) which are reproduced on a disk drive device such
as the CD-ROM drive installed on the personal computer or
on a disk drive device connected to the personal computer
for example.
Namely, watermark check is executed on the content
data not based on SDMI.
If the watermark-checked content data are found no
good, the content data are copy-disabled on the SDMI data
path (DP23 to DP25). Specific handling of copy
disablement depends on the software design. For example,
the content data may be stored in the HDD but may not be
transferred for copying or moving to other recording
media or the content data may not be stored in the HDD in
the processing of SDMI - compliant content.
If the content data have passed watermark check,
namely if a watermark is found in the content data and a
control bit indicates the permission of copy, then the
content data are found rightfully copyable. Next, whether
or not the content data are to be handled on the basis of
SDMI is determined (DP24). Whether or not to handle these
content data as compliant with SDMI may be determined by
the software design or user setting.
If the content data are not handled as compliant
with SDMI, then the content data are regarded as non-SDMI
content and excluded from the content data path compliant
with SDMI (DP26). For example, these content data may be
transferred to recording apparatuses which are not
compatible with SDMI.
On the other hand, if the content data are to be
handled as compliant with SDMI, then these content data
are encrypted and stored in the HDD as SDMI content (DP24
to DP22). For example, these content data are stored in
the form of E(CK, A3D) or E(CK', A3D).
The above-mentioned data path stores, in the
primary recording medium such as HDD, the content handled
as compliant with SDMI obtained via a network (hereafter
referred to as SDMI network content) and the content
handled as compliant with SDMI retrieved from a disk such
as CD-DA (hereafter referred to as SDMI disk content).
The SDMI content (SDMI network content or SDMI disk
content) stored in the HDD is transferred to a
recording/reproducing apparatus compliant with SDMI to be
copyable to the secondary recording medium compliant with
SDMI. The recording/reproducing apparatus compliant with
SDMI is a portable recorder/player based on memory card
for example, which is compatible with the encryption
based on SDMI.
In the case of SDMI disk content, a transfer
handling rule (or a usage rule) corresponding to SDMI
disk content is defined, on the basis of which the
transfer for copy to an SDMI - compliant
recording/reproducing is authorized (DP28).
It should be noted that the transfer for copy from
the primary recording medium (HDD) to the secondary
recording medium (memory card for example) which is
recorded and reproduced by an SDMI - compliant
recording/reproducing apparatus is referred to as
"checkout." The transfer for move from the secondary
recording medium to the primary recording medium is
referred to as "check-in." It should be noted that the
move from the secondary recording medium to the primary
recording medium deletes the transferred content data
from the secondary recording medium.
The rules of transferring SDMI disk content may
define a checkout upper limit count that each piece of
content data can be checked out a maximum of three times
for example. Therefore, SDMI disk content can be copied
up to three SDMI-compliant secondary recording media for
example. If a checkout takes place, the checkout count of
the content data managed in the personal computer having
the HDD is decremented. Consequently, even after the
copying to three SDMI - compliant secondary recording media,
if content data are checked in from one of these
secondary recording media to the primary recording medium
(HDD), the checkout count of content data managed in the
personal computer is incremented by one. As a result, the
content is made copyable once again from the primary
recording medium (HDD) to an SDMI - compliant secondary
recording medium. Namely, content data are allowed to
exist always on up to three SDMI-compliant secondary
recording media.
In the case of SDMI network content, a transfer
handling rule (usage rule) corresponding to SDMI network
content is also defined, on the basis of which the
transfer for copy to an SDMI - compliant
recording/reproducing apparatus is authorized (DP27).
This transfer handling rule specifies the upper
limit of checkout count for example as with the rule for
SDMI disk content. The upper limit count may be the same
as or different from the rule for SDMI disk content. For
example, the upper limit checkout count may be one. In
this case, one piece of content data can be copied to
only another one SDMI - compliant secondary recording
medium; however, if content data are checked in from that
secondary recording medium, the content data can be
transferred for copy again.
When SDMI content is transferred for copy to an
SDMI-compliant secondary recording medium in accordance
with these handling rules, the content data are
transmitted as encrypted on a transmission path. Namely,
the content data are transmitted in the above-mentioned
state of E(CK, A3D) or E(CK', A3D).
Further, on the SDMI - compliant
recording/reproducing apparatus which has received the
encrypted SDMI content, the received SDMI content is
copied to the secondary recording medium as encrypted.
If the SDMI-compliant recording/reproducing
apparatus reproduces the SDMI content from the secondary
recording medium, the content data read from the
secondary recording medium are decrypted. Namely, the
content data copied to the secondary recording medium in
the state of E(CK, A3D) or E(CK', A3D) are decrypted by
key CK or key CK1.
More specifically, the original content data are
restored as the ATRAC3 data (A3D) decrypted as D{CK, E(CK,
A3D)} - A3D or D{CK', E(CK', A3D)} = A3D. The decrypted
content data are then decompressed from ATRAC3
compression to be demodulated as audio data for example,
which are reproduced as music.
According to the SDMI - compliant data path, the
encrypted content data are transmitted from a server on
the network to a secondary recording medium and the
copying of these content data is controlled by
predetermined rules, so that the copyright of the content
data can be properly protected.
However, the following drawbacks may occur from the
copying of content data to SDMI - compliant secondary
recording media.
Assume here that a Mini Disc (a kind of magnetooptical
disk) currently in wide use be used as the
secondary recording medium.
For example, if an SDMI - compliant Mini Disc
recording apparatus is used, this Mini Disc recording
apparatus records checked out SDMI content to a Mini Disc
in the encrypted state of E(CK, A3D) or E(CK', A3D).
In reproduction, ATRAC3 data (A3D) decrypted as
D{CK, E(CK, A3D)} - A3D or D{CK', E(CK', A3D)} = A3D must
be obtained to be decoded in a predetermined manner, the
result, music for example, being outputted for
reproduction.
Currently popular Mini Disc systems cannot record
encrypted data to Mini Discs. Obviously, no Mini Disc
reproducing device has a decoder for decrypting encrypted
data.
If, in the future, an SDMI - compliant Mini Disc
recording apparatus is developed and encrypted content
data can be recorded to a Mini Disc, the encrypted
content data recorded to the Mini Disc cannot be
reproduced by many non- SDMI - compliant Mini Disc players.
Namely, such a system will not provide the compatibility
in reproduction.
This may eventually restrict the proper use of the
SDMI content purchased by general users, thereby
significantly lowering the value and satisfaction to
general users of SDMI content providing services.
In consideration of the above-mentioned problem, a
system may be proposed in which SDMI content is
transferred, in a decrypted state, to a non-SDMI Mini
Disc recording apparatus for example to be copied to a
secondary recording medium such as a Mini Disc.
However, if this manner of copying is permitted,
content data can be copied easily, including unauthorized
copy. This may prevent the implementation of copyright
protection which is the inherent intent of SDMI.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention
to maintain copyright protection capability without
restricting the proper use by users of content data such
as music requiring copyright protection. To implement
this object, the present invention provides a data
transfer apparatus, a data recording apparatus, and a
data transfer system composed of these apparatuses, a
data transfer method which is executed in the data
transfer apparatus and a recording medium storing an
operation program which implements the data transfer
apparatus.
In carrying out the invention and according to one
aspect thereof, there is provided a data transfer
apparatus including a transmitter for transferring
content data encrypted in a predetermined manner from a
first memory which can store encrypted content data to an
external apparatus, a discriminator for discriminating
between a first external apparatus which can record only
encrypted content data to a second memory accommodated in
the external apparatus connected to the data transfer
apparatus and a second external apparatus which can
record only decrypted content data to the second memory,
and if the first external apparatus is discriminated by
the discriminator, a controller for decrementing a
transfer count of the encrypted content data when
transferring the encrypted content data from the first
memory to the external apparatus, incrementing the
transfer count when the encrypted content data are
returned from the first external apparatus, and disabling
the transfer of the content data from the first memory to
the external apparatus if the transfer count has exceeded
a predetermined limit value and, if the second external
apparatus is discriminated by the discriminator, the
controller disabling the return of the encrypted content
data from the second external apparatus.
