How do you catch a murderer?
If you watch enough detective shows and true crime dramas,
you’ll be familiar with most of the mechanics here:
Fleeing the scene of a crime, bad guys unwittingly touch things -
door handles, windows sills, cookie jars...
Fingerprints end up on everything we touch,
leaving behind evidence of our movements
without us being aware we’ve done anything at all.
And that, believe it or not, is exactly what you are doing.
Yep. Right now.
You're allowing yourself to be tracked - with your digital fingerprint.
When we think about online tracking, the first thing that comes to mind
tends to be cookies.
Not THOSE, cookies.
Small files put on your hard drive by websites you visit
which store information about you.
But don’t fall into the trap of thinking that knowing about cookies
means knowing all about online tracking.
In fact, digital fingerprints are sometimes referred to as
“Cookieless monsters”, because they don’t rely on cookies at all.
Instead, they make use of information your browser shares with websites you visit.
Most of this information is harmless, and it’s used to optimise sites
to display and run as efficiently as possible.
What computer and operating system you’re running, what browser and version number,
what fonts you have installed, your screen resolution.
Hardly deeply personal stuff.
But this information varies a lot from computer to computer,
and user to user. So when combined, these seemingly innocuous bits of trivia
can start to build up a unique picture of you:
A fingerprint.
And the more of them there are, the more accurate that picture can be.
Think of it this way:
My name is Michael Lamb.
Now in the US alone, there are around 4.5 million people called Michael,
and about seventy thousand people with the surname Lamb.
But if you combine those two pieces of information,
you’d find there are only around 950 Michael Lambs.
Add in any other piece of information, like my birthday, or my favourite film,
and you’d be able to single me out pretty quickly.
This is how digital fingerprinting works.
What seems like a small amount of information at first
ends up quickly forming a profile easily identifiable as you.
On top of that, if websites share this information between them
- which they do, by the way, extensively -
then it becomes easy to expand that profile
to include information on everywhere you’ve been online.
Now this does have some positive applications,
it can help combat credential stuffing and fraud in general
by allowing websites to compare digital fingerprints to a database,
in order to verify the identity of the person logging on.
But it also adds up to an invasion of your privacy,
and makes you vulnerable to targeted marketing.
Advertisers can take advantage of data collected across multiple sites
even if you have the typical cookie controls in place.
The big question here is this:
how do you stop leaving your digital fingerprint on everything you touch?
It’s tempting to panic and throw all kinds of security measures
at the problem in an attempt to gain peace of mind.
Vow to use a VPN religiously, and permanently enable Incognito Mode.
But while neither of these is a bad idea, they don’t really address the problem.
VPNs hide your IP address, but not your digital fingerprint.
And as for Incognito Mode,
while it does limit the amount of information your browser shares,
it’s still sharing a fair bit, and as we’ve just learned,
it really doesn’t take that much information to make you identifiable.
So what can you do?
Well, there isn’t really a perfect answer to that question yet.
You can disable JavaScript, which is how your fingerprint information is collected.
But many websites heavily rely on JavaScript,
so disabling it risks making your online experience a lot clunkier,
and even breaking some sites all together.
You can download security centric browsers
like "Tor", to mask any revealing information about yourself,
but again these browsers often mean
sacrificing the speed and fluidity most web users have come to expect.
Ultimately, much like your real-life fingerprints, the reality is that
your digital fingerprint is just a fact of existing online,
and while there are certainly privacy issues to consider here,
it does still serve a useful purpose.
But as companies and browsers work harder
to increase the fluidity of the online experience,
there will be more and more techniques like digital fingerprinting
going on behind the scenes.
None of these are, or will be, intrinsically bad.
But it’s never a bad idea to be aware of them, so you can stay informed
and ultimately make the best decisions about your own online security.