Title of Invention

RECORDING MEDIUM, REPRODUCTION DEVICE, MESSAGE ACQUISITION METHOD, MESSAGE ACQUISITION PROGRAM, INTEGRATED CIRCUIT

Abstract The present invention provides a recording medium that allows the content provider to control messages. The recording medium is provided by a content provider and records thereon content and a program which is executed at the time of playback of the content by a playback apparatus. The program causes the playback apparatus to execute: an interacting step of interacting with a different program prestored in the playback apparatus and executed at the time of the playback of the content; and an output step of transmitting, to the different program, a message determined according to the result of the interaction. The playback apparatus comprises: a reading unit operable to read the program from the recording medium at the time of the playback of the content; a startup unit operable to start up the read program; an interaction unit operable to interact with the program; and a processing unit operable to receive a message corresponding to result of the interaction from the recording medium and perform a process corresponding to the received message.
Full Text DESCRIPTION
RECORDING MEDIUM, REPRODUCTION DEVICE, MESSAGE ACQUISITION METHOD,
MESSAGE ACQUISITION PROGRAM, INTEGRATED CIRCUIT
Technical Field
[0001]
The present invention relates to a technology for displaying a
message to the user during content playback, especially to a technology
for displaying a message reflecting an intention of a content provider.
Background Art
[0002]
A widely prevailing system, along with the development of higher-
capacity recording media in recent years, is one to digitize content
data of copyrighted works, such as movies, and distribute the digitaized
data stored in digital optical disks or other recording media. With the
use of such a system, copyright protection of the content data is
necessary, and playback and duplication of the content data must be
conducted only within the limits to which the copyright holders have
consented. A common system used for protecting copyrighted works from
being illegally copied without consent of the copyright holders has a
mechanism in which content data is encrypted using a content key that is
managed by the copyright holder and then stored in a disk, and only
terminals having a corresponding content key can decrypt the encrypted
content data in the disk. Here, in order to obtain the content key, an
agreement with the copyright holder on provisions regarding copyright
protection must be made.
[0003]
1

This kind of system has means for informing the user of a
playback anomaly in the case when a playback anomaly caused by some
reasons during playback is determined on a terminal apparatus that plays
back content data read from a recording medium, as disclosed in Patent
Reference 1.
Japanese Laid-ppen Patent Application H08-
186795
Disclosure of the Invention
[Problems that the Invention is to Solve]
[0004]
However, in the conventional technology, messages used for
informing the user of anomalies are decided by the manufacturer of the
playback apparatus, and the problem therefore remains that the content
provider cannot control the messages.
Therefore, the present invention aims at offering a recording
medium, a playback apparatus, a message acquisition method, a message
acquisition program, and an integrated circuit of the playback apparatus,
all of which allow the content provider to control messages.
[Means to Solve the Problem]
[0005]
In order to achieve the object above, the present invention is a
recording medium provided by content provider and recording thereon
content and a program which is executed during playback of the content
by a playback apparatus. The program causes the playback apparatus to
execute: an interacting step of interacting with a different program
that is prestored in the playback apparatus and executed during the
playback of the content; and an output step of transmitting, to the
2

different program, a message determined according to the result of the
interaction.
[Advantageous Effects of the Invention]
[0006]
According to the structure above, since the recording medium
records thereon a program including an output step of transmitting a
message in accordance with the result of the interaction, the playback
apparatus can receive a message in accordance with the result of the
interaction with the recording medium. Herewith, the content provider
is capable of controlling messages to be output to the playback
apparatus by recording the program on the recording medium.
[0007]
In this case, the interaction step may acquire apparatus unique
information unique to the playback apparatus by interacting with the
different program, and the output step may output, to the different
program, a message determined according to the apparatus unique
information.
According to the structure above, since the output step of the
program recorded on the recording medium outputs a message in accordance
with the apparatus unique information, the content provider is capable
of controlling messages to be output according to the apparatus unique
information.
[0008]
In this case, the output step may include: an acquisition step
of acquiring, according to the apparatus unique information, a message
which the playback apparatus is capable of displaying; and a
transmission step of transmitting the acquired message to the different
program.
3

According to the structure above, the program recorded on the
recording medium acquires a message which the playback apparatus is
capable of displaying according to the apparatus unique information, and
transmits the acquired message to a different program in the playback
apparatus. Herewith, the content provider is capable of causing the
playback apparatus to display messages to be output according to the
apparatus unique information.
[0009]
In this case, the acquisition step may acquire, in the case where
the apparatus unique information indicates that the playback apparatus
is unauthorized or anomalous, a message indicating that the playback
apparatus is unauthorized or anomalous.
According to the structure above, in the case where the playback
apparatus is unauthorized or anomalous, the acquisition step of the
program recorded on the recording medium acquires a message indicating
accordingly. Herewith, the content provider is capable of notifying the
user that the playback apparatus is an unauthorized or anomalous
apparatus.
[0010]
In this case, the interacting step may acquire apparatus state
information indicating an operating state of the playback apparatus by
interacting with the different program, and the output step may transmit,
to the different program, a message determined according to the
apparatus state information.
According to the structure above, since the output step of the
program recorded on the recording medium outputs a message in accordance
with the apparatus state information, the content provider is capable of
4

controlling messages to be output according to the apparatus state
information.
[0011]
In this case, the output step may include: an acquisition step
of acquiring, according to the apparatus state information, a message
which the playback apparatus is capable of displaying; and a
transmission step of transmitting the acquired message to the different
program.
According to the structure above, the program recorded on the
recording medium acquires a message which the playback apparatus is
capable of displaying according to the apparatus state information, and
transmits the acquired message to a different program in the playback
apparatus. Herewith, the content provider is capable of causing the
playback apparatus to display messages to be output according to the
apparatus state information.
[0012]
In this case, the acquisition step may acquire, in the case where
the apparatus state information indicates that the playback apparatus is
in an unauthorized or anomalous state, a message indicating that the
playback apparatus is in the unauthorized or anomalous state.
According to the structure above, the acquisition step of the
program recorded on the recording medium acquires, in the case where the
playback apparatus is in an unauthorized or anomalous state, a message
indicating accordingly. Herewith, the content provider is capable of
notifying the user that the playback apparatus is in the unauthorized or
anomalous state.
[0013]
5

In this case, the recording medium may include a storage area
storing therein the message.
According to the structure above, since the recording medium
includes a storage area that stores therein the message, the content
provider is capable of storing, in the recording medium, messages to be
output to the playback apparatus.
Here, in the case where the message indicates one of (1) the
playback apparatus being unauthorized or anomalous and (2) the playback
apparatus being in an unauthorized or anomalous state, the program may
cause the playback apparatus to execute, in addition to the output of
the message, a playback inhibition step of inhibiting the playback of
the content.
[0014]
According to the structure above, since the program of the
recording medium includes the playback inhibition step, it can cause the
playback apparatus to inhibit the playback of the content. Herewith,
the content provider is capable of inhibiting an unauthorized or
anomalous playback apparatus and a playback apparatus in an unauthorized
or anomalous state from playing back the content.
In this case, the content may include image data, the playback
apparatus may play back an image based on the image data, and the
program may further cause the playback apparatus to execute an overlay
display step of displaying the message over the image of the contents
being played back.
[0015]
According to the structure above, since the program of the
recording medium includes the overlay display step, it can cause the
playback apparatus to display a message over an image of the content
6

being played back. Herewith, the content provider is capable of
displaying a message desired to be notified to the user over the image
of the content being played back.
In this case, the message may indicate one of (1) the playback
apparatus being unauthorized or anomalous and (2) the playback apparatus
being in an unauthorized or anomalous state, and the program may further
cause the playback apparatus to execute a process selection step of
receiving, from the user, an instruction of whether to inhibit the
playback of the content or to display the message over an image of the
content being played back.
[0016]
According to the structure above, since the program of the
recording medium includes the process selection step, it can cause the
playback apparatus to perform either inhibition of the playback of the
content or overlay display of a message based on an instruction of the
user.
In this case, the program may include control information
indicating performing one of (1) an operation of inhibiting the playback
of the content and (2) an operation of displaying the message over an
image of the content being played back, and the output step may further
transmit the control information to the different program.
[0017]
According to the structure above, the program of the recording
medium includes the control information, and the output step transmits
the control information to the playback apparatus. Herewith, it can
cause the playback apparatus to perform a process based on the control
information.
7

The present invention is also a playback apparatus for playing
back content from a recording medium that is provided by content
provider. Here, the recording medium records thereon the content and a
program which is executed during the playback of the content. The
playback apparatus comprises: a reading unit operable to read the
program from the recording medium during the playback of the content; a
startup unit operable to start up the read program; an interaction unit
operable to interact with the program; and a processing unit operable to
receive a message in accordance with result of the interaction from the
recording medium and perform a process in accordance with the received
message.
[0018]
According to the structure above, since the playback apparatus
receives, from the recording medium, a message in accordance with the
result of the interaction, the content provider is capable of
controlling the playback apparatus by messages.
In this case, the interaction unit may notify, to the program,
apparatus unique information unique to the playback apparatus, and the
processing unit may receive a message in accordance with the apparatus
unique information from the recording medium as the result of the
interaction.
[0019]
According to the structure above, the playback apparatus receives,
from the recording medium, a message in accordance with the apparatus
unique information, the content provider is capable of controlling the
playback apparatus by messages.
In this case, the apparatus unique information may be prestored
in the playback apparatus.
8

According to the structure above, since the apparatus unique
information is prestored in the playback apparatus, the convent provider
is capable of readily generating a message in accordance with the
apparatus unique information.
[0020]
In this case, the interaction unit may notify, to the program,
apparatus state information indicating an operating state of the
playback apparatus.
According to the structure above, since the playback apparatus
receives, from the recording medium, a message in accordance with the
apparatus state information, the content provider is capable of
controlling the playback apparatus according to the apparatus state
information.
In this case, the interaction unit may acquire the apparatus
state information which indicates an operating state of the playback
apparatus during the playback of the content stored in the recording
medium, and notify the acquired apparatus state information to the
program. Here, the processing unit receives a message corresponding to
the apparatus state information from the recording medium as the result
of the interaction.
[0021]
According to the structure above, the playback apparatus is able
to acquire apparatus state information in accordance with the operation
during the playback of the content and notify the acquired apparatus
state information to the program. Herewith, the content provider is
capable of controlling the playback apparatus according to change in the
operation during the playback.
9

