# Cardano (ADA) Quantum Readiness Report

> Cardano has a QRI score of 12/100 and is assessed at Stage 2 (Mitigation / Development) with medium evidence confidence.

Evaluation date: 2026-08-13. Review status: draft. Evaluated scope: Cardano L1 native asset (ADA) and core protocol, including Ouroboros consensus, eUTXO transaction model, Mithril state proofs, and Plutus smart-contract platform.

Cardano scores 12/100 (Stage 2: Mitigation/Development), capped at 25 by the 'roadmap/proposal only; no public code, prototype, or testnet' Readiness & Risk Cap. The production network relies entirely on classical elliptic curve cryptography: Ed25519 for transaction signatures and KES, ECVRF (Ed25519-based) for Ouroboros leader election, and BLS12-381 for Mithril state proofs — all vulnerable to Shor's algorithm. No post-quantum code exists in any public repository, and no testnet, prototype, or mainnet PQ path is available. The eUTXO model provides a structural mitigation by hashing public keys in addresses until first spend, protecting never-spent UTXOs from long-exposure attacks, but spent and reused-address holdings remain fully exposed. Post-quantum work is active at the research and proposal level: CPS-0027 (merged May 2026) surveys PQ signature approaches for Plutus builtins, Vision 2026 WP1.2 targets TRL 1–4 with PQ VRF design work progressing, and Project Nightstream was announced (February 2026) as an IOG initiative for lattice-based PQ cryptography with research collaborators linked to Google and Microsoft. However, no formal CIP, governance proposal, code release, or public specification for Nightstream has been published. The project earns full credit for its public cryptographic inventory (IOG Cryptography Handbook), quantum threat assessment (CPS-0027, Vision 2026 WP1.2), and security governance infrastructure (Intersect Security Council, bug bounty program), but these do not constitute production protection. Cardano should be monitored for progress on CPS-0027 transitioning to a formal CIP, Vision 2026 H2 deliverables (prototypes and CIP-ready recommendations), and any Nightstream specifications or code releases.

## Core resources

- [Cardano QRI report](https://qrindex.org/projects/cardano/): Human-readable assessment with score, stage, evidence, blockers, risks, and assurance notes.
- [Cardano structured report data](https://qrindex.org/projects/cardano/report.json): Complete report as JSON for deterministic machine processing.
- [QRI methodology](https://qrindex.org/methodology/): Scoring model, evidence handling, readiness stages, confidence, assurance, and report status.
- [All QRI project reports](https://qrindex.org/llms.txt): Score-ranked index of every published project assessment.
- [Cardano official website](https://cardano.org): Project-maintained website.
- [Cardano source repository 1](https://github.com/IntersectMBO/cardano-node): Project source code referenced by QRI.



## Evidence sources

- [Evidence source 1](<https://input-output-hk.github.io/cryptography_spec/specs/ed25519.html>): Public source cited by the Cardano QRI assessment.
- [Evidence source 2](<https://github.com/IntersectMBO/cardano-base>): Public source cited by the Cardano QRI assessment.
- [Evidence source 3](<https://docs.rs/cardano-crypto/1.0.8>): Public source cited by the Cardano QRI assessment.
- [Evidence source 4](<https://developers.cardano.org/docs/learn/core-concepts/addresses/>): Public source cited by the Cardano QRI assessment.
- [Evidence source 5](<https://input-output-hk.github.io/cryptography_spec/specs/vrf25519.html>): Public source cited by the Cardano QRI assessment.
- [Evidence source 6](<https://cardano.org/ouroboros/>): Public source cited by the Cardano QRI assessment.
- [Evidence source 7](<https://cips.cardano.org/>): Public source cited by the Cardano QRI assessment.
- [Evidence source 8](<https://mithril.network/doc/>): Public source cited by the Cardano QRI assessment.
- [Evidence source 9](<https://github.com/IntersectMBO/cardano-node>): Public source cited by the Cardano QRI assessment.
- [Evidence source 10](<https://developers.cardano.org/docs/operators/basics/cardano-key-pairs/>): Public source cited by the Cardano QRI assessment.
- [Evidence source 11](<https://github.com/cardano-foundation/CIPs/pull/1144>): Public source cited by the Cardano QRI assessment.
- [Evidence source 12](<https://cardanocube.com/>): Public source cited by the Cardano QRI assessment.
- [Evidence source 13](<https://www.iog.io/news/ior-shares-cardano-vision-26-mid-year-report>): Public source cited by the Cardano QRI assessment.
- [Evidence source 14](<https://technicalsteeringcommittee.docs.intersectmbo.org/about/security-council>): Public source cited by the Cardano QRI assessment.
- [Evidence source 15](<https://opensourcecommittee.docs.intersectmbo.org/about/paid-open-source-model-posm/bug-bounty-program>): Public source cited by the Cardano QRI assessment.
- [Evidence source 16](<https://static.iohk.io/docs/audits/icarus-audit.pdf>): Public source cited by the Cardano QRI assessment.
- [Evidence source 17](<https://github.com/Biglup/cardano-c/pull/128>): Public source cited by the Cardano QRI assessment.