With the fast development of computer science and technology, more and more web-based applications of computational intelligence are faced with security and trusted problems, and more and more security and trusted problems need computational intelligent techniques to solve. It has been a necessary and urgent task to cross-fertilize ideas and integrate the techniques of these two important fields: computational intelligence (CI) and information security (IS).

International Conference on Computational Intelligence and Security (CIS) is a major annual international conference to bring together researchers, engineers, developers, and practitioners from academia and industry working in all areas of two crucial fields in information processing: computational intelligence (CI) and information security (IS), to share the experience, and exchange and cross-fertilize ideas. In particular, the series of CIS conference provides an ideal platform to explore the potential applications of CI models, algorithms, and technologies to IS. The 7th International Conference on Computational Intelligence and Security (CIS'2011) (http://www.cis-lab.org/) will be held in Sanya, Hainan, China, on December 3-4, 2011. This special issue will select a part of extended and revised full-length high-quality papers from CIS2011. We invite potential authors to contribute original research as well as review articles to our conference. Potential topics include, but are not limited to:

• Genetic algorithms and applications
• Particle swarm optimization and applications
• Optimization methods with applications in engineering
• Mathematical modeling and algorithms in machine learning
• Mathematical modeling and algorithms in fuzzy systems
• Mathematical modeling and algorithms in neural networks
• Mathematical methods in data mining
• Mathematical methods in data mining

Before submission authors should carefully read over the journal's Author Guidelines, which are located at http://www.hindawi.com/journals/mpe/guidelines/. Prospective authors should submit an electronic copy of their complete manuscript through the journal Manuscript Tracking System at http://mts.hindawi.com/ according to the following timetable: