Intrusion alert correlation is multi-step processes that receives alerts from heterogeneous log resources as input and produce a high-level description of the malicious activity on the network. The objective of this study is to analyse the current alert correlation technique and identify the significant criteria in each technique that can improve the Intrusion Detection System(IDS) problem such as prone to alert flooding, contextual problem, false alert and scalability. The existing alert correlation techniques had been reviewed and analysed. From the analysis, six capability criteria have been identified to
improve the current alert correlation technique. They are
capability to do alert reduction, alert clustering,identify multistep attack, reduce false alert, detect known attack and detect unknown attack
