Ethereum and Solana Post-Quantum Plans: What Is Real in 2026
Ethereum: four things to fix
The ethereum.org quantum resistance page lists four areas where Ethereum relies on quantum-vulnerable cryptography, and a proposed answer for each:
| Area | Today | Proposed direction |
|---|---|---|
| Validator signatures | BLS | Hash-based leanXMSS, aggregated with leanVM proofs |
| Data availability | KZG commitments | Research into STARK or lattice replacements |
| Account signatures | ECDSA | Account abstraction (EIP-8141) for per-account signature agility |
| Application proofs | KZG or similar | STARKs, already hash-based |
Vitalik Buterin laid out this four-area framing in February 2026, and the Ethereum Foundation formed a Post-Quantum Security team in January 2026. The page reports more than 10 client teams in weekly interop devnets and says EIP-8141 is being considered for the Hegota upgrade in the second half of 2026. All milestones are described as planning targets, with about 2029 for core infrastructure.
For regular users, the page says nothing needs to be done now. Once post-quantum signatures are widely supported, wallet software is expected to guide a move. The hardest unsolved question is dormant wallets whose owners may never migrate, which has no community consensus. The STARK piece of the plan is unpacked in Ethereum plans.
Solana: an opt-in vault and a testnet
Winternitz Vault (January 2025). Researcher Dean Little published an optional Solana vault using Winternitz one-time signatures. Each transfer uses a fresh key pair whose public key is hashed into a Merkle root, leftover funds go to a refund account, and the vault closes. It uses truncated Keccak256, which the author says offers 224 bit resistance against quantum attacks. Limits: it is opt-in, standard wallets do not include it, the contract is technically demanding, and keys must never be reused.
Project Eleven testnet (reported December 2025). The Solana Foundation said it worked with post-quantum security firm Project Eleven on a threat assessment and a testnet with post-quantum signatures, aiming to see whether quantum-resistant transactions could run at network level on current technology. A Decrypt report said the foundation framed this as preparation, noting that quantum computers are not here yet. Reports on performance conflict: one says the test showed security can be added without hurting performance, while a republishing site claims a significant speed decline. We could not confirm which scheme the testnet used or any benchmark numbers, so we make no performance claim.
Solana already has good reasons to care about speed, so the block space squeeze is an especially interesting design problem there. For basics on how accounts and signatures work on Solana see accounts and programs and how transactions work.
How to read all this
Ethereum is further along in published planning and Solana has shipped an optional tool plus an evaluation, while neither has switched its main network to post-quantum signatures. That is normal for a threat that is not here yet. It is also encouraging that two of the largest ecosystems have public work to point at, and developers can learn from each other. See the roadmaps compared for the wider view.
Education only, not financial advice and not a prediction about ETH, SOL or QNT. QNT is an independent memecoin on Solana and has no link to Quantinuum Ltd, the Solana Foundation or Project Eleven.
Sources and further reading
- ethereum.org: quantum resistance roadmap
- The Quantum Insider: Solana Winternitz Vault
- Decrypt: Solana and Aptos harden blockchains
- MojoAuth: Solana advances post-quantum security
Reported as of 2026-10-09. Roadmaps and proposals change often, so check the primary documents. Nothing here is financial advice. The QNT memecoin is independent of Quantinuum Ltd, the real company, and of every lab, chain and government named on this page.
Frequently asked questions
Is Ethereum quantum safe today?
No. Its signatures are not post-quantum. Ethereum.org describes a multi-year roadmap with about 2029 as a planning target, and says users need to do nothing now.
What is the Solana Winternitz Vault?
An optional vault using one-time hash-based signatures, published in January 2025. You must choose to use it and it generates fresh keys for each transfer.
Has Solana switched to post-quantum signatures?
Not on mainnet, per the sources we read. It ran a testnet study with Project Eleven, reported in December 2025.
Keep reading
- Quantum and Crypto Roadmaps Compared: Bitcoin, Ethereum, Solana and Others
Side by side: how Bitcoin, Ethereum, Solana, Algorand and Aptos are planning for post-quantum security, with dates and status as reported in 2026. - What Governments and Blockchains Are Saying About Quantum and Crypto
How Solana, Bitcoin and Ethereum are responding to the quantum threat in 2026, and how it links to government post-quantum policy. - Will Quantum Computers Break Bitcoin and Solana?
A calm, factual look at the quantum threat to Bitcoin, Solana and other blockchains, what is safe now, and what could change.
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