Computer Security: an endless war between hacker and network administrator

Computer security is always a big concern for those who use computers inside a network, from the smallest scale home network, to the huge national wide network. In the following, I would like to share my knowledge about the high-tech battle between hacker and network administrator in different scale. 

The smallest computer network that we used daily is our home network, most of which are wireless with a router and based on WIFI protocol. In the early days when home networks were just introduced, people set up the wireless network without a password. In this way, your neighborhood might be able to use your network to surf on the internet. That might not sound bad, especially if you are a generous person. However, if some personal photos or important documents can also be released in this way, you might need to seriously think about the security issue of the home network. A safe and practical way is to add an access password to your home network, which might be set based on your router. However, if your password is very simple, then it will be easily decoded by some kind of machine available on Ebay. One solution is to improve your password to be more complex. A safer way is to provide a white list which contains the unique network card ID’s of all devices that you have. In this way, no password needed and it will be very hard to hack, while it brings with a little troublesome if you want to share your home network to a guest.

The medium size computer network might be the intranet used inside a company or an institute. Since most companies have lots of confidential data which should not be released to outside without permission. In this way, they need to have stringent control on the network access to these data. On the other hand, companies will need to provide a good network environment to support co-work and communications among their employee and customers. Therefore, an open network is also needed for companies. The two contradictory requirements bring big challenges for network administrators. A kind of software named firewall is commonly used to monitor the network activities of the whole company network, and will report alarms when unauthorized visits are identified. However, hackers have developed many tools to bypass the firewall by using some bugs of the network systems and obtained the administrator right to do some hacking and peep at the confidential data. A better way to protect company data is to physically quarantine the high-confidential data from the outside network. In this way, hacker can’t find any ways to attack the network from outside. A good example is the computer network system to control the nuclear plant in Iran, which used physical isolation for security issues. It is still not unassailable, since the isolated network itself is still vulnerable to attacks. Some reports showed that the network has been attached from internal, which are done by some Special Forces soldiers who dive into the plan and uploaded the virus to the network system.

Ref: Inside a Cyber War Room: The Fight Against Hacking,  
http://www.cnbc.com/id/100716315

The biggest size network will be the national wide or even earth wide network, like the well-known internet. Basically, it is open to the whole people on the planet. However, each nation has its rules for the data exposed on the internet, and more and more nations have a special network troop to handle the attacks on the network from other countries to some critical department and also organize similar attacks to other countries. Put a pirate flag on the top of some public website might not trouble the user a lot, while disable the bank system of a country will be a much bigger issue and its results might be equal to a real war. In this way, national wide network security is highly emphasized by most government and there will be a long term war in this field.