In carrying out the invention and according to
another-aspect thereof, there is provided a data transfer
system having a data transfer apparatus and at least one
of a first external apparatus and a second external
apparatus which can be selectively connected to the data
transfer apparatus, the data transfer apparatus including
a transmitter for transferring content data encrypted in
a predetermined manner from a first memory which can
store encrypted content data to an external apparatus, a
discriminator for discriminating between a first external
apparatus which can record only encrypted content data to
a second memory accommodated in the external apparatus
connected to the data transfer apparatus and a second
external apparatus which can record only decrypted
content data to the second memory, and if the first
external apparatus is discriminated by the discriminator,
a controller for decrementing a transfer count of the
encrypted content data when transferring the encrypted
content data from the first memory to the external
apparatus, incrementing the transfer count when the
encrypted content data are returned from the first
external apparatus, and disabling the transfer of the
content data from the first memory to the external
apparatus if the transfer count has exceeded a
predetermined limit value and, if the second external
apparatus is discriminated by the discriminator, the
controller disabling the return of the encrypted content
data from the second external apparatus, the second
external apparatus including a receiver for receiving the
content data encrypted in a predetermined manner from the
transmitter, a decryption element for decrypting the
content data encrypted in a predetermined manner received
by the receiver and a recording element for recording the
content data decrypted by the description element into
the second memory.
In carrying out the invention and according to
still another aspect thereof, there is provided a data
recording apparatus which receives encrypted content data
from a data transfer apparatus having a first recording
medium storing the encrypted content data and records the
received encrypted content data to a second recording
medium, including a communication line for performing
bidirectional communication with the data transfer
apparatus, an authorization processor for performing
authentication with the data transfer apparatus through
the communication line, a decryption element for
decrypting the encrypted content data supplied from the
data transfer apparatus through the communication line, a
recording element for recording the content data
decrypted by the description element to the second
recording medium and a controller for disabling the
return of the content data from the second recording
medium to the data transfer apparatus through the
communication line.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects of the invention will be
seen by reference to the description, taken in connection
with the accompanying drawing, in which:
FIG. 1 is a schematic diagram illustrating the
content flow and usage rule formulated by SDMI;
FIG. 2 is a block diagram illustrating an overall
system applicable to the invention;
FIG. 3 is a block diagram illustrating a primary
recording medium side apparatus applicable to the
invention;
FIG. 4 is a block diagram illustrating a secondary
recording medium side apparatus applicable to the
invention;
FIG. 5 is a transaction diagram illustrating a
procedure of authentication processing between the
primary recording medium side apparatus and the secondary
recording medium side apparatus;
FIG. 6 illustrates the content flow and usage rule.,
practiced as a first embodiment of the invention;
FIG. 7 illustrates the content flow and usage rule
practiced as a second embodiment of the invention;
16
FIG. 8 illustrates the content flow and usage rule
practiced as a third embodiment of the invention; and
FIG. 9 illustrates the content flow and usage rule
practiced as a fourth embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
This invention will be described in further detail
by way of example with reference to the accompanying
drawings in the following order:
1. System configuration
2. Exemplary configuration of data transfer apparatus
(primary recording medium side apparatus = PC)
3. Exemplary configuration of data recording apparatus
(secondary recording medium side apparatus =
recording/reproducing apparatus)
4. Authentication processing
5. Example of SDMI content transfer processing
1. System configuration
Referring to FIG. 2, there is shown an exemplary
system configuration. A primary recording medium side
apparatus 1 corresponds to a data transfer apparatus
associated with the present invention. A secondary
recording medium side apparatus 20A corresponds to a data
recording apparatus associated with the present invention,
Therefore, the configuration made up of the primary
recording medium side apparatus 1 and secondary recording
medium side apparatus 20A shown in FIG. 2 corresponds to
a data transfer system associated with the present
invention.
The primary recording medium side apparatus 1 is
constituted by a personal computer for example. In what
follows, the primary recording medium side apparatus 1 is
also referred to as a personal computer (PC) 1 for the
convenience of description. However, the primary
recording medium side apparatus 1 may not always be
constituted by a personal computer; it may be any device
installed with software and having a mass storage device.
The primary recording medium side apparatus 1
functions as the data transfer apparatus as referred to
herein by executing the software, which is activated on a
personal computer for example, for storing and/or
transferring SDMI content data.
An HDD 5 incorporated in (or externally attached
to) the personal computer 1 serves as a primary recording
medium (and a primary recording medium drive means). It
should be noted that, in the description of the
embodiments, the HDD 5 is the primary recording medium;
however, it will be apparent that the primary recording
medium may also be a disk medium such as optical disk or
magneto-optical disk or a semiconductor memory which is
incorporated or portable (such as memory card) for
example.
The primary recording medium side apparatus 1 is
communicable with a content server 91 via a communication
network 110, downloading content data such as music from
the content server 91. Obviously, there are a plurality
of content servers 91, from which the user of the
personal computer 1 can use various downloading services
as desired.
The content data to be downloaded from the content
server 91 to the personal computer 1 includes SDMI -
compliant content data and non-SDMI- compliant content
data.
A transmission path constituting the communication
network 110 may be a. wired or wireless public switched
line network or a dedicated line arranged between the
personal computer 1 and the content server 91. The
communication network 110 may be communication satellite
line, ISDN (Integrated Services Digital Network), analog
telephone line, or Bluetooth, for example.
The HDD 5 of the personal computer 1 can also store
content data such as music reproduced from package media
90 (hereafter also referred to as a disk 90) such as CDDA
and DVD by an incorporated or externally attached disk
drive.
The personal computer 1 is connected to the
secondary recording medium side apparatus 20A or 20B, to
which the content data can be transferred from the HDD 5.
The secondary recording medium side apparatus 20A or 20B
is a recording apparatus or a recording and reproducing
apparatus for the secondary recording media. The
secondary recording medium side apparatus 20A or 20B can
copy the content data transferred from the personal
computer 1 to the secondary recording media.
The secondary recording medium side apparatuses 20A
and 20B are various in specific form. The secondary
recording medium side apparatus 20B herein is an SDMIcompliant
recording apparatus. Namely, the SDMI - compliant
recording/reproducing apparatus shown in FIG. 1
corresponds to the secondary recording medium side
apparatus 20B. In this case, the secondary recording
medium is an SDMI-compliant memory card based on a
semiconductor memory such as flash memory, for example.
Therefore, the secondary recording medium side apparatus
20B is a recording/reproducing apparatus compatible with
SDMI - compliant memory cards for example. In this case,
SDMI content is recorded to the secondary recording
medium as encrypted.
On the other hand, the secondary recording medium
side apparatus 20A corresponds to the data recording
apparatus referred to herein. The secondary recording
medium side apparatus 20A stores the copyright-protected
SDMI content in the secondary recording medium as
decrypted, of which details will be descried later. One
example herein of the secondary recording medium is the
Mini Disc. Therefore, the secondary recording medium side
apparatus 20A is a Mini Disc recording/reproducing
apparatus. In what follows, the secondary recording
medium side apparatus 20A may also be referred to as the
recording/reproducing apparatus 20A.
