Educause Security Discussion mailing list archives
Re: Password Complexity and Aging
From: Gary Dobbins <dobbins () ND EDU>
Date: Mon, 13 Apr 2009 17:43:14 -0400
What is often left out (or defaulted to a common average period) is that the period of password change should be commensurate with the likelihood of its exposure to others - the degeneration of its initial secrecy. A root password that's written down and placed in a safe (and not used) is never exposed to being learned and so should not need frequent changes. One that is often transmitted in the clear, or which has a higher probability of being learned by others, should change periodically just to keep that audience growth in check. Chances are you may never hear of a successful incursion prevented by a periodic pwd change, since the attacker who knew it is unlikely to call and complain that you changed it.
-----Original Message----- From: The EDUCAUSE Security Constituent Group Listserv [mailto:SECURITY () LISTSERV EDUCAUSE EDU] On Behalf Of Karl Heins Sent: Monday, April 13, 2009 5:13 PM To: SECURITY () LISTSERV EDUCAUSE EDU Subject: Re: [SECURITY] Password Complexity and Aging Several years ago our external auditors (PWC) made a recommendation to change the password aging from 90 to 60 days at one campus and also made a recommendation to change the password aging from 60 to 30 days at another campus. The CIO asked me what would be the basis for either the 30 or 60 days. This started my interest in this topic. With over 20 years of IT audit experience, including 10 years at a large CPA firm (3 years in the national office), and after spending some time on the topic, I was unable to identify a good basis for either the 30, 60 or any number of days. So, working with the System wide UC CIO, we looked into our experiences with the password aging. With hundreds of systems and many problems with our combined experience, we were not able to find a single actual case where just aging out a password would have made a difference. I also challenged our auditors PWC to show a basis for their recommendations, no factual cases where there would have been a change in results. As a result I see little value in changing passwords just because of the passage of time. Aging passwords seems like good idea, however there appears little factual evidence supporting this effort. While my work was antidotal and lacks the rigor of good research, it would help if I could point to a single factual case where not aging passwords would have prevented a problem. To date, I have no such case. Don't feel that I am soft on controls or passwords, I consider other password controls critical to a good internal control system. I can point to plenty of cases where sharing passwords caused a problem. Problems that cost the organization real dollars of loss. I also feel that strong passwords are important, I feel that passwords should be hashed (not saved in the clear), and that anytime a password compromised it should be changed. Password be a good, effective, inexpensive control if handled properly. I realize that the password changing process is a part of every auditor, regulator and security person's standard checklist. I am not oppose to changing passwords periodically, I just see very little value in changing because the passage of time. An I continue to look for that first case where aging would have made a difference. Respectfully and with an open mind Karl ------------------------ Karl Heins Chief Information Security Officer University of California, Santa Barbara Karl.Heins () oist ucsb edu (805) 893-8843
Current thread:
- Re: Password Complexity and Aging, (continued)
- Re: Password Complexity and Aging Ryan Fox (Apr 13)
- Re: Password Complexity and Aging Allison Dolan (Apr 13)
- Re: Password Complexity and Aging Morrow Long (Apr 13)
- Re: Password Complexity and Aging Schumacher, Adam J (Apr 13)
- Re: Password Complexity and Aging Dexter Caldwell (Apr 13)
- Re: Password Complexity and Aging Basgen, Brian (Apr 13)
- Re: Password Complexity and Aging Gary Dobbins (Apr 13)
- Re: Password Complexity and Aging Doty, Timothy T. (Apr 13)
- Re: Password Complexity and Aging Karl Heins (Apr 13)
- Re: Password Complexity and Aging Basgen, Brian (Apr 13)
- Re: Password Complexity and Aging Gary Dobbins (Apr 13)
- Re: Password Complexity and Aging Mclaughlin, Kevin (mclaugkl) (Apr 13)
- Re: Password Complexity and Aging Mclaughlin, Kevin (mclaugkl) (Apr 13)
- Re: Password Complexity and Aging Perloff, Jim (Apr 13)
- Re: Password Complexity and Aging Basgen, Brian (Apr 13)
- Re: Password Complexity and Aging Mclaughlin, Kevin (mclaugkl) (Apr 13)
- Re: Password Complexity and Aging Mclaughlin, Kevin (mclaugkl) (Apr 13)
- Re: Password Complexity and Aging Lucas, Bryan (Apr 13)
- Re: Password Complexity and Aging David L. Wasley (Apr 13)
- Re: Password Complexity and Aging David L. Wasley (Apr 13)
- Re: Password Complexity and Aging Mclaughlin, Kevin (mclaugkl) (Apr 13)
(Thread continues...)