In this case, the processing unit may display the received
message.
According to the structure above, since the playback apparatus
displays the received message, the content provider is capable of
controlling messages to be displayed by the playback apparatus.
[0022]
Here, in the case where the received message indicates one of (1)
the playback apparatus being unauthorized or anomalous and (2) the
playback apparatus being in an unauthorized or anomalous state, the
playback apparatus may further comprise: a playback inhibiting unit
operable to inhibit the playback of the content in addition to
displaying the message.
According to the structure above, the playback apparatus is able
to inhibit the playback of the content. Herewith, the content provider
is capable of inhibiting an unauthorized or anomalous playback apparatus
and a playback apparatus in an unauthorized or anomalous state from
playing back the content.
[0023]
In this case, the content may include image data which is a basis
of an image to be played back by the playback apparatus, and the
processing unit may display the message over the image of the content
being played back.
According to the structure above, the playback apparatus is able
to display a message over an image of the content being played back.
Herewith, the content provider is capable of displaying a message
desired to be notified to the user over the image of the content being
played back.
[0024]
10

In this case, the message may indicate one of (1) the playback
apparatus being unauthorized or anomalous and (2) the playback apparatus
being in an unauthorized or anomalous state, and the processing unit may
perform one of (1) an operation of inhibiting the playback of the
content and (2) an operation of displaying the message over an image of
the content being played back.
According to the structure above, the content provider is capable
of either inhibiting the playback of the content or notifying the user
by displaying a desired message over an image of the content being
played back.
[0025]
In this case, the processing unit may receive, from the user, an
instruction of whether to inhibit the playback of the content or to
display the message over the image of the content being played back, and
perform the process based on the received instruction.
According to the structure, the playback apparatus is capable of
performing either inhibition of the playback of the content or overlay
display of a message based on an instruction of the user.
[0026]
In this case, the program may record thereon control information
indicating one of (1) inhibiting the playback of the content and (2)
displaying the message over the image of the content, and the processing
unit may read the control information from the program and performs the
process based on the read control information.
According to the structure above, the playback apparatus is
capable of performing either inhibition of the playback of the content
or overlay display of a message based on the control information
included in the program of the recording medium.
11

Brief Description of the Drawings
[0027]
FIG. 1 is a block diagram showing structures of a recording
medium 101 and a content playback apparatus 102 according to Embodiment
1;
FIG. 2 is a flowchart showing operations of a content playback
process according to Embodiment 1;
FIG. 3 shows an example of a data configuration of an anomalous-
apparatus table according to Embodiment 1;
FIG. 4 is a flowchart showing operations of a bytecode execution
process according to Embodiment 1;
FIG. 5 is a flowchart showing operations of a revocation
confirmation process of the content playback apparatus according to
Embodiment 1;
FIG. 6 is a flowchart showing operations of a content key
generation process according to Embodiment 1;
FIG. 7 is a block diagram showing structures of a recording
medium 101A and a content playback apparatus 102A according to
Embodiment 2;
FIG. 8 is a flowchart showing operations of a content playback
process according to Embodiment 2;
FIG. 9 shows an example of a data configuration of an anomalous-
state table according to Embodiment 1;
FIG. 10 is a flowchart showing operations of a bytecode startup
process according to Embodiment 2;
FIG. 11 is a flowchart showing operations of a bytecode execution
process according to Embodiment 2;
FIG. 12 shows a specific example of revocation information 115;
12

FIG. 13 is a flowchart showing detailed operations of Step S404;
FIG. 14 is a flowchart showing detailed operations of Step S405;
FIG. 15 is a flowchart showing detailed operations of Step S404A;
and
FIG. 16 is a flowchart showing detailed operations of Step S405A.
Explanation of References
[0028]
101, 101A recording medium
102, 102A content playback apparatus

111, 111A playback control information
112, 112A bytecode
113, 113A protected content data
114, 114A encrypted content key
115, 115A revocation information

121, 121A disk reading unit
122, 122A playback control unit
123, 123A user operation reception unit
124, 124A bytecode execution unit
125, 125A decryption unit

127, 127A demultiplexing unit
128, 128A video decoder
129, 129Aaudio decoder
130, 130A content key generation unit
131, 131A revocation information processing unit
132, 132A device key storage unit
133 apparatus unique information storage unit
134, 134A display control unit
13

135, 135A display unit
136A apparatus state information acquisition unit
Best Mode for Carrying Out the Invention
[0029]
The following explains the best modes for implementing the
present invention with reference to drawings.
EMBODIMENT 1
FIG. 1 shows structures of a recording medium 101 and a content
playback apparatus 102 of one embodiment of the present invention.
On the recording medium 101, playback control information 111, a
bytecode 112, protected content data 113, an encrypted content key 114,
and revocation information 115 are recorded. As the recording medium
101, a BD (Blu-ray Disc) is, for example, assumed here; however, other
types of recording media may also be used.
[0030]
Embodiment 1 assumes that one content is composed of multiple
pieces of MPEG2-TS (Motion Picture Expert Group 2-Transport Stream) data.
It is the playback control information 111 that specifies the playback
order of the protected content data 113 when the content is played back.
A JAVA (registered trademark) bytecode is an example of the
bytecode 112, which is an executable code composed of fixed-length
instruction sets. Some process, such as obfuscation of bytecode, may be
performed so that confidential information and detailed processes
included in the software are not revealed by analytical techniques. In
this case, the bytecode execution unit 124 has a function of removing
the obfuscation or the like. Details on the execution performed by the
bytecode 112 are described later. Note that the present embodiment is
14

described using a JAVA, byte code as an example; however, an execution
program other than that can be employed.
[0031]
The protected content data 113 is data created by performing an
encryption process on MPEG2-TS data using a content key. Here, MPEG2-TS
data is the data in plaintext which can output image using a decoder.
Therefore, in order to play back the protected content data 113, a
decryption process using the content key needs to be performed on the
protected content data 113 to thereby restore the plain-text MPEG2-TS
data.
The encrypted content key 114 is data created by, with the use of
a media key, encrypting the content key used for decrypting the
protected content data. The media key is explained later.
[0032]
Next, the revocation information 115 is described. The key
management authority has a group of multiple device keys and multiple
media keys. The key management authority assigns one device key and a
key ID number of the device key to each content playback apparatus 102,
and gives the assigned device key and key ID number to the content
playback apparatus 102. Also, the key management authority assigns one
media key to the recording medium 101. Next, the key management
authority creates an encrypted media key by encrypting a media key using
the device key assigned to each content playback apparatus 102, and
creates a list itemizing encrypted media keys and key ID numbers for all
device keys.
[0033]
This list is the revocation information 115. Note however that
this simple method has a shortcoming that, as the number of the content
15

playback apparatuses 102 becomes large, the data size of the revocation
information 115 becomes unrealistically large. Therefore, a method
disclosed in "Digital Content Hogo-you Kagi Kanri Houshiki (Key
Management Method for Protecting Digital Contents)" (Nakano, Ohmori and
Tatebayashi, Symposium on Cryptography and Information Security,
SCIS2001 5A-5, Jan. 2001) can be used to compress the revocation
information 115 to thereby reduce the data size. The data compression
method is not limited to this, and a different method may also be
adopted.
[0034]
The content playback apparatus 102 comprises: a disk reading
unit 121; a playback control unit 122; a user operation reception unit
123; a bytecode execution unit 124; a decryption unit 125; a
demultiplexing unit 127; a video decoder 128; an audio decoder 129; a
content key generation unit 130; a revocation information processing
unit 131; a device key storage unit 132; an apparatus unique information
storage unit 133; a display control unit 134; and a display unit 135.
[0035]
A computer system composed of a CPU, a work memory, a flash
memory, a BD drive and a remote controller is a practical embodiment of
the content playback apparatus 102. The disk reading unit 121 is the BD
drive; the device key storage unit 132 and apparatus unique information
storage unit 133 are the flash memory; and the user operation reception
unit 123 is the remote controller. The playback control unit 122, byte
code execution unit 124, decryption unit 125, demultiplexing unit 127,
video decoder 128, audio decoder 129, content key generation unit 130,
revocation information processing unit 131, display control unit 134,
and display unit 135 can be configured by software operating with the
16

use of the CPU and work memory; however, these units can be realized by
hardware implementation, and the present invention is not limited to the
software implementation.
[0036]
Thus concludes the descriptions on the structures of the
recording medium and the content playback apparatus, which are one
embodiment of the present invention.
Content Playback Process
The following describes a content playback process with reference
to FIG. 2.
First, the content playback process starts when a user's request
for content playback start is received by the user operation reception
unit 123.
[0037]
When the user operation reception unit 123 receives a content
playback request, the content playback apparatus 102 reads the bytecode
112 from the recording medium 101, and the bytecode 112 is executed by
the bytecode execution unit 124 (Step S201). The detailed description
of the process performed by the bytecode execution unit 124 is given
later.
In the case where the content playback process is continued as
result of Step S201, the following steps are carried out.
The revocation information processing unit 131 performs the
revocation confirmation process of the content playback apparatus 102
(S202). The detail of the revocation confirmation process is described
later.
[0038]
17

The subsequent process branches depending on whether the
generation of the media key in the revocation confirmation process S202
is successful or not (S203).
When the generation of the media key in the revocation
confirmation process S202 is successful, the content playback apparatus
102 reads the encrypted content key 114 from the recording medium 101
and generates a content key (S204) . The detail of the content key
generation is described later.
[0039]
If the generation of the media key in the revocation confirmation
process S202 fails, the content playback apparatus 102 aborts the
process.
After the completion of S204, in order to play back a content
requested by the user, the playback control unit 122 instructs start of
reading the protected content data 113, which is to be a playback target,
in accordance with the playback control information 111 (S205) .
Until all the protected content data 113 is read, the following
process is repeated (S206) .
[0040]
Using the content key generated by the content key generation
unit 130, the decryption unit 125 performs a decryption process on the
protected content data 113 read from the recording medium 101 (S207) .
AES (Advanced Encryption Standard) is used for the encryption of the
protected content data; however, the present invention is not limited to
this. The decrypted content data is MPEG2-TS data in plain text, which
is then demultiplexed into video and audio streams by the demultiplexing
unit 127. These video and audio streams are sent to the video decoder
128 and audio decoder 129, respectively, and subsequently output to a
18

video-audio apparatus, such as a TV (S208) . During the playback of the
content, the decryption of the protected content data 113 (S207) is
performed in parallel.
[0041]
At the completion of reading all the protected content data 113
corresponding to the content requested by the user, the content playback
process ends (S206).
Thus concludes the description of the content playback process.
Note that the procedure of the content playback process shown
here is merely one example; the present invention is not limited to this.
[0042]
Bytecode Execution Process
The bytecode 112 stored in the recording medium 101 includes an
anomalous-apparatus table listing therein (i) apparatus unique
information of, for example, apparatuses where bugs have been found,
apparatuses that have been identified as unauthorized, and/or emulators
(all of such apparatuses are hereinafter referred to as "anomalous
apparatus") and (ii) messages to these apparatuses.
FIG. 3 shows an example of the anomalous-apparatus table. As
shown in FIG. 3, the apparatus unique information is information unique
to each content playback apparatus 102, and is composed of, for example,
an apparatus maker ID, a model number of the playback apparatus, a
manufacturing serial number of the playback apparatus, and a version
number of playback process firmware of the playback apparatus. As to
the messages, besides messages informing the user that the playback
process cannot be carried out, messages can also be set that indicate
reasons for why the playback process cannot be performed and how to deal
with the problems (e.g. directing the user to update the firmware).
19

