Data comparison process

• US 7,167,980 B2
• Filed: 05/30/2002
• Issued: 01/23/2007
• Est. Priority Date: 05/30/2002
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Chiu, Chun Yang
• Primary Examiner(s): Zand; Kambiz
• Assistant Examiner(s): DOAN, TRANG T
• Application Number:
  US10/161,106
• Publication Number:
  US 20030226021A1
• Time in Patent Office: 1,699 Days
• Field of Search: 713/160, 713/176, 713/181
• US Class Current: 713/160
• CPC Class Codes: H04L 63/12 Applying verification of the received information cryptographic mechanisms or cryptographic arrangements for data integrity or data verification H04L9/32

Abstract

A process for comparing data, such as signatures in a data packet, includes retrieving, from a first hash table, a target value that corresponds to a segment of the data, processing the data in accordance with the target value to produce a checksum, locating an entry in a second hash table using the checksum, and comparing the data to the entry.

Claims

1. A method, comprising:

retrieving, from a first hash table, a target value that corresponds to a segment of the data, the target value identifying signature data, the signature data including the segment of data, and the signature data exceeding the segment of data in length;

locating the signature data in a data packet;

processing the signature data to produce a checksum;

locating an entry in a second hash table using the checksum; and

comparing the signature data to the entry and outputting an indication indicating whether or not the signature data matches the entry;

wherein the target value corresponds to a length of the signature data.

2. The method of claim 1, wherein the target value comprises a number of bytes in the signature data.

3. The method of claim 1, wherein processing the data comprises processing a number of bytes indicated by the target value to produce the checksum.

4. The method of claim 1, wherein the signature data comprises the segment of data plus an increment.

5. The method of claim 1, wherein the checksum comprises a first checksum, and the method further comprises:

obtaining a second target value that corresponds to the signature data plus an increment; and

determining a second checksum using the first checksum and the increment.

6. The method of claim 5, further comprising:

locating a second entry in the second hash table using the second checksum; and

comparing the signature data plus the increment to the second entry.

7. The method of claim 1, further comprising:

indicating a match if the signature data and the entry are the same.

8. The method of claim 1, wherein the signature data is used to identify the data packet to a network device.

9. The method of claim 1, wherein the signature data is located in the data packet using the target value.

10. An apparatus comprising:

a memory that stores executable instructions; and

a processor that executes the instructions to;

retrieve, from a first hash table, a target value that corresponds to a segment of the data, the target value identifying signature data, the signature data including the segment of data, and the signature data exceeding the segment of data in length;

locating the signature data in a data packet;

processing the signature data to produce a checksum;

locating an entry in a second hash table using the checksum; and

comparing the signature data to the entry and outputting an indication indicating whether or not the signature data matches the entry;

wherein the target value corresponds to a length of the signature data.

11. The apparatus of claim 10, wherein the target value comprises a number of bytes in the signature data.

12. The apparatus of claim 10, wherein processing the data comprises processing a number of bytes indicated by the target value to produce the checksum.

13. The apparatus of claim 10, wherein the signature data comprises the segment of data plus an increment.

14. The apparatus of claim 10, wherein the checksum comprises a first checksum, and the processor executes instructions to:

obtain a second target value that corresponds to the signature data plus an increment; and

determine a second checksum using the first checksum and the increment.

15. The apparatus of claim 14, wherein the processor executes instructions to:

locate a second entry in the second hash table using the second checksum; and

compare the signature data plus the increment to the second entry.

16. The apparatus of claim 10, wherein the processor executes instructions to:

indicate a match if the signature data and the entry are the same.

17. The apparatus of claim 10, wherein the signature data is used to identify the data packet to a network device.

18. The apparatus of claim 10, wherein the processor executes instructions to locate the signature data in the data packet using the target value.

19. An article comprising a machine-readable medium that stores executable instructions to compare data, the instructions causing a machine to:

retrieve, from a first hash table, a target value that corresponds to a segment of the data, the target value identifying signature data, the signature data including the segment of data, and the signature data exceeding the segment of data in length;

locating the signature data in a data packet;

processing the signature data to produce a checksum;

locating an entry in a second hash table using the checksum; and

comparing the signature data to the entry and outputting an indication indicating whether or not the signature data matches the entry;

wherein the target value corresponds to a length of the signature data.

20. The article of claim 19, wherein the target value comprises a number of bytes in the signature data.

21. The article of claim 19, wherein processing the data comprises processing a number of bytes indicated by the target value to produce the checksum.

22. The article of claim 19, wherein the signature data comprises the segment of data plus an increment.

23. The article of claim 19, wherein the checksum comprises a first checksum, and wherein the article comprises instructions for causing the machine to:

obtain a second target value that corresponds to the signature data plus an increment; and

determine a second checksum using the first checksum and the increment.

24. The article of claim 23, further comprising instructions that cause the machine to:

locate a second entry in the second hash table using the second checksum; and

compare the signature data plus the increment to the second entry.

25. The article of claim 19, further comprising instructions that cause the machine to:

indicate a match if the signature data and the entry are the same.

26. The article of claim 19, wherein the signature data is used to identify the data packet to a network device.

27. The article of claim 19, further comprising instructions to locate the signature data in the data packet using the target value.