Blockchain Fundamentals of Blockchain Security

Question 1

Which of the following is a key security feature of blockchain technology?

Accepted Answer

Immutability

Answer

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?

Accepted Answer

Verifies data integrity

Answer

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?

Accepted Answer

Gaining majority control to alter the chain

Answer

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?

Accepted Answer

Proof of Work

Answer

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?

Accepted Answer

Increases security through distributed control

Answer

Decentralization removes the single point of failure, making it harder for attackers to compromise the network.

Blockchain Practice Test