Common Threats and Blockchain Security Best Practices BBLC Practice Questions (Page 10)

Questions 46–50

1. 46application · medium

   A company is setting up a multi-signature wallet for managing its treasury funds. The wallet requires 3 out of 5 signatures to authorize a transaction. Which additional measure would BEST protect against the risk of a single key holder being compromised?

   • APrint all keys and store them in a single safe.
   • BDistribute the keys across different devices and locations, and use hardware wallets for each.
   • CStore all five private keys in the same password manager.
   • DUse the same passphrase for all keys to simplify management.
   Reveal Solution Discussion Select an answer first
2. 47application · medium

   A company operates a blockchain node that must be accessible to external partners for data synchronization. They want to protect the node from unauthorized access while allowing legitimate peers to connect. Which configuration is most appropriate?

   • ADisable the firewall entirely to ensure no connectivity issues.
   • BUse a shared password for all peers to authenticate.
   • CConfigure a firewall to allow inbound connections only from known peer IP addresses and on the required port.
   • DAllow all inbound traffic on any port.
   Reveal Solution Discussion Select an answer first
4. 48foundation · easy

   How does decentralization in a blockchain network help prevent a 51% attack?

   • AIt ensures that all nodes have the same amount of mining power.
   • BIt prevents any node from validating transactions.
   • CIt eliminates the need for consensus mechanisms entirely.
   • DIt makes it more difficult for any single entity to accumulate majority control of hash power or stake.
   Reveal Solution Discussion Select an answer first
5. 49application · medium

   A company runs a blockchain node that is publicly accessible on the internet. They have noticed a high volume of incoming connection requests that are consuming resources and making the node unresponsive. Which control is most effective to mitigate this specific issue?

   • AChange the node's private key to a new one.
   • BIncrease the node's logging level to debug.
   • CDeploy a DDoS protection service that filters malicious traffic before it reaches the node.
   • DDisable the node's peer discovery feature.
   Reveal Solution Discussion Select an answer first
6. 50application · medium

   A developer is writing a smart contract that will hold user funds. The contract has a function that transfers ether to a user-supplied address. Which practice is most important to include during development to prevent a reentrancy attack?

   • AUse a checks-effects-interactions pattern so that state updates occur before external calls.
   • BIncrease the gas limit for the transaction to ensure the external call completes.
   • CUse a random number generator to decide whether the transfer should succeed.
   • DAdd a require statement that checks the caller is the contract owner.
   Reveal Solution Discussion Select an answer first