CBSE Enterprise Blockchain Security 3

Question 1

In enterprise blockchain security audits, what does 'front-running' refer to?

Accepted Answer

Exploiting knowledge of pending transactions to gain unfair advantage

Answer

Front-running occurs when an actor observes a pending transaction in the mempool and submits their own transaction with a higher fee to be processed first.

Question 2

A smart contract written in Solidity uses the pattern 'transfer()' instead of 'call()' for ETH transfers. What security benefit does this provide?

Accepted Answer

It forwards exactly 2300 gas, preventing reentrancy in fallback functions

Answer

The 2300 gas stipend forwarded by transfer() is insufficient for the recipient to perform state-changing calls, effectively blocking reentrancy attacks.

Question 3

Which NIST framework publication is most directly applicable to evaluating cryptographic controls in an enterprise blockchain system?

Accepted Answer

NIST SP 800-57

Answer

NIST SP 800-57 provides recommendations for key management, which is foundational to the cryptographic integrity of any blockchain system.

Question 4

An attacker gains access to the private key of an ordering node in Hyperledger Fabric. What is the most severe immediate consequence?

Accepted Answer

Injecting arbitrary transaction ordering and censoring transactions

Answer

The ordering service controls transaction sequencing; a compromised orderer key allows an attacker to manipulate ordering, censor transactions, or create forks.

Question 5

What is the purpose of a 'time-lock' mechanism in enterprise blockchain smart contracts?

Accepted Answer

Delaying the execution of critical functions to allow governance review

Answer

Time-locks introduce a mandatory delay before sensitive actions execute, giving stakeholders a window to detect and respond to malicious proposals.

(CBSE) Certified Blockchain Security Expert Practice Test

(CBSE) Certified Blockchain Security Expert Practice Test

CBSE Enterprise Blockchain Security 3