Challenges in Blockchain Consensus Mechanisms BFC Practice Questions (Page 1)

Questions 1–5

1. 1expert · hard

   A blockchain platform for a national digital identity system must be highly decentralized to prevent any single entity from controlling the network, but it also must handle a high volume of identity verification requests with low latency. The team is considering a sharded Proof of Stake design. What is the primary trade-off they must manage?

   • ASharding eliminates the need for a global consensus
   • BSharding increases throughput but introduces cross-shard communication overhead and security risks
   • CSharding increases latency because all transactions must be processed by every node
   • DSharding reduces decentralization because only a few nodes validate each shard
   Reveal Solution Discussion Select an answer first
2. 2foundation · easy

   In the context of blockchain consensus mechanisms, what is the primary trade-off when a network increases its block size to improve scalability?

   • AIt typically reduces the need for consensus because more transactions are confirmed per block, but it also increases the risk of network forks.
   • BIt typically reduces transaction latency but increases the risk of 51% attacks because more transactions are processed per block.
   • CIt typically improves security by making the blockchain more immutable, but it also increases energy consumption.
   • DIt typically increases transaction throughput but may reduce decentralization because larger blocks require more storage and bandwidth, favoring nodes with greater resources.
   Reveal Solution Discussion Select an answer first
4. 3foundation · easy

   Which of the following best describes the 'blockchain trilemma' often cited as a core challenge in consensus mechanism design?

   • AThe inherent trade-off among decentralization, security, and scalability in a blockchain network.
   • BThe problem of ensuring that all nodes agree on the same transaction order without a central authority.
   • CThe difficulty of achieving high throughput, low latency, and high energy efficiency simultaneously.
   • DThe challenge of balancing the interests of miners, developers, and users in a consensus protocol.
   Reveal Solution Discussion Select an answer first
5. 4foundation · easy

   In a blockchain consensus mechanism, what is the typical trade-off when the number of validating nodes is reduced to increase transaction throughput?

   • AThe network becomes more secure because there are fewer points of failure.
   • BThe network becomes more energy-efficient because fewer nodes are mining.
   • CThe network becomes more decentralized because fewer nodes are needed to reach consensus.
   • DThe network becomes less decentralized, increasing the risk of censorship or manipulation by a small group of validators.
   Reveal Solution Discussion Select an answer first
6. 5expert · hard

   A consortium blockchain for trade finance is facing a governance dilemma. A proposal to upgrade the consensus protocol to improve scalability has been approved by the majority of validators, but a minority of validators, including two major banks, refuse to upgrade. They threaten to fork the network. What is the most appropriate course of action to minimize disruption?

   • ACancel the upgrade entirely to maintain consensus
   • BProceed with the upgrade and let the minority fork if they wish
   • CForce the upgrade by removing the minority validators from the network
   • DNegotiate a compromise that addresses the minority's concerns, such as a phased upgrade or additional features
   Reveal Solution Discussion Select an answer first