Architectural and Protocol Innovations BDC Practice Questions (Page 6)

Questions 26–30

1. 26expert · hard

   A cross-chain protocol is being designed to enable communication between a public blockchain and a private enterprise blockchain. The enterprise chain requires that no transaction data leaves its network, but it needs to verify that a payment was made on the public chain. Which interoperability approach best satisfies both requirements?

   • AA federated bridge that relays the full transaction data to the private chain
   • BA hash-locking atomic swap between the two chains
   • CA sidechain that stores a copy of the public chain's blocks on the private chain
   • DA zero-knowledge proof generated on the public chain that is verified on the private chain
   Reveal Solution Discussion Select an answer first
2. 27expert · hard

   A cross-chain DeFi protocol needs to enable users to move assets between Ethereum and a proof-of-stake sidechain. They want to minimize the risk of bridge hacks while keeping the user experience simple. Which design should they choose?

   • AA light-client bridge that verifies the sidechain's consensus on Ethereum.
   • BA federated bridge with a multisig of trusted validators.
   • CA hash-locked atomic swap.
   • DA centralized exchange as an intermediary.
   Reveal Solution Discussion Select an answer first
4. 28expert · hard

   A cross-chain NFT marketplace wants to allow users to buy an NFT on one blockchain and sell it on another. They need to ensure that the NFT is locked on the source chain and minted on the destination chain atomically. Which interoperability approach should they use?

   • AA bridge with a lock-and-mint mechanism.
   • BA hash-locked atomic swap.
   • CA notary scheme with a trusted third party.
   • DA sidechain with a two-way peg.
   Reveal Solution Discussion Select an answer first
5. 29application · medium

   A startup wants to build a decentralized social media platform where users control their data. They want to avoid high storage costs on-chain and ensure that content is verifiable. Which architectural approach should they use?

   • AUse a sidechain to store content and periodically sync to the main chain.
   • BStore all content directly on the blockchain.
   • CUse a centralized server with a blockchain-based access control list.
   • DStore content on IPFS and anchor hashes on a blockchain.
   Reveal Solution Discussion Select an answer first
6. 30application · medium

   A blockchain team is designing a public network that must support high transaction throughput while keeping node hardware requirements low. They plan to partition the network into multiple shards, each processing its own transactions, and use a beacon chain to coordinate cross-shard communication. Which additional protocol-level feature is most essential to ensure that a malicious actor cannot gain disproportionate influence by concentrating stake in one shard?

   • AA higher block gas limit on the beacon chain than on individual shards
   • BA single global mempool shared by all shards to ensure transaction ordering
   • CRandomized shard assignment that periodically reselects validators for each shard
   • DA longer block time for each shard to reduce cross-shard communication overhead
   Reveal Solution Discussion Select an answer first