--- title: Is Cardano quantum-safe? chain: Cardano ticker: ADA hardy_score: 37.5 rank: 14 of 23 tier: "3: Committed" url: "https://hardyindex.com/chains/cardano" updated: 2026-08-11 methodology_version: 1.1 --- # Is Cardano quantum-safe? **Hardy Score 37.5 / 100. Rank 14 of 23. Tier 3: Committed. As of 11 August 2026.** No, not today. Cardano signs transactions with Ed25519 and elects slot leaders using an elliptic-curve verifiable random function, and a sufficiently large quantum computer breaks both. Cardano's answer is a research programme rather than a deployment schedule. Input Output's Cardano Vision 2026 names post-quantum security as one of three strategic pillars and sets out a bottom-up plan: assess state-of-the-art post-quantum building blocks, design a novel post-quantum verifiable random function to replace the one that currently elects slot leaders, produce an end-to-end security proof for an improved Ouroboros protocol, build a prototype, and publish a migration strategy as a Cardano Improvement Proposal. The stated ambition is to make Cardano the first mainstream proof-of-stake blockchain with a formally grounded, evidence-based post-quantum migration strategy. The deliverables are named but, at the time of writing, individual dates for them were not published beyond the 2026 programme cycle. > This is a security-readiness assessment, not investment advice. ## Summary Cardano Vision 2026 makes post-quantum security one of three strategic pillars, with named research deliverables running from primitive assessment to a published migration SIP. ## Where we are making a judgement call Cardano's post-quantum programme names deliverables but, at the time of writing, we could not find published dates for the individual deliverables beyond the 2026 programme cycle. We have dated D3.1 to 2027 as the terminal deliverable in a 2026 research cycle; treat that as our inference, not as a Cardano commitment. ## Score breakdown | # | Dimension | Score | Weight | Contribution | |---:|---|---:|---:|---:| | 1 | Signature scheme | 0/10 | 30% | 0.0 | | 2 | Deployment stage | 5/10 | 25% | 12.5 | | 3 | NIST alignment | 5/10 | 15% | 7.5 | | 4 | Migration path | 6/10 | 15% | 9.0 | | 5 | Exposure | 4/10 | 10% | 4.0 | | 6 | Verification | 9/10 | 5% | 4.5 | | | **Hardy Score** | | | **37.5** | ### 1. Signature scheme: 0/10 Cardano mainnet signs with Ed25519 and its slot-leader election uses an elliptic-curve VRF, both broken by Shor's algorithm. No post-quantum signature is available on mainnet in any form, opt-in or otherwise. Source: https://www.iog.io/news/cardano-vision-2026-the-research-program-securing-cardano ### 2. Deployment stage: 5/10 Tier 3: Committed. Post-quantum security is one of three named pillars of a funded research programme with named deliverables and an identified research lead, and nothing is live on mainnet. Source: https://www.iog.io/news/cardano-vision-2026-the-research-program-securing-cardano ### 3. NIST alignment: 5/10 The programme's first deliverable is assessing state-of-the-art post-quantum building blocks rather than committing to a NIST scheme, and the post-quantum VRF it plans to design is novel research with no standardised counterpart. Cardano has not yet named the signature scheme it intends to adopt. Source: https://www.iog.io/news/cardano-vision-2026-the-research-program-securing-cardano ### 4. Migration path: 6/10 A published migration strategy is deliverable D3.1, so the plan for the plan exists rather than the plan itself. Cardano's on-chain governance gives it a credible route to enact a change once designed, and its formal-methods culture means a migration SIP would arrive with proofs attached. Source: https://www.iog.io/news/cardano-vision-2026-the-research-program-securing-cardano ### 5. Exposure: 4/10 Cardano uses an extended UTXO model and addresses are built from hashes of payment and staking keys, so a public key is revealed when an output is spent rather than when an address is created. Never-spent holdings are therefore not yet harvestable, but staking keys are widely exposed and most circulating ADA has moved. Source: https://www.iog.io/news/cardano-vision-2026-the-research-program-securing-cardano ### 6. Verification: 9/10 Cardano's research is peer-reviewed and published, the programme names its research lead and enumerates deliverables, the protocol is open source, and the roadmap was put through Cardano's on-chain governance process rather than announced unilaterally. Source: https://www.iog.io/news/cardano-vision-2026-the-research-program-securing-cardano ## Signature scheme - **On mainnet today:** Ed25519 for transaction signing; elliptic-curve VRF for slot-leader election - **Post-quantum scheme:** Not yet selected. A novel post-quantum VRF and quantum-secure replacements for Cardano's signature and key-evolving signature primitives are in design. - **NIST standard:** None committed. Deliverable D1.1 is an assessment of post-quantum building blocks. - **Readiness tier:** Tier 3: Committed. A funded roadmap with public dates and active research exists, but no post-quantum signature is live on mainnet. ## Roadmap - **Deliverable D1.1** (in-progress): Assess state-of-the-art post-quantum cryptography building blocks for use in Cardano's core primitives. Source: https://www.iog.io/news/cardano-vision-2026-the-research-program-securing-cardano - **Deliverable D1.2** (planned): Design a novel post-quantum verifiable random function to replace the one currently used to elect slot leaders. Source: https://www.iog.io/news/cardano-vision-2026-the-research-program-securing-cardano - **Deliverable D2.1** (planned): Produce an end-to-end security proof for an improved, post-quantum-secure Ouroboros protocol. Source: https://www.iog.io/news/cardano-vision-2026-the-research-program-securing-cardano - **Deliverable D2.2** (planned): Build a prototype implementing the post-quantum Ouroboros design. Source: https://www.iog.io/news/cardano-vision-2026-the-research-program-securing-cardano - **Deliverable D3.1** (planned): Publish a post-quantum migration strategy as a Cardano Improvement Proposal. Source: https://www.iog.io/news/cardano-vision-2026-the-research-program-securing-cardano ## Exposure Cardano's extended UTXO model gives it a structural advantage over account-model chains. A Cardano address is built from hashes of the payment and staking keys, so the payment public key is not on-chain until an output is spent. ADA that has been received and never moved is therefore not harvestable today. The qualifier is that staking keys are widely visible through delegation certificates, and most circulating ADA has been spent at least once, so the unexposed share is smaller than the model alone would suggest. ## Frequently asked questions ### Is Cardano quantum-safe? No, not today. Cardano signs transactions with Ed25519 and elects slot leaders using an elliptic-curve verifiable random function, and a sufficiently large quantum computer breaks both. Cardano's answer is a research programme rather than a deployment schedule. Input Output's Cardano Vision 2026 names post-quantum security as one of three strategic pillars and sets out a bottom-up plan: assess state-of-the-art post-quantum building blocks, design a novel post-quantum verifiable random function to replace the one that currently elects slot leaders, produce an end-to-end security proof for an improved Ouroboros protocol, build a prototype, and publish a migration strategy as a Cardano Improvement Proposal. The stated ambition is to make Cardano the first mainstream proof-of-stake blockchain with a formally grounded, evidence-based post-quantum migration strategy. The deliverables are named but, at the time of writing, individual dates for them were not published beyond the 2026 programme cycle. ### Is Cardano quantum-safe? No. Cardano uses Ed25519 signatures and an elliptic-curve verifiable random function for slot-leader election, and a sufficiently large quantum computer breaks both. Cardano has a funded research programme aimed at replacing those primitives but nothing post-quantum is live on mainnet. ### What is Cardano Vision 2026 doing about quantum computing? It makes post-quantum security one of three strategic pillars alongside user-centric design and scalable architecture. The work is described as bottom-up: build quantum-secure replacements for Cardano's core primitives, including the signatures and key-evolving signatures that protect proof-of-stake security, then prove the resulting protocol secure end to end and publish a migration strategy. ### Why does Cardano need a post-quantum VRF and not just new signatures? Because Cardano's proof-of-stake security depends on the verifiable random function that elects slot leaders, not only on transaction signatures. If that VRF is built on elliptic curves, a quantum adversary could predict or manipulate leader election even if transaction signatures were already post-quantum. Deliverable D1.2 is designing a novel post-quantum VRF for exactly this reason. ### Has Cardano chosen a post-quantum signature scheme? Not yet. The programme's first deliverable is an assessment of state-of-the-art post-quantum building blocks, which means the selection is still open. That is the main reason Cardano scores 5 rather than higher on NIST alignment in this index: it has not committed to a standardised scheme. ## What this rating means if you hold Cardano Plain-language guidance from the same publication, with no product recommendation attached. - [Is my crypto safe from quantum computers?](https://hardyindex.com/guides/is-my-crypto-safe-from-quantum-computers.md) - [How to protect your crypto from quantum computers](https://hardyindex.com/guides/how-to-protect-crypto-from-quantum-computers.md) - [All guides](https://hardyindex.com/guides.md) Nothing on this profile is sponsored and nothing on it is an affiliate link. See https://hardyindex.com/how-we-make-money.md. ## Sources 1. [Cardano Vision 2026: the research program securing Cardano's next era](https://www.iog.io/news/cardano-vision-2026-the-research-program-securing-cardano): Input | Output (IOG) (primary, checked 11 August 2026) 2. [Cardano Vision 2026: Human Centred, Scalable, Post Quantum Secure (governance action)](https://gov.tools/outcomes/governance_actions/5ad10ad39f49a0f93ac91e70482f114fdbcbc05b20ac774dbe23a82efbcb820a): Cardano GovTool (primary, checked 11 August 2026) 3. [FIPS 204: Module-Lattice-Based Digital Signature Standard (ML-DSA)](https://csrc.nist.gov/pubs/fips/204/final): NIST (primary, checked 11 August 2026) --- Methodology: https://hardyindex.com/methodology (v1.1). Cite as: The Hardy Index, "Cardano", https://hardyindex.com/chains/cardano, as of 11 August 2026.