Security and Compliance in Smart Contracts BBLC Practice Questions (Page 8)

Questions 36–40

1. 36foundation · easy

   Which Solidity feature is specifically designed to prevent integer overflow and underflow in arithmetic operations?

   • AThe require statement
   • BThe SafeMath library (or built-in checked arithmetic in newer versions)
   • CThe modifier keyword
   • DThe assert statement
   Reveal Solution Discussion Select an answer first
2. 37expert · hard

   A smart contract contains a bug that allows users to withdraw more than they deposited. The contract is already deployed and has a large number of users. The team is considering whether to deploy a new contract and migrate, or to attempt a legal remedy. Which factor is most important in this decision?

   • AThe legal jurisdiction of the users.
   • BThe opinion of the blockchain community.
   • CThe immutability of the blockchain.
   • DThe cost and feasibility of migrating all users and funds to a new contract.
   Reveal Solution Discussion Select an answer first
4. 38expert · hard

   A team is auditing a complex DeFi smart contract with multiple interacting functions. They have a limited budget and need to choose between a comprehensive static analysis and a targeted formal verification of the most critical function. Which approach is most appropriate?

   • ASkip both and rely on a bug bounty program.
   • BRun static analysis on the entire contract and formal verification on the critical function.
   • COnly run static analysis on the entire contract.
   • DOnly run formal verification on the critical function.
   Reveal Solution Discussion Select an answer first
5. 39expert · hard

   A team has a limited budget and must choose between a manual audit, a static analysis tool, and a formal verification tool for their smart contract. The contract handles high-value transactions and has complex business logic. Which approach is the most balanced?

   • AUse only static analysis tools because they are automated and cheap.
   • BUse a combination of static analysis and a manual audit, with formal verification for critical functions.
   • CSkip audits and rely on bug bounties after deployment.
   • DUse only formal verification to mathematically prove correctness.
   Reveal Solution Discussion Select an answer first
6. 40application · medium

   A developer is writing a Solidity function that allows users to claim a reward if they have a valid proof of purchase. The function receives a proof string and a user address. Which combination of practices best ensures secure access control and input validation?

   • AUse a mapping of valid proofs and check that the proof is present and not already used.
   • BOnly allow the contract owner to call the claim function.
   • CHash the proof and compare it to a stored hash, but do not track usage.
   • DTrust the proof string and send the reward to msg.sender without further checks.
   Reveal Solution Discussion Select an answer first