Interoperability Challenges in Blockchain Systems BFC Practice Questions (Page 7)

Questions 31–35

1. 31foundation · easy

   Which regulatory challenge is particularly relevant when blockchain transactions cross national borders?

   • AThe inability to use cryptographic hashing
   • BThe need for a centralized authority to manage all transactions
   • CJurisdictional issues regarding which country's laws apply
   • DThe requirement for all nodes to be located in one country
   Reveal Solution Discussion Select an answer first
2. 32foundation · easy

   How does a sidechain help achieve blockchain interoperability?

   • AIt replaces the main chain's consensus mechanism
   • BIt increases the transaction speed of the main chain
   • CIt provides a centralized exchange for trading tokens
   • DIt allows assets to be moved between a main chain and a secondary chain
   Reveal Solution Discussion Select an answer first
4. 33application · medium

   A financial institution is considering adopting blockchain technology for cross-border payments. The institution's current systems are siloed and require manual reconciliation between different ledgers. The institution wants to reduce reconciliation effort and improve settlement speed. Which benefit of blockchain interoperability is most directly relevant to this goal?

   • AEnabling different blockchain networks to share data and assets seamlessly, reducing the need for manual reconciliation.
   • BEliminating the need for any trust between parties.
   • CProviding a single, centralized ledger that all parties must use.
   • DGuaranteeing that all transactions are final immediately.
   Reveal Solution Discussion Select an answer first
5. 34expert · hard

   A multinational bank is building a cross-border payment corridor using a blockchain interoperability protocol that connects a permissioned network in Country A (which has strict data localization laws) and a public blockchain in Country B (which has no such laws). The bank must comply with both countries' regulations and also meet anti-money laundering (AML) requirements. The protocol currently routes transaction data through nodes in both countries. Which approach best balances the conflicting requirements?

   • AUse a notary scheme where a trusted third party in Country B handles all cross-chain transfers.
   • BUse a private sidechain in Country A that stores all transaction data locally, and only send cryptographic proofs to the public blockchain in Country B.
   • CAnonymize all transaction data before it leaves Country A, so that data localization laws do not apply.
   • DRoute all transactions through Country B's nodes to avoid Country A's data localization laws.
   Reveal Solution Discussion Select an answer first
6. 35application · medium

   A cross-chain bridge uses a federation of 7 validators who sign off on transactions between a proof-of-work chain and a proof-of-stake chain. The bridge has been processing high-value transfers. A security auditor warns that the bridge is vulnerable to a specific attack where the federation colludes to sign a transaction that releases funds on the destination chain without the corresponding lock on the source chain. Which mitigation directly addresses this validator trust assumption?

   • AIncrease the federation size to 15 and require a two-thirds majority for each transfer.
   • BImplement a cryptographic proof of the source-chain transaction, such as a light-client proof, that the destination chain can verify without trusting the federation.
   • CRequire all 7 validators to sign every transfer instead of a majority.
   • DUse a decentralized oracle network to independently verify the source-chain lock before the destination chain releases funds.
   Reveal Solution Discussion Select an answer first