AmericanFortress, a Wyoming-based blockchain security and cryptography company focused on post-quantum security and digital asset infrastructure, has proposed a cryptographic system that it says could help Bitcoin and other blockchain wallets survive future quantum attacks without changing existing wallet addresses.
The proposal appears in a paper titled “ZKPoSP: Post-Quantum Zero-Knowledge Proofs for Hierarchical Deterministic Wallets.” In the paper, AmericanFortress researchers describe replacing traditional elliptic-curve signatures with zero-knowledge proofs while keeping compatibility with hierarchical deterministic wallets.
Paper targets the quantum threat to current wallet infrastructure
The researchers wrote that recent progress in quantum hardware, including Google’s Willow processor, has materially shortened the timeline to quantum computers that matter for cryptography.
They said that in blockchain systems, wallet management still depends heavily on address structures and key derivation standards such as BIP32, BIP44, and SLIP-10. If a quantum computer can run Shor’s algorithm at the required scale, it could recover any elliptic-curve private key from the matching public key, putting every wallet now in production at risk.
The paper is built around “Q-Day,” the point at which a fault-tolerant quantum computer could derive private keys from public keys using Shor’s algorithm. At that point, the elliptic-curve cryptography used by Bitcoin and many other blockchains would no longer be secure.
Seed-based ownership proof instead of moving funds to new addresses
Rather than requiring users to migrate funds into new quantum-safe addresses, the proposed design replaces digital signatures with zero-knowledge proofs that verify ownership of a wallet’s seed phrase.
Because the seed itself remains secret, the authors argue that a legitimate owner could still prove control of a wallet even if individual private keys had been compromised.
The paper introduces two key components:
- ZKPoSP, short for Zero-Knowledge Proof of Seed Provenance.
- QBIP32, a key derivation scheme built to support multiple elliptic curves while remaining compatible with existing hierarchical deterministic wallets.
Prototype built in Rust with RISC Zero
According to the study, the researchers implemented the system in Rust using the RISC Zero zero-knowledge virtual machine.
Prototype benchmarks showed proof generation times of roughly 12 to 13 seconds and verification times of about 9 to 10 milliseconds. The paper also describes a post-Q-Day mode that reduces proving time for some operations.
No blockchain network has adopted the system
The research has not been adopted by any blockchain network. The paper says any deployment would require support from developers, wallet providers, exchanges, miners, and users.
Interest in post-quantum cryptography has been rising as blockchain developers prepare for Q-Day. Bitcoin faces a specific issue because spending coins exposes public keys on-chain. A sufficiently powerful quantum computer could use those public keys to derive private keys and forge valid transaction signatures.
Part of a broader industry push on post-quantum security
The AmericanFortress paper is the latest in a broader set of efforts across the crypto industry aimed at preparing blockchain networks for a post-quantum future.
Earlier this month, Project Eleven proposed a post-quantum recovery mechanism that would let users prove ownership of a Bitcoin wallet through its seed phrase rather than a digital signature after Q-Day.
In March, BTQ Technologies released the first working implementation of BIP-360 on a dedicated “Bitcoin Quantum” testnet to evaluate quantum-resistant transaction formats.
In May, blockchain analytics firm Glassnode estimated that about 6.04 million BTC, roughly 30% of the circulating supply, already have publicly exposed keys. That same month, the U.S. Department of Commerce announced more than $2 billion in funding for quantum computing companies and manufacturing initiatives.
Last week, major companies including BlackRock, Coinbase, Strategy, Fidelity Digital Assets, and Galaxy formed the Bitcoin Security Consortium and committed $15 million over three years to support Bitcoin security research and defenses against quantum attacks.