CBCP Blockchain Scalability and Interoperability — Questions and Answers
Question 1: What three properties make up the blockchain trilemma?
- Speed, color, and size
- Decentralization, security, and scalability (Correct answer)
- Mining, staking, and burning
- Privacy, anonymity, and secrecy
Correct answer: Decentralization, security, and scalability
The trilemma says it is hard for a blockchain to maximize decentralization, security, and scalability at once. Improving one often costs another.
Question 2: What does a Layer 2 scaling solution do?
- Replaces the base layer's consensus entirely
- Processes transactions off the main chain and settles results back to it (Correct answer)
- Increases the block reward
- Deletes old blocks
Correct answer: Processes transactions off the main chain and settles results back to it
Layer 2 systems, such as rollups and state channels, handle transactions off-chain or in a separate execution layer. They periodically post proofs or data to the Layer 1 chain, which inherits its security.
Question 3: Which technique splits the network or database into smaller partitions that process transactions in parallel?
- Sharding (Correct answer)
- Hashing
- Forking
- Burning
Correct answer: Sharding
Sharding divides the state and transaction processing among subsets of nodes, increasing total throughput.
Question 4: What is the Lightning Network?
- A Layer 2 payment channel network for Bitcoin (Correct answer)
- A Bitcoin mining pool
- An Ethereum consensus upgrade
- A centralized exchange
Correct answer: A Layer 2 payment channel network for Bitcoin
Lightning uses bidirectional payment channels so that many transactions happen off-chain. Only channel opening and closing are settled on the Bitcoin blockchain.
Question 5: What is the main role of a cross-chain bridge?
- To mine blocks faster
- To transfer assets or data between different blockchains (Correct answer)
- To encrypt wallets
- To set gas prices
Correct answer: To transfer assets or data between different blockchains
Bridges lock or burn assets on one chain and mint or release equivalents on another. They enable interoperability but have been frequent targets of attacks.
Question 6: How do optimistic rollups differ from zero-knowledge (ZK) rollups?
- Optimistic rollups assume transactions are valid and rely on fraud proofs; ZK rollups submit validity proofs (Correct answer)
- Optimistic rollups use proof-of-work; ZK rollups use proof-of-stake
- They are identical
- ZK rollups cannot post data to Layer 1
Correct answer: Optimistic rollups assume transactions are valid and rely on fraud proofs; ZK rollups submit validity proofs
Optimistic rollups post batches that are presumed valid and can be challenged during a dispute window with fraud proofs. ZK rollups attach cryptographic validity proofs that show each batch is correct.
