Penumbra is the only chain where the worst-case scenario is silent. Shielded-by-default privacy built on Groth16 over BLS12-377 plus decaf377 discrete logs. Every historical tx is mathematically reversible once Shor lands. The shielded pool becomes the glass pool, retroactively, forever. Chaum's nightmare, shipped.
Summary
Penumbra is the starkest retroactive-deanon case in the batch. Private-by-default shielded chain built on Groth16 + BLS12-377 + decaf377 discrete logs. Every historical tx's privacy is mathematically reversible when Shor arrives — Chaum's worst-case. Band 2 (Acknowledged) due to low raw scores + small ecosystem, but underlying risk is severe. Zero privacy preserved in suddenly-pre-migration scenario.
What the gates say
- Hybrid: FAIL. No hybrid plan on file.
- 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 35 / 100
Strong primitive inventory — decaf377 + BLS12-377 + Poseidon named.
decaf377 (group based on BLS12-377 curve) · Groth16 zk-SNARKs over BLS12-377 · Poseidon hash · Ed25519 (consensus via CometBFT) · Rescue-PrimeAll primitives named with quantum tags.
2 HNDL Exposure 18 / 100
Shielded by default — full diversifier privacy, but spending keys derive from Ed25519-style material.
Same. Shielded pool all UM is inside.
Privacy commitments are long-lived — decaf377 group element commitments, ring signatures. Shor break retroactively de-anons ALL historical shielded tx.
Standard TLS. Private DEX (ZSwap) batch sealed-bid auctions — sealed-bid privacy relies on same Shor-breakable crypto.
3 Metadata & Privacy Exposure 35 / 100
Fully shielded by default — no transparent txs. Highest privacy profile.
Small ecosystem — Penumbra Labs-operated nodes.
IBC connects Penumbra to Cosmos — metadata leaks at IBC boundary despite shielded internals.
CRITICAL: Groth16 over BLS12-377 and decaf377 discrete-log commitments ARE Shor-broken. Every historical shielded Penumbra tx is retroactively de-anonymizable when Shor arrives. Worst-case Chaum scenario. Max score forced to 0-5.
4 Migration Architecture 20 / 100
Cosmos SDK module-based — theoretical extensibility, but zk-SNARK primitives are deeply embedded.
Limited AA.
Young mainnet (2024).
No plausible hybrid zk-SNARK envelope on BLS12-377.
5 Deployment Execution 0 / 100
6 Supply Chain Vendor Readiness 3 / 100
No major custodian support.
7 Governance & Coordination 30 / 100
Small validator set.
Post-launch iteration.
Penumbra Labs + Henry de Valence.
No precedent.
The X + Y vs Z inequality
X (data shelf life): infinite (historical shielded state is forever reconstructable)
Y (migration time): 10-15
Z10 (10% CRQC year): 2036 · Z50 (50%): 2041
Verdict: X+Y > Z (danger).
Four-scenario grid
| Scenario | Value preserved | Privacy preserved |
|---|---|---|
| quantum never | 100% | 100% |
| arrives suddenly pre migration | 5% | 0% |
| arrives slowly post migration | 70% | 5% |
| arrives slowly mid migration | 25% | 0% |
Peers in the privacy-L2 profile
Order-book view of the 5 chains closest to Penumbra 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.
Strong primitive inventory — decaf377 + BLS12-377 + Poseidon named.
All primitives named with quantum tags.
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
CRITICAL surprise in batch. Privacy chain with highest retroactive-deanon exposure. Scoring 3d=0/25 reflects that shielded privacy is entirely built on Shor-breakable primitives. Nano-cap ($1.9M MC per v1) limits immediate blast radius but methodologically Penumbra is the cautionary privacy example.
Scorecard metadata
- Profile: privacy-L2
- Scored: 2026-04-18 by
layerqu-v2-scoring-agent-4 - v1 reference:
chainscreen-v1-archive - QRI raw: 15 · after caps: 12
- Confidence interval: ±15
- PQC washing ratio: 1x
- Burn-vs-rescue: undeclared
Caps triggered
- Mosca (5a<20%)
- Sutor (5d=0)
- Preskill (<3 artifacts multiple dims → ×0.5)
- Casado (4 tiles pqc=0)
- Hybrid gate FAIL → QRI cap 60