Yes, I was aware that "man passwd" says that. Well, I think PAM could enforce a user to use more complex character sets for password setting. I have changed an appropriate PAM files (/etc/pam.d/common-password), so let me see if it really works. Thanks for your information. Soo-Hyun <div>On 11/5/07, Mario Vukelic <<a href="mailto:mario.vukelic@dantian.org">mario.vukelic@dantian.org </a>> wrote:<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> On Mon, 2007-11-05 at 14:49 +0000, Soo-Hyun Choi wrote: > I wonder how can I force a user to use complex password set instead of > simple character combination. I haven't actually tested it, but "man passwd" says, "Then, the password is tested for complexity. As a general guideline, passwords should consist of 6 to 8 characters including one or more characters from each of the following sets: · lower case alphabetics · digits 0 thru 9 · punctuation marks" So it looks to me that the default is to enforce complexity. Of course one should never assume stuff when looking for security. In any case, in modern linux distros log-in password configuration is done with the pam package . Look into the config file /etc/pam.d/common-password and 'man pam_unix' -- ubuntu-users mailing list <a href="mailto:ubuntu-users@lists.ubuntu.com">ubuntu-users@lists.ubuntu.com</a> Modify settings or unsubscribe at: <a href="https://lists.ubuntu.com/mailman/listinfo/ubuntu-users"> https://lists.ubuntu.com/mailman/listinfo/ubuntu-users</a> </blockquote></div>