Changing Your Password

An inherent element of good system security is a secure password. Linux passwords are no exception to the rules of the computer world in general. These rules are pretty simple:

A. Don’t use a password found in the dictionary. Many password cracking programs first scan through a huge dictionary looking for matches to your password. Most then work back through this dictionary looking for:

1. any word written backwards
2. any word with a punctuation character at the end
3. any word with a punctuation character at the beginning
4. any capitalized word
5. any two words with a number between them

B. Mix upper and lower-case characters in the password. As Linux is case-sensitive, this significantly increases the mathematical difficulty of cracking your password.

C. Throw in non-alphanumeric characters. %*%~ are all useful and, again, throw an increased degree of difficulty at password cracking programs.

D. Never, never make your user password in Linux the same as your root password.

E. Perhaps most importantly, change your password often.

In Linux, changing your password is almost a trivial task. From a console window, as the normal user, enter the command passwd. You’ll be prompted for a “New Unix Password.” Enter the password, then re-enter to confirm, and you’re done.

With the simple rules above and the passwd command in Linux, you’ll keep your system and your data safe and secure.