  Smart Services using Industrial Internet of Things (IIoT) applications are on
the rise, but still more often than not, traditional industrial protocols are
used to interconnect the entities of the resulting systems. These protocols are
mostly not intended for functioning in such a highly interconnected environment
and, therefore, often lack even the most fundamental security measures. To
address this issue, this paper reasons on the security of a communications
protocol, intended for Machine to machine (M2M) communications, namely the Open
Platform Communications Unified Architecture (OPC UA) and exemplifies, on a
smart energy system, its capability to serve as a secure communications
architecture by either itself or in conjunction with traditional protocols.