In addition to the Mini Disc, the media which is
recorded or reproduced by the secondary recording medium
side apparatus 20A include memory cards based on
semiconductor memory such as flash memory, the Mini Disc
as magneto-optical disk, CD-R (CD Recordable), CD-RW (CD
Rewritable), DVD-RAM, DVD-R, and DVD-RW, for example.
Therefore, the secondary recording medium side apparatus
20A may be any device that is compatible with these
recording media.
The personal computer 1 is connected to the
secondary recording medium side apparatus 20A or 20B on
the basis of a transmission protocol such as USB
(Universal Serial Bus) or IEEE 1394. It will be apparent
that control signals and content data may also be
transferred in between over a wired or wireless
transmission path based on other transmission protocol
such as Bluetooth or DS-SS (compliant with IEEE 802.lib).
2. Exemplary configuration of data transfer apparatus
(primary recording medium side apparatus = PC)
Referring to FIG. 3, there is shown a configuration
of the primary recording medium side apparatus 1 which
provides the data transfer apparatus. It should be noted
that, in this example, the primary recording medium side
apparatus 1 is constituted by a personal computer; it
will be apparent that the primary recording medium side
apparatus I may also be constituted as a data - transferonly
apparatus based on dedicated hardware having the
same capabilities.
In this example, when a software program for
executing the capabilities as the data transfer apparatus
is installed in the personal -.computer 1, the primary
recording medium side apparatus to provide the data
transfer apparatus is implemented. It should be noted
that "personal computer" or "computer" referred to herein
generically denotes a so-called general-purpose computer.
This software program can be stored beforehand in
the hard disk (HDD) 5 or the ROM 3 incorporated in the
computer as a recording medium.
Alternatively, this software program can be stored
(or recorded) temporarily or permanently in a removable
recording medium 90 such as floppy disk, CD-ROM (Compact
Disk Read Only Memory), MO (Magneto Optical) disk, DVD
(Digital Versatile Disk), magnetic disk, or semiconductor
memory. The removable recording medium 90 can be provided
as so-called package software.
It should be noted that, in addition to the
installation from the removable recording medium 90 into
the computer, the program can be downloaded from a
download site to the computer in a wireless manner via a
digital broadcast satellite or in a wired manner via the
network such as a LAN (Local Area Network) or the
Internet. The computer receives the downloaded program at
its communication section 8 and stores it into the
incorporated HDD 5.
The computer 1 shown .on FIG. 3 incorporates a CPU
(Central Processing Unit) 2. The CPU 2 is connected to an
input/output interface 10 via a bus 12. When a command is
inputted by the user by operating an input section 7
constituted by a keyboard, a mouse, and a microphone for
example, the CPU 2 accordingly executes the program
stored in the ROM (Read Only Memory) 3. In addition, the
CPU 2 executes the program stored in the HDD 5, the
program transferred from a communication satellite or a
network, received at the communication section 8, and
stored in the HDD 5, or the program read from the
removable recording medium 90 such as an optical disk
loaded in the drive 9 and installed in the HDD 5, by
loading the program into a RAM (Random Access Memory) 4.
Thus, the CPU 2 executes the processing as the data
transfer apparatus on SDMI content to be described later.
Then, the CPU 2 outputs the obtained processing
results from an output section 6 constituted by a LCD
(Liquid Crystal Display) and a speaker for example via
the input/output interface 10, transmits them from the
communication section 8, or records them to the HDD 5.
In the present example, the communication section 8
can communicate with various servers via the network 110
shown in FIG. 2. Namely, the computer 1 can download
network content such as music from an external content
server 91. The network content to be downloaded is
processed as SDMI-compliant content or non-SDMI- compliant
content by a procedure to be described later, the
processed SDMI content in the case of SDMI processing
being stored in the HDD 5. The SDMI content stored in the
HDD 5 becomes the content to be transferred to the
secondary recording medium side apparatus 20B compliant
with SDMI or the secondary recording medium side
apparatus (the recording/reproducing apparatus) 20A of
authorized type, which is the data recording apparatus
associated with the present invention.
A connection section 11 provides connection between
the primary recording medium side apparatus 1 and the
secondary recording medium side apparatuses 20A or 20B.
The connection section 11 is USB interface or IEEE 1394
interface for example. It will be apparent that other
standard interfaces, wired or wireless based on infrared
or radio may be used.
The authentication processing and data transfer
processing to be executed by the data transfer apparatus
of the present example will be described later. It should
be noted that these processing operations need not be
executed in a time-dependent manner along a procedure to
be described later; -they may be executed in parallel or
discretely (for example, in parallel processing or object
processing).
The above-mentioned programs may be processed by a
single computer or by two or more computers in a
distributed manner. Further, these programs may be
transmitted to remote computers for execution.
3. Exemplary configuration of data recording apparatus
(secondary recording medium side apparatus =
recording/reproducing apparatus)
Referring to FIG. 4, there is shown an exemplary
configuration of the secondary recording medium side
apparatus (the recording/reproducing apparatus) 20A
corresponding to the data recording apparatus associated
with the present invention.
In this example, the secondary recording medium
side apparatus 20A is configured as a Mini Disc recorder
for example. Therefore, a secondary recording medium 100
is the example of a Mini Disc (one kind of magnetooptical
disk) and therefore is also referred to as a Mini
Disc 100.
It should be noted that FIG. 4 shows only a
processing system for recording/reproducing data on the
Mini Disc as the secondary recording medium 100 and a
processing system for authentication and data transfer
with the above-mentioned primary recording medium side
apparatus 1, omitting the detailed illustration of a Mini
Disc 100 drive system, servo system, and reproduction and
output system because these systems are generally the
same as those of an ordinary Mini Disc
recording/reproducing apparatus.
A CPU 21 is a system controller for controlling the
entire recording/reproducing apparatus 20A. To be more
specific, the CPU 21 executes operations for controlling
rotary drive, spindle servo, focus servo, tracking servo,
sled servo, operations for controlling optical head laser
beam and magnetic head magnetism application, and
operations for controlling the encoding and decoding of
recorded and reproduced data, thereby recording and
reproducing the data on the Mini Disc 100. In addition,
the CPU 21 controls the communication for the
authentication with the personal computer 1 and the
indication for data generation, the transfer of various
commands issued from the personal computer 1, and the
processing of received content data.
Although not shown, an operator panel and a display
section are arranged as the user interface. The CPU 21
also executes the processing such as the monitoring of
user operations made at the operator panel and the
control of the display section.
A recording/reproducing section 25 has an optical
head, a magnetic head, a disk rotary drive system, a
servo system, and so on, thereby actually recording and
reproducing data on the Mini Disc 100.
An encoder/decoder 24 encodes the data to be
recorded to the Mini Disc 100 and decodes the data
reproduced therefrom. As is known, in the case of a Mini
Disc system, the data to be recorded are put through
ACIRC (Advanced Cross Interleave Reed Solomon Coding) and
EFM (Eight-to-Fourteen Modulation). Thus, the
encoder/decoder 24 performs ACIRC and EFM processing on
the recording data and supplies the resultant data to the
recording/reproducing section 25.
At reproduction, the encoder/decoder 24 performs
decoding such as binarization, EFM, and ACIRC on the data
supplied from the recording/reproducing section 25.
A codec 23 performs data compression and
decompression on the basis of the ATRAC/ATRAC3 algorithm.
As described above, the data to be recorded to the
Mini Disc 100 are compressed by ATRAC (Acoustic TRansform
Adaptive Coding) and then encoded. Therefore, if data not
compressed, for example PCM audio data are inputted in
the recording/reproducing apparatus secondary recording
medium side apparatus 20A as recording data, the inputted
data are compressed by the codec 23 on the basis of ATRAC
and the compressed data are supplied to the
encoder/decoder 24.
