Data processing apparatus, data processing system, and method for controlling the same

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.

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.

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.

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.

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.

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.

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.