[0043]
The bytecode 112 stored in the recording medium 101 further
includes: an acquisition step of acquiring apparatus unique information
from the apparatus unique information storage unit 133 of the content
playback apparatus 102; a judging step of judging whether the acquired
apparatus unique information is included in the anomalous-apparatus
table described above; and a display request step of, when the acquired
apparatus unique information is judged, in the judging step, to be
included in the anomalous-apparatus table, requesting the content
playback apparatus 102 to display a message for the apparatus, which is
set in the anomalous-apparatus table.
[0044]
The following describes the bytecode execution process with
reference to FIG. 4. Note that this process is the detail of S201 in
FIG. 2.
The bytecode execution unit 124 reads the bytecode 112 from the
recording medium 101 (S401).
Next, the bytecode execution unit 124 acquires apparatus unique
information from the apparatus unique information storage unit 133 of
the content playback apparatus 102 (S402). Here, the apparatus unique
information is information unique to each content playback apparatus 102,
and is composed of, for example, an apparatus maker ID, a model number
of the playback apparatus, a manufacturing serial number of the playback
apparatus, and a version number of playback process firmware of the
playback apparatus. Individual apparatus unique information is assigned
to each content playback apparatus 102. That is, with apparatus unique
information, each content playback apparatus 102 can be identified.
[0045]
20

Next, the bytecode is started (S403).
The bytecode execution unit 124 executes the acquired bytecode
112 to thereby judge whether the apparatus unique information acquired
in S402 is included in the anomalous-apparatus table (S404) .
In the case of FIG. 3, if the apparatus unique information
acquired in S402 matches the apparatus unique information of (1) in the
anomalous-apparatus table of FIG. 3-i.e. if the apparatus unique
information acquired in S402 includes "APPARATUS MAKER ID = A", a
request for displaying the message of (1) is made.
[0046]
Then, when judging in S404 that the apparatus unique information
is included in the anomalous-apparatus table, the bytecode execution
unit 124 transmits a request for displaying a message aimed for the
apparatus together with the message to the display control unit 134 of
the content playback apparatus 102; when judging that the apparatus
unique information is not included in the anomalous-apparatus table, the
bytecode execution unit 124 refrains from transmitting the request for
displaying a message aimed for the apparatus (S405).
Next, when receiving a request for displaying a message from the
bytecode execution unit 124, the display control unit 134 of the content
playback apparatus 102 indicates the display unit 135 to display the
message and ends the content playback process (S406) . The display unit
135 displays the message (S407).
[0047]
On the other hand, when not receiving a request for displaying a
message from the bytecode execution unit 124, the display control unit
134 of the content playback apparatus 102 carries on the content
playback process (to S202).
21

It is a copyright holder of the content that selects the bytecode
112 to be stored in the recording medium 101. Thereby, the copyright
holder is capable of having control of displaying a specified message
aimed for a specific content playback apparatus having a problem.
[0048]
Thus concludes the description of the bytecode execution process.
Revocation Confirmation Process of Content Playback Apparatus 102
The following describes the revocation confirmation process of
the content playback apparatus 102 with reference to FIG. 5. Note that
this process is the detail of S202 in FIG. 2.
The. revocation confirmation process is a process performed before
the content playback for checking, based on the revocation information
recorded on the recording medium 101, whether the content playback
apparatus 102 has been revoked.
[0049]
The revocation information processing unit 131 reads the device
key acquired from the device key storage unit 132 (S501) . The device
key is information unique to each content playback apparatus, therefore
being capable of identifying a particular content playback apparatus 102.
Next, the revocation information processing unit 131 reads the
revocation information 115 stored in the recording medium 101 (S502) ,
and generates a media key using the read device key and revocation
information 115 (S503).
[0050]
In the case where the content playback apparatus 102 has been
revoked, a media key cannot be generated. The generation of the media
key using the device key and revocation information 115 is described in
detail in "National Technical Report, Volume 43, Number 3, pp. 118-122
22

("Gijyutsu Somu" (technological general administration) Center,
Matsushita Electric Industrial Co., Ltd., issued on June 18, 1997).
Thus concludes the description of the revocation confirmation
process of the content playback apparatus 102.
[0051]
Content Key Generation Process
The following describes the content key generation process with
reference to FIG. 6. Note that this process is the detail of S204 in
FIG. 2.
The content key generation unit 130 acquires the media key
generated in S202 from the revocation information processing unit 131
(S601) . Next, the content key generation unit 130 reads the encrypted
content key 114 from the recording medium 101, and decrypts the
encrypted content key 114 using the media key acquired in S401 (S602) .
AES is used for encrypting and decrypting the content key; however, the
present invention is not limited to this.
[0052]
Thus concludes the description of the content key generation
process.
EMBODIMENT 2
FIG. 7 shows structures of a recording medium 101A and a content
playback apparatus 102A of one embodiment of the present invention. The
following describes the present embodiment, focusing on its differences
from Embodiment 1.
On the recording medium 101A, a bytecode 112A, protected content
data 113A, an encrypted content key 114A, and revocation information
115A are recorded. As the recording medium 101A, exactly the same
recording medium as that of Embodiment 1 can be used, and the detailed
23

explanation for the recording medium 101A is therefore not given here.
As to data recorded on the recording medium 101A, it is essentially the
same as that of Embodiment 1, except for details of the content of the
bytecode, and the detailed explanation for the recorded data is
therefore omitted here. Note that the details of the content of the
bytecode are described later.
[0053]
The content playback apparatus 102A comprises: a disk reading
unit 121A; a playback control unit 122A; a user operation reception unit
123A; a bytecode execution unit 124A; a decryption unit 125A; a
demultiplexing unit 127A; a video decoder 128A; an audio decoder 129A; a
content key generation unit 130A; a revocation information processing
unit 131A; a device key storage unit 132A; a display control unit 134A;
a display unit 135A; and an apparatus state information acquisition unit
13 6A.
[0054]
A computer system composed of a CPU, a work memory, a flash
memory, a BD drive and a remote controller is a practical embodiment of
the content playback apparatus 102A. The disk reading unit 121A is the
BD drive,- the device key storage unit 132A is the flash memory; and the
user operation reception unit 123A is a remote controller. The playback
control unit 122A, bytecode execution unit 124A, decryption unit 125A,
demultiplexing unit 127A, video decoder 128A, audio decoder 129A,
content key generation unit 130A, revocation information processing unit
131A, display control unit 134A, display unit 135A, and apparatus state
information acquisition unit 13 6A can be configured by software
operating with the use of the CPU and work memory; however, these units
24

can be realized by hardware implementation, and the present invention is
not limited to the software implementation.
[0055]
Thus concludes the descriptions on the structures of. the
recording medium and the content playback apparatus of one embodiment of
the present invention.
Content Playback Process
The following describes a content playback process with reference
to FIG. 8.
First, the content playback process starts when a user's request
for content playback start is received at the user operation reception
unit 123A.
[0056]
When the user operation reception unit 123A receives a content
playback request, the content playback apparatus 102A reads the bytecode
112A from the recording medium 101A, and the bytecode 112A is started by
the bytecode execution unit 124A (Step S201A) . The detailed description
of the process performed by the bytecode execution unit 124A is given
later.
The revocation information processing unit 131A performs the
revocation confirmation process of the content playback apparatus 102A
(S202A) . The detail of the revocation confirmation process is described
later.
[0057]
The subsequent process branches depending on whether the
generation of the media key in the revocation confirmation process S202A
is successful or not (S203A) .
25

When the generation of the media key in the revocation
confirmation process S202A is successful, the content playback apparatus
102A reads the encrypted content key 114A from the recording medium 101A
and generates a content key (S204A) . The detail ..of the content key
generation is described later.
[0058]
If the generation of the media key in the revocation confirmation
process S202A fails, apparatus state information (1A) indicating revoked
state due to the failure in the acquisition of the media key is notified
to the apparatus state information acquisition unit 13 6A as apparatus
state information. When notified of the apparatus state information
(1A) , the apparatus state information acquisition unit 136A notifies the
bytecode execution unit 124A of the apparatus state information (1A)
(S209A) . The process performed by the bytecode execution unit 124A
after the notification of the apparatus state information (1A) is
described later.
[0059]
After the completion of S204A, in order to play back a content
requested by the user, the playback control unit 122A instructs a start
of reading the protected content data 113A, which is to be a playback
target, in accordance with the playback control information 111A (S205A).
Until all the protected content data 113A is read, the following
process is repeated (S206A) .
[0060]
Using the content key generated by the content key generation
unit 130A, the decryption unit 125A performs a decryption process on the
protected content data 113A read from the recording medium 101A (S207A) .
26

At this point, if the decryption is not properly performed for
some reason (for example, a right content key was not generated by the
content key generation unit 13OA) , apparatus state information (2A)
indicating decryption anomalous state due to the failure in the
acquisition of the content key is notified to the apparatus state
information acquisition unit 136A as apparatus state information. When
notified of the apparatus state information (2A) , the apparatus state
information acquisition unit 136A notifies the bytecode execution unit
124A of the apparatus state information (2A) (S209A) . The process
performed by the bytecode execution unit 124A after the notification of
the apparatus state information (2A) is described later.
[0061]
AES (Advanced Encryption Standard) is used for the encryption of
the protected content data 113A; however, the present invention is not
limited to this. The decrypted content data is MPEG2-TS data in plain
text, which is then demultiplexed into video and audio streams by the
demultiplexing unit 127A. These video and audio streams are sent to the
video decoder 12 8A and audio decoder 12 9A, respectively, and
subsequently output to a video-audio apparatus, such as a TV (S208A) .
[0062]
During the playback of the content, the decryption of the
protected content data 113A (S207A) is performed in parallel.
At the completion of reading all the protected content data 113A
corresponding to the content requested by the user, the content playback
process ends (S206A) .
Thus concludes the description of the content playback process.
[0063]
27