It should be noted that there are two audio data
compression schemes; ATRAC and ATRAC3, the latter being
higher in compression efficiency than the former. As
compared with bit rate of 292 Kbps of ATRAC, ATRAC3
provides two bit rates 132 Kbps and 66 Kbps, one of which
can be selected. The Memory Stick (MS) recognized as an
SDMI - compliant secondary recording medium encrypts the
audio data compressed by ATRAC3 and stores the encrypted
data. Recently, some commercially available Mini Disc
apparatuses, which are non-SDMI-compliant secondary
recording media, have ATRAC encoder/decoder and ATRAC3
encoder/decoder to store unencrypted ATRAC and ATRAC3
data.
At reproduction, the data read by the
recording/reproducing section 25 and decoded by the
encoder/decoder 24 are the data compressed on the basis
of ATRAC. Hence, the compressed data are decompressed by
the codec 23. Consequently, digital audio data of 44.1
KHz and 16-bit quantized for example are demodulated. The
demodulated digital audio data are D/A converted, analog
signal processed, and amplified by output line circuits,
not shown, to become a speaker output signal, being
reproduced as music for example.
Alternatively, the digital audio data can be
outputted without change to another apparatus.
The above-mentioned configuration also applies to
the recording/reproducing apparatus of ordinary Mini Disc
systems. The recording/reproducing apparatus secondary
recording medium side apparatus 20A of the present
embodiment has an interface 26 and a decryption section
29 as sections corresponding to the personal computer as
the primary recording medium side apparatus 1.
The interface 26 connects to the connection section
11 of the personal computer 1 shown in FIG. 3, executing
data communication with the personal computer 1. Hence,
the interface 26 has a buffer 27 for buffering
send/receive data and a send/receive processor 28 for
performing signal processing on the interface. For
example, the interface 26 performs signal processing on
the basis of USB or IEEE 1394 communication protocol.
The communication with the personal computer 1
through the interface 26 includes the reception of
various commands from the personal computer 1, the
transmission and reception of the data necessary for
authentication processing to be described later, and the
reception of SDMI content.
The decryption section 29 decrypts SDMI content and
30
has a key storage section 30 and a decryption processor
31.
The key storage section stores keys (key CK and key
CK1 for example) for decrypting encrypted SDMI content.
These keys may be stored beforehand or transmitted from
the personal computer 1 to the recording/reproducing
apparatus 20A at a predetermined time. When the personal
computer 1 transmits these keys, they may be encrypted by
another key CCK, the received keys are decrypted on the
recording/reproducing apparatus 20A by use of the key CCK,
and the decrypted keys are stored in the key storage
section 30.
Storing the keys, such as the key CK and the like,
for decrypting SDMI content allows the decryption
processor 31 to decrypt the SDMI content received as
encrypted by key CK for example, namely the content in
the state of E(CK, A3D) for example. Namely, the data
compressed by ATRAC3 decrypted as D{CK, E(CK, A3D)} = A3D
can be obtained. The ATRAC3 data thus decrypted are
encoded by the encoder/decoder 24 to be recorded to the
Mini Disc 100 through the recording/reproducing section
25.
It should be noted that SDMI content is not always
ATRAC3-compressed data which are encrypted. For example,
SDMI content may be linear PCM data which are encrypted
by key CK. Namely, content in the state of E(CK, PCM) for
example may be inputted. In this case, obviously, the
linear PCM data decrypted as D{CK, E(CK, PCM)} = PCM can
be obtained in the decryption processor 31. In this case,
the PCM data is ATRAC3-compressed by the codec 23,
encoded by the encoder/decoder 24, and recorded to the
Mini Disc 100 through the recording/reproducing section
25.
The key storage section 30 may also store keys for
authentication processing. An exemplary authentication
processing to be described later uses public key P and
secret key S stored in the recording/reproducing
apparatus 20A. In this case, both public key P and secret
key S are stored in the key storage section 30.
4. Authentication processing
The recording/reproducing apparatus 20A as referred
to herein denotes a recording/reproducing apparatus
having a configuration as described in FIG. 4 and
successfully authenticated by the personal computer 1.
The recording/reproducing apparatus 20A records the SDMI
content received from the personal computer 1 to the Mini
Disc 100 as decrypted, which will be described later in
detail. Authentication checks the recording/reproducing
32
apparatus to see if it is valid as a device permitted for
performing recording operations.
This authentication processing is executed when a
recording/reproducing apparatus other than the SDMI -
compliant recording/reproducing apparatus 20B is
connected. It should be noted that, if the SDMI-compliant
recording/reproducing apparatus 20B is connected,
processing for checking if this apparatus is the SDMI -
compliant as referred to herein. Namely, if the connected
apparatus is found other than the SDMI-compatible
recording/reproducing apparatus 20B, the following
authentication processing will be performed to check to
see whether or not the connected apparatus is the
recording/reproducing apparatus 20A.
The authentication processing in the present
example uses an authentication scheme based on
asymmetrical cryptography (or public key cryptography).
In asymmetrical cryptography, the encryption key is
different from the decryption key. Let data before
encryption be Db, encryption key be CKe, and decryption
key be CKd, then encryption data C are encrypted by C =
E(CKe, Db) and data Db are decrypted by D(CKd, C) - Db.
Encryption key CKe and decryption key CKd are
called a key pair, one of them being made public as the
33
public key while the other being held in a predetermined
portion as the secret key.
In the following authentication processing, of the
key pair CKe and CKd, public key is represented by P and
the secret key is represented by S. As described above,
in this case, the recording/reproducing apparatus 20A
stores public key P and secret key S providing encryption
key CKe and decryption key CKd in the key storage section
When authentication processing is performed, the
CPU 2 of the primary recording medium side apparatus
(personal computer) 1 for example sends a command for
authentication request to the CPU 21 of the secondary
recording medium side apparatus 20A
(recording/reproducing apparatus) and then the following
processing takes place between the CPU 2 (primary
recording medium side apparatus 1 = personal computer 1)
and the CPU 21 (secondary recording medium side apparatus
20A = recording/reproducing apparatus 20A) as shown in
FIG. 5.
When authentication processing starts, the CPU 21
of the secondary recording medium side apparatus 20A
transmits public key P from the key storage section 30 to
the primary recording medium side apparatus 1 through the
interface 26 in step SI. It should be noted that public
key P is also known by the primary recording medium side
apparatus 1.
Receiving public key P, the CPU 2 of the primary
recording medium side apparatus 1 generates a random
number r in step S2. In step S3, the CPU 2 transmits the
generated random number r to the secondary recording
medium side apparatus 20A.
Next, the CPU 21 of the secondary recording medium
side apparatus 20A encrypts the received random number r
by use of secret key S stored in the key storage section
30 in step S4. In step S5, the CPU 21 transmits the
encrypted data E(S, r) to the primary recording medium
side apparatus 1.
Receiving the encrypted data E(S, r), the CPU 2 of
the primary recording medium side apparatus 1 decrypts
the received encrypted data E(S, r) by use of public key
P in step S6. Namely, the CPU 2 executes processing of
D{P, E(S, r)}.
In step S7, the CPU 2 compares the random number r
generated in step S2 with the decryption result D{P, E(S,
r)} obtained in step S6.
If public key P and secret key S are of an
appropriate key pair, then result r = D{P, E(S, r)}
should be obtained.
If a match is found, then it indicates that the
secondary recording medium side apparatus 20A holds
secret key S for public key P, upon which the procedure
goes from SB to S9, in which the secondary recording
medium side apparatus 20A is authenticated as an
authorized mate of connection.
On the other hand, if no match is found, the
procedure goes from S8 to S10, in which the connected
secondary recording medium side apparatus is regarded as
not the authorized mate of connection (namely the device
to which SDMI content can be transferred), thereby
failing authentication.
