METHOD FOR INDEXING ENCRYPTED COLUMN

• US 20100169665A1
• Filed: 09/28/2007
• Published: 07/01/2010
• Est. Priority Date: 10/04/2006
• Status: Active Grant

• Current Assignee: Eglobal System Company
• Original Assignee: Eglobal System Company
• Inventors: Kim, Yu-Ho, Kang, Hee-Chang, Mun, Dae-Won
• Granted Patent: US 8,281,153 B2
• Time in Patent Office: Days
• US Class Current: 713/189
• CPC Class Codes: G06F 16/2228 Indexing structures
• CPC Class Codes: G06F 21/6227 where protection concerns the structure of data, e.g. records, types, queries
• CPC Class Codes: H04L 9/00 Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols

Abstract

The present invention relates to a method of creating indexes so that an index scan can be worked for columns in a database encrypted by means of secrete key cipher algorithm. The method of creating indexes according to the present invention comprises the steps of: re-encrypting to be able to maintain the sort ordering based on a plain text; creating new indexes based on the re-encrypted data; and configuring domain index architecture of encrypted columns so that the created index is used for the index scan in a query

Claims

1. In a database to store a table having encrypted columns, a method of configuring indexes for the encrypted columns comprising the steps of:

(a) reading a encrypted column data from the table;

(b) decrypting the read encrypted column data;

(c) re-encrypting the decrypted column data to be able to maintain a sort ordering based on a plain text from the decrypted data;

(d) storing the re-encrypted column data in a table for indexes which is used by a domain index architecture;

(e) creating indexes of re-encrypted column of the table; and

(f) configuring a domain index which uses the table for the stored index and the stored indexes created in the table for indexes.

2. The method of claim 1, wherein said step of (d) storing the re-encrypted column data in a table for indexes which is used by a domain index architecture further comprises the steps of:

(d1) creating a table for indexes as a type of a index organized table or a general table with the re-encrypted column data; and

(d2) storing the re-encrypted column data in the table for indexes.

3. The method of claim 1, wherein the step of (e) creating indexes of re-encrypted column of the table further comprises the steps of:

(e1) creating a B-tree index for a column having a re-encrypted column data of the table for the stored indexes; and

(e2) creating an index type from a re-encrypted index to a function based index for the column stored the re-encrypted column data.