Note that the procedure of the content playback process shown
here is merely one example; the present invention is not limited to this.
ByteCode Execution Process
The bytecode stored in the recording medium includes an
anomalous-state table listing therein apparatus state information and
messages for respective apparatus states.
[0064]
FIG. 9 shows an example of the anomalous-state table. As shown in
FIG. 9, the apparatus state information includes: apparatus state
information (1A) indicating revoked state due to failure in acquisition
of the media key; apparatus state information (IB) indicating revoked
state due to other failure-i.e. anomaly in acquisition of information
that indicates it is a legitimate playback apparatus; apparatus state
information (2A) indicating decryption anomalous state due to anomaly in
acquisition of the content key; and apparatus state information (2B)
indicating decryption anomalous state due to other failure-i.e. anomaly
in acquisition of information required for content playback. In the
anomalous-state table, messages can be set that inform the user of the
state of the playback apparatus and/or what action for playback should
be taken.
[0065]
The bytecode 112A stored in the recording medium 101A further
includes: an acquisition step of acquiring apparatus state information
from the apparatus state information acquisition unit 136A of the
content playback apparatus 102A; a judging step of judging whether the
acquired apparatus state information is included in the anomalous-state
table described above; and a display request step of, when the acquired
apparatus state information is judged, in the judging step, to be
28

included in the anomalous-state table, requesting the content playback
apparatus 102A to display a message for the state of the apparatus,
which is set in the anomalous-state table.
[0066]
The following describes the bytecode startup process with
reference to FIG. 10. Note that this process is the detail of S201A in
FIG. 8.
The bytecode execution unit 124A reads the bytecode 112A from the
recording medium 101A (S401A) . Then, the bytecode execution unit 124A
starts the bytecode 112A (S402A) .
[0067]
The following describes the bytecode execution process with
reference to FIG. 11. Note that this process is the detail of S209A in
FIG. 8.
The bytecode execution unit 124A acquires apparatus state
information from the apparatus state information acquisition unit 136A
of the content playback apparatus 102A (S403A) .
The bytecode execution unit 124A executes the acquired bytecode
112A to thereby judge whether the apparatus state information acquired
in S403A is included in the anomalous-state table (S404A) .
[0068]
In the case of FIG. 9, if the apparatus state information
acquired in S403A matches the apparatus state information of (1) in the
anomalous-state table of FIG. 9-i.e. if the apparatus state information
acquired in S403A corresponds to (1A) "the revoked state due to failure
in acquisition of the media key," a request for displaying the message
of (1) is made.
29

Then, when judging in S404A that the apparatus state information
is included in the anomalous-state table, the bytecode execution unit
124A transmits a request for displaying a message for the state of the
apparatus together with the message to the display control unit 134A of
the content playback apparatus 102A; when judging that the apparatus
state information is not included in the anomalous-state table, the
bytecode execution unit 124A refrains from transmitting the request for
displaying a message for the state of the apparatus (S405A) .
[0069]
Next, when receiving a request for displaying a message from the
bytecode execution unit 124A, the display control unit 134A of the
playback apparatus 102A indicates the display unit 135A to display the
message and ends the content playback process (S406A) . The display unit
135A displays the message (S407A) .
On the other hand, when not receiving a request for displaying a
message from the bytecode execution unit 124A, the display control unit
134A of the content playback apparatus 102A carries on the content
playback process (to S203A, S206A) .
[0070]
It is a copyright holder of the content that selects the bytecode
112A to be stored in the recording medium 101A. Thereby, the copyright
holder is capable of having control of displaying a predetermined
message for a playback apparatus in specific anomalous state.
Thus concludes the description of the bytecode execution process.
Revocation Confirmation Process of Content Playback Apparatus
102A
30

Since the revocation confirmation process of the content playback
apparatus 102A is the same as that of the content playback apparatus 102
of Embodiment 1, the description is omitted here.
[0071]
Content Key Generation Process
Since the content key generation process is the same as that of
Embodiment 1, the description is omitted here.
Other Modifications
The present invention has been described based on the above
embodiments; it is however a matter of course that the present invention
is not limited to these embodiments. The following cases are also
within the scope of the present invention.
[0072]
(1) Embodiment 1 has a structure that stops, when the playback
apparatus is judged as an anomalous apparatus, the playback of the
content and displays only a message; however, the present invention is
not limited to this structure. For example, in the case where the user
has no malicious intent-e.g. the playback apparatus has been
manufactured by a manufacturer with malicious intent, or in the case
where a message to be displayed is firmware update notification, a
message may be displayed over the content being played back in the case
when the playback apparatus is judged as an anomalous apparatus.
Alternatively, the bytecode may be made to also include control
information that indicates whether to stop the content playback or to
display a message over the content being played back, and the playback
apparatus switches, based on the control information, between stopping
the content playback and displaying a message over the content being
played back.
31

[0073]
Similarly, Embodiment 2 has a structure that stops, when the
playback apparatus is judged as an anomalous state, the playback of the
content and displays only a message; however, the present invention is
not limited to this structure. For example, in the case where the user
has no malicious intent, a message may be displayed over the content
being played back in the case when the playback apparatus is judged as
being in anomalous state. Alternatively, the bytecode may be made to
also include control information that indicates whether to stop the
content playback or to display a message over the content being played
back, and the playback apparatus switches, based on the control
information, between stopping the content playback and displaying a
message over the content being played back.
[0074]
(2) Embodiment 1 has a structure in which the judgment of
whether an anomalous apparatus or not is made based on the apparatus
unique information and a message is displayed accordingly; however, the
present invention is not limited to the apparatus unique information.
Also, Embodiment 2 has a structure in which the judgment of
whether anomalous state or not is made based on the apparatus state
information and a message is displayed accordingly; however, the present
invention is not limited to the apparatus state information.
For example, the bytecode may be structured in such a way as to
request the playback apparatus to display a predetermined message if
other information received from the playback apparatus-e.g. content
associated information (including license information) and/or user
information (including user input information)-satisfies a
predetermined condition. This structure produces an effect that the
32

message to be displayed can be dynamically changed according to the
absence or presence of the license information of the content and
attributes of the user.
[0075]
(3) Embodiment 2 has a structure in which an appropriate message
is displayed in the case where acquisition of the media key is failed;
however, the present invention is not limited to this structure. For
example, an appropriate message may be displayed in the case where
acquisition of another information indicating that it is a compliant
playback apparatus is failed (the case of the apparatus state
information (IB) of FIG. 9).
Also, Embodiment 2 has a structure in which an appropriate
message is displayed in the case where generation of the decrypted data
is failed; however, the present invention is not limited to this
structure. For example, in the case where the protected content has
been generated by performing some conversion process on the content and
then encrypting the converted content with the use of a content key, the
decryption unit 125A of the playback apparatus first decrypts the
protected content using the content key, and then an inverse conversion
process which is inverse to the above conversion process is performed
the decrypted content. In this case, an appropriate message may be
displayed if the inverse conversion process is not properly performed
due to failure in acquisition of information necessary for the inverse
conversion process (the case of the apparatus state information (2B) of
FIG. 9).
[0076]
(4) Specifically speaking, each apparatus above is a computer
system composed of a microprocessor, ROM, RAM, a hard disk unit, a
33

display unit, a keyboard, a mouse and the like. A computer program is
stored in the RAM or the hard disk unit. The microprocessor operates
according to the computer program, and thereby each apparatus fulfills
its functions. Here, the computer program is. structured by combining
multiple instruction codes indicating commands to the computer to
achieve predetermined functions.
[0077]
(5) Part or all of the components making up the above individual
apparatuses may be assembled as a single system LSI (Large Scale
Integration) . The system LSI is an ultra-multifunctional LSI produced
by integrating multiple components on one chip, and more specifically,
is a computer system composed of a microprocessor, ROM, RAM, and the
like. A computer program is stored in the RAM. The microprocessor
operates according to the computer program, and thereby the system LSI
accomplishes its function.
[0078]
(G) Each element, part or all of the components making up the
above individual apparatuses may be assembled as an IC card detachable
from a device, or as a single module. The IC card/module is a computer
system composed of a microprocessor, ROM, RAM, and the like. The IC
card/module may include therein the above-mentioned ultra-
multifunctional LSI. The microprocessor operates according to a
computer program, and thereby the IC card/module accomplishes its
function. The IC card/module may be tamper resistant.
[0079]
(7) The present invention may be a method of accomplishing the
above-described system. The present invention may be a computer program
34

that achieves the method by a computer, or may be a digital signal
representing the computer program.
The present invention may also be achieved by a computer-readable
recording medium, such as a flexible disk, a hard disk, a CD-ROM, an MO
disk, a DVD, a DVD-ROM, a DVD-RAM, a BD (Blu-ray Disc) , or a
semiconductor memory, on which the above-mentioned computer program or
digital signal is recorded. The present invention may also be the
computer program or the digital signal recorded on such a storage medium.
[0080]
The present invention may also be the computer program or digital
signal to be transmitted via networks, as represented by
telecommunications, wire/wireless communications, and the Internet, or
via data broadcasting.
The present invention may also be a computer system having a
microprocessor and memory, wherein the memory stores the computer
program and the microprocessor operates according to the computer
program.
[0081]
The computer program or digital signal may be recorded on the
above storage medium and transferred to an independent computer system,
or alternatively, may be transferred to an independent computer system
via the above network. Then, the independent computer system may
execute the computer program or digital signal.
(8) The present invention includes a structure in which two or
more of the above embodiments and modifications are combined.

