What is the key function of a blockchain's consensus mechanism?

• a. Data encryption
• b. Transaction validation
• c. User authentication
• d. File storage

Which cryptographic technique is commonly used to secure transactions on a blockchain?

• a. RSA
• b. SHA-256
• c. AES
• d. MD5

What is a smart contract in the context of blockchain?

• a. A legal document
• b. A self-executing code
• c. A user authentication protocol
• d. A data storage mechanism

In a public blockchain, who can participate in the consensus process?

• a. Only miners
• b. Any participant
• c. Only government entities
• d. Verified businesses

What is the purpose of a nonce in a blockchain system?

• a. Transaction timestamp
• b. Random data
• c. Security key
• d. Unique identifier

Which blockchain feature ensures that once data is added, it cannot be altered or deleted?

•  a. Immutability

  
  

•  b. Flexibility  

  
  

•   c. Scalability  

  
  

•  d. Anonymity

  
  

What is a "fork" in the context of blockchain technology?

• a. A hardware component
• b. A software bug
• c. A protocol upgrade
• d. A data breach

What role do nodes play in a decentralized blockchain network?

• a. Transaction validation
• b. Data encryption
• c. User authentication
• d. File storage

Which consensus algorithm is known for its energy-efficient approach in blockchain networks?

• a. Proof of Work (PoW)
• b. Proof of Stake (PoS)
• c. Delegated Proof of Stake (DPoS)
• d. Byzantine Fault Tolerance (BFT)

What is the purpose of a private key in blockchain cryptography?

• a. Transaction approval
• b. Public ledger access
• c. Identity verification
• d. Smart contract execution