CBSA Blockchain Network Architectures 5

Question 1

What is the key difference between a 'light client' and a 'full node' in blockchain network participation?

Accepted Answer

Light clients only download block headers and rely on full nodes for transaction verification

Answer

Light clients (SPV nodes) download only block headers and use Merkle proofs to verify transactions, trusting full nodes for complete validation instead of processing the entire chain.

Question 2

In a blockchain network, what problem does the 'nothing-at-stake' attack specifically target?

Accepted Answer

Proof of Stake consensus mechanisms

Answer

The nothing-at-stake problem in PoS occurs when validators can simultaneously vote on multiple chain forks at no cost, potentially undermining consensus security.

Question 3

A blockchain architect needs to ensure data written five years ago cannot be altered even if current encryption is broken. Which design approach addresses this?

Accepted Answer

Migrating to quantum-resistant cryptography before deployment

Answer

Designing with quantum-resistant (post-quantum) cryptographic algorithms before deployment ensures long-term immutability even as computational capabilities advance.

Question 4

Which Hyperledger Fabric component is responsible for simulating chaincode execution and generating read-write sets for endorsement?

Accepted Answer

Peer node (endorser)

Answer

In Fabric's execute-order-validate flow, endorsing peers simulate chaincode transactions and produce read-write sets that are then collected by clients for ordering.

Question 5

What is the role of a 'Merkle tree' in blockchain network architecture?

Accepted Answer

It enables efficient and secure verification of large datasets by creating a tree of cryptographic hashes

Answer

Merkle trees allow any transaction within a block to be verified with minimal data (a Merkle proof) by hashing pairs of transactions upward to a single root hash stored in the block header.

(CBSA) Certified Blockchain Solution Architect Practice Test

(CBSA) Certified Blockchain Solution Architect Practice Test

CBSA Blockchain Network Architectures 5