Key technical topics covered in this session include:

• • The 5/9 Threshold Analysis: A deep dive into why Ryan selected the 5/9 (approximately 55.5%) threshold for Byzantine Fault Tolerance, providing a more robust guarantee than traditional 1/3 models in high-scale federated learning.
  • Theorem 1 BFT Formalization: Examining the Lean 4 source of truth (proofs/LeanFormalization/Theorem1BFT.lean) that defines the machine-checked proofs for this resilience.
  • Multi-Krum Filtering at Scale: How the aggregator performs robust node selection and filtering while maintaining a non-blocking hot-path ingestion rate of 160K+ ops/sec.
  • The "Seventh Theorem": Transitioning the defense model from merely fighting "liars" (adversarial nodes) to resisting "owners" (economic consolidation/centralization).
  • Sublinear Validation Behavior: Analyzing how the system achieves efficient validation even as node counts scale toward the 10-million-node architecture target