CBSA Consensus Mechanisms 5

Question 1

Which consensus property is violated when two honest nodes permanently disagree on the canonical state of the blockchain?

Accepted Answer

Safety

Answer

Safety (also called consistency) is violated when honest nodes commit conflicting blocks or states, as the system should ensure no two honest nodes ever finalize different values.

Question 2

A CBSA candidate is evaluating a public blockchain for a high-value asset tokenization platform. Which consensus feature is most critical for regulatory compliance?

Accepted Answer

Deterministic finality preventing transaction reversal

Answer

Asset tokenization for regulated markets requires deterministic finality so that settled transactions cannot be reversed, meeting financial regulators' settlement finality requirements.

Question 3

In the context of sharding and consensus, what challenge does 'cross-shard communication' introduce?

Accepted Answer

It requires atomic coordination across shards that operate with independent consensus

Answer

Cross-shard transactions require coordination protocols to ensure atomicity across independently-consensing shards, introducing complexity around deadlocks and partial failures.

Question 4

Nakamoto consensus achieves Sybil resistance in Proof of Work by tying voting power to:

Accepted Answer

Computational work (hash rate), making identity creation economically costly

Answer

PoW uses real-world energy and hardware investment as the basis for voting weight, making it prohibitively expensive to create enough fake identities (Sybils) to influence consensus.

Question 5

What is the primary trade-off when increasing the number of validators in a BFT consensus protocol?

Accepted Answer

Better decentralization but exponentially higher communication overhead (O(n²))

Answer

Classical BFT protocols require all-to-all message exchange during voting phases, resulting in O(n²) message complexity that becomes a bottleneck as the validator count grows.

(CBSA) Certified Blockchain Solution Architect Practice Test

(CBSA) Certified Blockchain Solution Architect Practice Test

CBSA Consensus Mechanisms 5