Consensus Mechanisms and Mining Flashcards
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Read the first 7 Consensus Mechanisms and Mining flashcards as text
In a Delegated Proof of Stake (DPoS) system, what role do 'witnesses' or 'delegates' play?
Answer: They are elected nodes responsible for producing blocks on behalf of token holders
In DPoS, token holders vote to elect a fixed set of delegates/witnesses who produce blocks and validate transactions on behalf of the network.
What is the primary purpose of the 'nonce' field in a Bitcoin block header?
Answer: To provide a variable miners iterate to find a valid proof-of-work hash
Miners repeatedly increment the nonce value until the resulting block header hash meets the network's difficulty target.
Which consensus mechanism is used by Ripple (XRP Ledger)?
Answer: Federated Byzantine Agreement (FBA)
The XRP Ledger uses Federated Byzantine Agreement, where each node maintains a Unique Node List (UNL) of trusted validators to reach consensus.
What happens to mining difficulty in Bitcoin when blocks are found faster than the 10-minute target?
Answer: Difficulty increases to make finding valid blocks harder
Bitcoin's difficulty adjustment algorithm increases difficulty every 2016 blocks when the average block time falls below 10 minutes.
What is 'selfish mining' in the context of blockchain consensus?
Answer: A strategy where miners withhold discovered blocks to gain a disproportionate reward advantage
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.
In Ethereum's Casper proof-of-stake, what is 'slashing'?
Answer: A penalty that destroys a portion of a validator's staked ETH for provably malicious behavior
Slashing penalizes validators who sign conflicting blocks or make other provably dishonest attestations by burning part of their staked ETH.
What distinguishes Proof of Elapsed Time (PoET) from traditional Proof of Work?
Answer: PoET uses trusted execution environments to randomly assign wait times, replacing energy-intensive computation
PoET, developed by Intel for Hyperledger Sawtooth, uses SGX trusted hardware to generate verifiable random wait times, achieving lottery-style leader election without mining energy costs.