Network Layer, Consensus, Smart Contract, and Node Security Best Practices BDC Practice Questions (Page 8)

Questions 36–40

1. 36application · medium

   A smart contract team has just completed an internal code review and wants to conduct an external audit before deploying a high-value DeFi protocol. The team has a limited budget and needs to choose the most effective use of resources. Which approach is most aligned with best practices?

   • ASkip the external audit and rely on the internal review, as it is cheaper.
   • BDeploy the contract to mainnet and fix any issues found after deployment.
   • COnly run a bug bounty program without an external audit to save costs.
   • DHire a reputable third-party audit firm to review the code and also run a bug bounty program to incentivize external researchers.
   Reveal Solution Discussion Select an answer first
2. 37application · medium

   A blockchain node is configured to accept incoming connections from any peer on the internet. The node operator is concerned about eclipse attacks, where an attacker surrounds the node with malicious peers. Which configuration change would be most effective in reducing the risk of an eclipse attack?

   • AConfigure the node to connect only to a whitelist of trusted peers and disable incoming connections from unknown IPs.
   • BEnable UPnP to automatically open ports for better connectivity.
   • CUse a random peer selection algorithm to make it harder for attackers to predict connections.
   • DIncrease the maximum number of peer connections to allow more honest peers.
   Reveal Solution Discussion Select an answer first
4. 38application · medium

   A blockchain network is experiencing a distributed denial-of-service (DDoS) attack that is flooding nodes with invalid transactions. Which mitigation strategy is most effective at the network layer?

   • AIncrease the block size to accommodate more transactions.
   • BUpgrade the node's CPU to handle more transactions per second.
   • CImplement rate limiting and transaction validation rules at the node level.
   • DDisable all peer connections temporarily.
   Reveal Solution Discussion Select an answer first
5. 39application · medium

   A blockchain node operator wants to ensure that the node's private keys are not exposed to the internet. The node is used for signing blocks and must be online to participate in consensus. Which approach best protects the keys while keeping the node operational?

   • AUse a hardware security module (HSM) or a separate signing service that keeps private keys in a tamper-resistant environment, while the node itself only sends signing requests.
   • BStore the private keys in a file on the node's disk and rely on the firewall to protect them.
   • CDisconnect the node from the internet and sign blocks manually.
   • DKeep the private keys in the node's memory and never write them to disk.
   Reveal Solution Discussion Select an answer first
6. 40foundation · easy

   Which of the following is a common threat modeling framework used to systematically identify potential attack vectors?

   • ASTRIDE
   • BCIS Controls
   • CISO 27001
   • DOWASP Top 10
   Reveal Solution Discussion Select an answer first