BAC-L0-FOUND-108
Fault tolerance and Byzantine faults
Telling a crashed node from a malicious one, and why the latter is structurally more expensive to tolerate.
- Level
- L0 — Foundation
- Duration
- 3 h
- Track
- Foundation
- Maintainer
- Developer Curriculum Architect
Learning objectives
- 01Distinguish crash faults from Byzantine faults by their observable effects
- 02Justify the two-thirds threshold in BFT protocols
- 03Explain the role of quorums in agreement
Guided lab
Simulate agreement across seven nodes, make two of them lie, and measure where agreement breaks.
Independent lab
Vary the number of faulty nodes and plot the experimental safety boundary.
Security angle
Cost of acquiring one third of the votes: turning a theoretical threshold into an attack budget.
Assessment
Submitted simulation with a safety curve and its interpretation.