A public blockchain network is considering a change to its consensus algorithm to reduce the risk of a 51% attack. Which change would be most effective?

Allow anyone to run a node without any cost.

Reduce the block reward to make mining less profitable.

Shorten the block time to increase transaction throughput.

Increase the cost of acquiring the resources needed to participate in consensus.

What is the purpose of formal verification in smart contract development?

To mathematically prove that the contract behaves according to its specification.

To encrypt the contract's code to prevent unauthorized viewing.

To increase the transaction throughput of the contract.

To create a backup of the contract on a centralized server.

Which of the following is a recommended practice for generating a private key?

Deriving the key from a public piece of information like your email address.

Using a secure random number generator from a trusted source.

Reusing a key from another application to save time.

Using a simple passphrase that is easy to remember.

A blockchain-based supply chain platform detects that a smart contract has been exploited, and funds have been drained. The incident response team needs to contain the damage. Which action should they take FIRST?

Analyze the attack transaction to understand the vulnerability.

Contact the exchange where the stolen funds might be sent and ask them to freeze the account.

Pause or disable the affected smart contract if the design includes a kill switch or circuit breaker.

Delete the blockchain node's logs to prevent further data exposure.

A smart contract has been deployed and is holding user funds. A security audit has identified a critical vulnerability that could allow an attacker to drain all funds. The contract does not have a kill switch. The team must decide how to respond. Which approach is the most appropriate?

Freeze all transactions on the blockchain by coordinating with miners.

Deploy a new version of the contract and migrate all users' funds to the new contract.

Do nothing and hope the attacker does not discover the vulnerability.

Contact the attacker and negotiate a bug bounty.

EC-CouncilBlockchain Business Leader Certification

Domain 2Objective 4

Common Threats and Blockchain Security Best Practices BBLC Practice Questions (Page 8)

Part of the Cryptography and Security in Blockchain domain, which makes up ~13% of our current practice bank.

52questions here

11free pages

10concepts

Questions 36–40

36application · medium
A public blockchain network is considering a change to its consensus algorithm to reduce the risk of a 51% attack. Which change would be most effective?
Select an answer first
37foundation · easy
What is the purpose of formal verification in smart contract development?
Select an answer first
38foundation · easy
Which of the following is a recommended practice for generating a private key?
Select an answer first
39application · medium
A blockchain-based supply chain platform detects that a smart contract has been exploited, and funds have been drained. The incident response team needs to contain the damage. Which action should they take FIRST?
Select an answer first
40expert · hard
A smart contract has been deployed and is holding user funds. A security audit has identified a critical vulnerability that could allow an attacker to drain all funds. The contract does not have a kill switch. The team must decide how to respond. Which approach is the most appropriate?
Select an answer first

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