Polkadot is the only chain in the batch with a named PQC roadmap. Dilithium and Falcon, both lattice-based, announced by W3F in June 2025. Forkless runtime upgrades mean they can ship without a hard fork. The architecture is further along than anyone's execution, including their own. Band 4 because paper is not production.
Summary
Polkadot is Band 4 (Architected) — the only chain in batch with a published PQC roadmap (June 2025 W3F paper naming Dilithium + Falcon). Forkless runtime upgrades give unmatched crypto-agility: Substrate can ship hybrid PQC via runtime upgrade without hard fork. Industry-leading Nakamoto coefficient 149 supports Gate 1 pass. Capped by Aaronson (architecture Dim 4 far exceeds execution Dim 5). No mainnet PQC shipped yet; lattice-monoculture risk from Dilithium+Falcon both being lattice-based.
What the gates say
- Hybrid: PASS. Hybrid-PQ design present.
- Evidence: PASS. Sources reconstructable by third party.
- Primitive naming: PASS. Named primitives at every scored sub-level.
Burn-vs-rescue policy on file
undeclared
Seven dimensions
Each dimension scores 0-100 internally; the weighted roll-up produces the QRI on the left. Open a row to read the sub-score detail.
1 Cryptographic Exposure 52 / 100
Comprehensive primitive inventory — multi-algorithm by design.
Sr25519 (Schnorr over Ristretto25519) · Ed25519 (GRANDPA finality) · BLS12-381 (BEEFY bridge) · BLAKE2b-256 · Sassafras VRFRoadmap names two PQC algorithms (Dilithium + Falcon) both lattice-based — lattice-monoculture concern but two schemes.
Specific NIST category selection not yet published in roadmap.
2 HNDL Exposure 28 / 100
90-100% of accounts expose Sr25519 pubkey on first tx. Validator session keys permanently on-chain.
Same 100% exposure.
Active validator keys rotate via session keys — better than static EOA chains.
libp2p + TLS for validator comms. No PQC announced.
3 Metadata & Privacy Exposure 40 / 100
Pseudonymous across relay chain + parachains.
OnFinality, Dwellir, Ankr — multi-provider.
XCM + Snowbridge — built-in bookkeeping but heterogeneous.
Some parachains (Phala) use TEE privacy. Most relay-chain data is public.
4 Migration Architecture 65 / 100
Substrate forkless runtime upgrades. Crypto module is pluggable. Can add new signature types via Wasm runtime upgrade without hard fork.
Proxy accounts + multisig. Session-key rotation native for validators.
Hundreds of forkless runtime upgrades. OpenGov referenda track record. Coordinated 2023 parachain vuln patch.
SS58 address format extensible. Runtime can accept hybrid signatures via envelope.
5 Deployment Execution 16 / 100
No PQC on mainnet.
QSB project on Substrate is external (Quantum Blockchains Inc), not Polkadot runtime.
Roadmap announced; no shipped code.
6 Supply Chain Vendor Readiness 10 / 100
7 Governance & Coordination 78 / 100
Nakamoto coefficient 149 — industry-leading.
Forkless runtime upgrades. Pi Day Reset 2026 (53.6% emission cut).
Web3 Foundation + Parity + JAM working group. Published PQC roadmap.
2023 parachain vuln: $200M saved via rapid coordinated patch.
The X + Y vs Z inequality
X (data shelf life): 10-15 (validator session keys rotate)
Y (migration time): 5-10
Z10 (10% CRQC year): 2036 · Z50 (50%): 2041
Verdict: X+Y < Z (safe).
Four-scenario grid
| Scenario | Value preserved | Privacy preserved |
|---|---|---|
| quantum never | 100% | 100% |
| arrives suddenly pre migration | 10% | 15% |
| arrives slowly post migration | 92% | 80% |
| arrives slowly mid migration | 55% | 50% |
Peers in the L1 profile
Order-book view of the 9 chains closest to Polkadot by QRI.
Public artifacts used for this scorecard
Each entry below is a sub-score citation. Clicking the link takes you to the public source. A third party should be able to reconstruct every number on this page from these URLs in 48 hours.
Comprehensive primitive inventory — multi-algorithm by design.
Substrate forkless runtime upgrades. Crypto module is pluggable. Can add new signature types via Wasm runtime upgrade without hard fork.
Proxy accounts + multisig. Session-key rotation native for validators.
Nakamoto coefficient 149 — industry-leading.
Supply chain snapshot
A chain's supply chain cannot migrate faster than its slowest dependency. Zero PQC roadmaps in any of the four categories is a structural blocker, not a lagging indicator.
Analyst notes on the scoring
Top of batch. Strongest combination of architectural agility + governance + named roadmap. Main gap is execution (Dim 5 = 16) and vendor ecosystem (Dim 6 = 10). If W3F ships Dilithium runtime module in next 2y, can climb to Band 6-7.
Scorecard metadata
- Profile: L1
- Scored: 2026-04-18 by
layerqu-v2-scoring-agent-4 - v1 reference:
chainscreen-v1-archive - QRI raw: 31 · after caps: 31
- Confidence interval: ±10
- PQC washing ratio: 1.5x
- Burn-vs-rescue: undeclared
Caps triggered
- Mosca (5a<20% → QRI max 60)
- Aaronson (Dim 4=65 vs Dim 5=16, delta>25 → QRI max 70)