Today, the cost of maintenance of network security is expensive. However, it is not sure whether your network is broken into or not.   It can be said that the probability of breaking into your network is low. You would hang back from paying for network security.

Internet appliance becomes a reality. Our life more and more depends on Internet. If it is expensive to maintain security of Internet appliance, all of us cannot benefit from it.

Therefore, network security should be low-cost, easy to understand and perfect. Two-heads hard disk drive should be the best solution for network security.