--- title: Is Quantum Resistant Ledger quantum-safe? chain: Quantum Resistant Ledger ticker: QRL hardy_score: 92 rank: 1 of 23 tier: "1: Native" url: "https://hardyindex.com/chains/qrl" updated: 2026-08-11 methodology_version: 1.1 --- # Is Quantum Resistant Ledger quantum-safe? **Hardy Score 92.0 / 100. Rank 1 of 23. Tier 1: Native. As of 11 August 2026.** Yes. The Quantum Resistant Ledger is post-quantum secure at mainnet today. Every QRL account is protected by XMSS, a hash-based signature scheme that is not broken by Shor's algorithm and that NIST approved for use in SP 800-208. There is no quantum-vulnerable elliptic-curve fallback on the network, and there never has been: QRL launched with XMSS in June 2018 rather than retrofitting it later. The trade-offs are real and worth stating plainly: XMSS is a stateful scheme, so reusing a one-time signature key can expose funds and users depend on wallet software to manage that state correctly, and QRL is a very small network by liquidity, developer activity and validator count compared with the chains below it in this index. QRL scores highest here because the index measures quantum readiness, not size, adoption or investment merit. > This is a security-readiness assessment, not investment advice. ## Summary The only chain in the index where a post-quantum signature is mandatory for every account on mainnet, and has been since 2018. ## Where we are making a judgement call QRL ranks first on quantum readiness and nothing else. It is a small network by liquidity, ecosystem and developer activity, and this index does not measure those things. A high Hardy Score is not a statement that a chain is a good asset, a good platform or a good investment. ## Score breakdown | # | Dimension | Score | Weight | Contribution | |---:|---|---:|---:|---:| | 1 | Signature scheme | 10/10 | 30% | 30.0 | | 2 | Deployment stage | 10/10 | 25% | 25.0 | | 3 | NIST alignment | 9/10 | 15% | 13.5 | | 4 | Migration path | 7/10 | 15% | 10.5 | | 5 | Exposure | 9/10 | 10% | 9.0 | | 6 | Verification | 8/10 | 5% | 4.0 | | | **Hardy Score** | | | **92.0** | ### 1. Signature scheme: 10/10 XMSS is the mandatory signature scheme for all accounts on the QRL mainnet that launched in June 2018. There is no elliptic-curve alternative on the network, so no account can opt back into a quantum-vulnerable scheme. Source: https://www.theqrl.org/2/ ### 2. Deployment stage: 10/10 Tier 1: Native. Post-quantum signatures have protected every unit of supply since genesis, which is the only case in this index where nothing needs to be migrated to reach quantum safety. Source: https://www.theqrl.org/2/ ### 3. NIST alignment: 9/10 XMSS is approved by NIST in SP 800-208, which supplements FIPS 186 to permit XMSS and LMS. It is a full approval rather than a candidate status, but NIST restricts stateful schemes to controlled applications, which is why this is not a 10. QRL 2.0 moves to ML-DSA-87 under FIPS 204. Source: https://csrc.nist.gov/pubs/sp/800/208/final ### 4. Migration path: 7/10 QRL holders have no quantum migration to make, because their keys were never elliptic-curve. The deduction is for the separate QRL 1 to QRL 2.0 chain migration, which remains ahead of the network: Zond has been on testnet since 2024 and its mainnet date is contingent on audit completion. Source: https://www.theqrl.org/2/ ### 5. Exposure: 9/10 No QRL public key is a quantum liability, because XMSS security does not rest on the discrete logarithm problem. The one point deducted reflects XMSS's operational hazard: signing twice from the same one-time key leaks private key material, so exposure risk here is a wallet-state problem rather than a cryptographic one. Source: https://csrc.nist.gov/pubs/sp/800/208/final ### 6. Verification: 8/10 QRL is open source and has run XMSS in production on a public mainnet for over eight years, which is the strongest form of verification available: the claim is checkable on-chain. QRL 2.0 is undergoing external audits that had not concluded at the time of writing. Source: https://www.theqrl.org/2/ ## Signature scheme - **On mainnet today:** XMSS (stateful hash-based), mandatory for all accounts - **Post-quantum scheme:** XMSS today; ML-DSA-87 in QRL 2.0 (Project Zond), with SPHINCS+ signalled post-mainnet - **NIST standard:** NIST SP 800-208 (XMSS) today; FIPS 204 (ML-DSA) in QRL 2.0 - **Readiness tier:** Tier 1: Native. Post-quantum secure at mainnet today, with quantum-resistant signatures built in from genesis. ## Roadmap - **June 2018** (shipped): QRL mainnet launches with XMSS as the mandatory signature scheme for every account. Source: https://www.theqrl.org/2/ - **Q1 2024** (shipped): QRL 