Mitigating Blockchain Attacks and Security Practices BFC Practice Questions (Page 6)

Questions 26–30

1. 26application · medium

   A company is about to launch a token sale smart contract. The development team has written extensive unit tests and believes the code is secure. Management wants an independent assessment before launch. Which action provides the most value?

   • ARely on the unit tests and launch as scheduled to avoid delays.
   • BConduct a third-party security audit that includes manual code review and automated analysis tools.
   • CPublish the code on GitHub and ask the community to review it informally.
   • DUse a bug bounty program after launch to find vulnerabilities.
   Reveal Solution Discussion Select an answer first
2. 27application · medium

   A public blockchain network has seen a sudden increase in transactions from thousands of new addresses, all sending tiny amounts to the same smart contract. The network is congested and transaction fees are rising. Which attack is most likely occurring?

   • AEclipse attack
   • BSybil attack
   • CReplay attack
   • D51% attack
   Reveal Solution Discussion Select an answer first
4. 28application · medium

   A blockchain startup stores user private keys in a cloud database protected only by a username and password. A security consultant recommends a more robust approach. Which option provides the strongest protection for the keys?

   • AUse a longer password for the database.
   • BMove keys to a hardware security module (HSM) and require multi-factor authentication for all access.
   • CEncrypt the database with a key stored in the same database.
   • DBackup the keys to a public cloud storage bucket for redundancy.
   Reveal Solution Discussion Select an answer first
5. 29expert · hard

   A security audit of a smart contract that handles regulated assets finds a critical vulnerability. The audit firm recommends immediate remediation, but the contract is already in production with significant user funds. The team must decide whether to pause the contract or deploy a fix. What is the most important consideration?

   • AThe cost of the audit firm's fees
   • BThe risk of continued exploitation versus the disruption to users
   • CThe availability of a testnet for testing the fix
   • DThe opinion of the community on social media
   Reveal Solution Discussion Select an answer first
6. 30foundation · easy

   Which activity is typically performed during a blockchain security audit?

   • ADeleting all transaction history to remove vulnerabilities
   • BChanging the consensus algorithm to a more secure one
   • CReviewing smart contract code for common vulnerabilities like reentrancy and integer overflow
   • DMining new blocks to increase the chain's security
   Reveal Solution Discussion Select an answer first