GATEWAY APPARATUS FOR IPSec SECURITY, PACKET TRANSMITTING METHOD OF IPSec GATEWAY AND NETWORK SYSTEM HAVING THE GATEWAY

摘要

An IPSec gateway device (140) according to the present invention comprises: a packet reception unit (141) which receives a packet from a terminal (110) or a server; a non-encrypted region analysis unit (142) which analyzes a non-encrypted region of the received packet, and determines whether the non-encrypted region coincides with IPSec session information possessed by the gateway device before receiving the packet; an encrypted region analysis unit (143) which decrypts an encrypted region of the packet and determines whether the decrypted information coincides with an encryption key value of the IPSec session information if the non-encrypted region does not coincide with the IPSec session information; an IPSec session information reset unit (144) which updates the IPSec session information with the information of the non-encrypted region if the decrypted information coincides with the encryption key value; and a packet transmission unit (145) which transmits a packet with updated IPSec session information.