Principle 7 of 10

Formal Verifiability

The consensus protocol must be formally specified and machine-verified.

Every major distributed systems failure in blockchain history — from the DAO hack to bridge exploits — involved behaviour that was unspecified or incorrectly specified in natural language. TLA+ and Lean 4 are the current standards for formal protocol specification. The obstacle is not capability — it is engineering investment that most projects decline.

Scoring Rubric

Score Criteria
7–10 TLA+ spec published and model-checked; cryptographic properties proven in Lean 4 or Coq; peer-reviewed.
4–6 Informal specification with test suite; or TLA+ spec without model checking.
0–3 Protocol specified only in natural language or reference implementation.

Data Sources

  • Published TLA+/Lean 4 specifications
  • Peer review letters
  • Model checking results

How Each Chain Scores on P7

Read the full specification in ProtoLedger Core v1.0 →