AmericanFortress proposes quantum-safe layer for crypto wallets

AmericanFortress published a technical proposal on the Cryptography ePrint Archive describing a method to add post-quantum protection to existing cryptocurrency wallets. The paper has not been peer reviewed. The company says the approach works with seed-based hierarchical deterministic wallets used by Bitcoin, Ethereum, Solana and other networks that rely on elliptic-curve cryptography.

The proposal layers a software-based post-quantum safeguard on top of current wallets rather than replacing the existing elliptic-curve keys. The paper describes deriving zero-knowledge proofs from a wallet’s original seed phrase. Network nodes would verify those proofs while users continue to sign transactions with their existing keys and keep the same addresses and seed phrases.

The paper cites an analysis that estimates up to $470 billion in Bitcoin could be at risk if sufficiently powerful quantum computers become available. The estimate has driven interest in options for protecting funds without forcing large-scale key rotations or address changes.

The AmericanFortress design differs from approaches that create post-quantum keys directly on hardware. Another company recently introduced a hardware wallet that generates post-quantum signatures using SPHINCS+C10 and integrates with ERC-4337 smart accounts. That hardware approach replaces signing keys with post-quantum-capable keys generated on a device, while AmericanFortress proposes a retrofit layer that preserves current keys and addresses.

Industry groups and protocol teams are exploring multiple paths. A consortium has pledged funding for Bitcoin quantum security research, the Ethereum community has published an account-migration proposal for quantum-resistant cryptography, and Algorand has outlined plans to offer quantum-resistant accounts by 2027. Developers and researchers are testing software-layer protections, dedicated hardware, and protocol-level migration plans.

AmericanFortress’s paper will require peer review and real-world testing before the approach can be evaluated for broader use. The proposal adds a software option to the range of strategies under consideration for defending blockchain accounts against future quantum-capable adversaries.