This part of the book provides a basic introduction to UNIX
host security. These chapters are intended to be accessible to both
users and system administrators.
Users and Passwords
about UNIX user accounts. It discusses the purpose of passwords,
explains what makes good and bad passwords, and describes how the
() password encryption
Users, Groups, and the Superuser
, 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
The UNIX Filesystem
, 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 on the computer system.
, discusses the role of encryption
and message digests in your security. It includes a discussion of
how various popular encryption schemes, including the PGP mail package,