CCE Blockchain Fundamentals & Architecture 5

Question 1

What is the primary difference between Layer 1 and Layer 2 blockchain solutions?

Accepted Answer

Layer 1 refers to the base blockchain protocol; Layer 2 refers to solutions built on top to improve scalability

Answer

Layer 1 is the base chain (Bitcoin, Ethereum) with its own consensus and security; Layer 2 solutions (Lightning, Rollups) extend L1 capacity by processing transactions off-chain while inheriting L1 security.

Question 2

What is a 'zero-knowledge proof' and how is it used in blockchain?

Accepted Answer

A cryptographic method allowing one party to prove knowledge of information without revealing the information itself

Answer

Zero-knowledge proofs (e.g., zk-SNARKs) let a prover demonstrate a statement is true (e.g., 'I have enough balance') without revealing the underlying data, enabling privacy and efficient rollups.

Question 3

In blockchain architecture, what is the 'Byzantine Generals Problem' and why is it relevant?

Accepted Answer

A distributed computing problem describing how decentralized nodes can reach consensus despite some acting maliciously

Answer

The Byzantine Generals Problem describes the challenge of achieving reliable consensus in a distributed system where some participants may be faulty or malicious — solving it is the core challenge of blockchain consensus.

Question 4

What does 'immutability' mean in the context of a public blockchain?

Accepted Answer

Once confirmed with sufficient depth, data on the chain is practically impossible to alter without redoing all subsequent proof-of-work

Answer

Blockchain immutability means that altering a historical transaction would require redoing the proof-of-work (or stake) for that block and all blocks after it, making it economically infeasible on large networks.

Question 5

What is the 'double-spend problem' and how does blockchain solve it without a central authority?

Accepted Answer

The risk of spending the same digital token twice; solved by distributed consensus that orders transactions globally

Answer

Without a central ledger, digital money can be copied and spent twice; blockchain solves this by having the entire network agree on a single ordered transaction history, making double-spends visible and rejectable.

(CCE) Certified Cryptocurrency Expert Practice Test

(CCE) Certified Cryptocurrency Expert Practice Test

CCE Blockchain Fundamentals & Architecture 5