Interoperability Challenges in Blockchain Systems BFC Practice Questions (Page 8)

Questions 36–40

1. 36expert · hard

   A bank is using a blockchain interoperability protocol to settle cross-border payments. The protocol uses a relay chain that verifies transactions on multiple source chains. The bank has noticed that some transactions are being delayed because the relay chain requires a certain number of confirmations on the source chain before it considers a transaction final. The bank wants to reduce settlement time but is concerned about the risk of chain reorgs. Which approach best balances settlement speed and safety?

   • AUse a notary scheme instead of a relay chain to speed up confirmations.
   • BUse a probabilistic finality model that estimates the risk of reorg and adjusts the confirmation threshold dynamically based on transaction value.
   • CReduce the number of required confirmations to the minimum that the relay chain supports.
   • DRequire the maximum number of confirmations for all transactions to ensure safety.
   Reveal Solution Discussion Select an answer first
2. 37expert · hard

   A team is developing a cross-chain bridge between a Proof-of-Work (PoW) blockchain and a Proof-of-Stake (PoS) blockchain. The bridge uses a set of validators to sign off on transfers. The team notices that the PoW chain has a longer block time and requires more confirmations for finality, while the PoS chain has faster finality. This discrepancy is causing delays and occasional disputes about whether a transaction is final. Which solution best addresses the finality discrepancy without compromising security?

   • AUse a notary scheme that waits for the PoW chain's finality before processing any transfer.
   • BImplement a relay chain that uses a light client to verify the PoW chain's consensus and treats a certain number of confirmations as final.
   • CSwitch the PoW chain to PoS to align finality models.
   • DRequire validators to manually agree on finality for each transaction, overriding the chains' consensus rules.
   Reveal Solution Discussion Select an answer first
4. 38application · medium

   A cross-chain bridge uses a set of 5 validators to confirm transactions between two blockchains. The bridge has been operating for a year without issues. A new auditor recommends replacing the validator set with a decentralized network of nodes that anyone can join. The team is concerned about the security implications. Which security risk is most directly introduced by this change?

   • AIncreased risk of validator collusion because anyone can join the network.
   • BIncreased risk of smart contract vulnerabilities because the bridge code is now open source.
   • CIncreased risk of data format inconsistencies because the decentralized network uses different data formats.
   • DIncreased risk of double-spending because the decentralized network may have lower security.
   Reveal Solution Discussion Select an answer first
5. 39application · medium

   A financial services company is planning to offer a service that lets customers move digital assets between a bank-issued stablecoin on a private blockchain and a public cryptocurrency network. The company wants to avoid maintaining separate accounts on each network and reduce operational overhead. What is the primary benefit of implementing blockchain interoperability in this context?

   • AIt enables seamless asset transfer between the networks, providing a unified experience for customers.
   • BIt allows the company to use a single consensus mechanism for both networks.
   • CIt ensures that both networks have identical transaction fees.
   • DIt eliminates the need for the public cryptocurrency network, consolidating everything onto the private blockchain.
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6. 40foundation · easy

   What is a potential impact of interoperability challenges on transaction settlement in financial infrastructure?

   • ADelayed settlement due to the need for manual reconciliation between different blockchains
   • BReduced need for regulatory compliance
   • CIncreased transaction fees due to lower network congestion
   • DImmediate settlement without any verification
   Reveal Solution Discussion Select an answer first