Mukaila Apata, System Auditor and Security Administrator with over 18 years of experience consider [11] that three areas of the computer activity should be monitored on a regular basis: user access control, system activity monitoring, and the audit trail. These activities are closed to the basic mechanisms for implementing security proposed by : (a) authenticating principals (“Who said that?” or “Who is getting that information?” - people, groups, machines, or programs); (b) authorizing access (“Who is trusted to do which operations on this object?”) and (c) auditing the decisions of the guard (“what happened and why”).