Sharing encrypted documents within and outside an organization

• US 10,523,423 B2
• Filed: 08/09/2017
• Issued: 12/31/2019
• Est. Priority Date: 08/10/2016
• Status: Active Grant

• Current Assignee: Nextlabs
• Original Assignee: Nextlabs
• Inventors: Lim, Keng, Fung, Poon
• Primary Examiner(s): Shaifer Harriman, Dant B
• Application Number:
  US15/673,338
• Publication Number:
  US 20180048464A1
• Time in Patent Office: 874 Days
• Field of Search: 713170
• CPC Class Codes: G06F 21/602 Providing cryptographic facilities or services
• CPC Class Codes: G06F 21/6218 to a system of files or objects, e.g. local or distributed file system or database
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/0442 wherein the sending and receiving network entities apply asymmetric encryption, i.e. different keys for encryption and decryption cryptographic mechanisms or cryptographic arrangements for public-key encryption H04L9/30
• CPC Class Codes: H04L 63/061 for key exchange, e.g. in peer-to-peer networks cryptographic mechanisms or cryptographic arrangements for key agreement H04L9/0838
• CPC Class Codes: H04L 63/062 for key distribution, e.g. centrally by trusted party cryptographic mechanisms or cryptographic arrangements for key distribution involving a central third party H04L9/0819
• 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 9/08 Key distribution or management, e.g. generation, sharing or updating, of cryptographic keys or passwords network architectures or network communication protocols for supporting key management in a packet data network H04L63/06
• CPC Class Codes: H04L 9/0822 using key encryption key
• CPC Class Codes: H04L 9/0866 involving user or device identifiers, e.g. serial number, physical or biometrical information, DNA, hand-signature or measurable physical characteristics
• CPC Class Codes: H04L 9/0894 Escrow, recovery or storing of secret information, e.g. secret key escrow or cryptographic key storage

Abstract

A method and system of creating and managing encryption keys that facilitates sharing of encrypted content. The system may include an information management system with a key management server and a computing device having an encryption service module. The encryption service module detects operations at the computing device and encrypts a document with an encryption key created using user information and a secret.

Claims

1. A method comprises:

providing an information management system having a key management server and a computing device;

providing the computing device having an encryption service module;

providing the key management server having a secret, wherein the secret is not known to the encryption service module;

at the computing device at a time T1, saving a document opened in an application program by a user;

at the encryption service module, detecting a file save operation on the document;

at the encryption service module, collecting user information of the user;

at the encryption service module, sending the user information to the key management server;

at the key management server, creating a document identifier for the document;

at the key management server, creating a first encryption key with the document identifier, the user information and the secret;

at the encryption service module, receiving the document identifier and the first encryption key from the key management server;

at the encryption service module, creating a second encryption key;

at the encryption service module, encrypting the document with the second encryption key to produce encrypted content;

at the encryption service module, encrypting the second encryption key with the first encryption key to produce an encrypted second encryption key;

at the encryption service module, storing the document identifier, the user information, the encrypted second encryption key and the encrypted content in an encrypted document;

at the computing device at a time T2, opening the encrypted document in the application program by the user, wherein T2 happens some time after T1;

at the encryption service module, detecting a file open operation on the encrypted document;

at the encryption service module, retrieving the document identifier and the user information in the encrypted document;

at the encryption service module, sending the document identifier and the user information to the key management server;

at the key management server, creating a third encryption key with the document identifier, the user information and the secret;

at the encryption service module, receiving the third encryption key from the key management server;

at the encryption service module, decrypting the encrypted second encryption key in the encrypted document with the third encryption key to produce a fourth encryption key; and

at the encryption service module, decrypting the encrypted content in the encrypted document with the fourth encryption key to produce unencrypted content.

2. The method of claim 1 wherein the secret is a cryptographic key.

3. The method of claim 1 wherein the secret is a cryptographic hash.

4. The method of claim 1 wherein the detecting a file save operation on the document is performed using code injection.

5. The method of claim 1 wherein the detecting a file save operation on the document occurs in a process of the application program, wherein the application program invokes the file save operation.

6. The method of claim 1 wherein the detecting a file save operation on the document occurs in an operating system kernel.

