Byzantine Fault Tolerant (BFT) Mechanisms BDC Practice Questions (Page 7)

Questions 31–35

1. 31application · medium

   A startup is designing a permissioned blockchain for a supply-chain network. They expect some nodes to occasionally crash (lose power or network) but they do not expect any node to intentionally send conflicting data. The team must choose a consensus algorithm that is simplest to implement while still tolerating the expected failures. Which approach should they choose?

   • APBFT
   • BRaft
   • CProof of Work
   • DTendermint
   Reveal Solution Discussion Select an answer first
2. 32foundation · medium

   In the Byzantine Generals Problem, what is the primary challenge that makes reaching consensus difficult?

   • AGenerals cannot communicate directly and must use a messenger who might be captured.
   • BSome generals may be traitors who send conflicting or false messages to prevent agreement.
   • CGenerals must agree on a time to attack, but they are in different time zones.
   • DGenerals may send messages that are delayed or arrive out of order.
   Reveal Solution Discussion Select an answer first
4. 33application · medium

   A blockchain startup is considering using PBFT for a public blockchain with thousands of nodes. Which limitation of PBFT makes it unsuitable for this use case?

   • APBFT requires a trusted third party to manage the validator set.
   • BPBFT is only suitable for synchronous networks.
   • CPBFT cannot tolerate any Byzantine faults in a public network.
   • DThe O(n^2) communication complexity causes excessive network traffic as the number of nodes grows.
   Reveal Solution Discussion Select an answer first
5. 34application · medium

   A consortium of 7 banks runs a permissioned blockchain for interbank settlements. Each bank operates one validator node. The network uses PBFT. The operations team is asked to determine the maximum number of validator nodes that can be compromised (including acting maliciously) while the network continues to safely finalize transactions. What is the correct maximum number?

   • A1
   • B3
   • C2
   • D4
   Reveal Solution Discussion Select an answer first
6. 35application · medium

   A blockchain network uses a PBFT-based consensus with 4 nodes. The system is designed to tolerate Byzantine faults. What is the maximum number of faulty nodes this network can tolerate while still ensuring safety and liveness?

   • A2
   • B3
   • C0
   • D1
   Reveal Solution Discussion Select an answer first