If the connected apparatus is successfully
authenticated as the secondary recording medium side
apparatus of the present example by the above-mentioned
authentication processing, the primary recording medium
side apparatus 1 recognizes that one of the conditions
for permitting the transfer of SDMI content to that
connected apparatus has been satisfied.
5. Example of SDMI content transfer processing
The following describes the transfer of SDMI
content from the primary recording medium side apparatus
(personal computer) 1 to the secondary recording medium
side apparatus 20A as one embodiment of the present
invention by use of first through fourth examples. These
examples will be described with reference to FIGS. 6
through 9 by use of the data paths as with FIG. 1. The
data path shown in each of FIGS. 6 through 9 is executed
by the processing of the CPU 2 of the personal computer 1
To be more specific, the CPU 2 executes the following
data path processing on the basis of a transfer
processing program installed from the removable recording
medium 90 for example.
It should be noted that the procedures/processing
on the data paths shown in FIGS. 6 through 9 are denoted
by DPI through DP11. In what follows, these references
are used for corresponding portions.
First example of transfer processing:
The following describes the first example of
transfer processing by use of the data path shown in FIG.
6.
Network content distributed from the content server
91 shown in FIG. 1 to the personal computer 1 via the
network 110 is determined whether or not it should be
copyright-protected on the basis of SDMI (DPI).
The network content to be distributed includes
SDMI - compliant content which is transmitted from the
server as content compliant with SDMI and non-SDMIcompliant
content.
In the case of SDMI-compliant content, its data are
encrypted by content key CK on the basis of key
cryptography such as DES. If the content data themselves
are data encoded by a compression scheme such as ATRAC3,
then the SDMI - compliant content is distributed in the
state of E(CK, A3D).
If the distributed content is SDMI - compliant
content, it is stored in the HDD 5, which is the primary
recording medium, as SDMI content (DPI to DP2).
In this case, the content data are written to the
HDD 5 in the distributed state of E(CK, A3D).
Alternatively, the content data are decrypted and then
encrypted by another key CK' (namely encryption keys are
changed) and then written to the HDD 5 in the state of
E(CK', A3D).
On the other hand, if the network content is non-
SDMI content, then it is watermark-checked, namely,
screened by watermark (DPI to DP3).
Further, the content data (disk content) read from
a package medium such as CD-DA or DVD for example which
is reproduced by the drive 9 such as CD-ROM drive of the
personal computer 1 or a disk drive connected thereto is
directly watermark-checked (DP3).
Namely, the content data not compliant with SDMI
are watermark-checked.
If the content data are found not passing the
watermark check, the content data are handled as noncopyable
on the SDMI data path (DPS to DPS) . Although the
specific handling depends on the software design used,
the failing content data are stored in the HDD 5 but not
transferred to another recording medium for copy or move
or not stored in the HDD 5 in the content processing
compliant with SDMI.
If the content data have passed the watermark check,
namely if a watermark is found in the content data and a
control bit indicates the permission of copy, then the
content data are found rightfully copyable. Next, whether
or not the content data are to be handled on the basis of
SDMI is determined (DP4). Whether or not to handle these
content data as compliant with SDMI may be determined by
the software design or user setting.
If the content data are not handled as compliant
with SDMI, then the content data are regarded as non-SDMI
content and excluded from the content data path compliant
with SDMI (DP6) . For example, these content data may be
transferred to recording apparatuses which are not
compatible with SDMI.
On the other hand, if the content data are to be
handled as compliant with SDMI, then these content data
are encrypted and stored in the HDD 5 as SDMI content
(DP4 to DP2). For example, these content data are stored
in the HDD 5 in the form of E(CK, A3D) or E(CK', A3D).
The above-mentioned data path stores, in the HDD 5,
the content handled as compliant with SDMI obtained via a
network (SDMI network content) and the content handled as
compliant with SDMI retrieved from a disk such as CD-DA
(SDMI disk content).
The SDMI content (SDMI network content or SDMI disk
content) stored in the HDD 5 is transferred to the
recording/reproducing apparatus 20B compliant with SDMI
to be copyable to the secondary recording medium
compliant with SDMI. In the present example, in addition
to the SDMI-compatible recording/reproducing apparatus
20B, the SDMI content can be transferred to the
successfully authenticated recording/reproducing
apparatus 20A under a predetermined condition.
First, the following operation takes place if the
SDMI - compliant recording/reproducing apparatus 20B is
connected to the connection section 11.
In the case of SDMI disk content, the transfer
handling rule (usage rule) corresponding to SDMI disk
content is determined. Therefore, under this handling
rule, the transfer to the SDMI - compliant
recording/reproducing apparatus 20B for copy is permitted
(DPS).
The rules of transferring SDMI disk content may
define a checkout upper limit count that each piece of
content data can be checked out a maximum of three times
for example. Therefore, SDMI disk content can be copied
up to three SDMI - compliant secondary recording media for
example. If a check-in takes place, the checkout count of
the content data is decremented. Consequently, even after
the copying to three SDMI-compliant secondary recording
media, if content data are checked in from one of these
secondary recording media, that content can be copied to
the SDMI - compliant media once again. Namely, content data
are allowed to exist together always on up to three SDMIcompliant
secondary recording media.
In the case of SDMI network content, a transfer
handling rule (usage rule) corresponding to SDMI network
content is also defined, on the basis of which the
transfer for copy to the SDMI-compliant
recording/reproducing apparatus 20B is authorized (DP7).
This transfer handling rule specifies the upper
limit of checkout count for example as with the rule for
SDMI disk content. The upper limit count may be the same
as or different from the rule for SDMI disk content. For
example, the upper limit checkout count may be one. In
this case, one piece of content data can be copied to
only another one SDMI - compliant secondary recording
medium; however, if content data are checked in from that
secondary recording medium, the content data can be
transferred for copy again.
When SDMI content is transferred for copy to an
SDMI - compliant secondary recording medium in accordance
with these handling rules, the content data are
transmitted as encrypted on the transmission path. Namely,
the content data are transmitted in the above-mentioned
state of E(CK, A3D) or E(CK', A3D).
Further, on the SDMI - compliant
recording/reproducing apparatus 20B which has received
the encrypted SDMI content, the received SDMI content is
copied to the secondary recording medium as encrypted.
If the SDMI-compliant recording/reproducing
apparatus 20B reproduces the SDMI content from the
secondary recording medium, the content data read from
the secondary recording medium are decrypted. Namely, the
content data copied to the secondary recording medium in
the state of E(CK, A3D) or E(CK', A3D) are decrypted by
key CK or key CK'.
More specifically, the original content data are
restored as the ATRAC3 data (A3D) decrypted as D{CK, E(CK,
A3D)} = A3D or D{CK', E(CK', A3D)} = A3D. The decrypted
content data are then decompressed from ATRAC3
compression to be demodulated as audio data for example,
which are reproduced as music.
As described, the SDMI - compliant content data are
kept encrypted on the data path up to a point at which
the content data are checked out and up to the secondary
recording medium and the copy control is executed by the
above-mentioned transfer handling rule check, thereby
protecting content data copyright.
The processing described so far is generally the
same as the normal SDMI data path described with
reference to FIG. 1.
The following describes the portion indicated by
dashed lines shown in FIG. 6, which is a difference from
the configuration shown in FIG. 1 (this difference forms
one of the features of the present invention).
If the recording/reproducing apparatus 20A
successfully authenticated as described above is
connected to the connection section 11, the following
processing is executed.
If the processing of transferring certain SDMI
network content stored in the HDD 5 to the
recording/reproducing apparatus 20A is requested, a
control signal attached to this SDMI network content is
checked to see whether or not "MDOK" flag is active (DP9)
This MDOK flag provides control information
indicative whether or not the content server 91 or the
copyright holder permits the copying and recording
certain content to a Mini Disc, which is the secondary
recording medium, in the decrypted state. Namely, the
MDOK flag is the control information which is preset on
the side of the content server 91.
