Architectural and Protocol Innovations BDC Practice Questions (Page 4)

Questions 16–20

1. 16application · medium

   A developer is building a dApp that requires frequent, low-cost micro-transactions between a known set of users. They want to minimize on-chain footprint. Which layer-2 solution is most appropriate?

   • AState channels.
   • BA sidechain.
   • CA zk-rollup.
   • DAn optimistic rollup.
   Reveal Solution Discussion Select an answer first
2. 17application · medium

   A gaming company wants to offer micro-transactions on a public blockchain but cannot afford high per-transaction fees. They plan to use a layer-2 solution that batches transactions off-chain and periodically settles them on the main chain. Which property is most important for the layer-2 solution to guarantee user funds are not lost if the operator becomes unresponsive?

   • AThe layer-2 solution uses a different consensus mechanism than the main chain
   • BThe layer-2 solution uses a centralized database for faster processing
   • CUsers can submit a fraud proof to the main chain to challenge invalid state transitions
   • DThe layer-2 solution has a native token that appreciates in value
   Reveal Solution Discussion Select an answer first
4. 18expert · hard

   A privacy-focused blockchain must allow users to prove that they have paid a tax without revealing the transaction amount or the recipient. The team is considering using a zero-knowledge proof system. Which property must the proof system have to prevent double-spending while preserving privacy?

   • AA trusted setup ceremony that generates a secret parameter
   • BA ring signature that hides the sender among a group
   • CNullifier sets that mark spent notes as used without revealing which note was spent
   • DA public ledger that records all transaction amounts in plaintext
   Reveal Solution Discussion Select an answer first
5. 19application · medium

   A consortium of banks wants to use a blockchain for interbank settlements. They need to ensure that transactions are private and that only participating banks can view them. They also want to avoid the energy consumption of proof-of-work. Which consensus mechanism should they choose?

   • APractical Byzantine Fault Tolerance (PBFT) with private transactions.
   • BProof-of-authority (PoA).
   • CProof-of-work (PoW) with a private network.
   • DProof-of-stake (PoS) with a public network.
   Reveal Solution Discussion Select an answer first
6. 20application · medium

   A team is building a blockchain-based supply chain solution that must handle a high volume of sensor data. They plan to use a layer-2 solution that periodically commits data to the main chain. Which layer-2 approach is most appropriate for this use case?

   • AA rollup that batches many transactions into a single main-chain transaction
   • BA sidechain with its own consensus mechanism
   • CA state channel that allows off-chain state updates
   • DA payment channel that allows bidirectional payments between two parties
   Reveal Solution Discussion Select an answer first