Validator Key Rotation Ceremony With On-Chain Consensus Commitment

[JamesEjembi]

Problem Statement / Feature Objective
Validators periodically rotate signing keys to limit cryptographic exposure. The codebase lacks a formalized key rotation ceremony that coordinates new key registration, old key deactivation, and on-chain consensus commitment. Without atomic rotation, a window exists where double-signing penalties can be triggered during the transition.

Technical Invariants & Bounds

• Rotation grace period: 256 epochs (~27 hours)
• Minimum stake to initiate rotation: 10,000 VERI
• Old key must remain inactive for 4,096 slots before final revocation
• Duplicate key registration must raise ERR_DUPLICATE_KEY within 500ms
• Signature threshold for rotation approval: 2/3 of active validator set

Codebase Navigation Guide

• src/keys/rotation-ceremony.ts - Orchestrates the multi-phase rotation flow
• src/consensus/commitment-broadcaster.ts - Gossips rotation commitments to peer validators
• src/keys/key-registry.ts - On-chain registry of active and retired public keys
• src/slashing/penalty-calculator.ts - Guards against double-signing during key overlap

Implementation Blueprint

1. Implement RotationCeremony class with phases: INITIATE, APPROVE, ACTIVATE, RETIRE
2. Add commitRotation() in commitment-broadcaster.ts that emits a ValidatorKeyRotation event and waits for 2/3 approval
3. Modify key-registry.ts to support PENDING, ACTIVE, RETIRED key states with epoch timestamps
4. Update penalty-calculator.ts to suppress slashing for signatures from newly registered keys within the grace period
5. Add integration test validating that concurrent rotations from different validators do not deadlock the registry

[frankosakwe]

hello maintainer i would like to work on this issue