Reducing the risk of a computer system attack can be achieved by making the system secure. But what is a secure computer system? Computer security is about lowering the risk of the system and ensuring that something can not happen rather than it can i.e. certain users can not access the word document. Security is also about control and creating layers of defence to reduce the risk of a malicious attack. A secure computer system is a system which achieves the three goals of computer security: confidentiality, integrity and availability.
The chances of a confidentiality breach in a system increases when access to the system is not monitored (through logs) or restricted (through ID and password or a biometric method) this leaves several vulnerabilities in the system ie if there is a breach not only is it easy to get into with no login there is no way of telling who attempted or when. Therefore by creating a barrier and restricting access the likelihood of someone entering the system will be reduced. Another example is patients’ records in a hospital, where security is imperative. Security would need to ensure that only authorised persons can access the protected data.
Integrity of the system is essential in relation to risk. Much like confidentiality, integrity of data is best kept by controlling who or what can access the data and in what ways. It involves keeping the data “original” and modified in acceptable ways by the correct people and processes. The example of a hospital environment can be used again since it is important that patient records are kept accurate when making medical decisions. The risk of an intruder entering the system and committing computer fraud, ie: altering patient details, is high unless protective barriers are created.
Availability is the final layer of security: the system must be in working order and usable. Availability focuses on the readiness of the system to perform and its capacity (items such as memory and connection speeds). If there is unavailability in the system or if some or all users are unable to access the system and perform required tasks efficiently and effectively (even authorised users) then the system is still at risk.
Having said this it is impossible to achieve one hundred percent security in today’s complex computer environments. Instead most security systems, specifically malware detection or ‘virus’ software such as Norton Anti-Virus focus on the idea of cutting the risk of being attacked. By building up protective layers to deter the attacker the security works on a “rob the next door” theory. This means that if the system has a lot of protection layers then the attacker will find it too difficult to compromise the system and instead will try another computer or ‘next door’.
Security plays an important role in our every day life and therefore failures of a security system have damaging effects. An example of this is Microsoft’s operating system called Microsoft XP which was released in 2001. The new operating system was a good target for attackers and Microsoft had been scrutinised for its lack of security in the system. The system had poor security this meant there were a lot of vulnerabilities or holes in the system and the risk of an attack compromising the systems data increased. In 2004 an update was released called Service Pack Two. Microsoft spent nearly US1 billion dollars creating this service pack proving the importance of security in computers. (Linn, 2004)
The definition of risk includes the impact of the attack. The impact of an attack has a range of consequences from endangering people’s lives and the environment such as a nuclear control stations to economic and monetary effects such as bank systems and home computers. This makes security a very important matter.
Security is important because it keeps a computer functioning. We (as computer users) need to ensure that a regular virus scans are performed and importantly regularly download the virus definition updates. In doing this any known vulnerabilites existing in the computer are minimised and therefore decreases the risk of a malicious attack. From this we can see that security is a way of reducing the probability of a threat.