Types of Consensus Mechanisms BFC Practice Questions (Page 4)

Questions 16–20

1. 16foundation · easy

   In a distributed ledger, why is a consensus mechanism necessary even when all participants are honest?

   • ATo ensure that every node stores a complete copy of the ledger
   • BTo assign unique identifiers to each node in the network
   • CTo agree on the order and validity of transactions in the absence of a central authority
   • DTo encrypt the ledger so that only authorized nodes can read it
   Reveal Solution Discussion Select an answer first
2. 17foundation · easy

   In Delegated Proof of Stake (DPoS), how are block producers selected?

   • ABy a central authority appointing validators
   • BBy token holders voting for a fixed number of delegates who then produce blocks
   • CBy solving a cryptographic puzzle
   • DBy a lottery based on the amount of stake each node holds
   Reveal Solution Discussion Select an answer first
4. 18expert · hard

   A large public blockchain project is experiencing high transaction fees and slow confirmation times due to network congestion. The development team is considering a migration from Proof of Work (PoW) to Proof of Stake (PoS) to improve scalability and reduce energy consumption. However, a vocal group of community members opposes the change, arguing that PoS will compromise the network's security and decentralization. As a blockchain architect, what is the most balanced assessment of this trade-off?

   • APoS is a clear upgrade over PoW, as it is more energy-efficient and can always achieve higher throughput without any security trade-offs.
   • BPoW is superior to PoS because it is the only mechanism that can provide true decentralization and security for a public network.
   • CThe migration to PoS involves a trade-off: it improves energy efficiency and scalability but introduces new security assumptions and potential centralization risks that must be carefully managed.
   • DThe migration should be rejected because PoS networks are inherently less secure than PoW networks and cannot be trusted for financial applications.
   Reveal Solution Discussion Select an answer first
5. 19foundation · easy

   Which consensus mechanism is designed to be used in permissioned networks where nodes are known and trusted, and it elects a leader for a term?

   • ARaft
   • BDelegated Proof of Stake (DPoS)
   • CProof of Work (PoW)
   • DProof of Stake (PoS)
   Reveal Solution Discussion Select an answer first
6. 20expert · hard

   A well-established cryptocurrency is facing criticism for its high energy consumption. The community is debating a switch from Proof of Work (PoW) to Proof of Stake (PoS). Proponents argue that PoS is more sustainable and scalable. Opponents argue that PoW's energy consumption is the price of true decentralization and security. As a blockchain consultant, what is the most technically sound assessment of this debate?

   • APoW is superior to PoS because it is the only mechanism that can provide true decentralization and security for a public network.
   • BPoS is a clear improvement over PoW, as it eliminates the need for energy-intensive mining and is always more secure.
   • CThe debate is a trade-off: PoW offers proven security and decentralization but at a high energy cost, while PoS offers energy efficiency and scalability but requires careful design to mitigate new security risks.
   • DThe debate is irrelevant because the choice of consensus mechanism does not affect the security or decentralization of a blockchain.
   Reveal Solution Discussion Select an answer first