Method and system for protecting electronic data in enterprise environment

• US 7,921,284 B1
• Filed: 05/31/2002
• Issued: 04/05/2011
• Est. Priority Date: 12/12/2001
• Status: Active Grant

• Current Assignee: Intellectual Ventures I LLC (Intellectual Ventures LLC)
• Original Assignee: Guardian Data Storage LLC
• Inventors: Kinghorn, Gary Mark, Garcia, Denis Jacques Paul
• Primary Examiner(s): Smithers; Matthew B
• Assistant Examiner(s): Abyaneh; Ali S
• Application Number:
  US10/159,220
• Time in Patent Office: 3,231 Days
• Field of Search: 713/182, 713/160, 713/165, 713/166, 380/45, 380/277, 726/26
• US Class Current: 713/160
• 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 21/6227 where protection concerns the structure of data, e.g. records, types, queries
• CPC Class Codes: G06F 2221/2107 File encryption
• CPC Class Codes: G06F 2221/2111 Location-sensitive, e.g. geographical location, GPS
• CPC Class Codes: G06F 2221/2113 Multi-level security, e.g. mandatory access control
• CPC Class Codes: G06F 2221/2137 Time limited access, e.g. to a computer or data
• CPC Class Codes: G06F 2221/2141 Access rights, e.g. capability lists, access control lists, access tables, access matrices
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/06 for supporting key management in a packet data network cryptographic mechanisms or cryptographic arrangements for key management H04L9/08
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 63/102 Entity profiles
• CPC Class Codes: H04L 63/105 Multiple levels of security
• 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
• CPC Class Codes: H04L 63/20 for managing network security; network security policies in general filtering policies H04L63/0227
• CPC Class Codes: H04L 67/01 Protocols

Abstract

Even with proper access privilege, when a secured file is classified, at least security clearance (e.g. a clearance key) is needed to ensure those who have the right security clearance can ultimately access the contents in the classified secured file. According to one embodiment, referred to as a two-pronged access scheme, a security clearance key is generated and assigned in accordance with a user'"'"'s security access level. A security clearance key may range from most classified to non-classified. Depending on implementation, a security clearance key with a security level may be so configured that the key can be used to access secured files classified at or lower than the security level or multiple auxiliary keys are provided when a corresponding security clearance key is being requested. The auxiliary keys are those keys generated to facilitate access to secured files classified respectively less than the corresponding security or confidentiality level.

Claims

1. A method for controlling access to a secured file that is classified to a classification level, comprising:

determining if an attempt to access the secured file conforms to access rules embedded in the secured file;

reading the classification level from a header of the secured file; and

using, in a computing machine, a clearance key and a second key to decrypt a first key encrypted in a portion of the secured file in response to determining that the attempt to access the secured file conforms to the access rules, wherein two or more user identifiers are assigned to a security clearance level of the clearance key and are thereby granted access to use the clearance key, wherein the clearance key is used to decrypt the first key based on a determination that the security clearance level of the clearance key allows access to the secured file, based on the classification level of the secured file being equivalent to or less than the security clearance level.

2. The method of claim 1, wherein reading the classification level comprises reading the classification level from a set of a plurality of classification levels.

3. The method of claim 1, wherein the two or more user identifiers are assigned to the security clearance level based on a level of trust of users associated with the two or more user identifiers in an organization.

4. The method of claim 3, wherein the level of trust pertains to job responsibility of the users associated with the two or more user identifiers in the organization or a role of the users associated with the two or more user identifiers in a task.

5. The method of claim 3, wherein at least one of the users associated with the two or more user identifiers is a human user, a group of users or a member thereof, a software agent, a device or an application.

6. The method of claim 1, wherein the two or more user identifiers represent members of a group of users assigned to the security clearance level, and access to use the clearance key is granted to members in the group, such that members in the group can access the secured file with the clearance key.

7. The method of claim 1, wherein at least one of the two or more user identifiers is additionally associated with a user key.

8. The method of claim 7, wherein a header portion of the secured file is encrypted, further comprising decrypting the header portion with the user key after authentication by the corresponding user identifier.

