Page 321 - From Smart Grid to Internet of Energy

Internet of things for smart grid applications Chapter 7 285

Smart objects and code segments can provide the IP security of IoT appli-
cations in the context of 6LoWPAN usage at link layer. The link layer security
that is inherited from IEEE 802.15.4 supports data encryption and integrity
check. On the other hand, security can be supported by using TLS and SSL that
includes a key mechanism to control the authentication, confidentiality, and
integration at the transport layer. The UDP based TLS namely DTLS is used
in 6LoWPAN enabled networks to increase the resiliency against attacks at net-
work layer [52].
Several sensors comprise sensor networks as its name implies, but additional
components such as microprocessors, communication devices, and power sup-
ply are also required to operate the system. The sensor nodes are featured to
acquire physical data of the measured system with humidity, temperature, pres-
sure and similar sensors or electrical data with current and voltage sensors. The
microprocessor can be any platform including 16- or 32-bit cores. The WSN is
an emerging application of sensor networks that is widely used in smart grid,
M2M, and IoT applications. The essential idea behind WSN is its wireless com-
munication infrastructure transmitting the acquired data in short or long dis-
tances corresponding to transmitter specifications. In the WSN infrastructure,
each sensor is supplied by a portable power source as battery and utilizes wire-
less communication interface. The sensor node can be stable at any measure-
ment section or it can be mobile. Although preliminary WSN applications
are implemented for military and defense usages, now it has a widespread
use in health, industrial, residential, and several engineering applications. Some
of WSN usage areas can be summarized as environmental issues as agriculture
and wildlife researches, energy harvesting applications, smart metering, indus-
trial measurement, and remote monitoring applications, tracking and localiza-
tion systems.
WSNs are mostly exposed to intrusion and threats since they transmit valu-
able data on communication medium. Therefore, security is a crucial topic in
WSN researches that aim to prevent DoS attacks and intrusion attempts. The
passive attacks try eavesdropping to obtain and analysis the traffic data as intro-
duced in the previous subsection. On the other hand, active attack types as inter-
ruption, modification and fabrication are widely met in WSN as seen in other
communication infrastructures. There are several methods such as node protec-
tion, cryptography, key management, secure routing and data aggregation have
been proposed to increase WSN security. The security issues of WSN are ana-
lyzed in two groups as protocol security and trust and privacy concepts. The
protocol security means entire layer protection instead of layer-by-layer secu-
rity. The layer protection includes authentication, encryption, secure wakeup
nodes, and tamper proofing approaches. Some combination security models
have been implemented to fulfill the requirement on layer security. These
security approaches are identified as low-level mechanisms while high level
mechanisms include secure group management, intrusion detection, privacy-
awareness, and secure data aggregation.