BCoT: Introduction to Blockchain-Based Internet …

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Resource constraints

IoT comprises low-power sensor nodes, controllers, actuators, and RFID-based

systems. These entities do not carry out computation-intensive execution of algo-

rithms, long-range communication, and high storage of data. Therefore, distributed

resource maintenance is a good solution for the proper operation of IoT.

Privacy Vulnerability

Resource constraint nodes, limited interoperability among various technologies, and

the requirement of cloud connectivity for centralized storage make the IoT base

system vulnerable to security attacks. The peer-to-peer communication architecture

of IoT requires distributed security mechanism for a resilient architecture.

The proliferation of intelligent devices with sensing-actuating-communicating

capabilities removes the cognizable difference between the physical and virtual

worlds. Moreover, real-time interfacing with the environment and AI-based decision-

making algorithms makes things act according to the user’s need. The introduction of

IoT and derived technologies has thus revolutionized the technical aspect of human

life.

5

Basic Architecture of Blockchain for IoT

In IoT, data is generated from a physical environment that suffers from noise,

sensor drift, trust, integrity, and authentication. Promising technology like blockchain

can overcome these limitations of IoT [70–74]. Blockchain enables trust between

distributed sensor nodes using cryptographic hash and consensus algorithm.

Blockchain also makes the model transparent, immutable, and secure [75–80]. Every

node in the blockchain needs to store a copy of the entire blockchain data, and it will

keep increasing over time. Most lightweight IoT devices cannot hold and maintain

this massive amount of data due to limitations in their architecture[81–84]. So to

integrate blockchain in IoT, optimized and efficient architecture is required. In this

section, we will cover the possible architecture models of IoT-enabled blockchain.

5.1

Blockchain in the Gateway of IoT Devices

In this design, the gateway act as a full node of the blockchain, and every gateway

is connected to sensors. It takes data from a different source as a transaction and

performs blockchain algorithms [85]. This architecture contains three layers (a) data

layer, (b) blockchain layer and c)application layer, as shown in Fig. 9.