A remittance company is choosing between two blockchain platforms for a new service. Platform A uses Proof of Stake with a 2-second block time and probabilistic finality. Platform B uses a BFT-based mechanism with a 5-second block time and immediate finality. The company's compliance team requires that once a transaction is shown as 'confirmed' to a customer, it must never be reversed. Which platform should the company choose?

Platform A, because faster block time means faster customer confirmation

Platform B, because a longer block time is more secure

Platform B, because immediate finality ensures confirmed transactions are irreversible

Platform A, because Proof of Stake is more energy-efficient

A blockchain network for supply chain finance uses a BFT-based consensus mechanism. The network has 7 validator nodes. An attacker compromises 2 validator nodes and attempts to cause a double-spend. What is the outcome?

The attack fails because BFT tolerates up to 2 faulty nodes out of 7

The attack fails only if the compromised nodes are detected and removed

The attack succeeds because 2 out of 7 nodes is more than 25% of the network

The attack succeeds because the compromised nodes can send conflicting messages

A central bank is designing a wholesale payment system using a permissioned blockchain. They require high throughput and low latency, but they also need to ensure that the system remains secure even if up to one-third of the validating nodes are compromised. Which consensus mechanism should they choose?

Practical Byzantine Fault Tolerance (PBFT)

A group of 15 banks is implementing a shared KYC (Know Your Customer) blockchain. They need to ensure that all banks agree on the order of KYC updates, even if some banks' nodes are temporarily offline. Which consensus mechanism is best suited for this permissioned environment?

Proof of Work, because it is the most widely used

Raft consensus, because it is simple and handles leader election

Practical Byzantine Fault Tolerance (PBFT), because it tolerates Byzantine faults and is designed for permissioned networks

Delegated Proof of Stake, because it is fast and efficient

EC-CouncilBlockchain Fintech Certification

Domain 2Objective 1

Blockchain Consensus Mechanisms BFC Practice Questions (Page 5)

Part of the Consensus Mechanisms for Financial Systems domain, which makes up ~11% of our current practice bank.

33questions here

7free pages

5concepts

Questions 21–25

21application · medium
A remittance company is choosing between two blockchain platforms for a new service. Platform A uses Proof of Stake with a 2-second block time and probabilistic finality. Platform B uses a BFT-based mechanism with a 5-second block time and immediate finality. The company's compliance team requires that once a transaction is shown as 'confirmed' to a customer, it must never be reversed. Which platform should the company choose?
Select an answer first
22application · medium
A blockchain network for supply chain finance uses a BFT-based consensus mechanism. The network has 7 validator nodes. An attacker compromises 2 validator nodes and attempts to cause a double-spend. What is the outcome?
Select an answer first
23expert · hard
A central bank is designing a wholesale payment system using a permissioned blockchain. They require high throughput and low latency, but they also need to ensure that the system remains secure even if up to one-third of the validating nodes are compromised. Which consensus mechanism should they choose?
Select an answer first
24application · medium
A group of 15 banks is implementing a shared KYC (Know Your Customer) blockchain. They need to ensure that all banks agree on the order of KYC updates, even if some banks' nodes are temporarily offline. Which consensus mechanism is best suited for this permissioned environment?
Select an answer first
25application · medium
A fintech company is building a blockchain-based invoice financing platform. They want to ensure that once an invoice is funded, the transaction cannot be double-spent or altered by any party. Which consensus mechanism property is most important to guarantee this?
Select an answer first

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Blockchain Consensus Mechanisms BFC Practice Questions (Page 5)

Questions 21–25

A blockchain network for supply chain finance uses a BFT-based consensus mechanism. The network has 7 validator nodes. An attacker compromises 2 validator nodes and attempts to cause a double-spend. What is the outcome?

A group of 15 banks is implementing a shared KYC (Know Your Customer) blockchain. They need to ensure that all banks agree on the order of KYC updates, even if some banks' nodes are temporarily offline. Which consensus mechanism is best suited for this permissioned environment?

A fintech company is building a blockchain-based invoice financing platform. They want to ensure that once an invoice is funded, the transaction cannot be double-spent or altered by any party. Which consensus mechanism property is most important to guarantee this?

Keep studying — Consensus Mechanisms for Financial Systems