It should be noted that "MDOK" is a flag name which
is given for the convenience of description in
correspondence with the case in which the Mini Disc is
used in the recording/reproducing apparatus 20A for
example. If the secondary recording medium 100 is other
than the Mini Disc, it does not mean that this flag
processing will not apply.
If the MDOK flag is active, the SDMI network
content can be transferred to the recording/reproducing
apparatus 20A.
However, as a further condition, the content data
which have been transferred once and then copied and
recorded to the Mini Disc 100 cannot be checked in.
When transferring SDMI network content to the
recording/reproducing apparatus 20A under these
conditions, the data transmission is executed on the
transmission path in the encrypted state. Namely, the
SDMI network content is transferred in the abovementioned
state of E(CK, A3D) or E(CK', A3D).
This encrypted SDMI network content is received at
the interface 26 of the recording/reproducing apparatus
20A shown in FIG. 4 and decrypted in the decrypting
section 29 into the original ATRAC3 compressed data (A3D)
for example. Then, the decrypted content data are encoded
by the encoder/decoder 24, and encoded content data are
supplied to the recording/reproducing section 25 to be
copied and recorded to the Mini Disc 100.
Therefore, to reproduce the SDMI content recorded
by the recording/reproducing apparatus 20A to the Mini
Disc 100, the data read from the Mini Disc 100 may only
be decoded in a Mini Disc system in a normal manner;
namely, EFM, ACIRC, and ATRAC decompression may only be
executed on the data read from the Mini Disc 100.
This indicates that the Mini Disc 100 copied and
recorded with content data can reproduce them also when
loaded on an ordinary Mini Disc player. Namely, by use of
an ordinary, non-SDMI- compliant Mini Disc player, the
user can play back the SDMI network content copied and
recorded to the Mini Disc 100 to enjoy music for example.
It should be noted that, if the MDOK flag of the
SDMI network content to be transferred is off, the
transfer is not permitted; namely, this SDMI network
content is handled as non-copyable (DP10).
The processing of transfer to other
recording/reproducing apparatuses than the SDMI - compliant
recording/reproducing apparatus 20B is summarized as
follows.
SDMI network content can be transferred to the
recording/reproducing apparatus 20A, namely copied and
recorded to the Mini Disc 100 in the unencrypted state
when the conditions (I) the recording/reproducing
apparatus 20A has been successfully authenticated, (2)
the MDOK flag of the content data to be transferred is
active (the transfer is authorized by the copyright
holder), and (3) check-in is disabled, are all satisfied.
Consequently, the user can effectively use the SDMI
network content recorded to the Mini Disc 100, thereby
enhancing the serviceability for users. At the same time,
while the transfer is permitted under the above-mentioned
three conditions, the SDMI network content data cannot be
transferred to other apparatuses than the SDMI-compliant
recording/reproducing apparatus 20B in an unconditional
manner and, because the SDMI network content is
transferred in the encrypted state, the copyright
protection capability is secured.
Second example of transfer processing:
The following describes the second example of
transfer processing with reference to the data path shown
in FIG. 7. It should be noted that DPI through DPS are
generally the same as shown in FIG. 6 and their
descriptions will be skipped; only the case in which the
authenticated recording/reproducing apparatus 20A is
connected to the personal computer 1. The portion which
differs from the first embodiment is indicated by dashed
lines in FIG. 7.
When the authenticated recording/reproducing
apparatus 20A is connected to the connection section 11,
the following processing is executed.
If the processing of transferring certain SDMI
network content stored in the HDD 5 to the
recording/reproducing apparatus 20A is requested, the
transfer handling rule check is first performed on the
SDMI network content (DP7). Namely, regardless whether
the connected apparatus is the SDMI-compliant
recording/reproducing apparatus 20B or the authenticated
recording/reproducing apparatus 20A, the upper limit of
checkout count is checked.
For example, if only one checkout is permitted as
the transfer handling rule for SDMI network content and
the SDMI network content in question is found checked out
in the past to the SDMI - compliant recording/reproducing
apparatus 20B (unless this content has been checked in),
then the transfer of this content to the authenticated
recording/reproducing apparatus 20A is disabled.
If the transfer handling rule for the SDMI network
content has been cleared, then the control signal
attached to the SDMI network content is checked to see
whether or not the MDOK flag is active (DP7 to DP9).
If the MDOK flag is found off, the transfer of this
content is disabled (DP10).
If the MDOK flag is found active, it indicates that
this SDMI network content can be transferred to the
secondary recording medium side apparatus 20A. In this
case, the content data are transferred on the
transmission path in the encrypted state. In the
recording/reproducing apparatus 20A, this network content
is copied and recorded to the Mini Disc 100 in the
decrypted state.
In this case, too, any content data that have been
transferred once and then copied and recorded to the Mini
Disc 100 cannot be checked in.
In this transfer processing example, the transfer
of SDMI network content to the recording/reproducing
apparatus 20A is permitted when the following conditions
are satisfied; (1) the recording/reproducing apparatus
20A has been successfully authenticated, (2) the MDOK
flag of the content data to be transferred is active (the
transfer is authorized by the copyright holder), (3)
check-in is disabled, and (4) the transfer handling rule
for not identifying the destination apparatus of SDMI
network content has been cleared. Then, the transfer to
the recording/reproducing apparatus 10A is permitted and
the SDMI network content can be copied and recorded to
the Mini Disc 100 in the decrypted state.
Consequently, the same effect as with the abovementioned
first example of transfer processing can be
obtained. At the same time, the upper limit of permitted
copy count is not exceeded by means of the common
transfer handling rule which does not identify connected
apparatuses, so that the copyright protection capability
becomes stronger than the first example of transfer
processing.
In the above-mentioned first embodiment, the
permitted copy count (the number of times checkout can be
performed) of SDMI network content from the primary
recording medium (HDD) to the secondary recording medium
(Mini Disc) is not restricted. In the above-mentioned
second embodiment, the MDOK flag is determined by
checking the handling rule of SDMI network content, so
that the permitted copy count of SDMI network content
from the primary recording medium to the secondary
recording medium can be restricted. Consequently,
stricter copyright protection control can be performed
than the first embodiment.
Third example of transfer processing:
The following describes the third example of
transfer processing with reference to the data path shown
in FIG. 8. It should be noted that DPI through DPS are
generally the same as shown in FIG. 6 and their
descriptions will be skipped; only the case in which the
authenticated recording/reproducing apparatus 20A is
connected to the personal computer-1.
When the authenticated recording/reproducing
apparatus 20A is connected to the connection section 11,
the following processing is executed.
If the transfer of certain SDMI network content
stored in the HDD 5 to the recording/reproducing
apparatus 20A is requested, the control signal attached
to this SDMI network content is checked to see whether or
not the MDOK flag is active (DP9).
If the MDOK flag is found off, the transfer of this
content is not permitted (DP9 to DP10).
If the MDOK flag is found active, then the transfer
handling rule for the SDMI network content is checked
(DP11). This check is performed independently of the
transfer handling check of DP7 which is executed when the
destination of connection is the SDMI - compliant
recording/reproducing apparatus 20B. Namely, regardless
of the checkout to the SDMI - compliant
recording/reproducing apparatus 20B, the upper limit of
permitted copy count is predetermined and the requested
transfer is checked if it is within the determined upper
limit.
If the requested transfer is found within the upper
limit count, this transfer handling rule check is
cleared; otherwise, the check is no good, thereby
disabling the requested transfer (DP11 to DP10).
