As a general guideline, passwords should consist of 6 to 8 characters
including one or more from each of following sets:
- Lower case alphabetics
- Upper case alphabetics
- Digits 0 thru 9
- Punctuation marks
Compromises in password security normally result from careless
password selection or handling. For this reason, you should not select
a password which appears in a dictionary or which must be written
down. The password should also not be a proper name, your license
number, birth date, or street address. Any of these may be used as
guesses to violate system security.
Your password must easily remembered so that you will not be forced to
write it on a piece of paper. Other methods of construction involve
selecting an easily remembered phrase from literature and selecting the
first or last letter from each word. An example of this is: "Ask not for
whom the bell tolls", which produces "An4wtbt".
You may be reasonably sure few crackers will have included this in their
dictionaries. You should, however, select your own methods for
constructing passwords and not rely exclusively on the methods given
here.
(excerpt from the manual pages for passwd) |
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