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Blockchain Technology

• Data Transit Attacks: As the nodes are often deployed in remote locations

with a limited network, security is challenging. The system is vulnerable to

MitM attacks and sniffing.

Application Layer (Frustaci et al. 2018): The risk at this level is linked with the

application it hosts. Depending on its utility, the availability, integrity and confiden­

tiality can be tolerable or intolerable. This layer has better and mature technology,

which makes it much more secure than other layers.

Common Attacks:

• Data Leakage: Vulnerable applications may lead to data loss and loss of

confidentiality.

• DoS Attacks: Attackers may attempt to launch an attack causing the appli­

cation to become unavailable.

• Malicious Code Injection: Vulnerable applications are prone to injection

attacks; attackers may inject malicious code.

4.5  IOT SECURITY

IoT security is often neglected for various reasons by manufacturers. Cost-cutting

needs and the limited resources in IoT often lead to security being neglected in IoT

devices (Frustaci et al. 2018). The deployment of IoT systems in a heterogeneous and

often not a secure environment makes them a unique domain with a different secu­

rity need than the traditional information technology (IT) system.

4.5.1  Lower-level Security Issues

The low-level security problems are related to the physical and data link layer. They

include the threat at the physical layer along with the communication at the data link

layer (Khan and Salah 2018.) The various security issues are:

• Jamming adversaries.

• Sybil and spoofing (low-level) attacks.

• Insecure physical interface.

• Sleep deprivation attack.

4.5.2  Intermediate-level Security Issues

The intermediate-level security issues are mainly related to network and transport

layers, including network communications, routing and sessions management (Khan

and Salah 2018) Some of the critical security issues are:

• Replay attacks (from packet fragmentation).

• Insecure neighbour discovery.

• Buffer reservation attack.