Consensus and Scalability Innovations BDC Practice Questions (Page 6)

Questions 26–30

1. 26expert · hard

   A blockchain foundation is planning a major upgrade to improve scalability. They are considering a combination of sharding and a new consensus mechanism. They want to maintain security while increasing throughput. Which combination is most promising?

   • ASharding with DPoS, where delegates are assigned to shards.
   • BSharding with a Proof of Stake consensus that uses random sampling of validators for each shard.
   • CSharding with a DAG-based structure, where each shard is a DAG.
   • DSharding with Proof of Work, where each shard mines its own blocks.
   Reveal Solution Discussion Select an answer first
2. 27application · medium

   A fintech firm operates a permissioned blockchain for internal asset tracking and wants to enable customers to transfer tokens to a public blockchain. They need a secure, auditable bridge that does not rely on a centralized custodian. Which approach should they choose?

   • ACreate a sidechain that is pegged to the public chain but controlled entirely by the fintech firm.
   • BManually export the asset ledger and re-import it on the public chain daily.
   • CUse a simple hash-locking atomic swap between the two chains for every token transfer.
   • DDeploy a cross-chain bridge with a set of validators that lock tokens on the source chain and mint equivalent tokens on the destination chain, using multi-signature custody.
   Reveal Solution Discussion Select an answer first
4. 28expert · hard

   A DeFi protocol wants to allow users to deposit collateral on one blockchain and borrow assets on another blockchain. They need to ensure that the collateral is not double-spent and that the protocol can operate across chains. Which approach is most appropriate?

   • AUse a cross-chain bridge with a locking contract on the source chain and a minting contract on the destination chain.
   • BUse a sidechain that is shared by both chains, but with separate consensus.
   • CUse a DAG-based consensus on both chains to automatically synchronize.
   • DUse a state channel that spans both chains to manage collateral.
   Reveal Solution Discussion Select an answer first
5. 29expert · hard

   A public blockchain project is trying to increase transaction throughput. They are considering moving from PoW to DPoS. However, community members are concerned about decentralization. What is the best way to address these concerns while still gaining the scalability benefits of DPoS?

   • AIncrease the number of elected delegates and implement regular rotation and voting mechanisms.
   • BUse a hybrid PoW/DPoS system, where PoW miners validate blocks and DPoS delegates govern.
   • CUse a DAG-based structure instead of DPoS to avoid centralization.
   • DKeep the delegate set small to ensure fast consensus.
   Reveal Solution Discussion Select an answer first
6. 30application · medium

   A blockchain developer is researching emerging scalability innovations. They want to combine a DAG-based structure with Layer 2 techniques to achieve high throughput and low latency. Which combination is most promising?

   • AUsing a DAG for the base layer to allow parallel transaction confirmation, and rollups for application-specific execution.
   • BUsing a DAG only for data availability, while keeping a linear chain for consensus.
   • CUsing a traditional linear chain with a DAG for off-chain storage.
   • DUsing state channels on top of a DAG to handle all transactions.
   Reveal Solution Discussion Select an answer first