Consensus and Scalability Innovations BDC Practice Questions (Page 11)

Questions 51–55

1. 51application · medium

   A social media platform is launching a public blockchain where users vote to elect a small group of block producers. The goal is to achieve high transaction throughput while keeping the network energy-efficient. Which consensus mechanism aligns with this design?

   • APractical Byzantine Fault Tolerance (PBFT), because it is permissionless and does not require voting.
   • BDelegated Proof of Stake (DPoS), where token holders vote for a fixed number of delegates who produce blocks.
   • CA DAG-based structure, because it does not require any consensus among nodes.
   • DProof of Work (PoW), because it is the only way to achieve high throughput in a public network.
   Reveal Solution Discussion Select an answer first
2. 52application · medium

   A blockchain research lab is exploring new consensus mechanisms that can scale to millions of users while maintaining security. They are looking at combining sharding with Proof of Stake. What is a primary challenge they must address?

   • AReducing the number of validators to increase throughput.
   • BEliminating the need for cross-shard communication.
   • CEnsuring that the random assignment of validators to shards is secure against adversarial manipulation.
   • DUsing a DAG structure instead of a blockchain to avoid sharding.
   Reveal Solution Discussion Select an answer first
4. 53foundation · easy

   How does a Directed Acyclic Graph (DAG) based structure differ from a traditional blockchain in terms of transaction processing?

   • ATransactions are processed sequentially in a single chain
   • BTransactions are grouped into blocks and mined
   • CMultiple transactions can be processed in parallel, each referencing previous ones
   • DTransactions are stored in a central database
   Reveal Solution Discussion Select an answer first
5. 54expert · hard

   A startup is designing a public blockchain for a decentralized social media platform. They need high transaction throughput to handle millions of daily posts, but they also want to keep the network permissionless and resistant to censorship. The team is debating between a pure Proof of Work (PoW) chain and a Proof of Stake (PoS) chain. Which consensus choice best balances the stated requirements?

   • APoW, because it is the only consensus mechanism that can support a permissionless network without any central authority.
   • BPoS, because it removes the energy-intensive mining race and allows faster block production while keeping the network permissionless.
   • CPoW, because it guarantees higher throughput than PoS due to its proven security model.
   • DPoS, because it completely eliminates the need for network validators and therefore maximizes decentralization.
   Reveal Solution Discussion Select an answer first
6. 55foundation · easy

   In Delegated Proof of Stake (DPoS), who is responsible for producing and validating blocks?

   • AMiners who solve computational puzzles
   • BAll token holders equally
   • CA randomly selected validator each round
   • DA small set of elected delegates
   Reveal Solution Discussion Select an answer first