With growing number of computers on internet coupled with the ever increasing world of crackers (the so called bad guys of internet), the probability of a computer system being intruded is very high. A recent example of computer system intrusion is the popular attacks of the groups like anonymous into the government websites of USA. The crackers might have their own reasons for these attacks but the reality is that not every cracker is doing this for a cause.
In this insecure world of internet where even the governments are struggling against intrusions then there has to be a safeguard that can help companies and individuals to strengthen the defence and retaliation capabilities of their computers. So, In this article we will discuss the basics of Intrusion detection systems or IDS.