(1) Structure of Recording Medium 101
35

The following presents a supplementary description of the
structure of the recording medium 101 of Embodiment 1.
[0082]
The recording medium 101 includes, as shown in FIG. 1: the
playback control information 111; the bytecode 112; the protected
content data 113; the encrypted content key 114; and the revocation
information 115.
(1.1) Bytecode 112
The bytecode 112 includes, for example, a JAVA (registered
trademark) byte code, and an executable code composed of fixed-length
instruction sets.
[0083]
As described above, the bytecode 112 includes: an anomalous-
apparatus table shown in FIG. 3; an acquisition step of acquiring
apparatus unique information from the apparatus unique information
storage unit 133 of the content playback apparatus 102; a judging step
of judging whether the acquired apparatus unique information is included
in the anomalous-apparatus table described above; and a display request
step of, when the acquired apparatus unique information is judged, in
the judging step, to be included in the anomalous-apparatus table,
requesting the content playback apparatus 102 to display a message for
the apparatus, which is set in the anomalous-apparatus table.
[0084]
Here, the acquisition step acquires apparatus unique information
by interacting the content playback apparatus 102. Note that
"interacting the content playback apparatus 102" means information
interaction between the bytecode 112 and a program different from the
bytecode 112 executed by the bytecode execution unit 124 of the content
36

playback apparatus 102-e.g. a program including Steps S401-403, 406,
and 407 of FIG. 4.
[0085]
(1.2) Protected Content Data 113
The protected content data 113 is data created by performing,
with the use of a content key, an encryption process on MPEG2-TS data in
plain-text which is able to output video using a decoder. An encryption
method used here is secret key cryptography.
(1.3) Encrypted Content Key 114
The encrypted content key 114 is data created by, with the use of
a media key, encrypting the content key used for decrypting the
protected content data. An encryption method used here is secret key
cryptography.
[0086]
(1.4) Revocation Information 115
The revocation information 115 is, as described above, a list
itemizing encrypted media keys, each of which corresponds to a device
key assigned to an individual content playback apparatus, and key ID
numbers.
Here, encrypted media keys and key ID numbers corresponding to
device keys assigned to revoked content playback apparatuses have been
removed from the list.
[0087]
Herewith, only a legitimate content playback apparatus (i.e. a
content playback apparatus having not been revoked) is capable of
decrypting the encrypted media key using the revocation information 115
and the device key assigned to the apparatus and acquiring the media key.
37

An encryption method used here is secret key cryptography. FIG.
12 shows a specific example of the revocation information 115.
[0088]
Here, device keys are denoted as DK1, DK2, ..., and DKn; key IDs as
Kl, K2, ..., and Kn; and a media key as MK. Enc(x, y) means information
generated by encrypting "y" using secret key cryptography and "x".
In FIG. 12, a content playback apparatus to which a key 3D "K3"
has been assigned has been revoked. A content playback apparatus to
which a key ID "Kl" is a legitimate apparatus (i.e. unrevoked apparatus),
and therefore is able to decrypt an encrypted media key "Enc (DK1, MK)"
using the device key "DK1" corresponding to the key ID "Kl" .
[0089]
(1.5) Playback Control Information 111
The playback control information 111 is information specifying a
playback order of the protected content data 113 for the time when the
content is played back.
(2) Structure of Content Playback Apparatus 102
The following presents a supplementary description of the
structure of the content playback apparatus 102 of Embodiment 1.
[0090]
As shown in FIG. 1, the content playback apparatus 102 comprises:
a disk reading unit 121; a playback control unit 122; a user operation
reception unit 123; a bytecode execution unit 124; a decryption unit
125; a demultiplexing unit 127; a video decoder 128; an audio decoder
129; a content key generation unit 130; a revocation information
processing unit 131; a device key storage unit 132; an apparatus unique
information storage unit 133; a display control unit 134; and a display
unit 135.
38

[0091]
Although not shown in the figure, the content playback apparatus
102 is connected to a monitor and a speaker. The content playback
apparatus 102 is connected to, for example, a TV having a monitor and
speakers.
(2.1) Apparatus Unique Information Storage Unit 133
The apparatus unique information storage unit 133 stores an
apparatus maker ID, a model number, a manufacturing serial number, and a
firm version number.
[0092]
The apparatus maker ID is an identifier for identifying a maker
that manufactured the content playback apparatus 102.
The model number is a number for identifying a type of the
content playback apparatus 102 among one or more types of content
playback apparatuses manufactured by the maker identified by the
apparatus maker ID.
The manufacturing serial number is a number for identifying each
of one or more content playback apparatuses having the same model number.
[0093]
The firm version number is a number indicating a version of the
playback process firmware incorporated in the content playback apparatus
102.
(2.2) Device Key Storage Unit 132
The device key storage unit 132 stores a device key assigned to
the content playback apparatus 102 and a key ID number.
[0094]
(2.3) User Operation Reception Unit 123
39

The user operation reception unit 123 receives a request for
starting the content playback (a content playback start request) from
the user, and outputs the received content playback start request to the
playback control unit 122.
(2.4) Playback Control Unit 122
The playback control unit 122 controls the content playback.
[0095]
When receiving a content playback start request from the user
operation reception unit 123, the playback control unit 122 outputs, to
the bytecode execution unit 124, a bytecode execution instruction that
instructs execution of the bytecode.
When receiving, from the bytecode execution unit 124, a playback
continuation instruction that instructs continuation of the content
playback, the playback control unit 122 outputs, to the revocation
information processing unit 131, a revocation check instruction that
instructs to check whether the content playback apparatus 102 has been
revoked or not.
[0096]
When receiving, from the display control unit 134, a playback
prohibition instruction indicating that the content playback is not
allowed, the playback control unit 122 ends the content playback. This
operation corresponds to the playback inhibiting unit of the present
invention.
When receiving, from the revocation information processing unit
131, an apparatus revocation instruction indicating that the content
playback apparatus 102 has been revoked, the playback control unit 122
ends the content playback.
[0097]
40

When receiving, from the decryption unit 125, a playback abort
instruction indicating to abort the content playback, the playback
control unit 122 aborts the content playback.
(2.5) Bytecode Execution Unit 124
When receiving a bytecode execution instruction from the playback
control unit 122, the bytecode execution unit 124 reads the bytecode 112
from the recording medium 101 via the disk reading unit 121. This
operation corresponds to the reading unit of the present invention.
[0098]
The bytecode execution unit 124 acquires the apparatus maker ID,
model number, manufacturing serial number, and firm version number
stored in the apparatus unique information storage unit 133.
Hereinafter, a set of the apparatus maker ID, model number,
manufacturing serial number, and firm version number is referred to as
apparatus unique information.
The bytecode execution unit 124 starts the read bytecode 112, and
thereby checks whether the content playback apparatus 102 is an
anomalous apparatus or not. At this point, the bytecode execution unit
124 interacts with the bytecode 112 in execution, and whereby notifies
the bytecode 112 of the acquired apparatus unique information. Note
that "interacts with the bytecode 112" means information interaction
between the bytecode 112 and a program different from the bytecode 112
executed by the bytecode execution unit 124-e.g. a program including
Steps S401-403, 406, and 407 of FIG. 4, as described above. Here, the
operation that the content playback apparatus starts the bytecode 112
corresponds to the startup unit of the present invention. Also, the
operation that the content playback apparatus 102 interacts with the
bytecode 112 and thereby notifies the bytecode 112 of the apparatus
41

unique information corresponds to the interaction unit of the present
invention.
[0099]
When receiving a display request for a message from the bytecode
112 and a message determined in the bytecode 112, the bytecode execution
unit 124 outputs the received display request and message to the display
control unit 134.
When not receiving a display request and a message from the
bytecode 112, the bytecode execution unit 124 outputs a playback
continuation instruction to the playback control unit 122.
[0100]
(2.6) Display Control Unit 134
When receiving a display request and a message from the bytecode
execution unit 124, the display control unit 134 outputs a playback
prohibition instruction to the playback control unit 122.
The display control unit 134 displays the received message on the
monitor via the display unit 135.
[0101]
(2.7) Display Unit 135
The display unit 135 displays, on the monitor, a message received
from the display control unit 134. The operation of the display unit
135 corresponds to an example of the processing unit of the present
invention.
(2.8) Revocation Information Processing Unit 131
When receiving a revocation check instruction from the playback
control unit 122, the revocation information processing unit 131
acquires the device key and key ID number from the device key storage
unit 132.
42

[0102]
The revocation information processing unit 131 reads the
revocation information 115 from the recording medium 101 via the disk
reading unit 121, and checks, using the read revocation information 115
and the acquired key ID number, whether the content playback apparatus
102 has been revoked.
When judging that it has been revoked, the revocation information
processing unit 131 outputs an apparatus revocation instruction to the
playback control unit 122.
[0103]
When judging that it has not been revoked, the revocation
information processing unit 131 generates a media key by decrypting the
encrypted media key using the read revocation information 115 and the
acquired device key and key ID number. The revocation information
processing unit 131 outputs the generated media key to the content key
generation unit 130.
(2.9) Content Key Generation Unit 130
When receiving a media key from the revocation information
processing unit 131, the content key generation unit 130 reads the
encrypted content key 114 from the recording medium 101 via the disk
reading unit 121.
[0104]
The content key generation unit 130 decrypts the read encrypted
content key using the media key to thereby generate a content key.
The content key generation unit 130 outputs the generated content
key to the decryption unit 125.
(2.10) Decryption Unit 125
43

When receiving a content key from the content key generation unit
130, the decryption unit 125 sequentially reads the protected content
data 113 from the recording medium 101 via the disk reading unit 121,
based on the playback control information 111.
[0105]
The decryption unit 125 decrypts the read protected content data
113 using the content key, generates content data, and outputs the
generated content data to the demultiplexing unit 127.
When reading of all protected content data to be played back is
completed, the decryption unit 125 outputs a playback end instruction to
the playback control unit 122.
[0106]
(2.11) Demultiplexing Unit 127
When receiving content data from the decryption unit 125, the
demultiplexing unit 127 demultiplex the content data into video and
audio streams, and outputs the video stream to the video decoder 128 and
the audio stream to the audio decoder 129.
(2.12) Video Decoder 128
When receiving a video stream from the demultiplexing unit 127,
the video decoder 128 decodes the received video stream to thereby
generate video data, and outputs the generated video data to the monitor.
[0107]
(2.13) Audio Decoder 129
When receiving an audio stream from the demultiplexing unit 127,
the audio decoder 129 decodes the received audio stream to thereby
generate audio data, and outputs the generated audio data to the
speakers.
(2.14) Disk Reading Unit 121
44

The disk reading unit 121 is able to access the recording medium
101, and reads data recorded on the recording medium 101.
[0108]
(3) Operation of Content Playback Apparatus 102
The following presents a supplementary description of the
bytecode execution process shown in FIG. 4.
(3.1) Details of Step S404
Detailed operations of Step S404 shown in FIG. 4 are described
with the use of the flowchart of FIG. 13.
[0109]
The bytecode 112 acquires apparatus unique information by
interacting with the content playback apparatus 102 (Step S500). This
operation corresponds to the acquisition step included in the bytecode
112. At this point, the bytecode execution unit 124 notifies the
acquired apparatus unique information to the bytecode 112. Here, the
interaction between the bytecode 112 and the content playback apparatus
102 means information interaction between the bytecode 112 and a program
different from the bytecode 112 executed by the bytecode execution unit
124-e.g. a program including Steps S401-403, 406, and 407 of FIG. 4, as
described above. At this point also, the content playback apparatus 102
notifies the apparatus unique information to the bytecode 112 by the
interaction, and this operation corresponds to the interaction step of
the present invention.
[0110]
The bytecode 112 searches the anomalous-apparatus table for a
message corresponding to the acquired apparatus unique information (Step
S505).
(3.2) Details of Step S405
45

