Consensus Algorithms and Protocols Flashcards
7 cards from real Blockchain Technology practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Consensus Algorithms and Protocols flashcards as text
In Ethereum's PoS, what is the role of an 'attestation'?
Answer: A validator's vote on the validity of a block
An attestation is a validator's signed vote confirming a block and the current chain head.
What is 'chain reorganization' (reorg) in a blockchain?
Answer: Replacing blocks with a different competing branch
A reorg occurs when nodes switch to a longer or heavier competing chain, discarding some blocks.
Which rule does Bitcoin use to choose the canonical chain among forks?
Answer: Longest/heaviest cumulative work chain
Bitcoin follows the chain with the greatest cumulative proof-of-work.
What is the purpose of the GHOST / fork-choice rule (e.g., LMD-GHOST) in Ethereum?
Answer: To select the head of the chain using accumulated votes
LMD-GHOST chooses the canonical head based on the latest attestations (votes) by validators.
In Proof of Stake, what is a 'validator deposit' or bond?
Answer: Capital locked as collateral to participate in consensus
Validators lock up a bonded deposit as collateral that can be slashed for misbehavior.
What does 'liveness' guarantee in a consensus protocol?
Answer: The system continues to make progress and process new transactions
Liveness ensures the protocol keeps producing decisions and does not stall.
Which consensus approach uses verifiable random functions (VRFs) to select block proposers privately?
Answer: Algorand's pure PoS
Algorand uses VRFs for cryptographic sortition to secretly and randomly select proposers.