Network Security x Hofmeyr forrest(1999, 2000) developing an artificial immune system that is distributed, robust, dynamic, diverse and adaptive, with applications to computer network security x Kim bentley(2001). Hybrid approach of clonal selection and negative selectionNetwork Security Hofmeyr & Forrest (1999, 2000): developing an artificial immune system that is distributed, robust, dynamic, diverse and adaptive, with applications to computer network security. Kim & Bentley (2001). Hybrid approach of clonal selection and negative selection