Common sense in choosing and protecting passwords can prevent many hacker penetrations to Fermilab computers. For example:

  • Don't make your password easy to guessónot the same as the username; not personal information, even backwards; not dictionary words; and especially not no password.

  • Use at least six alphanumeric characters. Passphrases are fine, especially if deliberatly misspeled, but remember most UNIX systems only use the first eight characters.

  • Don't put passwords in files.

  • Change your password frequentlyóat least twice annuallyóand donít change it back to a previously used password.

  • Don't give your password to someone else. If you find that someone knows it, change it immediately.