Key Takeaways:
Blockchain security firm AmericanFortress has proposed a cryptographic scheme to protect existing cryptocurrency wallets from future quantum attacks without requiring users to move funds, rotate keys or change wallet addresses.
AmericanFortress published a technical paper on the Cryptography ePrint Archive proposing a zero-knowledge proof scheme to protect Bitcoin, Ethereum and Solana wallets from future quantum attacks without requiring fund migration or key rotation. The paper has not yet been peer-reviewed.
"Today's implementation is already practical for institutional settlement, and hardware acceleration and proving-system improvements will bring signing times down further," Michal "Mehow" Pospieszalski, chief executive officer of AmericanFortress, said.
The scheme, called Zero-Knowledge Proof of Seed Provenance, or ZK-PoSP, uses zero-knowledge proofs derived from a wallet's original seed phrase rather than replacing the elliptic curve cryptography underlying existing wallets. Participating nodes would verify those proofs while users continue signing transactions with their existing keys. AmericanFortress said generating a one-time proof to secure an address costs about $0.002 on a 16-core server, while each transaction proof costs roughly $0.00125. The company cited a Bloomberg analysis estimating that up to $470 billion in Bitcoin could be vulnerable to quantum attacks if sufficiently powerful quantum computers become available.
The proposal arrives as institutional interest in post-quantum security grows. A consortium led by Strategy, including BlackRock, Coinbase and six other companies, pledged $15 million over three years to fund Bitcoin quantum security research through the newly formed Bitcoin Security Consortium. The Ethereum Foundation formed a dedicated post-quantum team in January and is testing hash-based signatures, a minimal zero-knowledge virtual machine and migration tools, according to its quantum-security roadmap. Algorand outlined plans to introduce quantum-resistant accounts by 2027.
Competing approaches emerge for post-quantum wallet security
AmericanFortress is not alone in developing post-quantum protections. Freedom Factory on Tuesday unveiled PQ1, a post-quantum hardware wallet designed for Ethereum and other EVM-compatible networks. Unlike AmericanFortress's software-based approach, PQ1 uses SPHINCS+C10 signatures generated on dedicated hardware and ERC-4337 smart accounts to secure transactions against future quantum attacks.
ZK-PoSP relies on hash functions and the soundness of its zero-knowledge proof system. The paper says post-quantum security is "conjectured" because the underlying assumptions have not been tested against a cryptographically relevant quantum computer. No such machine currently exists, though Google's Quantum AI team estimated that breaking 256-bit elliptic curve cryptography could require fewer than 1,500 logical qubits and tens of millions of quantum gates — far beyond the noisy physical qubits available in present systems.
Until a network adopts and enforces ZK-PoSP verification through a node-level software upgrade, addresses with public keys already visible onchain would remain exposed to a future quantum attack. AmericanFortress plans to license its software development kit to blockchains and other projects, meaning adoption depends on independent cryptographic review, implementation audits and sufficient network agreement to deploy.
This article is for informational purposes only and does not constitute investment advice.
