CBSA Blockchain Architecture & Design Principles 4

Question 1

Which data structure allows efficient membership proofs in a blockchain without revealing all stored elements?

Accepted Answer

Merkle Patricia trie

Answer

The Merkle Patricia trie (used in Ethereum) supports efficient O(log n) inclusion proofs and state lookups while encoding all state in a single root hash.

Question 2

In a federated Byzantine agreement (FBA) model like Stellar, how is consensus reached?

Accepted Answer

Each node chooses its own quorum slice, and consensus emerges from overlapping slices

Answer

FBA allows each node to define which other nodes it trusts (quorum slices); global consensus emerges when slices overlap sufficiently.

Question 3

What is the purpose of a 'genesis block' in blockchain design?

Accepted Answer

It is the hardcoded first block that establishes the initial chain state

Answer

The genesis block is block zero, hardcoded into the client software; it anchors the entire chain history and sets initial parameters like difficulty or token allocations.

Question 4

Which architectural consideration is most critical when integrating an oracle into a blockchain solution?

Accepted Answer

Preventing single-oracle dependency to avoid a central point of failure and manipulation

Answer

A single oracle is a centralized trust point; decentralized oracle networks (e.g., Chainlink) aggregate data from multiple sources to prevent manipulation and downtime.

Question 5

In Hyperledger Fabric's architecture, what component is responsible for ordering transactions into blocks?

Accepted Answer

Ordering service (orderer)

Answer

The ordering service in Fabric receives endorsed transactions, sequences them deterministically, and cuts them into blocks distributed to committing peers.

(CBSA) Certified Blockchain Solution Architect Practice Test

(CBSA) Certified Blockchain Solution Architect Practice Test

CBSA Blockchain Architecture & Design Principles 4