Linux® For Dummies®, 8th Edition

Choosing Secure Passwords

The first line of defense from intruders is the passwords used on your system. For each account you have set up on your system, the passwords must be strong and difficult to figure out. If even one of the accounts has a weak password, you may be in for some trouble. Amazingly enough, in 70 percent of the cases where unauthorized individuals gained access to systems, the password for an account was the word password itself! When choosing good passwords, follow these rules:

✓	Don’t use any part of your name.
✓	Don’t use the names of friends, loved ones, or pets.
✓	Don’t use birthdays, anniversaries, or other easily guessed dates.
✓	Don’t use dictionary words.
✓	Don’t keep your password written down near your computer, unless it’s buried in something else, such as writing it into an address.
✓	Don’t tell anyone your password. If someone needs to access specific files, give the person an account and set up permissions and groups properly so that they can do so.
✓	Do use a mix of lowercase letters, capital letters, and numbers.
✓	Do ensure that your password contains a minimum of eight characters.
✓	Do use acronyms made from sentences, such as having the password M8yodniT to stand for “My eight-year-old dog’s name is Tabby.”

Every person on your system needs to follow these rules, including you! Consider keeping a sheet of paper with these rules on it next to the machine.

I can’t stress this advice enough: Never give out your password. Make sure that the people using your ...