Blockchain Consensus Mechanisms Questions and Answers

Question 1

A major criticism of the Proof of Work (PoW) consensus mechanism is its high energy consumption.
Which of the following consensus mechanisms was primarily designed as a more energy-efficient alternative by replacing computational work with an economic stake?

Accepted Answer

Proof of Stake (PoS)

Answer

Proof of Authority (PoA)

Answer

Delegated Proof of Stake (DPoS)

Answer

Proof of Burn (PoB)

Question 2

A consortium of international banks plans to create a private blockchain for interbank settlements. They require high transaction throughput, low latency, and the ability to function even if some participating nodes become malicious or faulty. The participants are all known and permissioned entities. Which consensus mechanism would be most suitable for this scenario?

Accepted Answer

Practical Byzantine Fault Tolerance (pBFT)

Answer

Proof of Work (PoW)

Answer

Proof of Stake (PoS)

Answer

Delegated Proof of Stake (DPoS)

Question 3

Which of the following describes a key difference between Proof of Stake (PoS) and Delegated Proof of Stake (DPoS)?

Accepted Answer

In DPoS, token holders vote for a limited number of delegates to validate blocks, whereas in PoS, any user meeting the stake requirement can potentially be a validator.

Answer

PoS relies on computational puzzles, while DPoS relies on staking.

Answer

DPoS is significantly less energy-efficient than PoS.

Answer

PoS networks are immune to 51% attacks, while DPoS networks are not.

Question 4

In the context of Proof of Work (PoW) blockchains, what does the term 'probabilistic finality' mean?

Accepted Answer

The certainty of a transaction being irreversible increases as more blocks are added after it, but never reaches 100%.

Answer

A transaction is considered final as soon as it is included in a block.

Answer

The network's validators vote to finalize each block, making it irreversible.

Answer

There is a 50/50 chance that any given transaction will be reversed.

Question 5

A malicious actor gains control of 52% of the total hashing power on a Proof of Work (PoW) network. Which of the following actions can this actor successfully perform?

Accepted Answer

Prevent specific new transactions from being confirmed and potentially reverse their own recent transactions.

Answer

Steal cryptocurrency directly from another user's wallet.

Answer

Change the fundamental consensus rules of the blockchain, such as the block reward amount.

Answer

Create new coins out of thin air, exceeding the protocol's supply limit.

Question 6

In a Proof of Stake (PoS) consensus mechanism, what is the primary role of a 'validator'?

Accepted Answer

To propose and verify new blocks of transactions after being selected based on their economic stake.

Answer

To solve complex mathematical puzzles faster than other participants.

Answer

To vote for delegates who will then be responsible for securing the network.

Answer

To provide storage space on their hard drives to secure the network.

A major criticism of the Proof of Work (PoW) consensus mechanism is its high energy consumption.Which of the following consensus mechanisms was primarily designed as a more energy-efficient alternative by replacing computational work with an economic stake?

A major criticism of the Proof of Work (PoW) consensus mechanism is its high energy consumption.
Which of the following consensus mechanisms was primarily designed as a more energy-efficient alternative by replacing computational work with an economic stake?