Finality in Blockchain Consensus BFC Practice Questions (Page 2)

Questions 6–10

1. 6foundation · easy

   What is a chain reorganization (reorg) in a blockchain?

   • AA way to speed up transaction confirmation
   • BA situation where a competing chain replaces the current chain, causing some blocks to be discarded
   • CA process of merging two different blockchains
   • DA method of increasing the block size
   Reveal Solution Discussion Select an answer first
2. 7foundation · easy

   Why is finality in Proof of Work considered 'probabilistic'?

   • ABecause miners use probabilistic algorithms to select transactions
   • BBecause the network may randomly decide to reverse transactions
   • CBecause there is always a small probability that a longer chain could replace the current chain, reversing transactions
   • DBecause the block reward is determined by probability
   Reveal Solution Discussion Select an answer first
4. 8application · medium

   A financial institution is required by regulators to ensure that once a transaction is settled, it cannot be reversed. Which type of finality is most aligned with this regulatory requirement?

   • AImmediate finality
   • BProbabilistic finality
   • CSocial finality
   • DEconomic finality
   Reveal Solution Discussion Select an answer first
5. 9application · medium

   A blockchain analyst is explaining to a client why a Bitcoin transaction with 6 confirmations is considered 'safe enough' for a large payment. Which reasoning is most accurate?

   • AThe transaction is included in the longest chain
   • BThe probability of a reorg decreases exponentially with each confirmation
   • CAfter 6 confirmations, the transaction is permanently final
   • DMiners cannot reverse transactions after 6 blocks
   Reveal Solution Discussion Select an answer first
6. 10application · medium

   A blockchain analytics firm is analyzing a PoW blockchain and observes that a transaction has received 100 confirmations. What can the firm conclude about the transaction's finality?

   • AThe transaction is absolutely final and cannot be reversed
   • BThe transaction is final because it has been included in a block
   • CThe transaction is highly likely to be final, but not absolutely guaranteed
   • DThe transaction is final only if the majority of miners agree
   Reveal Solution Discussion Select an answer first