Secure data file erasure

• US 20020181134A1
• Filed: 06/04/2001
• Published: 12/05/2002
• Est. Priority Date: 06/04/2001
• Status: Active Grant

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: deJong, Edward P., Bunker, Keith G.
• Granted Patent: US 6,731,447 B2
• Time in Patent Office: Days
• US Class Current: 360/60
• CPC Class Codes: G06F 21/62 Protecting access to data via a platform, e.g. using keys or access control rules
• CPC Class Codes: G06F 21/6209 to a single file or object, e.g. in a secure envelope, encrypted and accessed using a key, or with access control rules appended to the object itself
• CPC Class Codes: G06F 2221/2143 Clearing memory, e.g. to prevent the data from being stolen
• CPC Class Codes: G06F 3/0623 in relation to content
• CPC Class Codes: G06F 3/0652 Erasing, e.g. deleting, data cleaning, moving of data to a wastebasket
• CPC Class Codes: G06F 3/0676 Magnetic disk device
• CPC Class Codes: G11B 5/024 Erasing
• CPC Class Codes: G11B 5/09 Digital recording

Abstract

A process that ensures the destruction of data files a user wishes to completely erase from a storage medium, such as a hard drive or removable disk. A system administrator can select a quantity of and pattern to be used in overwrites of the data file so that no one can recover the data from the storage medium. In embodiments, a graphical user interface (GUI) can be provided to allow user triggering of and parameter setting for the process. The GUI can be implemented at a device in which the storage medium is a component or can be implemented in a device driver GUI on a personal computer in communication with the device.

Claims

1. A device comprising:

an erase trigger;

a drive sector analyzer in communication with a CPU that has addressed a data file stored on the storage medium, the drive sector analyzer retrieving data file location data from the CPU in response to activation of the erase trigger;

a secure storage medium eraser in communication with the drive sector analyzer that overwrites the data file according to a predetermined secure erase method;

an erase pattern determiner in communication with the erase trigger and the secure storage medium eraser, the erase iteration determiner sending to the secure storage eraser a type and number of times to overwrite the data file in response to the erase trigger and according to predetermined criteria.

2. The device of claim 1 further comprising a set of patterns stored in a storage medium in communication with the system.

3. The device of claim 2 wherein the set of patterns is a table resembling the pseudocode expression:

PatternTable (N)←

Pattern1, Pattern2, Pattern3, . . . PatternN.

4. The device of claim 1 wherein the predetermined criteria includes erase control parameters and the device further comprises an erase control parameter selector addressable by a user to select parameters with which to erase the data file.

5. The device of claim 4 wherein the parameters include at least one pattern to be used to erase the data file.

6. The device of claim 4 wherein the parameters include at least a number of times to overwrite the data file.

7. The device of claim 4 wherein the parameters include at least one pattern NumPatternToUse to be used and a number of times N to overwrite the data file according to the pseudocode expressions:

For count←

1 to NumPatternTo Use Do

Overwrite data file with PatternTable(count).

8. The device of claim 7 wherein multiple patterns NumPatternToUse are used N_i times, respectively, to overwrite the data file.

9. The device of claim 1 further including at least one graphical user interface (GUI) element in communication with the erase trigger and which accepts from a user parameters with which to overwrite the data file.

10. The device of claim 9 wherein the at least one GUI element includes a button.

11. The device of claim 9 wherein the at least one GUI element includes a virtual numerical keypad with which a user selects a number as a parameter.

12. The device of claim 9 wherein the at least one GUI element includes a pattern selector with which a user can select a pattern as a parameter.

14. The method of claim 13 further comprising determining a number of times to perform the at least a number of times to overwrite the data file.

15. The method of claim 13 further comprising providing a set of patterns stored in a storage medium in communication with the system, the set of patterns being at least part of the predetermined criteria.

16. The method of claim 15 further including providing the set of patterns as a table resembling the pseudocode expression:

PatternTable (N)←

Pattern1, Pattern2, Pattern3, . . . PatternN.

17. The method of claim 13 wherein the predetermined criteria include at least one user-selected parameter and the method further comprises receiving at least one user-selected parameter with which to erase the data file.

18. The method of claim 17 wherein the at least one user-selected parameter includes at least one pattern to be used to erase the data file.

19. The method of claim 17 wherein the at least one user-selected parameter includes at least a number of times to overwrite the data file.

20. The method of claim 17 wherein the at least one user-selected parameter includes at least one pattern NumPatternTo Use to be used and a number of times N to overwrite the data file according to the pseudocode expression:

For count←

1 to NumPatternTo Use Do

Overwrite region of storage media that stored the data file with PatternTable(count).

21. The method of claim 20 further including overwriting the data file with multiple patterns NumPatternTo Use used N_i times, respectively.

22. The method of claim 13 further comprising providing at least one graphical user interface (GUI) element in communication with the erase trigger and accepting from the at least one GUI element a user parameters with which to overwrite the data file.

23. The method of claim 22 further comprising providing a button as at least part of the at least one GUI element.

24. The method of claim 22 further comprising providing a virtual numerical keypad as at least part of the at least one GUI element and with which a user selects a number as a parameter.

25. The method of claim 22 further comprising a pattern selector as at least part of the at least one GUI element and with which a user can select a pattern as a parameter.

13. A method of securely erasing at least one data file from a storage medium, the method comprising:

providing an erase trigger;

determining a location of the data file on the storage medium;

overwriting the data file according to a predetermined secure erase method;

determining at least a number of times to overwrite the data file in response to the erase trigger and according to predetermined criteria.

26. An apparatus including:

an erase trigger;

a drive sector analyzer in communication with a CPU that has addressed a data file stored on the storage medium, the drive sector analyzer retrieving data file location data from the CPU in response to activation of the erase trigger;

a secure storage medium eraser in communication with the drive sector analyzer that overwrites the data file according to a predetermined secure erase method; and

an erase pattern determiner in communication with the erase trigger and the secure storage medium eraser, the erase iteration determiner sending to the secure storage eraser a type and number of times to overwrite the data file in response to the erase trigger and according to predetermined criteria;

the apparatus performing a method of securely erasing at least one data file from a storage medium, the method comprising;

providing an erase trigger;

determining a location of the data file on the storage medium;

overwriting the data file according to a predetermined secure erase method; and

determining at least a number of times to overwrite the data file in response to the erase trigger and according to predetermined criteria.