The Design of GrIDS – A whitepaper on a graph based Intrusion Detection System. GrIDS is a prototype intrusion detection system that was designed to explore the issues involved in doing large scale IDS.
You can download it from the following link: https://packetstormsecurity.com/files/download/10717/grids.pdf
Source: https://packetstormsecurity.com/files/10717/grids.pdf.html