9. The method of claim 8, wherein decrypting the header comprises accessing encrypted versions of the first key, the second key, and the embedded access rules.

10. The method of claim 9, further comprising decrypting the encrypted access rules with the user key.

11. The method of claim 10, further comprising retrieving the second key only after the access rules are successfully satisfied by an access privilege of the user identifier.

12. The method of claim 11, further comprising retrieving the first key using the retrieved second key in response to determining that the secured file is not classified.

13. The method of claim 12, further comprising decrypting an encrypted data portion in the secured file using the first key.

14. The method of claim 11, further comprising retrieving the first key using the retrieved second key, together with the clearance key, in response to determining that the secured file is classified.

15. The method of claim 14, further comprising decrypting an encrypted data portion in the secured file using the first key as a file key, and further comprising using the second key as a protection key together with the clearance key to access the file key.

16. The method of claim 1, further comprising releasing or activating the clearance key for a corresponding user identifier of the two or more user identifiers when the user identifier is accessing the secured file.

17. The method of claim 1, wherein determining that the attempt to access the secured file conforms to the access rules comprises using the access rules to determine at least one of a user identifier permitted to access the secured file, an access privilege of the user identifier permitted to access the secured file, a method by which the secured file may be accessed, a time when the secured file may be accessed, a date when the secured file may be accessed, or a location where the secured file may be accessed.

18. The method of claim 1, further comprising:

granting access to use a second clearance key associated with a second security clearance level to the two or more user identifiers, the granting access based on the two or more user identifiers'"'"' assignment to the security clearance level, the security clearance level being higher than the second security clearance level,

wherein the clearance key facilitates decryption of at least portions of files associated with the security clearance level, and

wherein the second clearance key facilitates decryption of at least portions of files associated with the second security clearance level.

19. The method of claim 1, wherein the clearance key facilitates decryption of at least portions of files associated with the security clearance level and one or more additional security clearance levels below the security clearance level.

20. A method for controlling access to electronic data, comprising:

maintaining a user account, including a user identifier, a user key and a clearance key in response to determining that a user associated with the user identifier is authorized to access a classified file, wherein two or more user identifiers are assigned to a security clearance level of the clearance key and are thereby granted access to use the clearance key;

comparing access privileges associated with the user identifier to a plurality of access rules in a portion of the file;

retrieving a protection key from the file in response to a determination that the access privileges conform to the access rules;

reading a classification level from a header of the file; and

in response to determining that the file is classified, decrypting, in a computing machine, an encrypted cipher key in the file, with the protection key and the clearance key, to decrypt an encrypted data portion in the file, wherein the clearance key is used to decrypt the encrypted cipher key based on a determination that the security clearance level of the clearance key allows access to the file based on the classification level of the file being equivalent or less than the security clearance level.

21. The computer implemented method of claim 20, wherein:

comparing access privileges comprises comparing access privileges to access rules that comprise at least one of a rule specifying;

a user identifier permitted to access the electronic data, an access privilege of the user identifier permitted access the electronic data, a method by which the electronic data may be accessed, a time when the electronic data may be accessed, a date when the electronic data may be accessed, or a location where the electronic data may be accessed.

22. The computer implemented method of claim 20, further comprising:

comparing the access rules to an access privilege of the user identifier; and

retrieving a protection key from the file in response to a determination that the user identifier has proper access privilege.

23. The computer implemented method of claim 20, further comprising:

decrypting an encrypted cipher key in the file, with the protection key, to decrypt an encrypted data portion in the file, in response to determining that the file is not classified.

24. A method for controlling access to an electronic file, comprising:

maintaining a user account including a user identifier, a user key, and a clearance key if the user identifier is authorized to access a classified file, wherein two or more user identifiers are assigned to a security clearance level of the clearance key and are thereby granted access to use the clearance key;

encrypting, in a computing machine, the file with a cipher key;

encrypting the cipher key with a protection key as well as the clearance key, and storing a classification level in a header of the file;

applying a plurality of access rules to protect the protection key such that the protection key can be obtained by meeting the access rules by access privileges associated with the user identifier; and

encrypting the access rule so that an authorized user identifier can decrypt the access rule by using an authenticated key,

wherein the clearance key is configured to be used to decrypt the cipher key based on a determination that the security clearance level of the clearance key allows access to the file based on the classification level of the file being equivalent to or less than the security clearance level.

