ABSTRACT
Currently, power companies are building their own intranet to support information construction. Company intranet and Internet are isolated; with the expansion of the intranet’s scale, information security problems are becoming more prominent[1-2]. Most of network security focus the external network, firewall, IDS, IPS, VPN, anti-virus software and other hardware and software technology are developed. Although these technologies are costly, they are not enough to deal with intranet security problems. It turns out that security problems arising from company intranet are the greatest threat to the stable operation of the power grid, the thorny issue for company security managers[3].
