Page 6 - Logistics News June 2016

RFID
Hack-proof RFID chips
have arrived
Researchers at MIT and Texas Instruments have developed a new type of radio
frequency identification (RFID) chip that is virtually impossible to hack. This new
technology could secure credit cards, key cards, and pallets of goods in warehouses.
IF SUCH chips were widely adopted, it could
mean that an identity thief couldn’t steal your
credit card number or key card information
by sitting next to you at a café, and high-tech
burglars couldn’t swipe expensive goods from a
warehouse and replace them with dummy tags.
Some manufacturers have built several
prototypes of the new chip, to the researchers’
specifications, and in experiments the chips have
behaved as expected. The chip is designed to
prevent so-called side-channel attacks. Side-
channel attacks analyse patterns of memory
access or fluctuations in power usage when a
device is performing a cryptographic operation, in
order to extract its cryptographic key.
The idea in a side-channel attack is that a
given execution of the cryptographic algorithm
4 June 2016 | Logistics News
By Larry Hardesty, MIT News Office
only leaks a slight amount of information. So it is
necessary to execute the cryptographic algorithm
with the same secret many, many times to get
enough leakage to extract a complete secret.
One way to thwart side-channel attacks is to
regularly change secret keys. In that case, the
RFID chip would run a random-number generator
that would spit out a new secret key after each
transaction. A central server would run the same
generator, and every time an RFID scanner
queried the tag, it would relay the results to the
server, to see if the current key was valid.
Such a system would still, however, be
vulnerable to a ‘power glitch’ attack, in which
the RFID chip’s power would be repeatedly cut
right before it changed its secret key. An attacker
could then run the same side-channel attack
thousands of times, with the same key. Power-
glitch attacks have been used to circumvent limits
on the number of incorrect password entries in
password-protected devices, but RFID tags are
particularly vulnerable to them, since they’re
charged by tag readers and have no onboard
power supplies.
Two design innovations allow the MIT
researchers’ chip to thwart power-glitch attacks:
One is an on-chip power supply whose connection
to the chip circuitry would be virtually impossible
to cut, and the other is a set of ‘non-volatile’
memory cells that can store whatever data the
chip is working on when it begins to lose power.
For both of these features, the researchers use
a special type of material known as a ferroelectric
crystal. As a crystal, a ferroelectric material
consists of molecules arranged into a regular
three-dimensional lattice. In every cell of the
lattice, positive and negative charges naturally
separate, producing electrical polarisation. The
application of an electric field, however, can align
the cells’ polarisation in either of two directions,
which can represent the two possible values of a
bit of information.
When the electric field is removed, the cells
maintain their polarisation. •