CBSA Consensus Mechanisms 2

Question 1

Which consensus mechanism is used by Hyperledger Fabric to order transactions before they are committed to the ledger?

Accepted Answer

Raft or Kafka-based ordering service

Answer

Hyperledger Fabric uses a pluggable ordering service (Raft or previously Kafka) to sequence transactions into blocks before peers validate and commit them.

Question 2

In a Practical Byzantine Fault Tolerant (PBFT) network with 10 nodes, what is the maximum number of faulty nodes the system can tolerate?

Accepted Answer

3

Answer

PBFT tolerates at most f faulty nodes in a network of 3f+1 nodes, so 10 nodes can tolerate floor((10-1)/3) = 3 faulty nodes.

Question 3

What is the primary purpose of the 'finality' property in blockchain consensus mechanisms?

Accepted Answer

To ensure a committed block cannot be reversed or reorganized

Answer

Finality guarantees that once a block is added to the chain, it is irrevocable and no reorganization can remove or alter it.

Question 4

Ethereum's move from Proof of Work to Proof of Stake (The Merge) primarily aimed to achieve which benefit?

Accepted Answer

Reduce energy consumption by ~99.95%

Answer

The Merge transitioned Ethereum to PoS, drastically cutting energy use since validators stake ETH instead of performing energy-intensive mining.

Question 5

In Delegated Proof of Stake (DPoS), token holders participate in consensus by:

Accepted Answer

Voting for a fixed set of elected delegates who produce blocks

Answer

DPoS uses a democratic voting model where token holders elect delegates (witnesses/block producers) who are responsible for block production and validation.

(CBSA) Certified Blockchain Solution Architect Practice Test

(CBSA) Certified Blockchain Solution Architect Practice Test

CBSA Consensus Mechanisms 2