When the transfer handling rule check for the
recording/reproducing apparatus 20A has been cleared for
the SDMI network content, this SDMI network content can
be transferred to the recording medium side apparatus 20A,
In this case, the content data are transmitted on the
transmission path in the encrypted state. In the
recording/reproducing apparatus 20A, the content data are
copied and recorded to the Mini Disc 100 in the decrypted
state.
In this case, too, any content data that have been
transferred once and then copied and recorded to the Mini
Disc 100 cannot be checked in.
In this transfer processing example, the transfer
of SDMI network content to the recording/reproducing
apparatus 20A is permitted when the following conditions
are satisfied; (1) the recording/reproducing apparatus
20A has been successfully authenticated, (2) the MDOK
flag of the content data to be transferred is active (the
transfer is authorized by the copyright holder), (3)
check-in is disabled, and (4) the transfer handling rule
for the case where the destination of SDMI network
content data is the recording/reproducing apparatus 20A
has been cleared. Then, the transfer to the
recording/reproducing apparatus 10A is permitted and the
SDMI network content can be copied and recorded to the
Mini Disc 100 in the decrypted state.
Consequently, the same effect as with the case
where the connected apparatus is the
recording/reproducing apparatus 20A. At the same time,
the transfer handling rule for the case where the
connected apparatus is the recording/reproducing
apparatus 20A is checked as one of the transfer
permission conditions, so that the copyright protection
capability is stronger than the first example of transfer
processing but less strict than the second example of
transfer processing. "Less strict" as used herein denotes
that the authorized usage range of users is widened to
some extent and does not denote that unauthorized copy
activities are facilitated (at least, these activities
are made more difficult by the copyright protection
capability of the level of the first example of transfer
processing).
Fourth example of transfer processing:
The following describes the fourth example of
transfer processing with reference to the data path shown
in FIG. 9. It should be noted that DPI through DPS are
generally the same as shown in FIG. 6 and their
descriptions will be skipped. The processing (DP9 and
DP10) for transferring SDMI network content when the
authenticated recording/reproducing apparatus 20A is
connected to the personal computer 1 is the same as shown
in FIG. 5.
In what follows, the handling of SDMI disk content
will be described.
When the above-mentioned authenticated
recording/reproducing apparatus 20A is connected to the
connection section 11 and the processing of transferring
certain SDMI disk content stored in the HDD 5 to the
recording/reproducing apparatus 20A is requested, the
transfer of this SDMI disk content to the
recording/reproducing apparatus 20A is permitted. On the
transmission path, the content data are transmitted in
the encrypted state. In the recording/reproducing
apparatus 20A, the content data are copied and recorded
to the Mini Disc 100 in the decrypted state.
In this case, too, any content data that have been
transferred once and then copied and recorded to the Mini
Disc 100 cannot be checked in.
In this example of transfer processing, the
transfer of SDMI disk content to the
recording/reproducing apparatus 20A is permitted and the
content data can be copied and recorded to the Mini Disc
100 when the following conditions are satisfied; (1) the
recording/reproducing apparatus 20A has been successfully
authenticated and (2) check-in is disabled.
Consequently, the usage range of the SDMI disk
content can also be widened as copied to the Mini Disc
100. At the same time, the copyright protection
capability can be secured by that the transfer
destination apparatus is identified, check-in is disabled,
and the transmission is made in the encrypted state.
In this example, the MDOK flag check is not
performed unlike the foregoing examples. This is because
the control information such as MDOK flag is not recorded
to widely used CD-DA and others. Hence, the intent of the
copyright holder is not reflected. However, this does not
mean that the copyright protection capability of the
fourth example of transfer processing is insufficient,
because, as for digital copy, the copy count is
controlled by the conventional SCMS (Serial Copy
Management System).
In addition, the copyright protection capability
for SDMI disk content can be further enhanced by
performing the transfer handling rule check with the
transfer destination not identified or by performing the
transfer handling rule check with the
recording/reproducing apparatus 20A being the transfer
destination.
Thus, the preferred embodiments of the present
invention have been described by way of example. It will
be apparent that the present invention is not limited to
these examples.
For example, the data transfer processing
operations mentioned above are applicable to not only
SDMI content but also various other data which require
copyright protection.
The primary recording medium is not only the HDD
but also many other storage devices.
It will also be apparent that the secondary
recording medium and the secondary recording medium side
apparatus 20A are not only the Mini Disc and the Mini
Disc player, but also various other devices. The
secondary recording medium 100 may also be CD-R, CD-RW,
DVD-RAM, DVD-R, DVD-RW, or memory card. Therefore, the
secondary recording medium side apparatus 20A may be any
recording device that is compatible with these recording
media.
In the foregoing description, the secondary
recording medium side apparatus is connected to the
personal computer, which is the primary recording medium
side apparatus, in a wired or wireless manner and
copyrighted content data are transmitted in this
configuration. It will be apparent that the personal
computer, which is the primary recording medium side
apparatus, may be arranged with a slot for loading the
secondary recording medium (MD, CD-R, or others) not
compliant with SDMI, thereby copying copyrighted content
data without using the secondary recording medium side
apparatus.
In the above-mentioned embodiments, the check-in
from the secondary recording medium to the primary
recording medium is disabled from the personal computer.
It will be apparent that this disablement may be
controlled from the secondary recording medium
recording/reproducing apparatus.
As described and according to the invention, the
transfer of content data stored in the primary recording
medium in the data transfer apparatus as the content data
to be copyright-protected such as SDMI content for
example to the data recording apparatus is permitted if
conditions such as the successful authentication of the
data recording apparatus connected to the data transfer
apparatus and the prohibition of the check-in from the
data recording apparatus. Further, the transfer to the
data recording apparatus is permitted if the provider
(copyright holder or server) of SDMI content permits the
transfer. Still further, the transfer to the data
recording apparatus is permitted if the transfer
permission condition specifying the upper limit of
permitted copy transfer count is satisfied. The data
recording apparatus records the received content data to
the secondary recording medium in the decrypted state.
Consequently, the secondary recording medium (for
example, Mini Disc) recorded with content data can be
played back by conventional players, thereby removing the
unnecessary restrictions to the usage of content. This
eventually enhances the serviceability to general users.
The permission of content transfer and copy under
these conditions prevents the unconditional, unauthorized
copy of content from taking place. All content data on
the transmission paths are encrypted. These novel
configurations contribute to the protection of the
copyright of content.
While the preferred embodiments of the present
invention have been described using specific terms, such
description is for illustrative purposes only, and it is
to be understood that changes and variations may be made
without departing from the spirit or scope of the
appended claims.

WHAT IS CLAIMED IS:
1. A data transfer apparatus comprising:
transfer means for transferring content data encrypted in a predetermined manner from a first recording means which can store encrypted content data to an external apparatus;
discrimination means for making discrimination between a first external apparatus which can record only encrypted content data to a second recording means accommodated in said external apparatus connected to said data transfer apparatus and a second external apparatus which can record only decrypted content data to said second recording means; and
if said first external apparatus is discriminated by said discrimination means, control means for decrementing a transfer count of the encrypted content data when transferring said encrypted content data from said first recording means to said external apparatus, incrementing said transfer count when said encrypted content data are returned from said first external apparatus, and disabling the transfer of said content data from said first recording means to said external apparatus if said transfer count has exceeded a predetermined limit value and,

if said second external apparatus is determined by said discrimination means, said control means disabling the return of the encrypted content data from said second external apparatus.
2. The data transfer apparatus according to claim 1, wherein said second recording means accommodated in said first external apparatus is a flash memory.
3 . The data transfer apparatus according to claim 1, wherein said second recording means accommodated in said second external apparatus is a magneto-optical disk.
