By Bruce Schneier
Uncle Milton Industries has been selling ant farms to children since
1956. Some years ago, I remember opening one up with a friend. There
were no actual ants included in the box. Instead, there was a card that
you filled in with your address, and the company would mail you some
ants. My friend expressed surprise that you could get ants sent to you
in the mail.
I replied: "What's really interesting is that these people will send a
tube of live ants to anyone you tell them to."
Security requires a particular mindset. Security professionals -- at
least the good ones -- see the world differently. They can't walk into a
store without noticing how they might shoplift. They can't use a
computer without wondering about the security vulnerabilities. They
can't vote without trying to figure out how to vote twice. They just
can't help it.
SmartWater is a liquid with a unique identifier linked to a particular
owner. "The idea is for me to paint this stuff on my valuables as proof
of ownership," I wrote when I first learned about the idea. "I think a
better idea would be for me to paint it on your valuables, and then call
Really, we can't help it.
This kind of thinking is not natural for most people. It's not natural
for engineers. Good engineering involves thinking about how things can
be made to work; the security mindset involves thinking about how things
can be made to fail. It involves thinking like an attacker, an adversary
or a criminal. You don't have to exploit the vulnerabilities you find,
but if you don't see the world that way, you'll never notice most
I've often speculated about how much of this is innate, and how much is
teachable. In general, I think it's a particular way of looking at the
world, and that it's far easier to teach someone domain expertise --
cryptography or software security or safecracking or document forgery --
than it is to teach someone a security mindset.
Which is why CSE 484, an undergraduate computer-security course taught
this quarter at the University of Washington, is so interesting to
watch. Professor Tadayoshi Kohno is trying to teach a security mindset.
You can see the results in the blog the students are keeping. They're
encouraged to post security reviews about random things: smart pill
boxes, Quiet Care Elder Care monitors, Apple's Time Capsule, GM's
OnStar, traffic lights, safe deposit boxes and dorm-room security.
The most recent one is about an automobile dealership. The poster
described how she was able to retrieve her car after service just by
giving the attendant her last name. Now any normal car owner would be
happy about how easy it was to get her car back, but someone with a
security mindset immediately thinks: "Can I really get a car just by
knowing the last name of someone whose car is being serviced?"
The rest of the blog post speculates on how someone could steal a car by
exploiting this security vulnerability, and whether it makes sense for
the dealership to have this lax security. You can quibble with the
analysis -- I'm curious about the liability that the dealership has, and
whether their insurance would cover any losses -- but that's all domain
expertise. The important point is to notice, and then question, the
security in the first place.
The lack of a security mindset explains a lot of bad security out there:
voting machines, electronic payment cards, medical devices, ID cards,
internet protocols. The designers are so busy making these systems work
that they don't stop to notice how they might fail or be made to fail,
and then how those failures might be exploited. Teaching designers a
security mindset will go a long way toward making future technological
systems more secure.
That part's obvious, but I think the security mindset is beneficial in
many more ways. If people can learn how to think outside their narrow
focus and see a bigger picture, whether in technology or politics or
their everyday lives, they'll be more sophisticated consumers, more
skeptical citizens, less gullible people.
If more people had a security mindset, services that compromise privacy
wouldn't have such a sizable market share -- and Facebook would be
totally different. Laptops wouldn't be lost with millions of unencrypted
Social Security numbers on them, and we'd all learn a lot fewer security
lessons the hard way. The power grid would be more secure. Identity
theft would go way down. Medical records would be more private. If
people had the security mindset, they wouldn't have tried to look at
Britney Spears' medical records, since they would have realized that
they would be caught.
There's nothing magical about this particular university class; anyone
can exercise his security mindset simply by trying to look at the world
from an attacker's perspective. If I wanted to evade this particular
security device, how would I do it? Could I follow the letter of this
law but get around the spirit? If the person who wrote this
advertisement, essay, article or television documentary were
unscrupulous, what could he have done? And then, how can I protect
myself from these attacks?
The security mindset is a valuable skill that everyone can benefit from,
regardless of career path.
Bruce Schneier is CTO of BT Counterpane and author of Beyond Fear:
Thinking Sensibly About Security in an Uncertain World. You can read
more of his writings on his website.
Subscribe to InfoSec News