Blockchain Fundamentals of Blockchain Security 1 — Questions and Answers
Question 1: Which of the following is a key security feature of blockchain technology?
- Centralized storage
- Immutability (Correct answer)
- Manual ledger updating
- Dynamic block editing
Correct answer: Immutability
Immutability ensures that once data is recorded in the blockchain, it cannot be changed, which is crucial for maintaining integrity.
Question 2: What role does hashing play in blockchain security?
- Encrypts the entire blockchain
- Prevents mining
- Ensures transaction anonymity
- Verifies data integrity (Correct answer)
Correct answer: Verifies data integrity
Hashing converts data into a fixed-length string, making it nearly impossible to reverse-engineer and ensuring data integrity.
Question 3: What is a 51% attack in blockchain?
- A DDoS on miners
- Tampering with a single block
- Gaining majority control to alter the chain (Correct answer)
- Unauthorized access to wallets
Correct answer: Gaining majority control to alter the chain
A 51% attack occurs when a single entity gains majority control of the network's hashing power, allowing them to manipulate transactions.
Question 4: Which consensus algorithm is most commonly used in Bitcoin?
- Proof of Stake
- Proof of Authority
- Proof of Burn
- Proof of Work (Correct answer)
Correct answer: Proof of Work
Proof of Work is the original consensus mechanism used by Bitcoin, requiring computational effort to validate transactions.
Question 5: Why is decentralization important in blockchain security?
- Allows faster updates
- Minimizes power usage
- Increases security through distributed control (Correct answer)
- Simplifies data storage
Correct answer: Increases security through distributed control
Decentralization removes the single point of failure, making it harder for attackers to compromise the network.
Question 6: Which of the following helps prevent double spending in blockchain?
- Off-chain storage
- Consensus algorithms (Correct answer)
- Token burning
- Hash collisions
Correct answer: Consensus algorithms
Consensus mechanisms like Proof of Work prevent double spending by requiring network agreement before transactions are finalized.
Blockchain Fundamentals of Blockchain Security 1
Which of the following is a key security feature of blockchain technology?