Detailed operations of Step S405 shown in FIG. 4 are described
with the use of the flowchart of FIG. 14.
[0111]
According to the result of the search of Step S505, the bytecode
112 judges whether the message is present (Step S550). This operation
corresponds to the judging step included in the bytecode 112. Note that
the operation composed of Steps S505 and S550 may be the judging step,
instead.
When determining that the message is present ("YES" in Step S550),
the bytecode 112 acquires the message corresponding to the acquired
apparatus unique information (Step S555). The bytecode 112 outputs the
acquired message and a display request to the bytecode execution unit
124 of the content playback apparatus 102 (Step S560). This operation
corresponds to the display request step included in the bytecode 112.
Note that the operation composed of Steps S555 and S560 may be the
display request step, instead.
[0112]
When determining that the message is absent ("NO" in Step S550) ,
the bytecode 112 ends the process, and thereby the bytecode execution
unit 124 of the content playback apparatus 102 outputs a playback
continuation instruction to the playback control unit 122. Herewith,
the content playback apparatus 102 moves to Step S202.
As to operations after Step S560, when receiving a message and a
display request from the bytecode 112, the bytecode execution unit 124
of the content playback apparatus 102 outputs the received message and
display request to the display control unit 134. Herewith, the content
playback apparatus performs Step S406 and the subsequent process.
[0113]
46

(4) Structure of Recording Medium 101A
The following presents a supplementary description of the
structure of the recording medium 101A of Embodiment 2.
The recording medium 101A includes, as shown in FIG. 7: the
playback control information 111A; the bytecode 112A; the protected
content data 113A; the encrypted content key 114A; and the revocation
information 115A.
[0114]
The playback control information 111A, protected content data
113A, encrypted content key 114A, and revocation information 115A are
the same as the playback control information 111, protected content data
113, encrypted content key 114, and revocation information 115,
respectively, and therefore, their descriptions are omitted here.
The following explains the bytecode 112A.
[0115]
As described above, the bytecode 112A stored in the recording
medium 101A includes: an anomalous-state table shown in FIG. 9; an
acquisition step of acquiring apparatus state information from the
apparatus state information acquisition unit 13 6A of the content
playback apparatus 102A; a judging step of judging whether the acquired
apparatus state information is included in the anomalous-state table
described above; and a display request step of, when in the judging step
the acquired apparatus state information is judged to be included in the
anomalous-state table, requesting the content playback apparatus 102A to
display a message for the state of the apparatus which is set in the
anomalous-state table.
[0116]
47

Here, the acquisition step acquires apparatus state information
by interacting the content playback apparatus 102A. Note that
"interacting the content playback apparatus 102A" means information
interaction between the bytecode 112A and a program different from the
bytecode 112A executed by the bytecode execution unit 124A of the
content playback apparatus 102A-e.g. a program including Steps 403A,
406A, and 407A of FIG. 11.
[0117]
(5) Content Playback Apparatus 102A
The content playback apparatus 102A, as shown in FIG. 7,
comprises: a disk reading unit 121A; a playback control unit 122A; a
user operation reception unit 123A; a bytecode execution unit 124A; a
decryption unit 125A; a demultiplexing unit 127A; a video decoder 128A;
an audio decoder 129A; a content key generation unit 130A; a revocation
information processing unit 131A; a device key storage unit 132A; a
display control unit 134A; a display unit 135A; and an apparatus state
information acquisition unit 136A.
[0118]
(5.1) Device Key Storage Unit 132A
Since the device key storage unit 13 2A is the same as the device
key storage unit 132, the description is omitted here.
(5.2) User Operation Reception Unit 123A
Since the user operation reception unit 123A is the same as the
user operation reception unit 123, the description is omitted here.
[0119]
(5.3) Playback Control Unit 122A
The playback control unit 122A controls the content playback.
48

When receiving a content playback start request from the user
operation reception unit 123A, the playback control unit 122A outputs,
to the bytecode execution unit 124A, a bytecode startup instruction that
instructs startup of the bytecode.
[0120]
When receiving a startup completion instruction that indicates
completion of startup of the bytecode 112A, the playback control unit
122A outputs, to the revocation information processing unit 131A, a
revocation check instruction that instructs to check whether the content
playback apparatus 102A has been revoked or not.
When receiving, from the display control unit 134A, a playback
canceling instruction indicating to cancel the content playback, the
playback control unit 122A ends the content playback. This operation
corresponds to the playback inhibiting unit of the present invention.
[0121]
When receiving a playback end instruction from the decryption
unit 125A, the playback control unit 122A ends the content playback.
(5.4) Apparatus state information Acquisition Unit 136A
The apparatus state information acquisition unit 136A acquires,
as apparatus state information, result of the process performed by the
revocation information processing unit 131A. The apparatus state
information acquisition unit 136A stores the acquired apparatus state
information. The result of the process performed by the revocation
information processing unit 131A is, for example, a code indicating
whether the process ended normally, and also indicating, in the case
where the process ended abnormally, the type of the trouble. "1A" and
"IB" of FIG. 9 represent codes for abnormal ends.
[0122]
49

The apparatus state information acquisition unit 136A acquires,
as apparatus state information, result of the process performed by the
decryption unit 125A. The apparatus state information acquisition unit
136A stores the acquired apparatus state information. The result of the
process performed by the revocation information processing unit 131A is,
for example, a code indicating whether the process ended normally (an
error code), and also indicating, in the case where the process ended
abnormally, the type of the trouble. "2A" and "2B" of FIG. 9 represent
codes for abnormal ends.
[0123]
Here, the apparatus state information acquisition unit 13 6A
stores therein only the latest apparatus state information, discarding
other apparatus state information. That is, when acquiring one piece of
apparatus state information, the apparatus state information acquisition
unit 136A deletes apparatus state information having been stored therein
up to that point.
(5.5) Bytecode Execution Unit 124A
When receiving a bytecode execution instruction from the playback
control unit 122A, the bytecode execution unit 124A reads the bytecode
112 from the recording medium 101A via the disk reading unit 121A. This
operation corresponds to the reading unit of the present invention.
[0124]
The bytecode execution unit 124A starts the read bytecode 112A.
At this point, the bytecode 112A is in a state of waiting an input.
When startup of the bytecode 112A is completed, the bytecode
execution unit 124A outputs a startup completion instruction to the
playback control unit 122A.
50

When receiving, from the revocation information processing unit
131A, an apparatus revocation instruction indicating that the content
playback apparatus 102A has been revoked, the bytecode execution unit
124A acquires apparatus state information from the apparatus state
information acquisition unit 136A. The bytecode execution unit 124A
provides, as information, the acquired apparatus state information to
the running bytecode 112A, and thereby checks whether the content
playback apparatus 102A is in an anomalous state. At this point, the
bytecode execution unit 124A interacts with the bytecode 112A in
execution, and whereby notifies the acquired apparatus state information
to the bytecode 112A. Note that "interacts with the bytecode 112A"
means information interaction between the bytecode 112A and a program
different from the bytecode 112A executed by the bytecode execution unit
124A of the content playback apparatus 102A-e.g. a program including
Steps S403A, 406A, and 407A of FIG. 11, as described above. Here, the
operation that the content playback apparatus starts the bytecode 112A
corresponds to the startup unit of the present invention. Also, the
operation that the content playback apparatus 102A interacts with the
bytecode 112A and thereby notifies the apparatus state information to
the bytecode 112A corresponds to the interaction unit of the present
invention.
[0125]
Also, when receiving, from the decryption unit 125A a decryption
failure instruction indicating that decryption of the protected content
data has been failed, the bytecode execution unit 124A acquires
apparatus state information from the apparatus state information
acquisition unit 136A. The bytecode execution unit 124A provides, as
information, the acquired apparatus state information to the running
51

bytecode 112A, and thereby checks whether the content playback apparatus
102A is in an anomalous state.
[0126]
When receiving a display request for a message from the bytecode
112A and a message determined in the bytecode 112, the bytecode
execution unit 124A outputs the received display request and message to
the display control unit 134A.
When not receiving a display request and a message from the
bytecode 112, the bytecode execution unit 124A outputs a process
continuation instruction indicating to continue the process to a source
that has output the instruction (i.e. the revocation information
processing unit 131A or the decryption unit 125A).
[0127]
(5.6) Display Control Unit 134A
When receiving a display request and a message from the bytecode
execution unit 124A, the display control unit 134A outputs a playback
prohibition instruction to the playback control unit 122A.
The display control unit 134A displays the received message on
the monitor via the display unit 13 5A.
[0128]
(5.7) Display Unit 135A
The display unit 135A displays, on the monitor, a message
received from the display control unit 134A. The operation of the
display unit 135A corresponds to an example of the processing unit of
the present invention.
(5.8) Revocation Information Processing Unit 131A
When receiving a revocation check instruction from the playback
control unit 122A, the revocation information processing unit 131A
52

acquires the device key and key ID number from the device key storage
unit 132A.
[0129]
The revocation information processing unit 131A reads the
revocation information 115A from the recording medium 101A via the disk
reading unit 121A, and checks, using the read revocation information
115A and the acquired key ID number, whether the content playback
apparatus 102A has been revoked.
When judging that it has been revoked, the revocation information
processing unit 131 issues error code indicating the type of the trouble
that led to the abnormal end, and outputs the issued error code to the
apparatus state information acquisition unit 136A. The revocation
information processing unit 131A outputs an apparatus revocation
instruction to the bytecode execution unit 124A.
[0130]
When judging that it has not been revoked, the revocation
information processing unit 131A issues a code indicating that the
process has ended normally, and outputs the issued code to the apparatus
state information acquisition unit 136A. The revocation information
processing unit 131A decrypts the encrypted media key using the read
revocation information 115A and the acquired device key and key ID
number to generate a media key. The revocation information processing
unit 131A outputs the generated media key to the content key generation
unit 130A.
[0131]
When receiving a process continuation instruction from the
bytecode execution unit 124A, the revocation information processing unit
131A continues the process.
53

(5.9) Content Key Generation Unit 130A
The content key generation unit 130A is the same as the content
key generation unit 130, the description is omitted here.
[0132]
(5.10) Decryption Unit 125A
When receiving a content key from the content key generation unit
130A, the decryption unit 125A sequentially reads the protected content
data 113A from the recording medium 101A via the disk reading unit 121A,
based on the playback control information 111A.
The decryption unit 125A decrypts the read protected content data
113A using the content key, generates content data, and outputs the
generated content data to the demultiplexing unit 127A. Here, if
failing decryption of the protected content data 113A, the decryption
unit 125A outputs an appropriate error code to the apparatus state
information acquisition unit 136A and outputs a decryption failure
instruction to the bytecode execution unit 124A. When succeeding the
decryption of the protected content data 113A, the decryption unit 125A
outputs an appropriate code to the apparatus state information
acquisition unit 136A and continue the process.
[0133]
When reading of all protected content data to be played back is
completed, the decryption unit 125A outputs a playback end instruction
to the playback control unit 122A.
When receiving a process continuation instruction from the
bytecode execution unit 124A, the decryption unit 125A continues the
process.
(5.11) Demultiplexing Unit 127
54

