

Using a belt sander to foil biometric fingerprints - Luc
http://jacquesmattheij.com/The+belt+sander+and+the+battle+for+privacy+a+body+hack

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teilo
A belt sander is a bit harsh. The micro-fine sandpapers used by plastic model
hobbyists work much better, and are much less likely to harm your fingers.

I remember reading this trick in the old spy novels, and being a model
hobbyist at the time, I had to try it (on one finger, anyway). It worked -- so
far as eliminating fingerprints. Of course, back then biometrics was a rather
exotic technology, low res, and not in common use.

~~~
wiredfool
My experience making balsa wood aircraft indicates that the combination of
gluing your fingers to a wing with CA, prying them off, then sanding the glue
off was a pretty effective way of getting rid of the fingerprints, on one hand
at least.

Do it with two hands and it got very hard to pry the first hand off.

------
DanI-S
People would be better of putting their bountiful tin-foil-hat energies to use
campaigning against the governments that introduce these laws. Writing a
letter to your MP is far more meaningful than grinding off the ends of your
fingers.

~~~
scotch_drinker
It's all dependent on your definition of meaningful. If you want to be an
activist, writing a letter is an excellent way to go about it. If you want a
passport to travel sometime during your lifetime but would prefer to not have
to worry too much about privacy concerns, writing a letter isn't going to help
you much.

I hardly think it's tin-foil hat territory to look at the state of most
Western governments and deduce that they are becoming more fascist and less
democratic all the time, completely in the name of preventing terrorism.
Sanding your fingertips off and writing a letter to your MP serve two
distinctly different prongs of a fight against that fascism.

~~~
DanI-S
The 'tin foil hat' madness isn't really in suspecting that there are people
out there trying to control your mind. It's in believing that wearing a tin
foil hat is going to stop them.

~~~
stcredzero
A better plan would be: move somewhere so isolated, electronic media can't
reach you?

Any plans that _don't_ result in shortened life span?

------
iuguy
The title really should read, "Using a belt sander to ensure your biometric
prints never match your actual prints".

Jacques is in for a world of hurt when he next travels abroad.

~~~
mahmud
_Jacques is in for a world of hurt when he next travels abroad._

To my knowledge, it's ONLY the U.S. that finger-prints foreigners. Jacques is
Dutch, and all he has to do to avoid "a world of hurt" is to not come to the
U.S.

~~~
WildUtah
_To my knowledge, it's ONLY the U.S. that finger-prints foreigners_

Japan and the USA, I'm pretty sure.

And this system would only catch nationals of the country in question being
fingerprinted upon re-entering that country.

~~~
po
Yeah and it doesn't work very well:

[http://www.japantoday.com/category/national/view/deported-s-...](http://www.japantoday.com/category/national/view/deported-
s-korean-woman-passed-through-japans-biometric-immigration-screening)

This woman snuck back in a few times after being deported by using "special
tape." I really wonder how special the tape is. On the other hand:

 _846 foreign nationals were refused entry_

So, I doubt they will ever get rid of the program.

~~~
Luc
> I really wonder how special the tape is.

There's some blister plasters that are very thin and transparent.

Herpes plasters for around the mouth are quite hard to spot (though with a
picture as blurry as in this article you would expect them to be):
[http://www.primped.com.au/blogs/zoes-blog/if-you-get-cold-
so...](http://www.primped.com.au/blogs/zoes-blog/if-you-get-cold-sores-then-
you-must-by-law-read-this)

------
m0nastic
I had a cousin who worked construction (and consequently didn't really have
fingerprints).

He also got arrested a lot (like most of my family) and they took to taking
palm prints when they booked him.

They would grow back if he went awhile without doing work though; it was
definitely a temporary solution.

~~~
Luyt
_"they took to taking palm prints"_

Well, you could sand those off, too. And while you're at it: sand your toes.
And your heels.

Now what would you do when iris scans become a commonplace biometric? Sand off
the back of your eyeballs? ;-)

~~~
adrianN
Your iris doesn't leave prints on your gun.

------
softbuilder
I had the opportunity to learn a little bit about fingerprints during a
programming gig. The part he's missing here is that what he thinks is a smudge
can sometimes still be used as part of a print. Partials aren't just from TV
dramas, they get used all of the time in real cases. Also one thing most
people don't know about is that prints can be "massaged" by law enforcement in
what is essentially a photoshop-like process, so if a human technician can
make a fairly good guess about what the print should look like, they still
might be able to find a match.

------
bhousel
I've heard of people doing this before, removing their fingerprints with a
sander..

But I believe the fingerprints will grow back after a while. Couldn't you get
into more trouble if they grow back and you are carrying around a passport
with no fingerprints in it? Or do you plan to keep sanding them off for the
rest of your life? (or the life of the passport)

~~~
seven
They do grow back. Just destroy the chip, then there is no way to read them
out again.

~~~
bhousel
Now you have two problems..

~~~
rdtsc
Why? Does a chip that cannot be read render your passport invalid?

