Abstract: A method of detecting a web application attack is provided. The method includes the steps of when packets forming HTTP traffic are received, a web application firewall recombining the HTTP traffic, analyzing the recombined HTTP traffic and determining whether or not the recombined HTTP traffic includes the attack-relevant content, if the recombined HTTP traffic does not include the attack-relevant content, sending the recombined HTTP traffic to a web server or a user server and normally processing the recombined HTTP traffic, and if the recombined HTTP traffic includes the attack-relevant content, detecting the recombined HTTP traffic as an attack and reprocessing the same.

Abstract: Query processing system and method by query transformation transform a user request query based on an original DB structure, destined to a DBMS of a DB with some columns encrypted, into a query based on an encrypted DB structure so that the DBMS processes the query. The query is processed irrespective of whether or not the query includes an encryption-related item, and query-processing performance is remarkably improved.

Abstract: In order to encrypt plaintext data while maintaining high security, the plaintext data is received and divided into a plurality of plaintext data blocks, each of which has the same bit length. A preset master key is used to obtain a set of round subkeys, and each of the plaintext data blocks is encrypted by using the preset master key and combining the encrypted blocks to thereby provide cipheitext data having a bit length which is identical to that of the plaintext data.