59

Blockchain for IoT Security

• Three-layered architecture – sensor, network and application layers (Khari

et al. 2016).

• Another five-layered IoT model has been proposed (R. Khan et al. 2012).

However, broadly, all the models define work on three primary layers (Jing et al.

2014) which are:

1. Perception.

2. Transport.

3. Application.

Perception Layer (Frustaci et al. 2018): This layer consists of the sensors deployed

and is primarily responsible for data collection. It is the most susceptible layer

because of the physical exposure of IoT devices. Moreover, systems in this layer have

limitations such as hardware limitations, technological heterogeneity and resource

limitations, limiting the implementation of security controls (Amit, Holczer, and

Levente 2011). The standard attacks are:

• Node Tampering: Attackers can access the physical node and also tamper with

it. Physical nodes and sensors are often placed in vulnerable physical locations.

The attackers may replace the entire device with a malicious one or connect

to the device to extract information for accessing the data in the layers above.

• Malicious Code Injection: The attacker may tamper with the device’s code/

application and inject malicious code after gaining physical access.

• Impersonation: Attackers may introduce a new device impersonating a gen­

uine device by exploiting the weak authentication mechanisms.

• Denial of Service: IoT nodes have minimal computational powers. Thus,

these can be easily overloaded, making the nodes unavailable.

• Routing Attacks: Intermediate nodes may be exploited to modify the rout­

ing paths, leading the collected data to somewhere else or routing erroneous

data forward.

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

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

Man in the Middle (MitM) attacks and sniffing.

Transportation Layer (Frustaci et al. 2018): As a result of the weaknesses in the

standard wireless communications and threats, this layer, as compared with the per­

ception layer, has a lower risk level. Much research has been done to address the

threats at this level, which makes it more secure (Amit et al. 2001).

Common Attacks:

• Routing Attacks: Intermediate nodes may be exploited to modify the rout­

ing paths leading the collected data to somewhere else or routing erroneous

data forward.

• DoS Attacks: Intermediate nodes may be exploited to modify the routing

paths leading the collected data to somewhere else or routing erroneous

data forward.