Password on Math Computers

It is important to keep our Math Network secure. One aspect involves changing your password on the computers in our systems. Following are some of the rules we have established for passwords.

  1. We want everyone to make a new password on the Math computers at least once a year.
  2. This password should be different than your password on other computer networks including the password for your NU netid (modem pool). It definitely should not be used at another university.
  3. Your password should be at least 7 or 8 characters long. It should NOT be (a) in any dictionary (any language), (b) a place name, or (c) anyone's name or nickname. Also dates, street addresses and license plate numbers are a bad idea. Punctuation marks, digits, and even most control characters are allowed in passwords, but do not just replace letters with symbols that look alike such as letter O with number 0, like in "passw0rd".
  4. Northwestern requires the use of some characters which are not letters, and this is a good idea on our system too, but not absolutely required. Passwords are case-sensitive, i.e., capital letters are distinguished from lower case letters.
  5. Passphrases: A way to get s strong password, hard to guess but easy to remember, is to pick a sentence and construct a password from parts of it. For example, "SW&t7d's" stands for the phrase ``Snow White and the seven dwarfs''.
  6. We may run password guessing software to detect weak passwords on our system. If your password is guessed it may be forced to expire prematurely.

To change your password on the public Linux computers in Lunt use the yppasswd command: 

     yppasswd

You will be prompted for your Old password and then asked to type in your new password twice. Each time you are prompted, you type your old or new password as requested. As is always the case with passwords, nothing appears on the screen. That is why you are asked to retype the new password to confirm that you got it right.

If you have a computer in a private office you will probably need to change the password separately on that computer. (The computers in many of the graduate student offices are treated as "public" computers.)

In order to change your password in a private computer, log in and type 

     passwd
and follow the instructions.

If you have any questions ask our System Administrator.

Written by Clark Robinson, March 4, 1998
Updated by Miguel A. Lerma: 9/7/1999, 8/29/2001, 8/13/2009