Abstract:
In past years, cryptography has been considered a dif cult task to achieve on sensor nodes for
the Internet of Energy (IoE) owing to the resource-constrained nature of 8- and 16-bit microcontroller units
(MCUs). Previous attempts at implementing cryptographic services on wireless sensor nodes have resulted
in high power consumptions, long operating times, and the depletion of memory resources. Over the last
decade, however, processors for the IoT and IoE have improved; with increased operating power and memory
resources, longer data bus widths and low-power consumption. With the improvements made to processors
suitable for building IoT devices, the question remains whether endpoint nodes should still be considered
capable of only supporting the most lightweight of cryptographic mechanisms. We evaluate the capabilities
of a device family (Cortex-M series processors) commonly found in programmable logic controllers
to implement standard, veri ed software cryptographic libraries in terms of execution times, memory
occupation, and power consumption in order to determine their adequacy for use in smart grid applications.
It was seen that the MCUs were easily capable of running standard cryptographic algorithms. However,
the use of public key cryptography may still require the inclusion of a hardware crypto accelerator or the use
of a secure MCU implementing public key cryptography; as the relatively long execution times seen during
the operation of ECDSA, for example, could be intolerable within a real time IoE application.
