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Blockchain Technology

16.3  REVIEW OF RELATED WORKS

This section reviews literature related to blockchain, IOTA Tangle and IoT.

16.3.1  Related Work in Blockchain Technology

Studies show that blockchain application is progressively extending from cryptocur­

rency to other industrial domains, including health (Engelhardt, 2017; Radanovic

and Likic, 2018); energy grid and smart cities (Sun et al., 2016; Gupta and Vyas,

2021); banking and finance (Hyvarinen et al., 2017); business economics (Kim and

Laskowski, 2018); and document protection (Haber and Stornetta, 1991; O’Dair and

Beaven, 2017). A systematic study by Xu et al. (2019) shows that Bitcoin takes 80%

of the blockchain research share, while the remaining 20% goes to other domains.

This section reviews blockchain applications in IoT and smart grids. ​

IoT has broad applications, typically in healthcare devices, energy grids, and lots

more. The machines are heterogeneous and lack standardization. Among other things,

these generic features expose the gadgets to security and privacy risks (Dorri et al., 2017).

The PoW model used in verifying transactions for security purposes in the con­

ventional blockchain consumes high computation resources and is not ideal for IoT

implementation. It results in traffic and processing overheads (Dorri et al., 2017).

Therefore, adopting the traditional blockchain in IoT might solve the insecurity and

privacy problem but might compromise the response time. The response time is criti­

cal, especially in a heterogeneous environment like IoT. Dorri et al. (2017) proposed

a modified blockchain technology called overlay blockchain to address this chal­

lenge. The result showed an improved performance compared with the traditional

blockchain technology (Dorri et al., 2017).

Novo (2018) proposed another improved blockchain technology for access control

in IoT. The author adopts the management hub to decentralize access control among

IoT devices using blockchain technology. Typically, access control in IoT devices is

centralized. Therefore, one point of failure could be catastrophic. As the number of

devices increases, the network becomes more insecure. Novo’s research focus was to

address scalability issues with an extensive network of numerous IoT devices in real

time. Although the management hub provided a relatively better solution than other

access control solutions like DOAuth and “fairAccess”, process overhead remains a

significant challenge (Novo, 2018).

The smart grid is the integration of electric power producers and consumers. It

is a concept that enables small-scale power generators to produce and sell energy to

consumers. Anak Agung GdeAgung, Rini Handayani (in press) proposed a smart

grid based on blockchain technology. The research focuses on electricity genera­

tion and supply between producers and consumers to ensure transparency, security,

immutability and efficiency. The system is implemented on the Ethereum platform;

therefore, the transaction token is Ether. Ethereum is a type of blockchain network

that majors in developing smart contracts. Ethereum uses PoW as a consensus mech­

anism. According to the authors, although the system attempts to address transpar­

ency and immutability, it has some limitations. Only 15 transactions/second could

be processed on the Ethereum platform, resulting in a slow response time. Also, the

cost of sustaining miners used in PoW would increase the energy consumption cost.