Nowadays we live in cyber space molded by computer network as well as real space perfect protection in cyber space is essential to the economy and the security because the optical fiber-connection among millions of computers made the system of private and public facilities the huge web-unity. Accordingly, terrorism for cyber space is getting frequent by reason of the stake of economic and political problems. In information age, It is impossible to repair these disaster in a short period. But our current countermeasures against cyber terrorism are so feeble that the internet servers on schools, companies, public organizations and goverment are defenselessly exposed to foreign hacker`s attack.