if you have a new vehicle with keyless entry keyless start or keyless go then
you may have heard of all the vehicle thefts happening using a method called
relay attack. check out this security video clip on the toronto city news
article talking about an actual relay attack used to steal this suv. contrary
to what the caption says the relay attack does not disable the car's
security system. what actually happens is the criminals only use readily available
tools bought online to relay the signals from the key fob, located in the house,
back to the vehicle. doing this allows the suv to detect the key fob as if it
was right next to it. this allows the criminals to unlock the doors, start it
and drive off even without physical access to the keys. if you are concerned
about this then you will want to have your keys stored in a proper faraday box
when at home. while you may have heard of advice to use a metal box, aluminum foil
or even a microwave to store your keys in, they don't necessarily work well and
are not that practical. metal boxes can leak a small amount of signal that can
be amplified by the relay attack tools and need to be tested before you use
them. aluminum foil can work if enough layers are wrapped around but it is
unsightly and cumbersome to use. and note that as you use and reuse the foil over
time, holes and tears can form that leak the radio frequency signals.
and lastly, a microwave doesn't work to protect your keys.
now, this brings us to making your own faraday box for home that actually works.
Frakking Creations. showing you the good stuff on diy faraday boxes. by the way, if
you need a portable faraday box or bag for when you are out and about then
check out our diy videos on making these cool pocket size faraday box and faraday
bag. if you also want to stop key cloning attacks check out our obd port lock
video too. what box to use. i'm going to use this cool box i have for this
project. you can use any box or container of your liking from metal boxes, cash
boxes to different types of book boxes and book safes of your liking. that's
what's great about this project. you can use your favorite box and make it into a
faraday cage to protect your key fob and vehicle. you just need to make sure you
seal the box from any radio frequency leakage and test it out properly.
throughout the process we are going to use this app to test for leakage of cell,
bluetooth and wi-fi radio signals. you can do the same too. find links to the
android and ios apps in the video description below. i will also test the
box out using the key fob. you need to properly test your box out because it is
very easy for a small opening to leak enough signal that can be picked up and
defeat the purpose of the box. i had to make modifications to the original
design after testing revealed that the box was still leaking some rf signals.
find out how i solved the problem later in this video. if you need to you can
skip to the chapter of interest using the chapters feature in the playback bar
or in the description. this includes the testing chapters too. look for links to
any resources and products i talk about in our video description below. what
shielding material to use. you could do this project using aluminum foil, copper
tape or special faraday fabric like this. it's up to you. i chose this titan rf
faraday fabric since they have been lab tested. plus, it has a nice finish. it's a
nicely woven fabric made of about 25% metallic copper, 13% nickel and 62%
polyester so it's pretty easy to work with. plus you also get a small strip of
conductive faraday fabric tape which is pretty useful. there is a helpful
information sheet that is provided too. it gives you tips for your faraday
enclosure projects and also some testing information on their fabric. you can see
in this chart the different frequencies that have been tested and the amount of
signal reduction or attenuation a single, double or triple layers of fabric are
able to provide. first attempt. i measure, draw out and cut out one piece of the
faraday fabric that will fold up into the shape of the inside of the box.
there are tabs to overlap the corners and the lip of the box to close up any
holes that could leak any signals. there is also an additional shielded panel
added to the lid which will close into the box. when the lid is closed this will
hopefully reduce signals that could leak around the opening.
testing first attempt. at this point the box looks great but we
need to test. i get some baseline readings for cell, bluetooth and wi-fi
signal strength before sealing the smartphone with the app running into the
box. the test is run for about 30 seconds.
we see that only the cell signals are blocked. bluetooth and wi-fi are still
getting through. note that the wi-fi router and bluetooth speaker used for
the test are in the same room which means that the signal strengths are
quite high. if you look at the tip sheet provided it mentions that even the
tiniest hole can leak signal and that high strength signals like wifi may
require two or three layers of fabric on all sides for it to be blocked
completely. the single layer of shielding is not enough so back to the drawing
board to improve the shielding. second attempt. i decide to add additional
shielded side and bottom panels to the inside of the box. i'm also hoping that
the side panels will work with the inner lid panel to better seal the opening.
testing second attempt. testing reveals that both bluetooth and
wi-fi are still able to get through so i use some aluminum foil to test sealing
the lid better to see if that is the cause.
it looks like that helps block bluetooth now so only wi-fi left to deal with.
third attempt. i decide to add another layer around the inside of the box and
to further improve the sealing around the lid. this time, for the inner layer i
will use one piece of fabric and fold it into a box shape without any cuts. this
continuous sheet will ensure the corners are not leaking signals. after taping
this new inner layer into the box and reinstalling the five inner side and
bottom panels i retest. testing third attempt.
unfortunately, testing reveals that bluetooth and wi-fi are still not fully
blocked. it looks like the lid is still the main culprit. i verify this by
pressing down on the lid while testing and we then get the desired result. when
testing the fob it also shows that the signal leak is coming from the front of
the box. final modification.
before making any final modifications i'm going to test using the bottom panel
as an inner lid. this may be enough to resolve the leak
issue at the top. testing reveals that this works and so i will finalize the
design this way. final test of the faraday book box.
after the final modifications are complete a test reveals that the box is
now able to block cell, bluetooth and wi-fi signals even when we are in the
same room as the wi-fi router and bluetooth speaker.
conductance test. one thing that is important to remember as you are making
your own faraday box or enclosure is that all the sides of the box must
maintain conductivity in order to form a proper faraday cage. if one side is not
conductive with the rest of the box then it really isn't a faraday cage. so we can
test the resistance throughout all panels using a multimeter to make sure.
the resistance within the probe and fabric is about 0.4 ohms of resistance
so it should be the same throughout the box as well if constructed properly.
there you go. some great info for you to use in making your own diy faraday box.
make sure whatever you make, to fully test it using the app and a multimeter.
you should also test the boxes able to block whatever signal you are attempting
to block using the actual device. in our case, a key fob. if you enjoyed our video
please consider helping our channel grow by subscribing, liking and also sharing
our videos with friends and family.
Thanks for watching! ~ Frakking Creations ~