To select a miner for the next block generation, the PoW consensus

algorithm is used. As an example, Bitcoin uses the PoW consensus

algorithm. The idea here is to solve a complex mathematical puzzle

and give out a solution. The node which solves the puzzle as soon as

possible gets to mine the next block is the requirement of this

mathematical puzzle as a lot of computational power is required.

Figure 3.1: PoW consensus mechanism

Byzantine fault tolerance (BFT)

A logical dilemma that researchers Leslie Lamport, Robert Shostak,

and Marshall Pease explained in an academic paper is the “Byzantine

General’s problem” solution, and the name BFT comes from it. To fix

the issue of a rogue or an unreliable node BFT is used. The reliability

of the blockchain breaks down when any member of the community

sends inconsistent information to others about the transactions, and

there is no central authority that can step in to correct it. PoW already

offers BFT through its processing power to solve this. PoS needs a

more definite solution, on the other hand. In order to identify the true

transaction, nodes will regularly vote. The most promising approach to

approving transactions in the blockchain is to use a version of PoS

which works with BFT.

Practical Byzantine Fault Tolerance (PBFT)

The ability of a distributed computer network to correctly reach a

sufficient consensus despite malicious nodes in the system failing or

sending out incorrect information is byzantine fault tolerance, whose