Finality in Blockchain Consensus BFC Practice Questions (Page 3)

Questions 11–15

1. 11application · medium

   A financial regulator is evaluating a blockchain-based trading platform. The platform uses a PoS mechanism with economic finality. The regulator asks: 'Can a finalized transaction ever be reversed?' What is the most accurate answer?

   • AIt is theoretically possible if an attacker can accumulate enough stake to overpower the network
   • BOnly if the majority of users agree
   • CYes, any validator can reverse it
   • DNo, economic finality is absolute
   Reveal Solution Discussion Select an answer first
2. 12foundation · easy

   What is the 'liveness' of a consensus protocol?

   • AThe guarantee that once a transaction is confirmed, it cannot be reversed
   • BThe guarantee that the network will continue to produce new blocks and process transactions
   • CThe speed at which transactions are confirmed
   • DThe number of nodes that are online
   Reveal Solution Discussion Select an answer first
4. 13application · medium

   A securities settlement platform uses a PBFT-based permissioned blockchain. They value immediate finality but are concerned about the system becoming unresponsive if some nodes fail. Which characteristic of PBFT directly addresses this concern?

   • AIt allows any node to propose a block at any time
   • BIt tolerates up to one-third faulty nodes while maintaining liveness
   • CIt uses probabilistic finality with confirmations
   • DIt requires all nodes to agree on every block
   Reveal Solution Discussion Select an answer first
5. 14application · medium

   A financial institution is considering using a blockchain for cross-border payments. They need to ensure that once a payment is settled, it cannot be reversed. Which type of finality is most suitable?

   • AImmediate finality
   • BEconomic finality
   • CProbabilistic finality
   • DSocial finality
   Reveal Solution Discussion Select an answer first
6. 15foundation · easy

   Why is finality particularly important in financial systems built on blockchain?

   • AIt ensures that transactions cannot be reversed, which reduces settlement risk and provides certainty for parties
   • BIt guarantees that all transactions are anonymous
   • CIt ensures that transaction fees are always zero
   • DIt increases the speed at which transactions are processed
   Reveal Solution Discussion Select an answer first