4

D. De et al.

Fig. 1 Block creation in the blockchain network

technologies. The main function of this Distributed Ledger technology is creating an

immutable chain of blocks linked to the previous root genesis block that contains all

the transactions which happened till now, as shown in Fig. 1. The copy of the trans-

actions is broadcasted on all of the nodes that participate in the decentralizednetwork

[39–42]. Each transaction performed in the block before it is added to the network

is validated through a consensus algorithm.

2.1

Link List Structured Block

In blockchain architecture, every block contains the previous block’s hash, as shown

in Fig. 2. Therefore, any falsification in the last block is reflected throughout the

chain, and all blocks after the tempered block will be invalid.

2.2

Merkle Tree Structure

In blockchain technology, the Merkle tree structure is maintained, as shown in Fig. 3.

Every block contains Merkle tree’s root hash in this architecture, made with all

transaction hashes. Each Merkle tree node is created with concatenated values from

its two children. Any falsification in any node reflected on the above layer and the

root hash will also be affected. As a result, falsification is detected quickly.