Data processing method and data checking method

• US 7,373,525 B2
• Filed: 07/13/2004
• Issued: 05/13/2008
• Est. Priority Date: 07/23/2003
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Murakoshi, Sho
• Primary Examiner(s): Lamarre; Guy
• Assistant Examiner(s): Ahmed; Enam
• Application Number:
  US10/888,979
• Publication Number:
  US 20050022093A1
• Time in Patent Office: 1,400 Days
• Field of Search: 714/758, 713/194
• US Class Current: 713/194
• CPC Class Codes: G06F 11/1004 to protect a block of data words, e.g. CRC or checksum G06F11/1076 takes precedence; security arrangements for protecting computers or computer systems against unauthorized activity G06F21/00
• CPC Class Codes: G06F 21/64 Protecting data integrity, e.g. using checksums, certificates or signatures

Abstract

Cyclic-redundancy-check (CRC) processing is executed on data blocks each having a predetermined data amount, thereby calculating respective CRC values for the data blocks. Furthermore, CRC processing is executed on the respective CRC values a number of times determined according to random numbers that are generated sequentially, thereby generating sig values to be attached respectively to next data blocks.

Claims

1. A computer-implemented data processing method for processing a plurality of data blocks, the method, comprising:

calculating a cyclic-redundancy-check value by executing cyclic-redundancy-check processing on a data block of the plurality of data blocks having a predetermined data size;

executing cyclic-redundancy-check processing a random number of times on the cyclic-redundancy-check value to generate a check value that is to be attached to a next data block of the plurality of data blocks; and

storing said check value and said cyclic-redundancy check value in a memory.

2. The data processing method according to claim 1, wherein the random number of times is changed each time a check value is generated in the calculating step.

3. The data processing method according to claim 1, wherein, in a data area for storing a data block having the predetermined data size, the data block, a cyclic-redundancy-check value for the data block, and a check value generated from a cyclic-redundancy-check value of a data block that is stored in an immediately preceding data area are stored.

4. A computer-implemented data checking method for checking data in which each data block of a plurality of data blocks, having a predetermined data size, has a cyclic-redundancy-check value and a check value attached thereto, comprising:

comparing a value calculated by executing cyclic-redundancy-check processing a number of times on the cyclic-redundancy-check value attached to the data block with a check value attached to a next data block of the plurality of data blocks; and

determining whether the data block is valid based on a result of the comparing step.

5. The data checking method according to claim 4, wherein the number of times is determined according to random numbers that are generated sequentially, and is changed each time a check value is generated.

6. A data processing device for processing a plurality of data blocks, comprising:

means for calculating a cyclic-redundancy-check value by executing cyclic-redundancy-check processing on a data block of the plurality of data blocks having a predetermined data size;

means for executing cyclic-redundancy-check processing a random number of times on the cyclic-redundancy-check value to generate a check value that is to be attached to a next data block of the plurality of data blocks; and

means for storing said check value and said cyclic-redundancy check value in a memory.

7. The data processing device according to claim 6, further comprising means for changing the random number of times each time a check value is generated by the means for calculating.

8. The data processing device according to claim 6, further comprising means for storing, the data block, a cyclic-redundancy-check value for the data block, and a check value generated from a cyclic-redundancy-check value of a data block that is stored in an immediately preceding data area.

9. A data checking device for checking data in which each data block of a plurality of data blocks, having a predetermined data size, has a cyclic-redundancy-check value and a check value attached thereto, comprising:

a processor configured to compare a value calculated by executing cyclic-redundancy-check processing a number of times on the cyclic-redundancy-check value attached to a data block with a check value attached to a next data block of the plurality of data blocks, and to determine whether the data block is valid based on a result of the comparison.

10. The data checking devise according to claim 9, further comprising means for determining the number of times according to random numbers that are generated sequentially, and changing the number of time each time a check value is generated.