Blockchain security company AmericanFortress has put forward a cryptographic proposal designed to protect existing cryptocurrency wallets from potential quantum computing threats. The scheme aims to add post-quantum safeguards without requiring holders to move funds, rotate private keys or generate new wallet addresses.

The company detailed the approach in a technical paper posted to the Cryptography ePrint Archive. The work has not yet undergone peer review. It targets seed-based hierarchical deterministic wallets commonly used on networks that rely on elliptic-curve cryptography, including Bitcoin, Ethereum and Solana.

How the Scheme Works

At the center of the proposal is a method known as Zero-Knowledge Proof of Seed Provenance, or ZK-PoSP. Rather than replacing the elliptic-curve signatures that currently authorize spending, the wallet generates a zero-knowledge proof showing it knows the seed phrase from which the address was derived. Network nodes would verify that proof. Users would continue to sign transactions with their existing keys.

Because authorization no longer depends solely on an exposed public key, the design seeks to remove the primary attack surface that a sufficiently powerful quantum computer running Shor’s algorithm could exploit. Address formats remain unchanged, and no on-chain migration of assets is required.

The paper also discusses a related derivation component intended to support multiple elliptic curves, including secp256k1 used by Bitcoin and Ethereum and Ed25519 used by Solana. According to the authors, existing standards such as BIP32 and SLIP-10 already permit the necessary proofs without forcing wallets to adopt a new derivation path.

AmericanFortress reported laboratory figures showing a one-time address-protection proof costing roughly $0.002 on a 16-core server and subsequent transaction proofs around $0.00125. Signing currently takes approximately 12 seconds, while verification completes in nine to 10 milliseconds. The proofs rely on the RISC Zero system and do not require a trusted setup. The company plans to license a software development kit to blockchain projects and wallet providers.

Security Claims and Practical Limits

The paper describes the post-quantum security of the scheme as conjectured rather than proven. No cryptographically relevant quantum computer yet exists against which the assumptions could be tested in practice. Until network nodes upgrade to verify the new proofs and wallet software ships the proving capability, addresses whose public keys are already visible on-chain would remain exposed to a future quantum attack.

AmericanFortress cited a Bloomberg analysis estimating that as much as $470 billion in Bitcoin could be vulnerable if sufficiently powerful quantum machines become available. The company positions its approach as a way to reduce the operational and legal friction that large-scale address migration would impose on retail users, custodians and institutional holders.

Broader Industry Activity

AmericanFortress is one of several organizations working on quantum-resistant wallet technology. Freedom Factory recently introduced PQ1, a hardware wallet for Ethereum and other EVM-compatible networks. That product generates post-quantum signatures using SPHINCS+C10 schemes and relies on ERC-4337 smart accounts, representing a hardware-centric alternative to the software-based proofs described by AmericanFortress.

Separate initiatives continue across major networks. A consortium led by Strategy has committed $15 million over three years to Bitcoin quantum-security research. The Ethereum Foundation has formed a dedicated post-quantum team and published a roadmap that includes hash-based signatures and migration tools. Algorand has stated plans to introduce quantum-resistant accounts by 2027.

Google’s Quantum AI team has estimated that breaking 256-bit elliptic-curve cryptography could require fewer than 1,500 logical qubits together with tens of millions of quantum gates. Those figures refer to error-corrected logical qubits rather than the noisy physical qubits available today, and researchers note that no immediate practical threat has materialized.

For the AmericanFortress proposal to move beyond a technical paper, it will need independent cryptographic review, efficient implementation on network nodes, and coordinated adoption by wallet providers and protocol developers. Until those steps occur, the scheme remains a published design rather than a deployed network feature.