Blockchain Developer Consensus Mechanisms 2

Question 1

In Proof of Stake, what does 'slashing' refer to?

Accepted Answer

Penalizing a validator by destroying part of its staked funds

Answer

Reducing block size

Answer

Halving the block reward

Answer

Compressing transaction data

Question 2

What problem does the 'nothing-at-stake' issue describe in PoS systems?

Accepted Answer

Validators can vote on every fork at no cost

Answer

Validators have no incentive to validate multiple competing chains

Answer

Miners abandon the network

Answer

Nodes run out of storage

Question 3

Which consensus mechanism does Solana combine with Proof of Stake to order transactions?

Accepted Answer

Proof of History

Answer

Proof of Authority

Answer

Proof of Burn

Answer

Proof of Capacity

Question 4

In Delegated Proof of Stake (DPoS), how are block producers chosen?

Accepted Answer

By token holders voting for delegates

Answer

By raw hashing power

Answer

By random VRF only

Answer

By transaction fees paid

Question 5

What is the primary purpose of a 'finality gadget' like Casper FFG?

Accepted Answer

To provide checkpoints that make blocks irreversible

Answer

To increase block size

Answer

To compress the state trie

Answer

To distribute mining rewards

Question 6

In a Byzantine Fault Tolerant system tolerating f faulty nodes, what is the minimum total number of nodes required?

Accepted Answer

3f + 1

Answer

2f + 1

Answer

f + 1

Answer

4f

Question 7

What does 'weak subjectivity' mean in Proof of Stake networks?

Accepted Answer

Nodes need a recent trusted checkpoint to sync safely

Answer

Validators can be chosen subjectively by the founder

Answer

Blocks have no fixed time

Answer

Staking is optional