This part of the book provides a basic introduction to Unix host security. The chapters in this part are designed to be accessible to both users and administrators.
Chapter 4, is about Unix user accounts. It discusses the purpose of passwords, explains what makes good and bad passwords, and describes how the crypt( ) password encryption system works.
Chapter 5, describes how Unix groups can be used to control access to files and devices. It also discusses the Unix superuser and the role that special users play. This chapter also introduces the Pluggable Authentication Module (PAM) system.
Chapter 6, discusses the security provisions of the Unix filesystem and tells how to restrict access to files and directories to the file's owner, to a group of people, or to everybody using the computer system.
Chapter 7, discusses the role of encryption and message digests in protecting your security.
Chapter 8. What if somebody gets frustrated by your super-secure system and decides to smash your computer with a sledgehammer? This chapter describes physical perils that face your computer and its data and discusses ways of protecting against them.
Chapter 9, explores who you employ and how they fit into your overall security scheme.