Searchable encrypted data

• US 9,256,764 B2
• Filed: 08/13/2013
• Issued: 02/09/2016
• Est. Priority Date: 08/15/2012
• Status: Active Grant

• Current Assignee: Visa International Service Association (Visa, Inc.)
• Original Assignee: Visa International Service Association (Visa, Inc.)
• Inventors: Aissi, Selim, Nagasundaram, Sekhar
• Primary Examiner(s): Shiferaw, Eleni
• Assistant Examiner(s): GIDDINS, NELSON S
• Application Number:
  US13/965,472
• Publication Number:
  US 20140052999A1
• Time in Patent Office: 910 Days
• Field of Search: 713/189
• US Class Current: 1/1
• CPC Class Codes: G06F 16/13 File access structures, e.g. distributed indices arrangements of input from, or output to, record carriers G06F3/06
• CPC Class Codes: G06F 16/137 Hash-based content-based indexing of textual data G06F16/31
• CPC Class Codes: G06F 16/14 Details of searching files based on file metadata
• CPC Class Codes: G06F 16/148 File search processing
• CPC Class Codes: G06F 16/152 using file content signatures, e.g. hash values
• CPC Class Codes: G06F 16/22 Indexing; Data structures therefor; Storage structures
• CPC Class Codes: G06F 16/2228 Indexing structures
• CPC Class Codes: G06F 16/9535 Search customisation based on user profiles and personalisation
• CPC Class Codes: G06F 21/606 by securing the transmission between two devices or processes
• CPC Class Codes: G06F 21/6245 Protecting personal data, e.g. for financial or medical purposes
• CPC Class Codes: G06F 21/64 Protecting data integrity, e.g. using checksums, certificates or signatures
• CPC Class Codes: G06F 2207/00 Indexing scheme relating to methods or arrangements for processing data by operating upon the order or content of the data handled
• CPC Class Codes: G06F 2207/025 String search, i.e. pattern matching, e.g. find identical word or best match in a string
• 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

Abstract

Embodiments of the invention broadly described, introduce systems and methods for enabling the searching of encrypted data. One embodiment of the invention discloses a method for generating a searchable encrypted database. The method comprises receiving a plurality of sensitive data records comprising personal information of different users, identifying one or more searchable fields for the sensitive data records, wherein each searchable field is associated with a subset of the personal information for a user, generating a searchable field index for each of the one or more searchable fields, and encrypting the sensitive data records using a database encryption key.

Claims

1. A data encryption computer, comprising:

a processor; and

a non-transitory computer-readable storage medium, comprising code executable by the processor for implementing a method comprising;

receiving a plurality of sensitive data records comprising personal information of different users;

identifying one or more searchable fields for the sensitive data records, wherein each searchable field is associated with a subset of the personal information for a user;

generating a searchable field index for each of the one or more searchable fields based on which one of at least three sensitivity levels that each searchable field corresponds to,

wherein when the searchable field corresponds to a first sensitivity level, the searchable field index is in a plain text format, when the searchable field corresponds to a second sensitivity level, the searchable field index is a hash value, and when the searchable field corresponds to a third sensitivity level, the searchable field index is an encrypted hash value;

encrypting the sensitive data records using at least one database encryption key;

providing the database encryption key to a plurality of client computers authorized to decrypt the encrypted data records; and

providing a searchable encrypted database comprising the searchable field indices and the encrypted sensitive data records to a database access server, wherein the plurality of client computers are operable to obtain the sensitive data records from the database access server using the database encryption key.

2. The data encryption computer of claim 1, wherein

the encrypted hash value is a hash-based message authentication code (HMAC) generated using a searchable field key.

3. The data encryption computer of claim 2, wherein

the searchable field key is sent to one or more of the plurality of client computers that are authorized to search using the searchable field.

4. A system comprising:

the data encryption computer of claim 1;

a client computer in the plurality of client computers, wherein the client computer is configured to receive the database encryption key; and

the database access server, wherein the database access server is configured to receive the searchable encrypted database.

5. The data encryption computer of claim 1, wherein a sensitivity level of a searchable fields is determined based in part on whether a user identity is determinable from the searchable field.

6. The data encryption computer of claim 1, wherein when the searchable field corresponds to a second sensitivity level, generating the searchable field index includes determining a salt value for the searchable field.

7. The data encryption computer of claim 6, wherein the salt value is a username of the user.

8. The data encryption computer of claim 1, wherein a first subset of the sensitive data records containing a first type of personal information is encrypted with a first database encryption key, and a second subset of the sensitive data records containing a second type of personal information is encrypted with a second database encryption key.

9. The data encryption computer of claim 1, wherein a first subset of the sensitive data records corresponding to a first subset of users is encrypted with a first database encryption key, and a second subset of the sensitive data records corresponding to a second subset of users is encrypted with a second database encryption key.

10. A computer-implemented method comprising:

receiving, by a processor, a database decryption key for a searchable encrypted database from a data encryption computer;

receiving, by the processor, personal information of a user;

generating, by the processor, one or more index values, each associated with a searchable field index, using the personal information, wherein a format of each searchable field index is determined based on which one of at least three sensitivity levels that an associated searchable field corresponds to, and wherein when the searchable field corresponds to a first sensitivity level, the searchable field index is in a plain text format, when the searchable field corresponds to a second sensitivity level, the searchable field index is a hash value, and when the searchable field corresponds to a third sensitivity level, the searchable field index is an encrypted hash value;

sending, by the processor, the one or more index values to a database access server;

receiving, by the processor, one or more encrypted data records matching the index values from the database access server; and

decrypting, by the processor, the encrypted data records using a database decryption key.

11. The computer-implemented method of claim 10, wherein the encrypted hash value is a hash-based message authentication code.

12. The computer-implemented method of claim 10, further comprising:

receiving, by the processor, a searchable field key corresponding to a searchable field index, wherein generating the one or more index values includes determining, by the processor, a hash-based message authentication code using a field value corresponding to a searchable field, and the searchable field key.

13. A computer-implemented method comprising:

receiving, by a processor, from a data encryption computer, a searchable encrypted database comprising a plurality of searchable field indices and a plurality of encrypted data records, wherein the encrypted data records are encrypted using a database encryption key known to a plurality of client computers, wherein a format of each searchable field index is determined based on which one of at least three sensitivity levels that an associated searchable field corresponds to, and wherein when the searchable field corresponds to a first sensitivity level, the searchable field index is in a plain text format, when the searchable field corresponds to a second sensitivity level, the searchable field index is a hash value, and when the searchable field corresponds to a third sensitivity level, the searchable field index is an encrypted hash value;

receiving, by a processor, index values for one or more of the searchable field indices from a client computer in the plurality of client computers, wherein the index values are generated using personal information of a user;

retrieving, by the processor, one or more encrypted data records using the index values; and

sending, by the processor, the one or more encrypted data records to the client computer.

14. The computer-implemented method of claim 13, wherein the encrypted hash value is a hash-based message authentication code.

15. The computer-implemented method of claim 13, wherein the client computer is a service center computer, wherein the index values are generated using identification information provided by a user.

16. The computer-implemented method of claim 15, wherein the method further comprises:

when multiple encrypted data records match the index values, prompting the service center computer to send additional identification information.