Auditing, Testing, and Monitoring in Blockchain Security BDC Practice Questions (Page 7)

Questions 31–35

1. 31application · medium

   A blockchain network using a proof-of-work consensus mechanism has seen a steady decrease in hash rate. The security team is concerned about a 51% attack. What should they do first?

   • AIncrease the block reward to attract more miners
   • BImmediately switch to a proof-of-stake consensus mechanism
   • CAssess the feasibility of a 51% attack by comparing the cost to acquire the needed hash rate against the potential gains, and consider mitigations such as checkpoints or a consensus change
   • DMonitor the network's hash rate distribution and alert if a single miner or pool exceeds a threshold
   Reveal Solution Discussion Select an answer first
2. 32foundation · easy

   What is a flash loan attack in DeFi?

   • AAn attack that floods the network with transactions to cause delays
   • BAn attack that steals users' private keys through phishing
   • CAn attack that exploits a bug in the blockchain's consensus protocol
   • DAn attack that uses uncollateralized loans borrowed and repaid within a single transaction to exploit price discrepancies
   Reveal Solution Discussion Select an answer first
4. 33foundation · easy

   Which DeFi-specific risk involves manipulating the price feed used by a protocol to trigger unfair liquidations or trades?

   • ASybil attack
   • BReentrancy attack
   • C51% attack
   • DOracle manipulation
   Reveal Solution Discussion Select an answer first
5. 34expert · hard

   A team is developing a complex DeFi protocol with multiple interacting contracts. They have a limited testing budget and need to ensure the highest coverage. Which testing strategy is most effective?

   • AFocus on end-to-end tests on a testnet
   • BUse a combination of unit tests for individual functions, integration tests for contract interactions, and property-based tests for invariants
   • CWrite integration tests that deploy all contracts together and simulate real user flows
   • DWrite unit tests for each contract in isolation
   Reveal Solution Discussion Select an answer first
6. 35expert · hard

   An audit firm is scoping a security audit for a DeFi protocol that operates in multiple jurisdictions. The protocol uses a governance token and has a treasury. The client wants the audit to cover both security and regulatory compliance, but the budget is limited. Which scope is most appropriate?

   • AAudit only the governance token's compliance, because the client specifically mentioned regulatory compliance.
   • BAudit only the smart contracts that handle funds, and exclude the governance token because it is not a security.
   • CAudit the entire protocol, including all smart contracts, the frontend, the backend, and the governance process, to ensure nothing is missed.
   • DFocus the audit on the smart contracts that handle funds and governance, and include a review of the token's compliance with securities regulations in the jurisdictions where it is offered.
   Reveal Solution Discussion Select an answer first