1. Network Engineering and Security Group (NESG), Department of Signal Theory, Telematics and Communications, School of Computer Engineering and Telecommunications, University of Granada, Granada, Spain
2. Grupo de Inteligencia Computacional Aplicada (GICAP), Departamento de Ingeniería Informática, Escuela Politécnica Superior, Universidad de Burgos, Burgos, Spain
3. Superior Engineering School, University of Cadiz, Cádiz, Spain