Security Basics mailing list archives

more on strong passwords - a reply


From: "kenkousky" <kkousky () ip3inc com>
Date: Fri, 8 Aug 2003 12:23:17 -0400

To clarify some points:

I'm really simply advocating multi-factor authentication rather than
causing more damage than good through the misuse of passwords. Passwords
are suppose to be something you know. Many IT shops have changed this
making passwords so strong, they have to be written down to be remember
and so they become something you "have", not something you "know".

A false rejection occurs whenever we deny legitimate users access to
their resources. This is also the same as a denial of service. Our
legitimate users are denied access to their legitimate resources because
of the security we've put in place to protect them. If we're truly
worried about CIA - confidentiality, integrity and availability, then
we're giving up system availability in our attempts to protect the C and
I. 

This is extremely costly to most organizations and we usually fail to
enhance the security in terms of C and I because of the difficulty in
managing 20+ passwords, which survey data confirms is the reality for
knowledge workers.

The denial of service is the password system doing just what it's
suppose to do but our implementation of it causing the problem. 

The goal of authentication is strong confirmation of who's at the end of
a digital stream - we do this by testing for something they have,
something they know or through biometrics. 

When we make passwords strong, for the large majority of the world, they
become something you "have" and NOT something you know. You have to
write them down to keep them but if it's something you have, there are
far better technologies. Look at smart cards, cd cards, token
generators, etc.

I've worked with a F-1000 company that employs seven full time staffers
to do nothing but password resets. This is an easy point of exploit for
social engineering and is also a REAL and substantial cost.

If we make this kind of mess out of passwords, how are we ever going to
handle PKI? 

I'm a strong advocate for strong authentication but fortifying a system
through overbuilt passwords is a vulnerability, not a defense. It's like
shooting at mosquitoes with an Uzi. Far too much collateral damage. 

A better approach is multi-factor authentication.

KWK

-----Original Message-----
From: Adam Newhard [mailto:atnewhard () microstrain com] 
Sent: Friday, August 08, 2003 9:42 AM
To: security-basics () securityfocus com
Subject: Re: UNIX password auditing tool and the search for dictionaries
too

In terms of this comment to whoever posted it (sorry, I don't remember
who
it was):

Strong passwords are the number one source of denial of service in
most
environments due to the frequent false reject problem that occurs
when
users can't keep up with frequent changes and strong password.
They're
also one of the highest costs for security since it's the number one
task for help desks and sys admins to support.

How is it a high cost for security???  I've always found having someone
come
down and asking
for their id and some other mode of face to face identification makes it
pretty easy to reset someone's
password.  If you simply take advantage of all that garbage they pull on
a
lot of websites, like your security question is what's your mother's
maiden
name, you can get around them showing you a fake id...yeah, there are
ways
of finding out someone's info, but nothing is secure.  It's the
foundation
of your plan that guides your performance.

In terms of your dos attack, i might be misreading your question, but
strong
passwords being dos'd or brute forced (if you consider a really fast
brute
force attack a dos; i don't, but some do), a lot of places will put a
piece
of crap machine as their password authentication for their network.
yeah,
you may have a lot of people logging on and may get periodically bogged
down, but you need to find the right machine that'll cause the correct
amount of lag.  say for a "normal" company (my idea, not necessarily
yours)
you have 200 people.  probably, on average they log on maybe 2-3
times/day...some only once, some maybe 10 times, and those on vacation
never...so give them 3 times/day.  if you have a fast machine doing
password
checks and it takes only a second for the logon sequence (password
verification), it'll be about 600 seconds or 10 min (200 people x 3
logons/day x 1 sec)...theoretically, of course.  if i want to brute
force
the machine i can do 60/sec.  take a crap machine, stable mind you just
a
slower processor, that takes 10 seconds to verify a password and you've
dropped to 6 attempts/sec.  Yeah, you do go from 10 min/day of
verification
to 50 min (if my math is correct) so that's something you need to
consider
when you think about if it's worth it or not...after finding a
reasonable
value, it is to me.  You could consider it an easier target for dos b/c
it's
much slower, but then again, you also have to take into consideration
this...if you're gonna try to get in using someone's password, why would
you
attack a crap machine that's exceptionally slow...i'd just stand behind
them
while they type in their password.  i might've missed part of your
statement, so if i did...i apologize.

after reading your statement, one more thing...if strong password
authentication causes a lot of dos b/c people are trying to logon
constantly
w/the wrong password b/c of password changes, why are you even letting
them
attempt to logon so many times?  if a person mistypes their password 3-5
times, the account should either be deactivated until that person comes
and
gets you or for a certain number of minutes.  print a nice pretty
message to
the user that this has happened and send yourself a note also so you can
go
find them if need be.  there are holes to that one just like anything
(i.e.
your boss doesn't like it), but like i said before, nothing's really
perfect.  if dos'ing occurs b/c people keep entering the wrong password,
that's more your fault than theirs.  out of curiosity, where did you
find it
saying that dos is the number one problem w/strong passwords???
adam
----------------------------------------------------
Adam Newhard
Microstrain, Inc.
If vegetarians eat vegetables, watch out for humanitarians

----- Original Message ----- 
From: "Michael Martinez" <mmartinez () tamsco com>
To: <security-basics () securityfocus com>
Sent: Thursday, August 07, 2003 4:48 PM
Subject: RE: UNIX password auditing tool and the search for dictionaries
too


Before you go too far with strong passwords, remember, they do more
harm
than good in most cases. You trust your money to a four digit pin so
think about strong authentication, not strong passwords. Two factor
can
be done with a variety of inexpensive technologies.

Are you kidding me, you are under the impression that a 4 digit pin is
secure?  I for one have no illusions about how insecure a 4 digit pin
actually is!  Whatever security is provided by said 4 digit pin is
more
related to that fact that there are not freely available pin cracking
tools for ATM machines...as there are password cracking tools.

Strong passwords are the number one source of denial of service in
most
environments due to the frequent false reject problem that occurs
when
users can't keep up with frequent changes and strong password.
They're
also one of the highest costs for security since it's the number one
task for help desks and sys admins to support.

As a help desk supervisor, I assure you that the related cost of time
and money supporting the reset of passwords is minimal and therefore a
small price to pay for increased security.

...

In terms of dictionaries, I think the aggressive approach would
include
concatenations and number and special character injections into the
words. In more secure environments, were users are battered with
monthly
password changes they usually inject the numeric value for the month
somewhere in a common word. But the point is, it's not too difficult
to
build a really big database of words with special character and
numeric
injections, run them through the hash algorithm and have a table to
check for matches.

If someone were in an environment where they must change their
password
monthly...they are probably using the wrong technology.  Perhaps a
combination of different layers would be a better solution to monthly
changes.

...

-----Original Message-----
From: Shane Lahey [mailto:s.lahey () roadrunner nf net]
Sent: Monday, August 04, 2003 7:38 PM
To: james.easterling () ed gov; security-basics () securityfocus com
Subject: RE: UNIX password auditing tool

Alec Muffett Crack :: http://www.crypticide.org/users/alecm/

-----Original Message-----
From: james.easterling () ed gov [mailto:james.easterling () ed gov]
Sent: Monday, August 04, 2003 4:39 PM
To: security-basics () securityfocus com
Subject: UNIX password auditing tool



I have tried searches for UNIX password cracking tools and I have
come
up
with little value.  Can someone direct me to passwd auditing tools
besides "John The Ripper" that are free or cost?

Regards,
James



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