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T. Paul and S. Rakshit

4

Types of Blockchains

The most important need for a blockchain is to carry out information transactions

via a secure network. But how individuals use Blockchain and distributed ledger

technologies differs from case to case. There are primarily four types of blockchains;

Public, Private, Consortium, and Hybrid Blockchain. Each of the four forms of

Blockchain is comprised of a cluster of nodes (i.e., users) connected via a peer-to-

peer network. Each node in the network maintains an updated copy of the shared

ledger. Each node is capable of verifying transactions, authorizing or receiving them,

and constructing blocks [13].

4.1

Public Blockchain

As the names imply, Public Blockchain is freely available and has no limit on

who could participate or who can be a Validator. No one in Public Blockchains

has complete control over the network. That guarantees data protection and helps

immutability because a single individual cannot control the Blockchain. Therefore, a

public blockchain is a non-restrictive, less-permission-distributed ledger framework.

Anyone with an internet connection can register to become a blockchain platform’s

authorized participant (node) and a member of a blockchain network. A user (node)

that is a member of the public Blockchain may access both current and historical

data, validate transactions, or do proofs of work for the received block, as well as

engage in mining operations [7].

The authority on the Blockchain is equally divided between each node on the

network, and, as a result, Public Blockchains are considered to be completely

distributed. One of the important applications of public blockchains is to mine and

trade cryptocurrencies. Bitcoin, Ethereum, and Litecoin blockchains are examples

of some popular public blockchains. Public blockchains are largely protected when

users strictly obey security rules and methods. However, it is only troublesome if the

participants do not follow the safety precautions sincerely [19].

Advantages of Public Blockchain

• There is no need for participants (nodes) to think about the reliability of the

others. In this case, one node does not need to personally trust the other nodes

since the proof-of-work mechanism is responsible for validating each transaction.

Therefore, one participant can blindly rely on public blockchains without feeling

the need to trust individual participants.

• The public network can have as many users or nodes as possible, making it a secure

network. The wider the network, the more records are circulated, and the harder

it is for hackers to access the entire network. Besides, the transaction verification

and proof-of-work will be performed by each node, making each transaction and