The security of a password depends upon the strength of the encryption algorithm and the size of the key space. The UNIX System encryption method (used at COINET and thousands of other networks) is based on the NBS DES algorithm and is very secure. The size of the key space depends upon the randomness of the password which is selected. The longer and more random the password the greater time needed to crack it.
Compromises in password security normally result from careless password selection or handling. For this reason, you should select a password which does not appear in a dictionary or which must be written down. The password should also not be a proper name, your license number, birth date, street address, pet's name, etc. 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. One way this can be accomplished by
appending two small words together and separating each with a special
character or digit. For example, Pass%word.
Other methods of construction involve selecting an easily remembered phrase from literature and selecting the first or last letter from each. 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 dictionary. You should, however, select your own methods for constructing passwords and not rely exclusively on the methods given here
Please don't use the examples just given as passwords!