CIPHERING CONTROLLING METHOD AND NETWORK SYSTEM, PORTABLE DEVICE AND OPERATING METHOD THEREOF SUPPORTING THE SAME

摘要

PURPOSE: An encryption control method, a network system, a terminal, and a terminal operation method are provided to support a normal communication processing procedure by managing encryption information in the terminal. CONSTITUTION: A network system(200) confirms a history table stored in a system storage unit based on authentication information and identification information which a terminal(100) transmits and encryption information corresponding to received IMEI(International Mobile Equipment Identity). The network system transmits a first encryption mode command message to the terminal. The terminal transmits and receives a signal with a network system by generating an encryption mode completion message based on an encryption algorithm designated in the message. [Reference numerals] (100) Terminal; (200) Network system;