Investigations on computational intelligence based techniques for efficient security threat controls

Abstract

Computer security is defined as the protection of computing systems against threats to confidentiality, integrity and availability. The threats to security in computing are interception, interruption, modification and fabrication. The work in the thesis centers around investigating computational intelligence based approaches such as Genetic Algorithms (GA) and the two paradigms of swarm intelligence viz Ant Colony Optimization (ACO) and Particle Swarm Optimization (PSO) to overcome the drawbacks existing in the traditional methods of controls available to combat threats in security in computing. Group rekeying for secure multicast is achieved using an ACO/GA based Boolean Function Minimization Technique (BFMT) when the users join in or leave a group. Ant Colony Optimization (ACO) based approach termed Ant Colony Optimization Boolean Expression Evolver (ABXE) is proposed to obtain a minimized boolean expression. A stream cipher method using swarm intelligence approach (ACO/PSO) of keystream generation is proposed. A firewall is a security guard placed at the point of entry between a private network and the outside network. An Ant Colony Optimization (ACO) based approach is proposed for packet filtering in the firewall rule set. Termed Ant Colony Optimization Packet Filtering (ACO-PF) algorithm, the scheme unlike its predecessors, considers all multiple occurrences of the same IP address or ports in the firewall rule set during its search process. The other parameters of the rule matching with the compared IP address or ports in the firewall ruleset are retrieved and the firewall decides whether the packet has to be accepted or rejected. The novelty is this scheme has a search space lesser than that of sequential search and binary search. It also strictly filters the packets according to the filter rules in the firewall rule set. It is shown that ACO-PF performs well when compared to other existing packet filtering methods. newline