CompTIA SecurityX (CAS-005)Security EngineeringMedium
A global financial institution is implementing a new payment processing system that requires extremely high assurance of transaction integrity and resistance to tampering, even in the presence of malicious nodes. The system must maintain consensus on transaction order and validity across a distributed network of participants, some of whom may be untrustworthy. Which of the following advanced consensus mechanisms would BEST meet these requirements?
- AProof of Work (PoW)
- BProof of Stake (PoS)
- CDelegated Proof of Stake (DPoS)
- DPractical Byzantine Fault Tolerance (PBFT)
Show answer & explanationAnswer & explanation
Correct answer: D. Practical Byzantine Fault Tolerance (PBFT)
Practical Byzantine Fault Tolerance (PBFT) is designed to provide high assurance and resistance to tampering in distributed systems, even when some nodes are malicious. It ensures consensus among nodes by tolerating Byzantine faults, making it suitable for critical financial applications where transaction integrity is paramount.
Why the other options are wrong
- A. Proof of Work is energy-intensive and can be slow, making it less suitable for high-throughput financial transactions requiring rapid finality.
- B. Proof of Stake offers better energy efficiency than PoW but may still have slower finality and different security assumptions than PBFT for critical financial systems.
- C. Delegated Proof of Stake is a variation of PoS, offering similar benefits and drawbacks, and is generally less robust against Byzantine faults than PBFT for critical systems.
Practical Byzantine Fault Tolerance (PBFT)
A distributed consensus algorithm designed to tolerate Byzantine faults (arbitrary, malicious behavior) in an asynchronous network, providing strong consistency and integrity.
- Achieves consensus with malicious nodes present.
- Suitable for high-assurance, low-latency distributed systems.
- Requires a known set of participants.
Memory trick: To BEFT the system, you need Byzantine Fault Tolerance.