CBCP Consensus Mechanisms and Mining 2

Question 1

In a Delegated Proof of Stake (DPoS) system, what role do 'witnesses' or 'delegates' play?

Accepted Answer

They are elected nodes responsible for producing blocks on behalf of token holders

Answer

In DPoS, token holders vote to elect a fixed set of delegates/witnesses who produce blocks and validate transactions on behalf of the network.

Question 2

What is the primary purpose of the 'nonce' field in a Bitcoin block header?

Accepted Answer

To provide a variable miners iterate to find a valid proof-of-work hash

Answer

Miners repeatedly increment the nonce value until the resulting block header hash meets the network's difficulty target.

Question 3

Which consensus mechanism is used by Ripple (XRP Ledger)?

Accepted Answer

Federated Byzantine Agreement (FBA)

Answer

The XRP Ledger uses Federated Byzantine Agreement, where each node maintains a Unique Node List (UNL) of trusted validators to reach consensus.

Question 4

What happens to mining difficulty in Bitcoin when blocks are found faster than the 10-minute target?

Accepted Answer

Difficulty increases to make finding valid blocks harder

Answer

Bitcoin's difficulty adjustment algorithm increases difficulty every 2016 blocks when the average block time falls below 10 minutes.

Question 5

What is 'selfish mining' in the context of blockchain consensus?

Accepted Answer

A strategy where miners withhold discovered blocks to gain a disproportionate reward advantage

Answer

Selfish mining involves a miner secretly keeping a discovered block, continuing to mine on it privately, then releasing multiple blocks to orphan honest miners' work.

CBCP - Certified Blockchain Professional Practice Test

CBCP - Certified Blockchain Professional Practice Test

CBCP Consensus Mechanisms and Mining 2