An apparatus for protecting information from attacks in a computer system including a host with a processor, the apparatus comprising: a quarantine station adapted to generate and to transmit control information and security information to the host, the quarantine station being code on a smart card, peripherical component interconnect or an internal memory, which is connected to the host; and a quarantine-station extension unit adapted to implement a secure area in the computer system using the quarantine station, wherein the quarantine-station extension unit comprises: a state change unit for changing a state of at least one of a memory, a register, and a port in the computer system so as to change an instruction to be executed by the processor; a state calculation unit for calculating state information of a sensitive region in a current state, in which the state information may be one of several state values, such as checksum, hash, MAC, integrity check function value and the like; a security-threat-element elimination unit for eliminating security threat elements from the computer system; a communication unit for transmitting the state information calculated by the state calculation unit to the quarantine station, or receiving control information for controlling the computer system based on the state information, from the quarantine station; and a security execution unit for receiving security information from the quarantine station to execute a specific program when the computer system is faultless, wherein the quarantine station is further adapted to check if the state information received from the communication unit is correct and received at a proper timing and if the state information is correct and received at a proper timing, generate and transmit control information to the host, and wherein the state information and the control information are transmitted or received until the computer system is faultless repeatedly, and when this repetitive process ends and then it is determined that the received state information is correct and in time, the quarantine station is further adapted to determine that the processor is faultless and to transmit to the quarantine-station extension security information enabling security codes to be normally executed; and wherein the control information is a value for influencing operation of the quarantine-station extension. a quarantine station adapted to generate and to transmit control information and security information to the host, the quarantine station being code on a smart card, peripherical component interconnect or an internal memory, which is connected to the host; and a quarantine-station extension unit adapted to implement a secure area in the computer system using the quarantine station, wherein the quarantine-station extension unit comprises: a state change unit for changing a state of at least one of a memory, a register, and a port in the computer system so as to change an instruction to be executed by the processor; a state calculation unit for calculating state information of a sensitive region in a current state, in which the state information may be one of several state values, such as checksum, hash, MAC, integrity check function value and the like; a security-threat-element elimination unit for eliminating security threat elements from the computer system; a communication unit for transmitting the state information calculated by the state calculation unit to the quarantine station, or receiving control information for controlling the computer system based on the state information, from the quarantine station; and a security execution unit for receiving security information from the quarantine station to execute a specific program when the computer system is faultless, a state change unit for changing a state of at least one of a memory, a register, and a port in the computer system so as to change an instruction to be executed by the processor; a state calculation unit for calculating state information of a sensitive region in a current state, in which the state information may be one of several state values, such as checksum, hash, MAC, integrity check function value and the like; a security-threat-element elimination unit for eliminating security threat elements from the computer system; a communication unit for transmitting the state information calculated by the state calculation unit to the quarantine station, or receiving control information for controlling the computer system based on the state information, from the quarantine station; and a security execution unit for receiving security information from the quarantine station to execute a specific program when the computer system is faultless, wherein the quarantine station is further adapted to check if the state information received from the communication unit is correct and received at a proper timing and if the state information is correct and received at a proper timing, generate and transmit control information to the host, and wherein the state information and the control information are transmitted or received until the computer system is faultless repeatedly, and when this repetitive process ends and then it is determined that the received state information is correct and in time, the quarantine station is further adapted to determine that the processor is faultless and to transmit to the quarantine-station extension security information enabling security codes to be normally executed; and wherein the control information is a value for influencing operation of the quarantine-station extension.