horizontally

Chances of monopoly is less

Regulation and maintenance

is a perpetual challenge

configure,

develop,

test,

debug, and maintain

Consensus of all players

may face a challenge

Hence synchronization and

consistency won’t be as

smooth as the centralized

systems

Table 1.1: Comparison of features of centralized, distributed, and decentralized

servers

1.5.5 Consensus

Consensus is a process through which the owner of an ecosystem

agrees for a transaction to get committed in the data store. In a

centralized system, it hardly matters as the ownership itself is

centralized. However, in Blockchains, it’s pretty complex as there are

multiple stakeholders of the ecosystem and they all have to agree on

the validity of the transaction. Let’s discuss the different types of

consensus models that have been used so far in the different

decentralized ecosystems.

1.5.5.1 Proof of Work (PoW)

PoW is the original consensus process of Bitcoin and Ethereum

where every node is an equal participant in the consensus process.

The final consensus is arrived at after the fastest validator node

wins, followed by a voting process of all the nodes. Such a model is

slow as well as resource intensive, and hence, not fit for use by most

of the industry use cases.

1.5.5.2 Proof of Stake (PoS)

Proof of Stake is an energy-saving consensus model that has been

adopted in some of the later Blockchain protocols that appeared in

the market post Bitcoin. Here, only the nodes that have invested

some stake in the Blockchain network are eligible to participate in

the validating transactions. In this process, they get rewarded with