Since the demultiplexing unit 12 7A is the same as the
demultiplexing unit 127, the description is omitted here.
[0134]
(5.12) Video Decoder 128A
Since the video decoder 128A is the same as the video decoder 128,
the description is omitted here.
(5.13) Audio Decoder 129A
Since the audio decoder 12 9A is the same as the audio decoder 129,
the description is omitted here.
[0135]
(5.14) Disk Reading Unit 121A
Since the demultiplexing unit 12 7A is the same as the
demultiplexing unit 127, the description is omitted here.
(6) Operation of Content Playback Apparatus 102A
The following presents a supplementary description of the
bytecode execution process shown in FIG. 11.
[0136]
(6.1) Details of Step S404A
Detailed operations of Step S404 shown in FIG. 11 are described
with the use of the flowchart of FIG. 15.
The bytecode 112A acquires apparatus state information by
interacting with the content playback apparatus 102A (Step S500A) . This
operation corresponds to the acquisition step included in the bytecode
112A. At this point, the bytecode execution unit 124A notifies the
acquired apparatus state information to the bytecode 112A. Here, the
interaction between the bytecode 112A and the content playback apparatus
102A means information interaction between the bytecode 112A and a
program different from the bytecode 112A executed by the bytecode
55

execution unit 124A-e.g. a program including Steps S403A, 406A, and
407A of FIG. 11, as described above. At this point also, the content
playback apparatus 102A notifies the apparatus state information to the
bytecode 112A by the interaction, and this operation corresponds to the
interaction step of the present invention.
[0137]
The bytecode 112A searches the anomalous-state table for a
message corresponding to the acquired apparatus state information (Step
S505A) .
(6.2) Details of Step S405A
Detailed operations of Step S405A shown in FIG. 11 are described
with the use of the flowchart of FIG. 16.
[0138]
According to the result of the search of Step S505A, the bytecode
112A judges whether the message is present (Step S550A) . This operation
corresponds to the judging step included in the bytecode 112A. Note
that the operation composed of Steps S505A and S550A may be the judging
step, instead.
When determining that the message is present ("YES" in Step
S550A) , the bytecode 112A acquires the message corresponding to the
acquired apparatus state information (Step S555A) . The bytecode 112A
outputs the acquired message and a display request to the bytecode
execution unit 124A of the content playback apparatus 102A (Step S560A) .
This operation corresponds to the display request step included in the
bytecode 112A. Note that the operation composed of Steps S555A and
S560A may be the display request step, instead.
[0139]
56

When determining that the message is absent ("NO" in Step S550A),
the bytecode 112A ends the process. The byteccde execution unit 124A of
the content playback apparatus 102A then outputs a process continuation
instruction indicating continuation of the process to a source of
calling the bytecode execution process (i.e. the revocation information
processing unit 131A or the decryption unit 125A). Herewith, the
content playback apparatus 102 moves to Step S203A or Step S206A.
[0140]
As to operations after Step S560A, when receiving a message and a
display request from the bytecode 112A, the bytecode execution unit 124A
of the content playback apparatus 102A outputs the received message and
display request to the display control unit 134A. Herewith, the content
playback apparatus performs Step S406A and the subsequent process.
(7) Modifications
(7.1) In Embodiment 2, the messages for display are associated
with error codes; however, the present invention is not limited to this
case.
[0141]
The error codes may be associated with state identification
information that identifies events taking place when the content
playback apparatus is in operation.
Accordingly, if an event that was not envisioned at the time of
manufacture occurs during the operation, it is possible to treat the
event as an error even after the shipment of the content playback
apparatus.
Such an event occurring during the operation is, for example, the
speed of fast-forwarding during the playback reaches its performance
limit. Another example is an event of decryption failure. In
57

Embodiment 2, the content playback apparatus performs a two-stage
decryption (decryption of the encrypted content key, and decryption of
the protected content data) on the content. Here, if a three-stage
encryption has been performed on the content of the recording medium,
the two-stage decryption cannot be performed on it.
[0142]
(7.2) In Embodiment 1 above, in the case of displaying a message
corresponding to apparatus unique information of the content playback
apparatus, the playback control unit of the content playback apparatus
stops (aborts) the content playback; however, the present invention is
not limited to this.
A playback stop step for stopping '(aborting) the content playback
may be included in the bytecode in the case of displaying a message.
Here, the content playback apparatus can inhibit the content playback by
executing the playback stop step during the execution of the bytecode.
Herewith, the bytecode is capable of having the content playback
apparatus inhibit the content playback.
[0143]
Similarly, in the case of overlay display of a message, an
overlay display step for displaying a message over the content being
played back may be included in the bytecode. Here, the bytecode
execution unit of the content playback apparatus executes the overlay
display step during the execution of the bytecode, and thereby the
display unit is capable of displaying a message over the content being
played back.
[0144]
In addition, in the case of switching between stopping the
content playback and realizing overlay display, a switching step may be
58

included in the byteccde. In the switching step, a user instruction is
received, and either inhibiting of the content playback or overlay
display of a message is performed in accordance with the received
instruction. Here, the content playback apparatus executes the
switching step during the execution of the byteccde, and thereby
receives an instruction from the user and performs either inhibition of
the content playback or overlay display of a message in accordance with
the received instruction. Herewith, the byteccde is capable of having
the content playback apparatus take control to perform either inhibition
of the content playback or overlay display of a message.
[0145]
In the case of including control information in the byteccde as
described in (1) under Other Modifications, the content playback
apparatus is capable of reading the control information and performing
either inhibition of the content playback or overlay display of a
message based on the read control information. Alternatively, the
byteccde may output the control information to the byteccde execution
unit of the content playback apparatus by interacting with the content
playback apparatus and perform the process based on the control
information received by the byteccde execution unit. Note that
"interacting with the content playback apparatus" means interaction of
information between the byteccde and a program different from the
bytecode 112 executed by the bytecode execution unit 124 of the content
playback apparatus.
[0146]
The content playback apparatus may include in advance a process
control unit that takes control to perform either inhibition of the
content playback or overlay display of a message. The content playback
59

apparatus executes the operation of the process control unit in the case
of receiving a message indicating that the apparatus is in an anomalous
state by the interaction with the bytecode. The operation of the
process control unit includes, for example, receiving from the user
either an instruction for inhibiting the playback or an instruction for
overlay display of a message and performing either one of them according
to the received instruction. As another example, in the case where
control information is recorded on the recording medium, the process
control unit reads control information from the recording medium, and
performs either inhibition of the content playback or overlay display of
a message, based on the read control information.
[0147]
Note that, similarly in Embodiment 2, the step of stopping
(aborting) the content playback may be included in the bytecode. In
addition, the step of displaying a message over the content being played
back may be included in the bytecode. In addition, the switching step
may be included in the bytecode.
Alternatively, the content playback apparatus may include in
advance a process control unit that takes control to perform either
inhibition of the content playback or overlay display of a message. The
content playback apparatus executes the operation of the process control
unit in the case of receiving a message indicating that the apparatus is
in an anomalous state by the interaction with the bytecode.
[0148]
(7.3) In Embodiment 1, the anomalous-apparatus table is included
in the bytecode; however, the present invention is not limited to this
case.
60

The anomalous-apparatus table may be recorded, on the recording
medium, in an area different from the area recording the bytecode.
Similarly, in Embodiment 2, the anomalous-state table may be
recorded, on the recording medium, in an area different from the area
recording the bytecode.
[0149]
(7.4) The apparatus unique information of the present invention
is information including at least one of the apparatus maker ID, model
number, manufacturing serial number, and firm version number stored in
the apparatus unique information storage unit 133.
(7.5) The present invention includes a structure in which two or
more of the above embodiments and modifications are combined.
(8) Summary
Conventional technology is able to determine an anomalous state
that has been anticipated in advance (i.e. an anomalous state
anticipated at the time of manufacture of a terminal apparatus, such as
a content playback apparatus) and provide the user with a message
corresponding to the anomalous state. However, as to an anomaly that
has not been anticipated in advance (an anomalous state identified after
the shipment) , such as an anomalous state due to bugs, it cannot
determine the anomalous state and provide the user with a message
corresponding to the anomalous state.
[0150]
Additionally, in the conventional technology, how to notify the
user for what kind of anomalous state is generally an implementation
matter specified by the terminal apparatus manufacturer. It is
therefore difficult to reflect the intention of the content's copyright
holder, and/or to allow the copyright holder to control such messages.
61

Especially, the conventional technology is not capable of determining,
on a terminal apparatus manufactured by a manufacturer with malicious
intent, an anomalous state that has been predetermined in accordance
with the desire of the copyright holder, and providing the user with a
message corresponding to the anomalous state.
[0151]
Contrarily, the present invention is capable of determining an
anomalous state that has not been anticipated in advance and providing
the user of a message corresponding to the anomalous state. Also, it is
able to determine an anomalous state that has been predetermined in
accordance with the desire of the content's copyright holder and provide
a message corresponding to the anomalous state.
In addition, the recording medium, data processing apparatus (e.g.
the content playback apparatus mentioned above), and data processing
method of the present invention are useful in the field where content
data that is a copyrighted work, such as a movie, is stored on a
recording medium and the content data on the recording medium is played
back.
[0152]
(8.1) The present invention is a recording medium recording
thereon a program which is read and executed by a data processing
apparatus. This recording medium is characterized by the program
recorded thereon which comprises the steps of: receiving information
stored or acquire by the data processing apparatus; acquiring a message
corresponding to the received information; and presenting a display
request for the acquired message to the data processing apparatus.
[0153]
62