7. The method of claim 1 wherein the user information comprises a user identifier.

8. The method of claim 1 wherein the user information comprises a user identifier and an organization identifier.

9. The method of claim 1 wherein the document identifier is a universally unique identifier.

10. The method of claim 1 wherein the first encryption key is a symmetric key.

11. The method of claim 1 wherein the first encryption key is a private key of a public private key pair.

12. The method of claim 1 wherein the first encryption key is not stored on the key management server.

13. The method of claim 1 wherein the second encryption key is a symmetric key.

14. The method of claim 1 wherein the detecting a file open operation on the encrypted document is performed using code injection.

15. The method of claim 1 wherein the detecting a file open operation on the encrypted document occurs in a process of the application program, wherein the application program invokes the file open operation.

16. The method of claim 1 wherein the detecting a file open operation on the encrypted document occurs in an operating system kernel.

17. The method of claim 10 wherein the first encryption key and the third encryption key are identical.

18. The method of claim 11 wherein the third encryption key is a public key of a public private key pair.

19. The method of claim 1 wherein the second encryption key and the fourth encryption key are identical.

20. The method of claim 1 wherein the third encryption key does not exist before T2.

21. A method comprises:

providing an information management system having a key management server and a computing device;

providing the computing device having an encryption service module;

providing the key management server having a secret, wherein the secret is not known to the encryption service module;

at the computing device at a time T1, saving a document opened in an application program by a user;

at the encryption service module, detecting a file save operation on the document;

at the encryption service module, collecting user information of the user;

at the encryption service module, creating a document identifier for the document;

at the encryption service module, sending the user information and the document identifier to the key management server;

at the key management server, creating a first encryption key with the document identifier, the user information and the secret;

at the encryption service module, receiving the first encryption key from the key management server;

at the encryption service module, creating a second encryption key;

at the encryption service module, encrypting the document with the second encryption key to produce encrypted content;

at the encryption service module, encrypting the second encryption key with the first encryption key to produce an encrypted second encryption key;

at the encryption service module, storing the document identifier, the user information, the encrypted second encryption key and the encrypted content in an encrypted document;

at the computing device at a time T2, opening the encrypted document in the application program by the user, wherein T2 happens some time after T1;

at the encryption service module, detecting a file open operation on the encrypted document;

at the encryption service module, retrieving the document identifier and the user information in the encrypted document;

at the encryption service module, sending the document identifier and the user information to the key management server;

at the key management server, creating a third encryption key with the document identifier, the user information and the secret;

at the encryption service module, receiving the third encryption key from the key management server;

at the encryption service module, decrypting the encrypted second encryption key in the encrypted document with the third encryption key to produce a fourth encryption key; and

at the encryption service module, decrypting the encrypted content in the encrypted document with the fourth encryption key to produce unencrypted content.

22. The method of claim 21 wherein the first encryption key is not stored on the key management server.

23. The method of claim 21 wherein the second encryption key and the fourth encryption key are identical.

24. The method of claim 21 wherein the third encryption key does not exist before T2.

25. A method comprises:

providing an information management system having a key management server, a first computing device and a second computing device;

providing the first computing device having a first encryption service module;

providing the second computing device having a second encryption service module;

providing the key management server having a secret, wherein the secret is not known to the first encryption service module and the second encryption service module;

at the first computing device at a time T1, saving a document opened in a first application program by a first user;

at the first encryption service module, detecting a file save operation on the document;

at the first encryption service module, collecting user information of the first user;

at the first encryption service module, sending the user information to the key management server;

at the key management server, creating a document identifier for the document;

at the key management server, creating a first encryption key with the document identifier, the user information and the secret;

at the first encryption service module, receiving the document identifier and the first encryption key from the key management server;

at the first encryption service module, creating a second encryption key;

at the first encryption service module, encrypting the document with the second encryption key to produce encrypted content;

at the first encryption service module, encrypting the second encryption key with the first encryption key to produce an encrypted second encryption key;

at the first encryption service module, storing the document identifier, the user information, the encrypted second encryption key and the encrypted content in an encrypted document;

at the second computing device at a time T2, opening the encrypted document in a second application program by a second user, wherein T2 happens some time after T1;

at the second encryption service module, detecting a file open operation on the encrypted document;

at the second encryption service module, retrieving the document identifier and the user information in the encrypted document;

at the second encryption service module, sending the document identifier and the user information to the key management server;

at the key management server, creating a third encryption key with the document identifier, the user information and the secret;

at the second encryption service module, receiving the third encryption key from the key management server;

at the second encryption service module, decrypting the encrypted second encryption key in the encrypted document with the third encryption key to produce a fourth encryption key; and

at the second encryption service module, decrypting the encrypted content in the encrypted document with the fourth encryption key to produce unencrypted content.