CBSA Blockchain Network Architectures 4 — Questions and Answers
Question 1: What is the purpose of the 'gossip protocol' in blockchain peer-to-peer networks?
- To broadcast transaction fees to all nodes
- To efficiently propagate data across the network by having nodes share information with random peers (Correct answer)
- To identify and remove malicious nodes
- To synchronize clocks across distributed nodes
Correct answer: To efficiently propagate data across the network by having nodes share information with random peers
The gossip protocol allows blockchain networks to spread data (blocks, transactions) efficiently by having each node share information with a random subset of peers, achieving epidemic-like propagation.
Question 2: In a Layer 2 payment channel network (like Lightning Network), what must happen before two parties can transact off-chain?
- Both parties must hold validator licenses
- A funding transaction must be submitted and confirmed on the base layer (Correct answer)
- They must share their private keys with a mediator
- The channel must be registered with a central hub
Correct answer: A funding transaction must be submitted and confirmed on the base layer
Payment channels require an on-chain funding transaction that locks funds into a multi-signature contract before any off-chain transactions can occur.
Question 3: Which consensus mechanism is most commonly used in enterprise consortium blockchain networks due to its energy efficiency and fast finality?
- Proof of Work (PoW)
- Proof of Stake (PoS)
- Byzantine Fault Tolerant (BFT) variants (Correct answer)
- Proof of Authority (PoA)
Correct answer: Byzantine Fault Tolerant (BFT) variants
BFT-based consensus (e.g., PBFT, Istanbul BFT) is widely used in enterprise blockchains because it achieves fast, deterministic finality without energy-intensive mining.
Question 4: A solution architect is designing a blockchain network where nodes must continue operating even if 33% of validators are compromised. Which property is required?
- Sybil resistance
- Byzantine Fault Tolerance (Correct answer)
- Turing completeness
- Deterministic finality
Correct answer: Byzantine Fault Tolerance
Byzantine Fault Tolerance (BFT) ensures a network can reach consensus and continue operating correctly even when up to one-third of nodes behave maliciously or arbitrarily.
Question 5: What is a 'full node' in a blockchain network architecture?
- A node that can only send transactions
- A node that stores and validates the complete blockchain history (Correct answer)
- A node dedicated solely to mining new blocks
- A node that bridges two different blockchain networks
Correct answer: A node that stores and validates the complete blockchain history
Full nodes download, store, and independently validate every block and transaction in the blockchain's history, providing the highest level of trustless verification.
Question 6: In designing a cross-border supply chain blockchain, which interoperability pattern allows assets to move between two separate blockchain networks without a trusted intermediary?
- Notary scheme
- Hash Time-Locked Contracts (HTLC) (Correct answer)
- API gateway bridge
- Centralized exchange
Correct answer: Hash Time-Locked Contracts (HTLC)
HTLCs use cryptographic hash locks and time locks to enable atomic swaps between chains, ensuring either both transfers complete or neither does, without requiring a trusted third party.
Question 7: Which blockchain network design consideration directly impacts the 'CAP theorem' tradeoffs for a distributed ledger?
- The programming language used for smart contracts
- The consensus mechanism determining how nodes agree on network state (Correct answer)
- The block reward structure for validators
- The encryption algorithm used for wallet keys
Correct answer: The consensus mechanism determining how nodes agree on network state
The consensus mechanism determines how a blockchain balances consistency, availability, and partition tolerance, directly embodying the CAP theorem tradeoffs in distributed systems.
CBSA Blockchain Network Architectures 4
What is the purpose of the 'gossip protocol' in blockchain peer-to-peer networks?