2.0 (Project Zond) beta-testnet launches, moving the chain toward proof of stake and ML-DSA. Source: https://www.theqrl.org/2/ - **Q1 2025** (shipped): Zond Testnet V1 goes live. Source: https://www.theqrl.org/2/ - **Q1 2026** (shipped): Zond Testnet V2 launches as the audit-ready public testnet, using NIST-standardised ML-DSA-87. Source: https://www.theqrl.org/2/ - **Date not published** (planned): QRL 2.0 mainnet launch, explicitly contingent on audit outcomes and network stability rather than a fixed date. Source: https://www.theqrl.org/2/ ## Exposure QRL has no harvest-now-decrypt-later exposure in the usual sense. Because XMSS security rests on hash function preimage resistance rather than the discrete logarithm problem, an attacker who records every QRL public key today gains nothing from a future quantum computer. The residual risk is operational: XMSS is stateful and each one-time signature key must be used exactly once, so a wallet that loses or mismanages its signing state can expose a key through reuse rather than through cryptanalysis. ## Frequently asked questions ### Is Quantum Resistant Ledger quantum-safe? Yes. The Quantum Resistant Ledger is post-quantum secure at mainnet today. Every QRL account is protected by XMSS, a hash-based signature scheme that is not broken by Shor's algorithm and that NIST approved for use in SP 800-208. There is no quantum-vulnerable elliptic-curve fallback on the network, and there never has been: QRL launched with XMSS in June 2018 rather than retrofitting it later. The trade-offs are real and worth stating plainly: XMSS is a stateful scheme, so reusing a one-time signature key can expose funds and users depend on wallet software to manage that state correctly, and QRL is a very small network by liquidity, developer activity and validator count compared with the chains below it in this index. QRL scores highest here because the index measures quantum readiness, not size, adoption or investment merit. ### Is QRL quantum-safe? Yes, on the measure this index uses. QRL's mainnet has required XMSS hash-based signatures for every account since June 2018, and XMSS is not broken by Shor's algorithm. QRL is the only chain in this index with no quantum-vulnerable signature scheme available on mainnet at all. ### What is XMSS and why does it resist quantum attack? XMSS is the eXtended Merkle Signature Scheme, a hash-based signature system specified in RFC 8391 and approved by NIST in SP 800-208. Its security rests on the difficulty of finding hash preimages rather than on the elliptic-curve discrete logarithm problem, and Shor's algorithm only breaks the latter. Grover's algorithm weakens hash functions, but only quadratically, which the parameter sets already account for. ### What is the catch with XMSS? XMSS is stateful. Each signing key may be used exactly once, and the wallet must reliably track which keys have been consumed. If the same one-time key signs twice, an attacker can recover private key material without any quantum computer at all. NIST flags this in SP 800-208, which is why it restricts stateful hash-based schemes to applications where key use can be carefully controlled. ### Is QRL 2.0 live? No. QRL 2.0, also called Project Zond, is on a public testnet. Testnet V2 launched in Q1 2026 as the audit-ready release, using NIST-standardised ML-DSA-87. QRL has not published a fixed mainnet date and states that launch depends on audit outcomes and network stability. The original XMSS mainnet continues to run. ### Does a top Hardy Score mean QRL is a good investment? No. The Hardy Score measures quantum readiness only. It says nothing about liquidity, adoption, developer activity, security outside the quantum question, or price. QRL scores highest in this index because it deployed post-quantum signatures first and made them mandatory, which is exactly the one thing this benchmark measures. ## What this rating means if you hold QRL 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. [QRL 2.0: A blockchain engineered for the post-quantum world](https://www.theqrl.org/2/): The Quantum Resistant Ledger (primary, checked 11 August 2026) 2. [SP 800-208: Recommendation for Stateful Hash-Based Signature Schemes](https://csrc.nist.gov/pubs/sp/800/208/final): NIST (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) 4. [Project Zond, by QRL: a blockchain engineered for the post-quantum era](https://www.theqrl.org/project-zond/): The Quantum Resistant Ledger (primary, checked 11 August 2026) --- Methodology: https://hardyindex.com/methodology (v1.1). Cite as: The Hardy Index, "Quantum Resistant Ledger", https://hardyindex.com/chains/qrl, as of 11 August 2026.