(8.2) Here, as to the recording medium of (8.1) above, the
information may be apparatus unique information used for identifying an
unauthorized or anomalous data processing apparatus, and the message may
be a message notifying the user of the data processing apparatus that
the data processing apparatus is an unauthorized or anomalous one.
(8.3) Here, as to the recording medium of (8.1) above, the
information may be apparatus state information indicating that the data
processing apparatus is in an unauthorized or anomalous data processing
state, and the message may be a message notifying the user of the data
processing apparatus that the data processing apparatus is in an
unauthorized or anomalous data processing state.
[0154]
(8.4) The present invention is also a data processing apparatus
for executing a program read from the recording medium of one of (8.1)
to (8.3) above. The data processing apparatus is characterized by
comprising: a reading unit operable to reading the program from the
recording medium; a program executing unit operable to execute the read
program; a notifying unit operable to notify stored or acquired
information; and a display unit operable to display a message in
accordance with a message display request received from the program.
[0155]
(8.5) Here, as to the data processing apparatus of (8.4) above,
the information may be apparatus unique information used for identifying
an unauthorized or anomalous data processing apparatus, and the message
may be a message notifying the user of the data processing apparatus
that the data processing apparatus is an unauthorized or anomalous one.
(8.6) Here, as to the data processing apparatus of (8.4) above,
the information may be apparatus state information indicating that the
63

data processing apparatus is in an unauthorized or anomalous data
processing state, and the message may be a message notifying the user of
the data processing apparatus that the data processing apparatus is in
an unauthorized or anomalous data processing state.
[0156]
(8.7) The present invention is also a data processing method used
on a data processing apparatus that executes a program read from a
recording medium. The data processing method is characterized by
comprising: a reading step in which the data processing apparatus reads
the program from the recording medium; an execution step in which the
data processing apparatus executes the read program; a 1st notifying step
in which the data processing apparatus notifies stored or acquired
information to the executed program; a receiving step in which the
program receives the information notified from the data processing
apparatus; an acquisition step in which the program acquires a message
nci
corresponding to the received information; a 2 notifying step in which
the program notifies a display request for the acquired message; and a
display step in which the data processing apparatus displays the message
in accordance with the display request notified from the program.
Industrial Applicability
[0157]
The recording medium and content playback apparatus described
above can be used operationally, continuously and repeatedly in
industries supplying contents to users, manufacturing industries that
manufacture apparatuses for playing back contents, and marketing
industries that market apparatuses for playing back contents.
64

CLAIMS
1. A recording medium provided by content provider and recording
thereon content and a program which is executed during playback of the
content by a playback apparatus, wherein
the program causes the playback apparatus to execute:
an interacting step of interacting with a different program that
is prestored in the playback apparatus and executed during the playback
of the content; and
an output step of transmitting, to the different program, a
message determined according to result of the interaction.
2. The recording medium of Claim 1, wherein
the interaction step acquires apparatus unique information unique
to the playback apparatus by interacting with the different program, and
the output step outputs, to the different program, a message
determined according to the apparatus unique information.
3. The recording medium of Claim 2, where in
the output step includes:
an acquisition step of acquiring, according to the apparatus
unique information, a message which the playback apparatus is capable of
di splaying; and
a transmission step of transmitting the acquired message to the
different program.
4. The recording medium of Claim 3, wherein
65

the acquisition step acquires, in a case where the apparatus
unique information indicates that the playback apparatus is an
unauthorized or anomalous apparatus, a message indicating that the
playback apparatus is an unauthorized or anomalous apparatus.
5. The recording medium of Claim 1, wherein
the interacting step acquires apparatus state information
indicating an operating state of the playback apparatus by interacting
with the different program, and
the output step transmits, to the different program, a message
determined according to the apparatus state information.
6. The recording medium of Claim 5, wherein
the output step includes:
an acquisition step of acquiring, according to the apparatus
state information, a message which the playback apparatus is capable of
di splaying; and
a transmission step of transmitting the acquired message to the
different program.
7. The recording medium of Claim 6, wherein
the acquisition step acquires, in a case where the apparatus
state information indicates that the playback apparatus is in an
unauthorized or anomalous state, a message indicating that the playback
apparatus is in the unauthorized or anomalous state.
8. The recording medium of Claim 1, including a storage area that
stores therein the message.
66

9. The recording medium of Claim 1, wherein
in a case where the message indicates one of (1) the playback
apparatus being an unauthorized or anomalous apparatus and (2) the
playback apparatus being in an unauthorized or anomalous state, the
program causes the playback apparatus to execute, in addition to the
output of the message, a playback inhibition step of inhibiting the
playback of the content.
10. The recording medium of Claim 1, wherein
the content includes image data,
the playback apparatus plays back an image based on the image
data, and
the program further causes the playback apparatus to execute an
overlay display step of displaying the message over the image of the
contents being played back.
11. The recording medium of Claim 1, wherein
the message indicates one of (1) the playback apparatus being an
unauthorized or anomalous apparatus and (2) the playback apparatus being
in an unauthorized or anomalous state, and
the program further causes the playback apparatus to execute a
process selection step of receiving, from a user, an instruction of
whether to inhibit the playback of the content or to display the message
over an image of the content being played back.
12. The recording medium of Claim 1, wherein
67

the program includes control information indicating performing
one of (1) an operation of inhibiting the playback of the content and
(2) an operation of displaying the message over an image of the content
being played back, and
the output step further transmits the control information to the
different program.
13. A playback apparatus for playing back content from a recording
medium that is provided by content provider, wherein
the recording medium records thereon the content and a program
which is executed at the time of the playback of the content, and
the playback apparatus comprising:
a reading unit operable to read the program from the recording
medium at the time of the playback of the content;
a startup unit operable to start up the read program;
an interaction unit operable to interact with the program; and
a processing unit operable to receive a message corresponding to
result of the interaction from the recording medium and perform a
process in accordance with to the received message.
14. The playback apparatus of Claim 13, wherein
the interaction unit notifies, to the program, apparatus unique
information unique to the playback apparatus, and
the processing unit receives a message in accordance with the
apparatus unique information from the recording medium as the result of
the interaction.
15. The playback apparatus of Claim 14, wherein
68

the apparatus unique information is prestored in the playback
apparatus.
16. The playback apparatus of Claim 13, wherein
the interaction unit notifies, to the program, apparatus state
information indicating an operating state of the playback apparatus.
17. The playback apparatus of Claim 16, wherein
the interaction unit acquires the apparatus state information
which indicates an operating state of the playback apparatus during the
playback of the content stored in the recording medium, and notifies the
acquired apparatus state information to the program, and
the processing unit receives a message corresponding to the
apparatus state information from the recording medium as the result of
the interaction.
18. The playback apparatus of Claim 13, wherein
the processing unit displays the received message.
19. The playback apparatus of Claim 18, wherein
in a case where the received message indicates one of (1) the
playback apparatus being an unauthorized or anomalous apparatus and (2)
the playback apparatus being in an unauthorized or anomalous state, the
playback apparatus further comprises:
a playback inhibiting unit operable to inhibit the playback of
the content in addition to displaying the message.
20. The playback apparatus of Claim 18, wherein
69

the content includes image data which is a basis of an image to
be played back by the playback apparatus, and
the processing unit displays the message over the image of the
content being played back.
21. The playback apparatus of Claim 18, wherein
the message indicates one of (1) the playback apparatus being an
unauthorized or anomalous apparatus and (2) the playback apparatus being
in an unauthorized or anomalous state, and
the processing unit performs one of (1) an operation of
inhibiting the playback of the content and (2) an operation of
displaying the message over an image of the content being played back.
22. The playback apparatus of Claim 21, wherein
the processing unit receives, from a user, an instruction of
whether to inhibit the playback of the content or to display the message
over the image of the content being played back, and performs the
process based on the received instruction.
23. The playback apparatus of Claim 21, wherein
the program records therein control information indicating one of
(1) inhibiting the playback of the content and (2) displaying the
message over the image of the content, and
the processing unit reads the control information from the
program and performs the process based on the read control information.
70

24. A message acquisition method used on a playback apparatus that
plays content from a recording medium provided by content provider,
wherein
the recording medium records thereon the content and a program
which is executed at the time of the playback of the content, and
the message acquisition method comprises:
a reading step of reading the program from the recording medium
at the time of the playback of the content;
a startup step of starting up the read program;
an interaction step of interacting with the program; and
a processing step of receiving a message corresponding to result
of the interaction from the recording medium and perform a process
corresponding to the received message.
25. A message acquisition program used on a playback apparatus that
plays content from a recording medium provided by content provider,
wherein
the recording medium records thereon the content and a program
which is executed at the time of the playback of the content, and
the message acquisition program comprises:
a reading step of reading the program from the recording medium
at the time of the playback of the content;
a startup step of starting up the read program;
an interaction step of interacting with the program; and
a processing step of receiving a message corresponding to result
of the interaction from the recording medium and perform a process
corresponding to the received message.
71

26. The message acquisition program of Claim 25 stored in a computer-
readable recording medium.
27. An integrated circuit of a playback apparatus for playing back
content from a recording medium that is provided by content provider,
wherein
the recording medium records thereon the content and a program
which is executed at the time of the playback of the content, and
the integrated circuit comprising:
a reading unit operable to read the program from the recording
medium at the time of the playback of the content;
a startup unit operable to start up the read program;.
an interaction unit operable to interact with the program; and
72
a processing unit operable to receive a message corresponding to
result of the interaction from the recording medium and perform a
process corresponding to the received message.

The present invention provides a recording medium that allows the content provider to control messages. The recording medium is provided by a content provider and records
thereon content and a program which is executed at the time of playback of the content by a playback apparatus. The program causes the playback apparatus to execute: an interacting step of interacting with a different program prestored in the playback apparatus and executed at the time of the playback of the content; and an output step of transmitting, to the
different program, a message determined according to the result of the interaction. The playback apparatus comprises: a reading unit operable to read the program from the recording
medium at the time of the playback of the content; a startup unit operable to start up the read program; an interaction unit operable to interact with the program; and a processing
unit operable to receive a message corresponding to result of the interaction from the recording medium and perform a process corresponding to the received message.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=3oTjyAurgYgvu+AOxZ1lmg==&loc=wDBSZCsAt7zoiVrqcFJsRw==


Patent Number 269908
Indian Patent Application Number 267/KOLNP/2008
PG Journal Number 47/2015
Publication Date 20-Nov-2015
Grant Date 18-Nov-2015
Date of Filing 18-Jan-2008
Name of Patentee PANASONIC CORPORATION,
Applicant Address 1006, OAZA KADOMA, KADOMA SHI, OSAKA
Inventors:
# Inventor's Name Inventor's Address
1 SHUNJI HARADA C/O. MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. 1006, OAZA KADOMA, KADOMA-SHI, OSAKA 571-8501
2 MASAYUKI KOZUKA C/O. MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. 1006, OAZA KADOMA, KADOMA-SHI, OSAKA 571-8501
3 MASAYA YAMAMOTO C/O. MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. 1006, OAZA KADOMA, KADOMA-SHI, OSAKA 571-8501
4 SENICHI ONODA C/O. MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. 1006, OAZA KADOMA, KADOMA-SHI, OSAKA 571-8501
5 MINEHISA NAGATA C/O. MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. 1006, OAZA KADOMA, KADOMA-SHI, OSAKA 571-8501
6 KAORU MURASE C/O. MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. 1006, OAZA KADOMA, KADOMA-SHI, OSAKA 571-8501
PCT International Classification Number G11B 20/10,H04N 5/91
PCT International Application Number PCT/JP2006/312774
PCT International Filing date 2006-06-27
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 60/693,796 2005-06-27 U.S.A.