Network Layer, Consensus, Smart Contract, and Node Security Best Practices BDC Practice Questions (Page 5)

Questions 21–25

1. 21foundation · easy

   Which practice is most critical for securing the private keys of a blockchain node?

   • AUsing a hardware security module (HSM) or secure enclave
   • BStoring them in a plain text file on the node
   • CSharing them with the network administrator for backup
   • DEncrypting them with a weak password
   Reveal Solution Discussion Select an answer first
2. 22application · medium

   An organization runs a Bitcoin full node on a dedicated server. The node holds a hot wallet with a small amount of BTC for operational use. The security team wants to reduce the risk of key compromise and network-based attacks. Which set of measures best achieves this?

   • AKeep the private keys in a plaintext file on the node and disable the firewall to ensure maximum connectivity.
   • BUse a software wallet with a strong password and enable UPnP to automatically open the necessary ports.
   • CStore the hot wallet's private keys in a hardware security module (HSM) and configure the node's firewall to allow only necessary P2P and RPC traffic from trusted IPs.
   • DRun the node as the root user and rely on the operating system's default security settings.
   Reveal Solution Discussion Select an answer first
4. 23expert · hard

   A blockchain network uses a Delegated Proof-of-Stake (DPoS) consensus with 21 elected block producers. The team is concerned about a cartel of block producers colluding to censor transactions. Which design change would be most effective in reducing the risk of censorship while maintaining the efficiency of DPoS?

   • AAllow block producers to charge arbitrary fees for transaction inclusion.
   • BReduce the number of block producers to 5 to make consensus faster.
   • CImplement a mechanism for users to submit transactions to multiple block producers and add a penalty for producers who consistently exclude valid transactions.
   • DRemove the ability to vote out block producers to ensure stability.
   Reveal Solution Discussion Select an answer first
5. 24foundation · easy

   What is the purpose of network isolation for a blockchain node?

   • ATo enable faster synchronization with the network
   • BTo reduce the node's storage requirements
   • CTo increase transaction throughput
   • DTo limit exposure to untrusted networks and reduce attack surface
   Reveal Solution Discussion Select an answer first
6. 25expert · hard

   A blockchain team has deployed a monitoring system that alerts on unusual transaction patterns. They receive an alert about a sudden spike in failed transactions from a specific smart contract. What is the most appropriate first response?

   • AIncrease the alert threshold to reduce false positives.
   • BIgnore the alert because failed transactions are normal.
   • CInvestigate the smart contract's code and recent transactions to determine if there is an exploit.
   • DImmediately pause the smart contract without investigation.
   Reveal Solution Discussion Select an answer first