Easy impossibility proofs for distributed consensus problems
This paper gives impossibility results.
- Byzantine Agreement
- Weak Agreement
- Byzantine Firing Squad
- Approximate Agreement
- Clock Synchronization
To tolerate \(f\) faults, we need \(>3f\) nodes and \(2f+1\) connectivity. Assume deterministic (Locality Axiom) and no PKI + Byzantine (Fault Axiom).
Definitions
- Inadequate graphs: If the connectivity is less than \(2f+1\).
References
Michael J. Fischer, Nancy A. Lynch, and Michael Merritt. 1986. “Easy impossibility proofs for distributed consensus problems.” https://doi.org/10.1007/BF01843568.