4. The data transfer apparatus according to claim
1, wherein said first recording means is a hard disk.
5. The data transfer apparatus according to claim
1, wherein said second external apparatus has decryption
means for decrypting the encrypted content data
transferred from said data transfer apparatus, recording
the content data decrypted by said decryption means into
said second recording means.
6. The data transfer apparatus according to claim
1, further comprising:
first receiving means for receiving the encrypted content data and a control signal from a content server;
second receiving means for receiving unencrypted content data from a package medium; and

if said second external apparatus is discriminated by said discrimination means, determination means for determining whether or not to transfer said content data from said content server on the basis of said control signal attached to said content data supplied from said content server.
7. The data transfer apparatus according to claim
6, wherein said control means restricts the transfer
count of said content data supplied from said content
server, said content data being transferred from said
first recording means to said second external apparatus.
8. The data transfer apparatus according to claim
1, further comprising:
first receiving means for receiving encrypted content data and a control signal supplied from a content server;
second receiving means for receiving unencrypted content data supplied from a package medium; and
encryption means for encrypting said unencrypted content data supplied from said package medium and received by said second receiving means;
if said second external apparatus is discriminated by said discrimination means, the content data encrypted by said encryption means being supplied to said second

external apparatus.
9. A data transfer system having a data transfer apparatus and at least one of a first external apparatus and a second external apparatus which can be selectively connected to said data transfer apparatus, said data transfer apparatus comprising:
transfer means for transferring content data encrypted in a predetermined manner from a first recording means which can store encrypted content data to an external apparatus;
discrimination means for making discrimination between a first external apparatus which can record only encrypted content data to a second recording means accommodated in said external apparatus connected to said data transfer apparatus and a second external apparatus which can record only decrypted content data to said second recording means; and
if said first external apparatus is discriminated by said discrimination means, control means for decrementing a transfer count of the encrypted content data when transferring said encrypted content data from said first recording means to said external apparatus, incrementing said transfer count when said encrypted content data are returned from said first external

apparatus, and disabling the transfer of said content data from said first recording means to said external apparatus if said transfer count has exceeded a predetermined limit value and,
if said second external apparatus is discriminated by said discrimination means, said control means disabling the return of the encrypted content data from said second external apparatus;
said second external apparatus comprising:
receiving means for receiving the content data encrypted in a predetermined manner from said transfer means;
decryption means for decrypting said content data encrypted in a predetermined manner received by said receiving means; and
recording means for recording said content data decrypted by said description means into said second recording means.
10. The data transfer system according to claim 9,
wherein said second recording means accommodated in said
first external apparatus is a flash memory.
11. The data transfer system according to claim 9,
wherein said second recording means accommodated in said
second external apparatus is a magneto-optical disk.

12. The data transfer system according to claim 9,
wherein said first recording means is a hard disk.
13. The data transfer system according to claim 9,
wherein said second external apparatus has decryption
means for decrypting the encrypted content data
transferred from said data transfer apparatus, recording
the content data decrypted by said decryption means into
said second recording means.
14. The data transfer system according to claim 9,
further comprising:
first receiving means for receiving the encrypted content data and a control signal from a content server;
second receiving means for receiving unencrypted content data from a package medium; and
if said second external apparatus is discriminated by said discrimination means, determination means for determining whether or not to transfer said content data from said content server on the basis of said control signal attached to said content data supplied from said content server.
15. The data transfer system according to claim 14,
wherein said control means restricts the transfer count
of said content data supplied from said content server, said content data being transferred from said first

recording means to said second external apparatus.
16. The data transfer system according to claim 9,
wherein said data transfer apparatus further comprises:
first receiving means for receiving encrypted content data and a control signal supplied from a content server;
second receiving means for receiving unencrypted content data supplied from a package medium; and
encryption means for encrypting said unencrypted content data supplied from said package medium and received by said second receiving means;
if said second external apparatus is discriminated by said discrimination means, the content data encrypted by said encryption means being supplied to said second external apparatus.
17. A data transfer method for transferring
encrypted content data from a data transfer apparatus
having a first memory which can store encrypted content
data to a second memory accommodated in an external
apparatus connected to said data transfer apparatus, said
data transfer method comprising:
discrimination step for discriminating between a first external apparatus which can record only encrypted content data to a second memory accommodated in said

external apparatus connected to said data transfer apparatus and a second external apparatus which can record only decrypted content data to said second memory;
if said first external apparatus is discriminated by said discrimination means, first control step for decrementing a transfer count of the encrypted content data when transferring said encrypted content data from said first memory to said external apparatus, incrementing said transfer count when said encrypted data are returned from said first external apparatus, and disabling the transfer of said content data from said first memory to said external apparatus if said transfer count has exceeded a predetermined limit value; and,
if said second external apparatus is discriminated in said discrimination step, second control step for disabling the return of the encrypted content data from said second external apparatus.
18. The data transfer method according to claim 17,
wherein said second memory accommodated in said first
external apparatus is a flash memory.
19. The data transfer method according to claim 17,
wherein said second memory accommodated in said second
external apparatus is a magneto-optical disk.
20. The data transfer method according to claim 17,

wherein said first memory is a hard disk.
21. The data transfer method according to claim 17,
wherein, if the encrypted content data to be stored in
said first memory are supplied via a network, control
information is attached to said encrypted content data
and stored in said first memory, said data transfer method further comprising:
judgment step for judging whether there is said control information when transferring said encrypted content data from said first memory to said second external apparatus; and
if said second external apparatus has been discriminated in said discrimination step, determination step for determining whether to transfer said content data supplied from said content server depending on the presence of said control information.
22. The data transfer method according to claim 21,
further comprising:
restricting step for restricting a transfer count in which said content data supplied from said content server can be transferred from said first memory of said data transfer apparatus to said second external apparatus.
23. The data transfer method according to claim 17,
wherein, if encrypted content data to be stored in said

first memory are supplied from a package medium and said second external apparatus has been discriminated in the discrimination step, said encrypted content data are supplied to said second external apparatus.
24 . A data recording apparatus which receives encrypted content data from a data transfer apparatus having a first recording medium storing said encrypted content data and records the received encrypted content data to a second recording medium, comprising:
communication means for performing bidirectional communication with said data transfer apparatus;
authentication processing means for performing authentication with said data transfer apparatus through said communication means;
decryption means for decrypting said encrypted content data supplied from said data transfer apparatus through said communication means;
recording means for recording said content data decrypted by said description means to said second recording medium; and
control means for disabling the return of said content data from said second recording medium to said data transfer apparatus through said communication means.
25. A recording medium storing a computer - readable

program for transferring encrypted content data from a data transfer apparatus having a first memory storing said encrypted content data to a second memory accommodated in an external apparatus connected to said data transfer apparatus, said computer-readable program comprising:
discrimination step for discriminating between a first external apparatus which can record only encrypted content data to a second memory accommodated in said external apparatus connected to said data transfer apparatus and a second external apparatus which can record only decrypted content data to said second memory;
if said first external apparatus is discriminated in said discrimination step, first control step for decrementing a transfer count of the encrypted content data when transferring said encrypted content data from said first memory to said external apparatus, incrementing said transfer count when said encrypted data are returned from said first external apparatus, and disabling the transfer of said content data from said first memory to said..external apparatus if said transfer count has exceeded a predetermined limit value; and,
if said second external apparatus is discriminated in said discrimination step, second control step for

disabling the return of the encrypted content data from said second external apparatus.
26. A data transfer apparatus substantially as hereinbefore described
with reference to the accompanying drawings.
27. A data transfer system substantially as hereinbefore described with
reference to the accompanying drawings.
28. A data recording apparatus substantially as hereinbefore described
with reference to the accompanying drawings.