DATABASE MANAGEMENT SYSTEM AND ENCRYPTING METHOD THEREOF

摘要

PURPOSE: A DBMS and an encoding method in a database are provided to supply a column encoding function without the degradation of speed. CONSTITUTION: An encoding table of a database(500) includes a plurality of records(510). The database transmits a security policy to an external encoding unit(540) and receives an authentication result about the policy from the external encoding unit. The security policy is a name defined by the external encoding unit. The database encodes a plain text through an internal encoding unit(530) when authentication is permitted based on the authentication result. The internal encoding unit encodes the plain text as an encoded text and delivers a data value by decoding the encoded text when a user requests the data. The internal encoding unit generates an ECC(Encrypted Comparison Code)(560) based on the plain text by using an order preserving hash function. An encoding data type generating unit matches the encoded text with the ECC to store the same as an encoding data type. The comparison of the ECC can be performed without decoding and quick and range search are impalement because the ECC can perform an index function in a comparison procedure. [Reference numerals] (500) Database; (511) Record 1; (512) Record 2; (513) Record 3; (530) Internal encoding and decoding unit; (540) External encoding unit; (AA) Encoding table;