A Formal Approach to Block Production Verification in Polkadot (BABE Protocol)

Project Abstract

This system provides a web-based formal verification environment for the BABE (Blind Assignment for Blockchain Extension) protocol — the block production mechanism used by Polkadot. It simulates validator selection using VRF-based lotteries, produces SHA-256 linked blockchain hash chains, and verifies key safety and liveness properties using model checking techniques.

By translating complex rust-based consensus routines into formal state verification steps, students and developers can visualize validator slot ownership, analyze fork resolution protocols (such as GPFS - Golden Rule Fork Choice), and run verification scenarios representing adversarial block delays.

Core System Features

• VRF Validator Lottery Simulator: Visualizes Verifiable Random Function (VRF) evaluations to allocate validator production rights across specific time slots.
• Immutable Ledger Builder: Generates local blockchain mock lists using SHA-256 hashing, representing block header links.
• Fork Choice Resolution (GPFS): Implements Polkadot's specific GPFS rules to resolve forks dynamically when multiple validators claim the same block slot.
• Model Checking Interface: Interactive dashboard allowing users to inject message delays or duplicate block signatures to verify safety bounds (no double-production in a single slot).