NIU Department of Mathematical Sciences
Choosing and changing the password

The password on a multi-user system such as Unix protects your data from prying eyes and from vandals; it also protects the entire system from intruders. If you have just received a new temporary password, or if you think that someone might know the one you currently use, you should change it immediately. Do not share your password with other people.

Choose a word or phrase roughly 6 to 10 characters long, and contaning some non-alphabetic characters. Make it easy for you to remember, but hard for others to guess. Here are examples of what is not secure at all:

What works: anything that is hard to guess even by people who know you well! For example, Even these will be relatively easy to guess unless you put in some non-alphanumeric characters (-, =, @, _, and so on), and/or replace some letters with digits, e.g. 2 in place of t. You should also use a mixture of lower- and upper-case letters: passwords are case-sensitive, i.e. Joe is considered distinct from joe. Also note that even though you can use long strings as passwords, only the first eight characters are significant.

Changing the password

Log into one of the workstations. At the Unix command prompt type passwd (and hit Return). The computer will say something like this:
Changing NIS password for johndoe on denali.
Old password:
You should type in your current password (the computer simply makes sure that it's you at the keyboard, not someone else). You will then need to enter the new one twice, to make sure you didn't make a mistake; that's it. Next time you log in, use the new password.

Note: this procedure applies to all Unix systems, not just the Math Department computers.


Last modified: 7/19/2011 by webmaster@math.niu.edu