This course deals with security issues in a networked environment and the Internet, and with a guide to obtaining freely available security tools and references. It points out the inadequacies of existing products in keeping out intruders, and enables participants to better estimate their own security requirements, risks, and advantages. These include the World Wide Web security, proxy programs, integrity management tools, secure programming, and how to use secure TCP/IP services. It also covers security issues on passwords, filesystem, cryptography, backups, logging, firewalls, virtual private networks, proactive security strategies and policies, physical security and dealing with break-ins.