When the Internet became a public medium in 1992, every connected computer became an instant target for "crackers". This subject deals with Internet operating system security, including networking and operating system issues. Topics include , wrapper and proxy programs, securing TCP/IP services, host security and passwords, SUID/GUID files, cryptography, firewalls, root kitsaccess control lists, public key infrastructure, system logging, authentication schemes and intrusion prevention and detection, and dealing with break-insprevention.

* install and use encryption software * set up the Secure Shellmaintain user accounts and passwords * implement and use public key infrastructures * identify and disable unused system services * audit the security of a Linux system. * enable and use wrappers and proxies * recognize maintain file permissions and recover from various attacksaccess control lists * create implement and maintain manditory access controls * setup, maintain and monitor system backupslogs* * configure a Linux firewall** use current security tools* * setup intrusion prevention and detection systems* * monitor and restrict logins* * install, configure and administrate Pluggable Authentication Modulesauthentication schemes