25. The computer implemented method of claim 24, wherein:

applying a plurality of access rules comprises applying access rules that specify at least one of;

a user identifier permitted to access the electronic data, an access privilege of the user identifier permitted to access the electronic data, a method by which the electronic data may be accessed, a time when the electronic data may be accessed, a date when the electronic data may be accessed, or a location where the electronic data may be accessed.

26. The computer implemented method of claim 24, further comprising:

after the encrypting the file with a cipher key, encrypting the file with the protection key.

27. The computer implemented method of claim 24, further comprising:

encrypting the cipher key with a protection key, if the file is not being classified.

28. A non-transitory computer readable medium having instructions for controlling access to a secured file that is classified to a classification level stored thereon, the instructions comprising:

instructions to determine that access privileges associated with a user identifier conform to access rules embedded in the secured file;

instructions to read the classification level from a header of the secured file; and

instructions to use a clearance key and a second key to decrypt a first key encrypted in a portion of the secured file in response to determining that the access privileges associated with the user identifier conform to the access rules embedded in the secured file, wherein two or more user identifiers are assigned to a security clearance level of the clearance key and are thereby granted access to use the clearance key, wherein the clearance key is used to decrypt the first key based on a determination that the security clearance level of the clearance key allows access to the secured file, based on the classification level of the secured file being equivalent to or less than the security clearance level.

29. The computer readable medium of claim 28, wherein the instructions to read the classification level are configured to read the classification level from among a plurality of classification levels.

30. The computer readable medium of claim 28, further comprising instructions to assign the two or more user identifiers to the security clearance level based on a level of trust of users associated with the two or more user identifiers in an organization.

31. The computer readable medium of claim 30, wherein the instructions to assign the two or more user identifiers include instructions to assign the two or more user identifiers based on a level of trust that pertains to job responsibility of the users associated with the two or more user identifiers in the organization or a role of the users associated with the two or more user identifiers in a task.

32. The computer readable medium of claim 28, further comprising instructions to release or activate the clearance key for a corresponding user identifier of the two or more user identifiers when the user identifier is accessing the secured file.

33. A method comprising:

reading a classification level from a header of a secured file; and

using, in a computing machine, a clearance key to decrypt a file key encrypted in a portion of the secured file,

wherein the clearance key is used to decrypt the file key, the clearance key allowing access to the secured file based on the classification level of the secured file being equivalent to or less than a security clearance level of the clearance key, and

wherein two or more user identifiers are assigned to the security clearance level of the clearance key and are thereby granted access to use the clearance key.

34. The method of claim 33, wherein reading the classification level comprises reading the classification level from a set of a plurality of classification levels.

35. The method of claim 33, wherein the two or more user identifiers are assigned to the security clearance level based on a level of trust of users associated with the two or more user identifiers in an organization.

36. The method of claim 35, wherein the level of trust pertains to job responsibility of the users associated with the two or more user identifiers in the organization or a role of the users associated with the two or more user identifiers in a task.

37. The method of claim 35, wherein at least one of the users associated with the two or more user identifiers is a human user, a group of users or a member thereof, a software agent, a device or an application.

38. The method of claim 35, wherein the two or more user identifiers represent members of a group of users assigned to the security clearance level, and access to use the clearance key is granted to members in the group, such that members in the group can access the secured file with the clearance key.

39. The method of claim 35, wherein at least one of the two or more user identifiers is additionally associated with a user key.

40. The method of claim 39, wherein a header portion of the secured file is encrypted, further comprising decrypting the header portion with the user key after authentication by the corresponding user identifier.

41. The method of claim 40, wherein decrypting the header comprises accessing encrypted versions of the file key.

42. The method of claim 33, further comprising releasing or activating the clearance key for a corresponding user identifier of the two or more user identifiers when the user identifier is accessing the secured file.