  The conventional cryptography solutions are ill-suited to strict memory, size
and power limitations of resource-constrained devices, so lightweight
cryptography solutions have been specifically developed for this type of
applications. In this domain of cryptography, the term lightweight never refers
to inadequately low security, but rather to establishing the best balance to
maintain sufficient security. This paper presents the first comprehensive
survey evaluation of lightweight block ciphers in terms of their speed, cost,
performance, and balanced efficiency in hardware implementation, and
facilitates the comparison of studied ciphers in these respects. The cost of
lightweight block ciphers is evaluated with the metric of Gate Equivalent
(Fig.1), their speed with the metric of clock-cycle-per-block (Fig.2), their
performance with the metric of throughput (Fig.3) and their balanced efficiency
with the metric of Figure of Merit (Fig.4). The results of these evaluations
show that SIMON, SPECK, and Piccolo are the best lightweight block ciphers in
hardware implementation.(Abstract)
