Blockchain: Is it a hype or a hoax?  13

Algorithms

Advantages

Disadvantages

Use cases

Proof of Work (PoW)

• Stable

• Tested since 2009

• Huge Energy consumption

• Slow

• Not good for environment

Bitcoin, Ethereum, Litecoin, Dogecoin

Proof of Stake (PoS)

• Energy efficient

• Fast

• More expensive to attack than PoW

• Bit centralised.

• Participants with high stakes can vote

themselves in to become a validator

EOS, Lisk, ARC

Proof of Authority (PoA)

• Energy efficient

• Fast

• Bit centralised

• Usually used in permissioned private

Blockchains

VeChain

Delegated Proof of Stake (dPoS)

• Energy efficient

• Fast

Pre-approved

Proof of Stake, Proof of authority

Proof of Elapsed Time (PoET)

• Low cost of Participation

• Simple verification of the leader

• Use of specialised hardware

• Suitable for permissioned Blockchains

Hyperledger Sawtooth

Proof of Reputation (PoR)

• Energy efficient

• Fast

Usually used in permissioned private

Blockchains

GoChain

Proof of History (PoH)

• Fast

• High Throughout

• Low Fees

• Scalability

• Centralised

• Fewer DAppS compared to Ethereum

dApps

Solana

Byzantine Fault Tolerance

• Fast

• Scalable

Usually used in permissioned private

Blockchains

Hyperledger Fabric, Steller, Ripple

Directed Acyclic Graph (DAG)

• Highly Scalable

• Fast

• Every Efficient

Smart contracts implementation can only

be possible using Oracles

IOTA, HashGraph, Nano

Figure 1.6  Blockchain consensus algorithms.