As the internet users are getting increased drastically, the information leakage comes to the

threat to many organizations who use the internet. Many security-minded organizations, such

as government authorities, financial institutions, banks, intelligence agencies, are really wary

of the internet connectivity. Generally, they could not have gained the advantage of the internet

as the normal entrepreneur, relatively away from security-minded, do because of the fact that

they have their own network security policy.

     They have tried to find a proper solution in order to use the internet as protecting their

inportant information leakage. They paved dual network cables, one only for the internal and

the other only for the internet, and used 2 PCs for each individuals. Through this system,

physical separation between internal and external resources, they could furfill their security

policy and could be ensured their network to what extent from the hostile intruders existing

in the internet at the same time. But it is solutions that is clumsy and costly.

First, they have to invest twice of cost for paving dual network cables and providing 2 PCs for

each individuals. In addition, it is too far away from user-oriented solution. In order to access

into the internet, every user has to convert the IP address and make a reboot every time they

want to access the different network. It is really time-consuming thing. Except for that, there

are more things the make them hesitate, such as occupying lots of space and then some.

At the same time, those who can not afford the costly system as above dare not to use the

internet. Even thought there is tremendous advantage they can gain from the internet, the most

priority to them is to secure their sensitive and crucial information from the outside.

Because of these problems, they prefer closed networks, such as a preventive and better-safe

-than-sorry solution. They started to restrict on the use of the internet by their employees,

and only few restricted number of employees have the right to access to the internet.

It came to them work inefficiency and let the frustration of employees enlarge.