		Network Security

Security Threats

Three parts to a computer system:- Hardware, Software and Users (Wetware). All are equally important. However, it’s the Users who cause the worst problems...

Users
Administration
Software
Hardware
Network Operating Systems
Criminal Hackers

Users

By far the most threatening component of your networks will be the Users. Since they’re human, they will make mistakes, they will forget, or be unable to remember, passwords, they will write down or utter passwords and will discuss confidential details with others. (This is not an exhaustive list...) After simple human errors comes malicious behaviour. This can be as simple as a sacked staff member placing a password on a PC or formatting the hard disk or a programmer placing a logic bomb in a program.

Administration

Admin personnel are also human. Add to the common User problems, that of hubris and access to more powerful toys, er, tools.

Software

Software can simply be broken. It can have faults. Worse, it can have trap-doors or back-door access built in. (Programmers do this because they know that Users (and Admin) will lock themselves out.) “Features of the programming language can result in exploitable vulnerabilities.

Remember the movie "The Net" with Sandra Bullock? The Bad Guys were the Firewall vendors...

Hardware

PCs do not themselves pose much of a security risk as they are mostly passive devices in the network infrastructure. It is the active devices such as routers that can easily be compromised. A router usually comprises a set of Network Interface Cards (NICs) linked together by the routing program in the router. This program runs on some sort of Operating System. This O/S is accessible through the NICs. Unless the router has a high level of security, it can be accessed across the Network and its operation compromised.

Network Operating Systems

Network Operating Systems (NOSs) are delivered with a certain level of security. The Supervisor or Administrator password is

Criminal Hackers

These are the rarest of the threats but the most dangerous. They will know the deficiencies of the NOS, the Software and the Hardware. They can copy data without detection, alter it or delete it. If your system is not configured to monitor access and detect unusual operations you may never know that you’ve been visited, or how often. If data is changed or deleted your entire system has to be regarded as compromised. You might never trust your data or be trusted by others again.

Network Security