Computational Intelligence constitutes an umbrella of techniques, has proven to be flexible in solving dynamic and complex real-world problems. These techniques typically include Fuzzy Logic, Evolutionary Computation, Intelligent Agent Systems, Neural Networks, Cellular Automata, Artificial Immune Systems, Game Theory and other similar computational models. These techniques are now being widely used in different cyber security applications such as online behavior monitoring, e-fraud detection, robust decision support modules, etc. In order to protect Internet users from Identity Theft, Phishing, Spam and other cyber infrastructure threats, we need flexible, adaptable and robust cyber defense systems, which can make intelligent decisions (in near real-time) in detecting wide variety of threats and attacks, including active and passive attacks, external attacks and internal misuses, known and unknown attacks, viruses and spam, etc. Computational Intelligent (CI) techniques have demonstrated to enhance cyber security measures, and have been increasingly applied in the area of information security and information assurance. Moreover, the multi-faceted CI approaches appear to provide a new security paradigm to deal with influx of new threats in a large network of computers. These approaches can also be used to augment defense-in-depth architectures and to add necessary security enhancements to the design, implementation and operation of legacy and future cyber-enabled systems.