Standard Security Features

• file ownership split into three classes--owner, group, and other--permits the owner of files to specify who is allowed access to the files

• permissions split into three categories--read, write, and execute--permits the owner of files to specify the degree of access users may have to the files

• the ability to encrypt data, using the crypt(1) command

• individual user accounts, protected by individual, encrypted passwords

• tools for monitoring login attempts

• tools for monitoring system activity, including:

  • finding out which processes are running, using the ps(1) command

  • determining who is logged on the system, using the who(1) command

  • maintaining logs of system activity, using process accounting commands