@INPROCEEDINGS{4bit-ieeeRFID2009,
AUTHOR="Markus Vogt and Axel Poschmann and Christof Paar",
TITLE="Cryptography is Feasible on 4-Bit Microcontrollers - A Proof of Concept",
BOOKTITLE="International IEEE Conference on RFID",
ADDRESS="Orlando, USA",
PAGES="267-274",
DAYS=27,
MONTH=4,
YEAR=2009,
KEYWORDS="lightweight cryptography, PRESENT, efficient implementation, 4-Bit,
microcontroller",
ABSTRACT="The RFID technlogy in combination with cryptographic algorithms and
protocols is dicussed widely as a promising solution against product
counterfeiting. Usually the discussion is focussed on passive low-cost
RFID-tags, which have harsh power constraints. $4$-Bit microcontroller have
very low-power characteristics (100-200 $\mu$A) and are therefore an
interesting plattform for active and passive low-cost RFID-tags. To the
best of our knowledge there are no implementations of cryptographic
algorithms on a $4$-bit microcontroller published so far. Therefore, the
main contribution of this work is to demonstrate that cryptography is
feasible on these ultra-constrained devices and to close this gap. We chose
PRESENT~\cite{present-ches2007} as the cryptographic algorithm, because
contrary to many other ciphers, PRESENT uses a 4x4 S-Box. Our
implementation draws a current of $6.7\mu$A at a supply voltage of $1.8$V
and a frequency of $500$ KHz and requires less than $200$ ms for the
processing of one data block."
}