# US 8,543,840 B2 · Data processing apparatus, data processing system, and method for controlling the same

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- Number: US 8,543,840 B2
- Document ID: US8543840B2
- Status: Granted
- Kind: B2
- Application number: 13/094,103
- Filed: 2011-04-26
- Published: 2011-11-03
- Granted: 2013-09-24
- Earliest claimed: 2010-04-28
- Assignees: Canon Kabushiki Kaisha
- Applicants: Yoshiharu Imamoto
- Inventors: Yoshiharu Imamoto
- Web page: https://patentgrep.com/patent/US8543840B2

## CPC

- G11B 20/0021: {involving encryption or decryption of contents recorded on or reproduced from a record carrier}
- G11B 2220/218: Write-once discs
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)

## Abstract

A data processing apparatus acquires content, generates an encryption key by using an initial value written in an unwritten memory block in a write-once recording medium, encrypts the content by using the encryption key, and writes to the write-once recording medium the encrypted content and an address table for identifying the memory block storing the initial value used for generating the encryption key.

## Claims

### Claim 1

A data processing system including a media writing apparatus and a media destruction apparatus,
wherein the media writing apparatus comprises:
an acquisition unit configured to acquire content;
an encryption unit configured to generate an encryption key by using an initial value written in an unwritten memory block in a write-once recording medium, and to encrypt the content by using the encryption key; and
a writing unit configured to write to the write-once recording medium the encrypted content and an address table for identifying the memory block storing the initial value used for generating the encryption key, and
wherein the media destruction apparatus comprises:
a writing unit configured to change the initial value written in the memory block identified by the address table to a different data value, to prevent the encryption key from being generated.

### Claim 2

A data processing apparatus capable of reading and writing data from/to a write-once recording medium, the data processing apparatus comprising:
an acquisition unit configured to acquire content;
an encryption unit configured to generate an encryption key by using an initial value written in an unwritten memory block in the write-once recording medium, and to encrypt the content by using the encryption key; and
a writing unit configured to write to the write-once recording medium the encrypted content and an address table for identifying the memory block storing the initial value used for generating the encryption key,
wherein the writing unit changes the initial value written in the memory block identified by the address table to a different data value, to prevent the encryption key from being generated.

### Claim 3

A method for controlling a data processing apparatus capable of reading and writing data from/to a write-once recording medium, the method comprising:
acquiring content;
generating an encryption key by using an initial value written in an unwritten memory block in the write-once recording medium, and encrypting the content by using the encryption key;
writing to the write-once recording medium the encrypted content and an address table for identifying the memory block storing the initial value used for generating the encryption key; and
changing the initial value written in the memory block identified by the address table to a different data value, to prevent the encryption key from being generated.

### Claim 4

A non-transitory computer-readable storage medium storing a program which is read out and executed by a computer so as to cause the computer to carry out steps comprising:
acquiring content;
generating an encryption key by using an initial value written in an unwritten memory block in a write-once recording medium, and to encrypt the content by using the encryption key; and
writing to the write-once recording medium the encrypted content and an address table for identifying the memory block storing the initial value used for generating the encryption key; and
changing the initial value written in the memory block identified by the address table to a different data value, to prevent the encryption key from being generated.

### Claim 5

A data processing system including a media writing apparatus and a media destruction apparatus,
wherein the media writing apparatus comprises:
an acquisition unit configured to acquire content;
an encryption unit configured to identify N unwritten memory blocks in a write-once recording medium, to change an initial value in M memory blocks out of the N memory blocks to a different data value, to generate an encryption key by using a data group written in the N memory blocks, and to encrypt the content by using the encryption key; and
a writing unit configured to write to the write-once recording medium the encrypted content and an address table for identifying the N memory blocks used for generating the encryption key, and
wherein the media destruction apparatus comprises:
a writing unit configured to change an initial value in (N-M) unwritten memory blocks out of the N memory blocks identified by the address table to a different data value, to prevent the encryption key from being generated.

### Claim 6

A data processing apparatus capable of reading and writing data from/to a write-once recording medium, the data processing apparatus comprising:
an acquisition unit configured to acquire content;
an encryption unit configured to identify N unwritten memory blocks in the write-once recording medium, to change an initial value in M memory blocks out of the N memory blocks to a different data value, to generate an encryption key by using a data group written in the N memory blocks, and to encrypt the content by using the encryption key; and
a writing unit configured to write to the write-once recording medium the encrypted content and an address table for identifying the N memory blocks used for generating the encryption key,
wherein the writing unit changes an initial value in (N-M) unwritten memory blocks out of the N memory blocks identified by the address table to a different data value, to prevent the encryption key from being generated.

### Claim 7

A method for controlling a data processing apparatus capable of reading and writing data from/to a write-once recording medium, the method comprising:
acquiring content;
identifying N unwritten memory blocks in the write-once recording medium, changing an initial value in M memory blocks out of the N memory blocks to a different data value, generating an encryption key by using a data group written in the N memory blocks, and encrypting the content by using the encryption key;
writing to the write-once recording medium the encrypted content and an address table for identifying the N memory blocks used for generating the encryption key; and
changing an initial value in (N-M) unwritten memory blocks out of the N memory blocks identified by the address table to a different data value, to prevent the encryption key from being generated.

### Claim 8

A non-transitory computer-readable storage medium storing a program which is read out and executed by a computer so as to cause the computer to carry out steps comprising:
acquiring content;
identifying N unwritten memory blocks in a write-once recording medium, to change an initial value in M memory blocks out of the N memory blocks to a different data value, to generate an encryption key by using a data group written in the N memory blocks, and to encrypt the content by using the encryption key;
writing to the write-once recording medium the encrypted content and an address table for identifying the N memory blocks used for generating the encryption key; and
changing an initial value in (N-M) unwritten memory blocks out of the N memory blocks identified by the address table to a different data value, to prevent the encryption key from being generated.