Blockchain in IoT and Beyond: Case Studies …

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Blockchain and Interoperability: Case Study of Polkadot

and Contemporary Survey

In this section, we will discuss Blockchain and Interoperability issues in IoT with a

case study and survey. Section 4.1 describes the Role of Blockchain Interoperability

[32] in IoT, Sect. 4.2 gives a case study on Polkadot protocol, and finally, Sect. 4.3

gives a survey of contemporary interoperability Engines and Platforms.

4.1

Role of Blockchain Interoperability in IoT

Given that every day new developments are done in the field of blockchain and IoT

and soon they will be implemented side by side. Based on the requirements and use

case, different IoT projects can have their own blockchain network with different

networks interacting with each other as and when needed. For example, the Traffic

Lights can have their own blockchain network with a specific consensus mechanism

and smart cars have their own blockchain with a suitable consensus mechanism.

These two networks can interact with each other to fetch data or perform operations

when needed like when cars follow the traffic light, tokens are issued for the smart

car.

In our previous case study of Hyperledger Indy, we used the example of Network

D consisting of drones manufactured by three different entities but being operated in

the same network by an entity “ABC”. Consider a scenario where this identity-based

ledger solution needs to interoperate with another distributed ledger solution like

malicious activity detection. This specific DLT can be implemented using a different

framework than Hyperledger Indy (since Indy only specializes in Identity). It can

be a R3 Corda network or a Hyperledger Fabric one for example. However, for

accurate functioning, that specific network needs to interact with Network D for a

trustable proof of identity between communicating drones. If a drone has detected a

person where there should be none then it may need to relay that information to other

drones in the Network as well as record it in the ledger being used to record suspicious

activities. Here, we can see the need for a common ground when the IoT devices,

i.e., the drones in Network D want to relay information across different blockchain

types. This is where the phenomenon of Blockchain Interoperability comes into play.

The two networks made from two very different frameworks might not operate in

a compatible manner. This can be the result of different formats of API responses,

node architecture, or secure connection algorithms used.

For this reason, it is common to use another blockchain or interoperability engine

like an OS for making sure that transactions from one ledger can smoothly be trans-

lated onto a different one. Polkadot is the former. It is a ledger-based solution to the

problem. The following sections discuss Polkadot and its important components.