~~~
lwat
Only if there's evidence that you destroyed the chip on purpose.

~~~
Luyt
A strong EMP might destroy it without visual clue.

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tofumatt
Fingerprints will grow back unless you get down to dermal layers of skin and
that _will_ hurt quite a bit. Permanently removing your prints is a more
involved process than this, but it's certainly a cute idea.

------
Luc
It's a really funny, whimsical thing to do, but how will this help you to
increase your privacy? Next time you enter the US your finger prints won't
match the data on your passport, right?

~~~
DanI-S
They'll also be a perfect match to the last nutjob who filed off his own
fingerprints before mailing letterbombs to the IRS.

It probably only increases your chance of being detained, probed and
investigated. Unless you file off your face, they can still tell who you are.

Rather than adapting your body to quietly live within the 'instruments of
control', why not actively campaign against them?

~~~
adrianN
Why not do both?

------
JonnieCache
If you're feeling brave, microwave your passport for good measure.

~~~
imajes
According to most official documents, any passport which has a faulty rfid
will be assumed tampered with, and will become invalid. So unless you want to
be refused entry and forced to replace your passport, this is unadvisable.

~~~
danudey
You could cause even more of a hassle then by building an RFID zapper
(<http://en.wikipedia.org/wiki/RFID_Zapper>). A powerful one that fits inside
a suitcase could be set off in an airport concourse, frying a large number of
people's chips without them ever knowing (or any damage to the passport itself
occurring).

Do it on a busy travel day and suddenly the authorities have to deal with a
ton of broken passports. Either they arrest everyone, or they let everyone
through.

Of course, you probably couldn't get a suitcase-sized RFID zapper through
security, but you could show up, set it off a few times, and then leave
without arousing TOO much suspicion.

~~~
SeoxyS
So, you're essentially promoting terrorism… neat.

~~~
danudey
From the point of view of the TSA, maybe. In reality, it's just talking and
sharing information.

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impeachgod
What would be more interesting, would be if he found a way to grow _different_
fingerprints.

~~~
adrianN
Gummy Bears: <http://www.schneier.com/crypto-gram-0205.html#5>

------
brokentone
I feel like this is a little mis-titled. I expected a method to do something
to a biometric scanner, or to temporarily alter your fingerprints, not to
remove them entirely! Interesting read I suppose, if you're into that sort of
thing.

~~~
jbri
A method to do something to a biometric scanner, using a belt sander?

Somehow I don't think that would really be relevant for the "they're checking
my fingerprints at the passport office" situation.

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ahrens
The interesting thing is that fingers with the prints removed actually always
do have damages that make them unique. In fact, it is usually easier to
identify a print from your fingers now, than before. So good luck with that.

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cappaert
"It is estimated that 1 in 50 people do not have prints or prints clear enough
to be registered by the fingerprint readers currently in use."

Can you provide a source? I'd be interested in seeing data to back this up.

~~~
wazoox
Dig a 1m deep, 5m long trench in your garden with pickaxe and spade. I
guarantee you that you won't have the slightest trace of a fingerprint on both
hands for quite a while.

Given the number of people working regularly with such tools, that's quite a
sizeable number of smooth hands :)

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Tichy
Isn't that a very temporary solution. How long until everything is based on
genes, face recognition and so on? For all I know those governments taking my
fingerprints might use them to extract my DNA, too.

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famousactress
_It is estimated that 1 in 50 people do not have prints or prints clear enough
to be registered by the fingerprint readers currently in use._

Really!?

~~~
te_platt
I don't know just how accurate the 1 in 50 number is but it is pretty close to
my observations. I worked on a fingerprint recognition system several years
ago and collected many thousands of live fingerprints and processed hundreds
of thousands of other records (scans of inked prints for example). Recognizing
a good quality print is almost trivially easy. Most of the work is pulling
good information out of low quality images.

Fingerprints are a reliable source of information in most cases for most
people but are a far cry perfect form of identification most people think.

~~~
bhousel
So tell us.. Wouldn't being "that guy with no fingerprints" be a more clear
identifier, and draw more attention to yourself, than just having the same
boring blurry imperfect fingerprints that the rest of us have?

If the goal is to increase your privacy, walking around with sanded off
fingerprints sounds about as contrary to that goal as walking around with one
of those fake eyeglass-nose-mustache disguises.

~~~
madmoose
Ceramists and brick layers often have vague or worn-off fingerprints. Just say
you do a lot of ceramics.

~~~
pbhjpbhj
I came to mention that I do some ceramics and hadn't thought about losing
fingerprints before but definitely have pretty smooth fingers now. Using
grogged clay to throw with can be torture on your hands if you're not used to
it.

Like someone mentioned I imagine the prints can be gathered directly by a
photographic imaging method - my fingertips are smooth but they still have
visual fingerprint patterning. Perhaps if I'm throwing more regularly that
would go?

