Introduction to the theory and practice of computer and network security. Fundamentals of secure networks and systems. Symmetric cryptography primitives, block ciphers and modes of operation. Introduction to number theory and its applications to public key cryptography algorithms. Authentication and integrity concepts, Hash functions, Message Authentication Codes and Digital Signatures. Key distribution and management. Real-life Networking protocols (IPSec, SSL, wireless networks). TCP-IP with a threat focus and attacks. Packet filtering, Firewall, and Intrusion Detection systems. Ethical issues.