Information Technology Reference
In-Depth Information
struction of tag, because it would then be
difficult to destroy the tag without dam-
aging the item and vice versa. This same
method could be made use of to avoid de-
taching of tags from an item.
nism so as to allow only authorized us-
ers into the gateway. Another measure to
prevent misuse of gateway interface is to
place the gateway and the user interface in
a physically protected room so that only
authorized persons can access the room
and the user interface.
To avert discharging of battery in an active
tag, a sleep mode could be implemented
for the tag. Shifting of all the information,
apart from the tag's ID to backend can help
solve the problem.
A possible solution to avoid corrupted
drivers is to make use of signed drivers, i.e.
the legitimate drivers should be digitally
signed so that the gateway can verify that
the reader it is communicating with has a
genuine driver.
In case of a consumer that just bought
some tagged object, in which tag no longer
has any legitimate use, it could be shielded
by simply wrapping the tag in metal foil
or by placing it in aluminum coated bag
to prevent the tag from being read out by
intruders. Some of the new advanced tags
have a module that encrypts the commu-
nication that tag has with the reader, thus
preventing eavesdropping.
Different solutions have also been planned in
order to overcome or at least minimize the impact
of the technical issues put forward by RFID:
RFID reader collisions can be prevented
by making use of Anti-collision protocols,
also called as Singulation protocol, which
enable the RFID tags to take turns in trans-
mitting to a reader, thereby preventing
overlapping of queries from the readers.
No technical measures have been found to
overcome the blocking of tags, but one so-
lution could be to ban the use of blocker
tags in standard terms and conditions of
business.
Different systems have been invented to
isolate individual tags when they are pres-
ent in a large volume in a small area. The
systems can be varied by preference of the
vendor, for instance, when a reader rec-
ognizes that tag collision has occurred, it
can send a special signal like a gap pulse.
Then, upon receiving the signal, each tag
consults a random number counter to de-
termine the time interval after which it will
send its data to the reader. Since each tag
then gets a unique interval number, the tags
send their data at different times, thereby
preventing tag collisions.
To avoid jamming, the jamming transmit-
ters can be detected by performing random
measurements or by permanently install-
ing field detectors.
Two solutions have been thought of to pre-
vent relay attacks: one way is to shield the
tag by wrapping it in a metal foil or plac-
ing it in aluminum coated bag and other
way is to require validation by the user,
like submit PIN code, or fingerprint scan,
etc. to activate the tagged card. The latter
measure could however eliminate the con-
venience of a contactless system.
In order to prevent readers from faking
their id and gaining unauthorized access to
tags, an authentication method can be used
to verify the reader towards the tag. The
user interface also needs to be provided
with some kind of authentication mecha-
Another option would be to apply anti-collision
algorithms which aim at reducing the overall read
time as well as maximizing the number of tags
that can read simultaneously. Most companies
that manufacture readers make use of these algo-
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