Network infrastructure security issues, including perimeter security defenses, firewalls, virtual private networks, intrusion detection systems, wireless security, and network security auditing tools. Secure network applications. Network security protocols such as SSL, SSL/TLS, SSH, Kerberos, IPSec, IKE. Network threats and countermeasures. Network auditing and scanning. VoIP Security. Remote exploitation and penetration techniques. Network support for securing critical infrastructure. Design and development of software-based network security modules and tools based on hands-on experiences and state-of-the-art technologies. Note: SEC 521 cannot be taken for credit with CSE 551