1. Group of Analysis, Security and Systems (GASS), Department of Software Engineering and Artificial Intelligence (DISIA), School of Computer Science, Office 431, Universidad Complutense de Madrid (UCM), Calle Profesor José García Santesmases s/n, Ciudad Universitaria, 28040 Madrid, Spain
2. Electrical Engineering Department, University of Brasilia, Campus Universitário Darcy Ribeiro, Asa Norte, 70910-900 Brasilia, DF, Brazil
3. Department of Convergence Security, Sungshin Women's University, 249-1 Dongseon-dong 3-ga, Seoul 136-742, Republic of Korea