SECURE AND EFFICIENT METHODS FOR LOGGING AND SYNCHRONIZING DATA EXCHANGES

• US 20070255530A1
• Filed: 02/09/2007
• Published: 11/01/2007
• Est. Priority Date: 04/21/2006
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: WOLFF, GREGORY
• Granted Patent: US 7,809,685 B2
• Time in Patent Office: Days
• US Class Current: 702/187
• CPC Class Codes: G06F 21/64 Protecting data integrity, e.g. using checksums, certificates or signatures
• CPC Class Codes: G06F 2221/2101 Auditing as a secondary aspect

Abstract

A method and apparatus is disclosed herein for logging and/or synchronizing data exchanges. In one embodiment, the method comprises receiving a request from a requester to post data to a first log, identifying the log based on a context identifier in the request indicative of a location of the first log and digital data associated with a document corresponding to the first log, creating a first entry based on data in the request, appending the first log with the first entry, calculating a first identifier based on log entries in the first log, and sending the first identifier to the requester.

Claims

1. A method comprising:

receiving a request from a requester to post data to a first log;

identifying the log based on a context identifier in the request indicative of a location of the first log and digital data associated with a document corresponding to the first log;

creating a first entry based on the data in the request;

appending the first log with the first entry;

calculating a first identifier based on log entries in the first log; and

sending the first identifier to the requester.

2. The method defined in claim 1 wherein the first identifier comprises a checkpoint of the log entries.

3. The method defined in claim 1 further comprising sending a response with one or more items that have been posted in the first log.

4. The method defined in claim 3 wherein one or more items in the first log are in a sequence based on the time at which each of the one or more items were posted in the first log.

5. The method defined in claim 3 further comprising synchronizing a second log with the one or more items.

6. The method defined in claim 5 wherein synchronizing the second log with the one or more items comprises:

calculating an intersection of attribute entries that appear in first log and the second log that include first and second sequences, respectively, of content and attribute entries associated with each context punctuated by one or more checkpoints;

ordering entries according to their appearance in the first log;

determining whether each entry in the second log is in the intersection of attribute entries or is the next entry in the order; and

performing an additional comparison between the first and second logs starting only after checkpoints in each of the first and second logs subsequent to the first and second sets of sequences.

7. The method defined in claim 1 wherein the request is an HTTP POST.

8. The method defined in claim 1 further comprising:

maintaining the first log with a file format that includes a sequence of content and attribute entries associated with each context punctuated by one or more checkpoints; and

accessing the context log to review information stored therein.

9. The method defined in claim 8 wherein one content entry comprises a vector having the hash of a string and the string.

10. The method defined in claim 8 wherein one attribute entry comprises a vector having entries that include an identifier associated with a log file concatenated with an identifier of a content entry and one or more pairs consisting of a label of an attribute for the content entry in a context and a value associated with the attribute.

11. The method defined in claim 10 wherein the identifier of a content entry comprises a hash of the content entry and wherein the identifier associated with the first log comprises a hash of the context of attribute assignment.

12. The method defined in claim 8 wherein at least one checkpoint comprises a hash of the previous checkpoint concatenated with all entries between the previous checkpoint and the at least one checkpoint.

13. The method defined in claim 8 wherein the context is a combination of first and second identifiers, wherein the first identifier identifies a machine and the second identifier identifies a group of digital data.

14. The method defined in claim 1 wherein the first log is self-verifying.

15. The method defined in claim 1 further comprising verifying current state of the information stored in the first log.

16. The method defined in claim 15 wherein verifying current state of the information stored in the context log comprises verifying a current state of a document based on entries in the first log.

17. The method defined in claim 1 further comprising:

receiving a request for entries in the first log, the request including a checkpoint; and

sending the entries that are after the checkpoint to satisfy the request.

18. The method defined in claim 12 wherein the request for entries in the first log is a request for all entries after a checkpoint specified in the request;

and further comprising determining whether the checkpoint is in the first log.

19. The method defined in claim 18 wherein at least one of the entries includes a first hashed version of the data that has been propagated to other locations, wherein the data is used to verify the authenticity of the first log, and further comprising:

a machine receiving a request to prove that the machine created the first log; and

the machine sending the data, such that a hash may be applied to the data to create a second hashed version of the data compared to an instance of the first hashed version that had been propagated to prove the machine created the first log.

20. The method defined in claim 1 farther comprising:

calculating a hash of a portion of data received in the request;

comparing the hash to a list of one or more hashes in an identifier associated with the first log; and

accepting the post request if the hash appears in the list of hashes in the identifier.

21. A method comprising:

sending a request for entries in a first context log that occur after a first checkpoint;

receiving the entries that are after the first checkpoint to satisfy the request; and

adding one or more of the entries to a second context log to synchronize the second context log and the first context log.

22. The method defined in claim 21 wherein the first context log has a file format that includes a sequence of content and attribute entries associated with each context punctuated by one or more checkpoints

23. The method defined in claim 21 wherein the second context log is identical to the first context log after adding the one or more entries.

24. The method defined in claim 21 further comprising:

calculating an intersection of attribute entries that appear in first and second logs that include first and second sequences, respectively, of content and attribute entries associated with each context punctuated by one or more checkpoints;

ordering entries according to their appearance in the first log;

determining whether each entry in the second log is in the intersection of attribute entries or is the next entry in the order; and

performing an additional comparison between the first and second logs starting only after checkpoints in each of the first and second logs subsequent to the first and second sets of sequences.

25. An article of manufacture having one or more computer readable storage media storing instructions thereon which, when executed by a system, cause the system to perform a method comprising:

sending a request for entries in a first context log that occur after a first checkpoint;

receiving the entries that are after the first checkpoint to satisfy the request; and

adding one or more of the entries to a second context log to synchronize the second context log and the first context log.

26. A method comprising:

calculating an intersection of attribute entries that appear in first and second logs that include first and second sequences, respectively, of content and attribute entries associated with each context punctuated by one or more checkpoints;

ordering entries according to their appearance in the first log;

determining whether each entry in the second log is in the intersection of attribute entries or is the next entry in the order; and

performing an additional comparison between the first and second logs starting only after checkpoints in each of the first and second logs subsequent to the first and second sets of sequences.

27. A method comprising:

storing a first entry in a log that includes an identifier, wherein the identifier comprise a list of hashes;

receiving a request to post an new entry into the log, wherein the entry includes a portion of data; and

calculating the hash of the portion of data received in the request;

comparing the hash to a list of one or more hashes in the identifier; and

accepting the post request if the hash appear in the list of hashes in the identifier.

28. The method defined in claim 27 wherein the data comprises one selected from a group consisting of a phrase, an address, and a sequence of characters.